Development and Validation of an Ovarian Cancer Risk Prediction Model for Family Members of Ovarian Cancer Probands With BRCA1/2 Germline Mutations
Conditions: Hereditary Breast and Ovarian Cancer Syndrome, BRCA Mutations
Sponsor: Peking University Third Hospital

Development and Validation of an Ovarian Cancer Risk Prediction
Model for Family Members of Ovarian Cancer Probands With
BRCA1/2 Germline Mutations
2025-5-19

Contents
I. Project Rationale
II. Research Aims
III. Research Design
IV. Research Subjects
V. Research Outcome Measures
VI. Data Collection and Follow-up Plan
VII. Safety Considerations
VIII. Data Management
IX. Statistical Analysis
X. Quality Control Measures in Clinical Research
XI. Protection of Research Subjects
XII. Organization and Management
XIII. Informed Consent Form
I. Project Rationale
1. Research Objectives and Significance
Ovarian cancer is the gynecological malignancy with the highest mortality rate,
seriously threatening the life and health of women. One of the main reasons for its
high mortality rate is that approximately 70% of patients are diagnosed at an
advanced stage. Fortunately, about 1/5 of ovarian cancers are associated with
genetic factors, providing us with an opportunity to screen high-risk populations and
thereby prevent and diagnose the disease at an early stage and reduce the disease
burden. Currently, research related to hereditary ovarian cancer in China is still very
scarce, and clinical practice relies on data from foreign studies. However, hereditary
tumors have distinct regional and ethnic characteristics, making it urgent to conduct
clinical research based on the Chinese population to guide clinical practice in China.
Current research suggests that approximately 50% - 60% of hereditary ovarian
cancers are closely related to the BRCA1/2 genes. Therefore, accurately assessing the
risk of ovarian cancer in BRCA1/2 germline mutation carriers is of great significance
for the prevention and treatment of hereditary ovarian cancer. This project intends to
conduct a multicenter ambispective cohort study to describe the family characteristics
and gene mutation profiles of BRCA1/2 germline mutation carriers in China, analyze
the correlations between BRCA1/2 mutation characteristics, family characteristics,
clinical features, lifestyles, and the incidence of ovarian cancer; and on this basis,
develop and preliminarily validate an ovarian cancer risk prediction model tailored
for BRCA1/2 germline mutation carriers in the Chinese population.The clinical
significance of this study lies in the development of a predictive model to guide
precision clinical interventions. Through risk management strategies, including

prophylactic surgery for genetically high-risk populations and hereditary cancer
prevention measures, this approach will
enable comprehensive lifetime risk
surveillance and ultimately reduce the population-level incidence of ovarian cancer.
2. Current Research Status at Home and Abroad
The pathogenesis of tumors is complex, and the risk assessment of tumors is also
relatively complex and specific [1-2]. Different from the risk of ovarian cancer in the
general population, the risk assessment of hereditary ovarian cancer requires more
consideration of the role of genetic factors. Currently, all international risk prediction
models for ovarian cancer are established based on genetic and clinical data from
foreign populations and lack data support from the Chinese population. Moreover,
existing models only incorporate the presence or absence of mutations as binary
variable information into the model and do not consider the characteristics of gene
mutations, such as mutation types and sites.
Existing studies have shown that the characteristics of BRCA1/2 gene mutations,
such as mutation types and locations, have a significant impact on the age of onset of
ovarian cancer. For example, Rebbeck et al.'s study found that mutations in the c.1380
to c.4062 region of the BRCA1 gene (referred to as the ovarian cancer cluster region,
OCCR) are associated with a higher risk of ovarian cancer and an earlier age of onset.
Similarly, mutations in the c.3249 to c.5681 region of the BRCA2 gene are also
associated with an increased risk of ovarian cancer [3]. Marchetti et al.'s study further
pointed out that mutation types also have an important impact on the age of onset. For
instance, nonsense mutations are associated with an earlier age of onset of high-grade
serous ovarian cancer, while frameshift mutations are associated with a later age of
onset. This indicates that mutation types may affect the timing of cancer occurrence
[4]. Kuchenbaecker et al.'s study provided age-specific risk estimates, showing that
the cumulative risk of ovarian cancer in BRCA1 mutation carriers by the age of 80 is
44%, while the risk for BRCA2 mutation carriers is 17%. Additionally, the study
noted that the location of mutations within the BRCA genes can further influence
these risks [5-6]. In conclusion, the type and location of BRCA1/2 mutations are key
factors determining the age of onset of ovarian cancer. Certain mutation types and
regions are associated with earlier or later onset ages. This information is crucial for
personalized risk assessment and management of BRCA1/2 mutation carriers.
However, there is currently no effective risk prediction model for BRCA1/2 mutation
carriers that is applicable to the Chinese population and can guide clinical practice.
Therefore, it is necessary to establish a risk prediction model for BRCA1/2 germline
mutation carriers of ovarian cancer that is suitable for the Chinese population through
the construction of a BRCA1/2 gene mutation carrier cohort and to conduct
preliminary validation.
3. Support from the Previous Studies of the Research Team Directly Related to This
Project
The research team, relying on the National Clinical Research Center for
Obstetrics and Gynecology Diseases, has long been engaged in the clinical diagnosis,
treatment and scientific research of gynecological malignancies. It was among the
first in China to open a genetic counseling clinic for gynecological tumors and has

rich case resources of hereditary ovarian cancer and experience in molecular
diagnosis and treatment. Based on the hereditary gynecological tumor diagnosis and
treatment platform, the team has established a multi-center hereditary ovarian cancer
registration cohort (NCT 06564428) and successfully constructed a primary screening
tool for the risk of ovarian cancer in first-degree relatives. This model stratifies
first-degree relatives of ovarian cancer patients into risk groups based on five easily
obtainable clinical information such as the age of diagnosis of the proband and family
history. It aims to screen high-risk individuals without genetic testing information,
facilitating its promotion and application at the grassroots level. The results were
published in the Gynecologic Oncology journal.
References
[1]
National
Comprehensive
Cancer
Network.
Genetic/Familial
High-Risk
Assessment: Breast and Ovarian and Pancreatic, Version 1.2024.
[2] Force USPST, et al. Risk Assessment, Genetic Counseling, and Genetic Testing
for BRCA-Related Cancer: US Preventive Services Task Force Recommendation
Statement[J]. JAMA, 322(7): 652-665, 2019.
[3] Rebbeck TR, Mitra N, Wan F, et al. Association of Type and Location of BRCA1
and BRCA2 Mutations With
Risk of Breast and Ovarian Cancer. JAMA.
2015;313(13):1347-61.
[4] Marchetti C, Ataseven B, Cassani C, et al. Ovarian cancer onset across different
BRCA mutation types: a view to a more tailored approach for BRCA mutated patients.
Int J Gynecol Cancer. 2023;33(2):257-262.
[5] Kuchenbaecker KB, Hopper JL, Barnes DR, et al. Risks of Breast, Ovarian, and
Contralateral Breast Cancer for BRCA1 and BRCA2 Mutation Carriers.JAMA.
2017;317(23): 2402-2416.
[6]
National
Comprehensive
Cancer
Network.
Genetic/Familial
High-Risk
Assessment: Breast and Ovarian and Pancreatic, Version 1.2024.
II. Research Aims
1. Primary Research Aims
To develop and validate an ovarian cancer risk prediction model for family
members of ovarian cancer probands with BRCA1/2 germline mutations.
2. Secondary Research Aims
①To study the correlation between the clinical efficacy of ovarian cancer in
BRCA1/2 germline mutation carriers and the characteristics of BRCA1/2 mutations.

②To investigate the acceptance rate of risk-reducing salpingo-oophorectomy (RRSO)
among germline BRCA1/2 mutation carriers and the influencing factors.
III. Research Design (Including the type of research to be conducted, research
hypotheses and possible treatment plans involved)
Type of Research Design
This
study
will
adopt
a
multicenter
ambispective
cohort
study
design
to
comprehensively
collect
and
analyze
the
clinical
characteristics,
family
characteristics, gene mutation characteristics, and lifestyle data of BRCA1/2 germline
mutation carriers. For family members who have not yet developed ovarian cancer at
the time of enrollment, telephone follow-ups will be conducted once a year to
longitudinally monitor ovarian cancer incidence and to collect diagnostic evidence.
IV. Research Subjects (Including Inclusion Criteria, Exclusion Criteria, and
Recruitment Strategies for research Subjects)
Research subjects: Members of ovarian cancer families carrying BRCA1/2 germline
mutations
1. Ovarian cancer patients carrying BRCA1 or BRCA2 germline mutations
Inclusion criteria:
①Pathologically diagnosed with ovarian malignant tumor.
②Identified as carriers of BRCA1/2 germline pathogenic or likely pathogenic
mutations through genetic testing, in accordance with the "Standards and Guidelines
for the Interpretation of Sequence Variants" (2015 Edition) of the American College
of Medical Genetics and Genomics (ACMG).
③Age of 18 years or older.
④Voluntary participation in this research and signing of the informed consent form.
Exclusion criteria:
①Patients who refuse to provide necessary information.
2. Female first-degree relatives carrying BRCA1 or BRCA2 germline mutations
Inclusion criteria:
①Female first-degree relatives (daughters, mothers, sisters) of the aforementioned
ovarian cancer patients.
②Age of 18 years or older.
③Voluntary participation in this research and signing of the informed consent form.
Exclusion criteria:
①First-degree relatives without blood ties: such as adopted daughters or
stepmothers.
3. Withdrawal criteria
Participants can voluntarily withdraw from the study at any time without providing
any reasons.
V. Research Outcome Measures (Including Primary Outcome Measures and
Secondary Outcome Measures)

1. Primary outcome measure
Definition: Pathologically diagnosed with ovarian malignant tumors (ICD-10 C56).
2. Secondary outcome measures
2.1 Clinical efficacy of ovarian cancer in BRCA1/2 germline mutation carriers
Definition: Progression-free survival (PFS) and overall survival (OS) after standard
treatment (such as surgery + chemotherapy).
2.2 Acceptance
rate of
risk-reducing
salpingo-oophorectomy
(RRSO)
among
BRCA1/2 mutation carriers
Definition: The proportion of BRCA1/2 germline mutation carriers in the high-risk
population of ovarian cancer who undergo risk-reducing salpingo-oophorectomy
(RRSO). RRSO refers to the preventive surgical removal of both fallopian tubes and
ovaries to reduce the risk of ovarian cancer, fallopian tube cancer, and peritoneal
cancer.
VI. Data Collection and Follow-up Plan
1. Screening of the study population: This multicenter study will enroll ovarian
cancer patients with confirmed BRCA1/2 pathogenic variants identified via genetic
testing since January 1, 2016. Family pedigrees will be collected, and first-degree
relatives will be recruited. After providing informed consent, peripheral blood
samples will be obtained for BRCA1/2 germline mutation testing to identify eligible
carriers.
2. Enrollment of the study population: All BRCA1/2 germline mutation carriers,
including ovarian cancer patients and female first-degree relatives, will be enrolled
as research subjects and sign informed consent forms.
3. Data collection
Collection content
Personal history: Height, weight, use of oral contraceptives, use of hormone
replacement therapy, smoking, drinking, history of benign gynecological diseases,
long-term medication history, etc.
Menstrual and reproductive history: Age of menarche, whether menopause, age of
menopause, number of pregnancies, number of deliveries, etc.
Personal history of tumors: Presence of malignant tumors, tumor type,
pathological classification, tumor stage, time of onset, treatment methods, treatment
outcomes, etc.
Family history of tumors (collected only from probands): Presence of new
malignant tumor family history, number of first-, second-, and third-degree relatives
with malignant tumors, relationship to the patient, tumor type, pathological
classification, tumor stage, age of onset, genetic testing status, etc.
Other disease history: Presence of new-onset circulatory, respiratory, digestive
system diseases, etc.
For patients already diagnosed with ovarian cancer, relevant clinical and
pathological information of ovarian cancer and onset time should also be collected.
Genetic testing information
1. Basic information on gene mutations

Gene names: BRCA1, BRCA2.
Mutation types:
Point
mutations:
Missense
mutations,
nonsense
mutations,
synonymous
mutations.
Insertion/deletion mutations: Frameshift mutations, non-frameshift mutations.
Large
segment
rearrangements:
Deletions,
duplications,
inversions,
translocations.
Mutation location:
Nucleotide position: cDNA position based on the reference sequences (e.g.,
BRCA1: NM_007294.4, BRCA2: NM_000059.4).
Amino acid position: Protein position based on the reference sequences (e.g.,
BRCA1: NP_009225.1, BRCA2: NP_000050.2).
Mutation description:
HGVS nomenclature: Follow the nomenclature rules of the Human Genome
Variation Society (HGVS) (e.g., BRCA1: c.68_69delAG, p.Glu23Valfs*17).
Clinical significance: Classified according to the ACMG 2015 guidelines
(pathogenic, likely pathogenic, variant of uncertain significance, likely benign,
benign).
2. Information on detection technology
Sequencing technology: Sanger sequencing, next-generation sequencing (NGS),
whole exome sequencing (WES), whole genome sequencing (WGS).
Testing scope: Whether it covers the entire gene or specific regions (e.g., hotspot
mutation detection).
Testing platform: Illumina, Thermo Fisher, etc.
4. Follow-up plan
①Follow-up content
Personal history: Height, weight, use of oral contraceptives, use of hormone
replacement therapy, smoking, drinking, history of benign gynecological diseases,
long-term medication history, etc.
Risk-reducing salpingo-oophorectomy:
Whether RRSO was performed (yes/no), surgery time (precise to the year/month),
age at surgery (calculated based on the surgery time).
Surgical indication: Whether based on BRCA1/2 mutation status. Whether there
are other high-risk factors (such as family history, personal history).
Surgical details: Surgical method (laparoscopic/open), postoperative pathological
results (whether there is occult cancer).
Reasons for refusing RRSO (if applicable): Personal preference (such as
preserving fertility, fear of surgery), medical advice (such as surgical risk
assessment), others (such as economic factors, cultural factors).
Menstrual and reproductive history: Whether menopause, age of menopause,
number of pregnancies, number of deliveries, etc.
Personal history of tumors: Presence of new malignant tumors, tumor type,
pathological classification, tumor stage, time of onset, treatment methods, treatment
effects, etc.

Family history of tumors: Presence of new malignant tumor family history,
relationship to the patient, tumor type, pathological classification, tumor stage, age of
onset, genetic testing status, etc.
Other disease history: Presence of new-onset circulatory, respiratory, digestive
system diseases, etc.
②Follow-up interval
Those without malignant tumors will be followed up once every 12 months, and those
with malignant tumors will be followed up once every 6 months. The planned
follow-up period is 5 years.
VII. Safety Considerations
1. Protection of Participant Privacy
To ensure the privacy and personal information security of participants, we will take
the following measures:
- Data Anonymization: All collected data will be anonymized, removing any
information that can directly identify an individual (such as name, ID number, etc.).
Data will be stored and processed in the form of unique codes.
- Encrypted Storage: All electronic data will be stored on encrypted servers, and only
authorized researchers can access them through secure authentication.
- Physical Security: Paper documents and biological samples will be stored in places
with strict access control to ensure that only authorized personnel can access them.
2. Psychological Support
Since BRCA1/2 mutation carriers may experience higher levels of psychological
stress and anxiety, especially when they learn of their increased risk of ovarian
cancer, we will provide the following psychological support services:
- Professional Psychological Counseling: Free psychological counseling services will
be provided to each participant to help them cope with possible emotional
fluctuations and psychological burdens.
- Support Groups: Support groups will be established to give participants the
opportunity to communicate with others who have similar experiences and share
experience and emotional support.
3. Medical Monitoring and Intervention
To ensure the health of participants, we will implement strict medical monitoring
and intervention measures:
- Regular Physical Examinations: Assist all participants in undergoing regular
physical examinations, especially those related to BRCA1/2 mutation-related tumors
(such as ultrasound examinations, tumor marker tests, etc.), to detect potential
problems in a timely manner.
- Personalized Intervention Recommendations: Based on risk assessment results,
provide personalized prevention and intervention recommendations for high-risk
individuals, such as preventive surgeries and drug prevention.
4. Exit Mechanism
Respecting the autonomy of participants, allowing them to withdraw from the
study at any time without any adverse effects:

- Exit Procedure: Clearly inform participants how to withdraw from the study and
simplify the exit procedure to ensure they can do so easily and without burden.
- Follow-up Support: Even if participants withdraw from the study, we will continue
to provide them with necessary medical and psychological support.
VIII. Data Management
Researchers will design the CRF according to the study protocol and submit it to
the Academy of Advanced Medical Sciences data management team for review and
modification. The study will use the REDCap electronic data collection system for
data collection and management. The system is a data collection platform based on
computer networks and used for data collection, data transmission, and data
management in clinical trials. The system has functions such as real-time data entry,
real-time data questioning, data audit trails, data validation, data verification,
electronic signatures, data locking, data storage, and data export. The application of
the system can ensure the data quality, authenticity and integrity of clinical trials. The
entire data management process will be carried out in accordance with national laws
and regulations and relevant data management SOP. The main data management
processes are listed below, and other details can be found in the Data Management
Plan (DMP). The DMP, as a guiding document for data management, will be written
by the Data Manager (DM) and approved by the researchers. Data management work
will be carried out in accordance with the timelines, content specifications, and
methodologies defined in the DMP.
1.Data Collection Roles and Responsibilities
Data collection roles
Abbreviation
Responsibilities
Clinical
Research
Coordinator
CRC
1. Enter data;
2. Answer queries;
Sub-Investigator
Sub-I
1. Enter data;
2. Answer queries;
Principal Investigator
PI
1. Enter data;
2. Answer queries;
3. Electronic signatures;
Clinical
Research
Associate
CRA
1.
Verify
source
document
consistency;
2. Raise and close queries;
3. Freeze/Unfreeze data;
Project Manager
PM
1.
Verify
source
document
consistency;
2. Raise and close queries;
3. Freeze/Unfreeze data;
Data Manager
DM
1. Raise and close queries;
2. Freeze/Unfreeze data;
3. Lock data;
4. Account management.

2. Database Design and Establishment
The database (eCRF) for the project is established by the data manager at Academy
of Advanced Medical Sciences, following the SOP standards and setting up edit
checks in accordance with the Data Verification Plan (DVP). After passing the test
and being approved by the authorized researcher, it is released for use. All role
personnel,
including
PI,
Sub-I,
CRC,
PM,
CRA,
and
DM,
must
complete
protocol-defined training before being granted system access privileges.
3. Data Entry
In accordance with the REDCap user manual, the entry personnel (PI, Sub-I, or CRC)
should promptly enter the clinical trial data into the EDC system. The research data
should come from original documents such as original medical records and
laboratory test reports and be consistent with the original documents. All
observations and examination results obtained during the trial must be documented in
the eCRF promptly, accurately, completely, clearly, and truthfully in compliance with
regulatory standards, and no unauthorized modifications shall be made. All items in
the eCRF must be filled in, and no items should be left blank or omitted. If necessary,
when making data corrections in the eCRF, the reason for the data modification
should be filled as prompted by the system.
4. Data Verification
The REDCap system's automatic data logic verification function is used to
implement data verification, improving data management efficiency and data quality.
The logic verification program is designed based on the safety and efficacy indicators
specified in the clinical protocol and the eCRF. The data logic program includes the
verification of valid values and valid ranges for individual data values and the logical
verification of the relationships between multiple data values or data values across
modules.
5. Source Data Verification and Query
The Clinical Research Associate (CRA) is responsible for on-site monitoring at
the center, verifying 100% of the eCRF entered data for correctness and completeness,
and consistency with original documents such as the original medical records and
laboratory test reports. If any issues are found, they can raise Queries online at any
time.
The data manager manages the queries of the trial data based on the Data
Verification Plan (DVP). When data are entered into the EDC system and there are
any data that do not conform to logic, the system will automatically verify and raise
Queries; these Queries need to be reviewed and answered by the researcher or
authorized personnel. In addition to the system's automatic verification, any Queries
raised through SAS programming or manual verification by the data manager can be
manually
added
to
the
EDC
system
when
requiring
the
researcher
to
clarify/verify/confirm.
6. Data Query Resolution
Researchers need to promptly answer queries. Data managers, monitors, and
medical personnel provide query responses. If necessary, queries can be raised again
until the data is "clean".

7. Data Review
After data cleaning is completed, the data quality needs to be reviewed. Key data
(important data determined by the research protocol) should be 100% checked, and a
certain range of non-key data should be spot-checked, and a final Data Verification
Report (DVR) and population classification resolution should be formed.
8. Researcher's Signature
The data manager needs to ensure that all queries are cleared, and the
researcher conducts an electronic signature review and confirmation. If there are any
data revisions after signing, a new signature is required.
9. Data Locking and Exporting
According to the database locking procedure, the data manager, statistical
analyst, clinical monitor representative, and researcher sign a written approval of the
database lock document. The data manager exports and organizes the standardized
database and hands it over to the statistician for statistical analysis. Once the data is
locked, it cannot be edited. If there is definite evidence that unlocking is necessary
after the data is locked, the researcher and relevant personnel need to sign the
database unlock document.`
10. eCRF Archiving
After the study is completed, the data manager will standardize the names of all
electronic documents generated during the study, categorize them into standardized
folders, and convert important final draft documents into PDF format. Data should be
encrypted. Documents that require signatures for archiving need to be printed and
signed by the corresponding personnel, and organized into standard folders in
chronological order. Project documents should be kept for at least five years.
IX. Statistical Analysis
1. Basis for Sample Size Determination
The main objective of the study is to develop an accurate model for predicting
the risk of ovarian cancer in BRCA1/2 mutation carriers. To achieve this objective, it
is necessary to ensure that there is a sufficient sample size to capture the complex
relationships between different risk factors and to guarantee the stability and
accuracy of the model.
Sample size for model development: Considering that the model will include
multiple predictor variables (such as gene loci, family characteristics, lifestyle, etc.),
it is expected that 10-15 variables will be included in the model. According to the rule
of thumb, the number of ovarian cancer cases in the development cohort should be at
least 10 times the number of expected included variables, requiring at least 150
probands with primary ovarian cancer. This study plans to include a total of 1,000
people including probands with primary ovarian cancer and their first-degree
relatives from Peking University Third Hospital and Peking University First Hospital
as the development cohort, with an expected inclusion of at least 500 proband cases
and 500 first-degree relatives. It is expected that the development cohort will meet the
sample size requirements for model development.
Sample size for model validation: According to previous literature, the ROC of
the currently published models is 75%. This study's model is expected to reach 80%,

with a reliability of 95% and a validity of 80%. The ratio of probands with primary
ovarian cancer to first-degree relatives is 1:1, and it is expected that 702 people will
be needed, including 351 proband cases and 351 first-degree relatives. This study
plans to include 1,000 people from the Cancer Hospital, Chinese Academy of Medical
Sciences, Peking University People's Hospital, and other institutions, with 500
proband cases and 500 first-degree relatives. It is expected to meet the sample size
requirements.
2. Statistical Analysis Methods
In this study, we will employ a series of statistical methods and machine learning
techniques to ensure the scientific rigor of data processing and the reliability of the
results. The detailed statistical analysis methods are as follows:
(1) Descriptive Statistical Analysis
- Basic Feature Description: Including age, mutation type, family history, menstrual
history, etc. Use mean, median, standard deviation, interquartile range, etc. to
describe continuous variables; use frequency and percentage to describe categorical
variables.
- Chart Presentation: Data distribution was visualized using bar charts, pie charts,
boxplots, and other graphical tools for intuitive representation.
(2) Univariate Analysis
- Chi-square Test: Used for the association analysis between categorical variables
(such as mutation type, family history, etc.) and the incidence of ovarian cancer.
- t-test or Mann-Whitney U Test: Used for the association analysis between
continuous variables (such as age) and the incidence of ovarian cancer.
(3) Multivariate Analysis
- Logistic Regression Model: Used to analyze the influencing factors of binary
outcomes (such as whether to have ovarian cancer), estimate the odds ratio (OR) and
its 95% confidence interval (CI) of each variable.
- Stepwise Regression Analysis: Screen out the variables that have a significant
impact on the incidence of ovarian cancer through forward selection, backward
elimination, or stepwise regression methods, and construct the optimal model.
(4) Machine Learning Models
- Model Selection: Select multiple machine learning algorithms (such as random
forest, support vector machine, gradient boosting trees, etc.) for model construction,
and
evaluate
the
performance
of
different
models
through
cross-validation
techniques.
- Feature Selection: Use recursive feature elimination (RFE), LASSO regression, and
other methods for feature selection to optimize model performance.
- Hyperparameter Tuning: Find the best hyperparameter combination through grid
search or random search methods to enhance the predictive ability of the model.
- Model Evaluation: Evaluate the predictive performance of the model using
indicators such as the area under the receiver operating characteristic curve (AUC),
sensitivity, specificity, F1 score, etc.
(5) Internal Validation and External Validation
- Internal Validation: Evaluate the stability and generalization ability of the model in

the development cohort through cross-validation (such as k-fold cross-validation) and
Bootstrap resampling methods.
- External Validation: Validate the predictive performance of the model in an
independent dataset to ensure generalizability across diverse populations.
(6) Sensitivity Analysis
- Missing Data Handling: Evaluate the impact of different missing data handling
methods (such as multiple imputation, maximum likelihood estimation, etc.) on the
results.
- Subgroup Analysis: Subgroup analyses were performed (e.g., by age strata or
mutation types) to validate model performance across distinct subpopulations.
X. Quality Control Measures in Clinical Research
1. Protocol Modification
During the implementation of the study, to guarantee the quality and scientific
rigor of the research, we will strictly adhere to the established protocol. However,
reasonable modifications to the protocol will be permitted when necessary. The
following
are
the
specific
regulations
and
procedures
regarding
protocol
modification:
(1) Reasons for Modification
- Scientific basis: Based on new scientific discoveries or research outcomes,
adjustments to the research methods or the addition of new variables might be
necessary.
- Ethical considerations: In accordance with the suggestions or requirements of the
ethics committee, modifications to the research protocol will be made to ensure
compliance with ethical standards.
- Operational feasibility: During the implementation of the study, if operational
difficulties or irrationalities are identified in certain steps or methods, reasonable
modification suggestions can be proposed.
- Participant feedback: Based on the feedback from participants, the communication
and follow-up mechanisms during the research process will be improved to enhance
participant compliance and satisfaction.
(2) Modification Process
- Proposal submission: Any proposed modifications to the protocol should first be
raised by the principal investigators within the research team and submitted as a
written proposal. The proposal must provide a detailed explanation of the rationale
for the changes, the specific modifications, and their anticipated impact.
- Internal review: After submission, the proposal will undergo preliminary evaluation
by an internal review committee within the research team. The review committee
consists of the project leader, statisticians, clinical doctors, and other relevant experts.
The committee will assess the scientific validity, feasibility, and necessity of the
proposal.
- Ethical review: For modifications involving ethical issues or having a significant
impact on participant rights, they must be submitted to the ethics committee for
review and approval. The ethics committee will evaluate whether the modification

conforms to ethical standards and provide corresponding opinions and suggestions.
- Formal approval: After obtaining approval from the ethics committee, the study
team will make the final revision to the protocol based on the review committee's
opinions and formulate a formal modified document. The modified document must be
signed and confirmed by all relevant parties and archived for future reference.
- Notification to participants: If the protocol modification pertains to participants’
informed consent form or other matters directly affecting participants, all recruited
participants must be promptly notified and their informed consent must be
re-obtained.
(3) Record-keeping and Reporting
- Detailed record-keeping: Each protocol modification must be recorded in detail,
including the modification date, a detailed description of changes, the approving
authority, and signatures of relevant personnel. All modification records will be
properly preserved as part of the research archive.
- Regular reporting: The study team will regularly report the status of protocol
modifications to the ethics committee and the funding agency to ensure that all parties
are promptly informed of the progress of the research and any significant changes.
2. Training
Prior to study initiation, all site investigators will receive clinical trial quality
control training conducted by clinical research associates (CRAs). The training
program will cover principal investigator，project coordinators, clinical research
coordinators (CRCs), laboratory personnel and other relevant site staff.
For the principal investigators and project coordinators, the training content
encompasses the research protocol, inclusion and exclusion criteria, specific
implementation procedures and details of the research. The principal investigators of
each sub-center are responsible for selecting research subjects, while the project
coordinators are responsible for supervising the progress of the trial at each center,
coordinating the budget, and addressing any issues that may arise during the
research to ensure its smooth implementation. For CRCs, the training content
includes the filling of CRF forms and precautions, training on the data entry system,
training on the informed consent process, and follow-up training. Laboratory
technicians will receive training on sample collection, handling, and BRCA gene
testing procedures, and standard operating procedures (SOPs) for sample collection,
handling, transportation and gene testing will be established.
3. Project Monitoring
For the management of biological samples involved in this study, standardized
procedures for sample collection, handling, storage, and transportation will be
established, and regular reviews by institutional clinical trial departments and ethics
committees across all participating sites will be conducted. Each year, research
progress will be reported and monitored, including the filling and storage of CRF
forms, the data quality of eCRF, the standardization of genetic testing reports, and
the qualifications of laboratories.
4. Quality Control during the Research Process
The study addresses the core issues of low response rate among first-degree

relatives of probands and difficulties in collecting biological samples by implementing
a three-level quality control system (self-check by researchers - quality control at
sub-centers - supervision by the headquarters), and adopts the following stratified
quality control strategies:
4.1 Ensuring the Compliance of Research Subjects
Through the following quality control measures, the response rate of first-degree
relatives (the proportion of those who participate in genetic testing among all
first-degree relatives) is expected to reach over 80%.
(1) Incentive Mechanism for Relative Participation
- Provide a health care package after blood collection (including interpretation of
physical examination reports and basic disease consultation services).
-
Establish
a
relative
tracking
database,
recording
contact
information,
communication time, and reasons for refusal (which need to be classified and coded:
such as geographical restrictions, time conflicts, privacy concerns, etc.).
(2) Informed Consent
- Implement a "double-check system" for telephone informed consent: after CRC
completes the communication, a quality control specialist will follow up within 48
hours to confirm the understanding level.
4.2 Standardization of Biological Sample Collection
(1) Construction of a Blood Collection Network
Open a "green channel for relative blood collection": relatives can have free blood
collection at local cooperative hospitals with an electronic authorization code (The
blood collection tubes are pre-labeled with dual QR codes: relative ID + proband
linkage code).
(2) Emergency Collection Protocol
Set up alternative plan: for those who cannot have venous blood collection, provide
an alternative plan of throat swab collection.
(3) No immunosuppressive drugs are allowed during blood sample and information
collection, and there should be no abuse of any drugs or alcohol.
4.3 Multi-dimensional Quality Control of Data Collection
(1) Remote Data Audit
- AI monitoring of the entire telephone interview process: real-time analysis of voice
emotions (such as resistance or confusion triggering the intervention of quality
control specialists).
- Develop a kinship data dashboard: dynamically display the geographical
distribution of response rates (with three-level drill-down: province-city-county),
statistics on reasons for loss to follow-up, and sample compliance rates.
(2) Data Cleaning Rules
- Establish a Kinship Data Integrity Index (KDI) = (collected data items / target data
items) × (valid biospecimens / target biospecimens)
- Set up automatic cleaning rules: for cases with KDI < 0.7, initiate a manual
supplementary collection process; remaining incomplete after 30 days will be flagged
as 'Partially Missing Data'.
4.4 Construction of Specialized Quality Control Teams

- Establish a kinship response rate task force: conduct weekly analyses of
lost-to-follow-up cases and monthly updates to the communication script library
(including specially designed dialect versions for elderly relatives).
- Develop an intelligent reminder system: automatically send care messages during
special occasions like relatives' birthdays and traditional festivals to maintain study
engagement.
4.5 Quantitative Indicators for Quality Assessment
Quality
Control
Dimension
Core Indicators
Compliance Standards
Response Rate
Genetic testing rate of first-degree
relatives
≥80%
Timeliness
Interval from informed consent to
blood collection completion
≤14 days
Completeness
Effective
completion
rate
of
electronic questionnaires
≥90%
Biological Samples
Proportion of hemolyzed samples
≤3%
Data Quality
Double-entry inconsistency rate
≤0.5%
XI. Protection of Research Subjects
1. Ethics Committee
The study and each sub-center must obtain approval from the Ethics Committee,
which comprises medical professionals, legal experts, and lay members to ensure that
the research protocol complies with ethical standards and safeguards subjects’ rights
and safety.
2. Obtaining Informed Consent from Research Subjects
Before the initiation of the study, researchers will provide all subjects with
detailed information, including the purpose, methods, and potential risks of the study,
to ensure they have sufficient knowledge to provide informed consent. For those who
are unable to sign paper-based informed consent forms, detailed study information
will be communicated via WeChat, followed by delivery of an electronic consent form
to obtain digital signatures. If neither the paper nor the electronic consent is feasible,
the research team will notify them and conduct verbal consent via telephone, with the
entire communication process audio-recorded as documentation.
3. Confidentiality and Privacy
The study employs anonymous or de-identified data collection methods and
manages the data uniformly through EDC to prevent data leakage and ensure data
security and the confidentiality of the subjects' personal information.
4. Risks and Benefits for Research Subjects

(1) Risks for Research Subjects: Participants in this study will have 4ml of peripheral
blood collected for genetic testing, which involves physiological risks. Additionally,
probands and their relatives need to visit the hospital to collect peripheral blood,
incurring economic and time risks.
(2) Benefits for Research Subjects: The greatest benefit for participants in this study
is that if the peripheral blood test results show BRCA germline mutations, they will be
proactively informed of the results and receive free professional genetic counseling
and subsequent treatment plans. Moreover, the cost of sending peripheral blood will
be covered by this study.
Although this study may initially impose certain financial and physical burdens
on participants, in the long term, each participant will gain clarity regarding their
BRCA mutation status, enabling access to more precise medical care. Furthermore,
this study aims to establish a BRCA1/2 mutation carrier-based ovarian cancer risk
prediction model tailored to the Chinese population. This model will predict ovarian
cancer risk in individuals carrying pathogenic or likely pathogenic variants, guiding
clinical intervention strategies for high-risk groups and ultimately benefiting broader
society.
5. Compensation and Reimbursement
For each study participant, 4ml of peripheral blood will be collected. The costs
associated with blood sample shipment and genetic testing for first-degree relatives
(excluding the proband) will be covered by this study.
XII. Organization and Management
1. Research Sites and Tasks
Institution
Role and Responsibilities
Planned
Enrollment
Numbers
Peking University Third
Hospital
Co-lead
site,
Patient
enrollment
800 cases
Peking
University
First
Hospital
Co-lead
site,
Patient
enrollment
200 cases
Institute
of
Advanced
Clinical Medicine, Peking
University
Protocol design(Yangfeng Wu,
Gaoqiang
Xie),
Data
management(Wenyao
Ma),
Project
management(Qian
Xu),
Statistical
analysis(Yongpei Yu)
0
Cancer Hospital, Chinese
Participating
site,
Patient
200 cases

Academy
of
Medical
Science
enrollment
Yunnan Cancer Hospital
Participating
site,
Patient
enrollment
200 cases
Tianjin Central Hospital
of Gynecology Obstetrics
Participating
site,
Patient
enrollment
200 cases
Peking
University
People's Hospital
Participating
site,
Patient
enrollment
200 cases
The Second Hospital of
Hebei Medical University
Participating
site,
Patient
enrollment
100 cases
General
Hospital
of
Ningxia
Medical
University
Participating
site,
Patient
enrollment
50 cases
Henan Cancer Hospital
Participating
site,
Patient
enrollment
50 cases
2. Preservation of Research Documents and Records
The original genetic test reports generated during the study will be retained by
each participating center. Scanned electronic versions of these reports will be stored
in the EDC database.
In this study, peripheral blood samples will be collected from all participants.
Laboratories and sample transport personnel involved in this study must be familiar
with the types and quantities of samples, as well as the types and methods of sample
transport in the hospital, and comply with the relevant provisions of the Regulations
of the People's Republic of China on the Administration of Human Genetic Resources
for sample transport and preservation.
3. Early termination of the study
This study involves long-term follow-up with no anticipated early termination.

Subject name：
Subject ID：
Informed Consent Document
Study Title: Development and Validation of an Ovarian Cancer Risk Prediction
Model for Family Members of Ovarian Cancer Probands with BRCA1/2 Germline
Mutations
Institution: Peking University Third Hospital
Principal Investigator: Professor Hongyan Guo, Department of Gynecology
Dear Participant,
You are invited to participate in the research study titled "Development and
Validation of an Ovarian Cancer Risk Prediction Model for Family Members of
Ovarian Cancer Patients with BRCA1/2 Mutations." This study is led by Peking
University Third Hospital, with Professor Hongyan Guo as the Principal Investigator,
and is conducted across nine hospitals in China. The study is supported by the Peking
University Century Golden Resources Tengyun Clinical Research Program. The study
protocol and this informed consent form have been approved by the Institutional
Review Board (IRB) of Peking University Third Hospital.
Before deciding whether to participate, please carefully review the information below.
It explains the purpose, procedures, duration, potential benefits, risks, and discomforts
associated with this research. You are encouraged to discuss this with family or
friends. The investigator will explain the study to you, and you may ask questions at
any time.
Background
Ovarian cancer is the most lethal gynecologic malignancy, posing a severe threat to
women’s health. Approximately 70% of patients are diagnosed at an advanced stage,
contributing to its high mortality. Notably, 20% of ovarian cancers are linked to
hereditary factors, providing an opportunity to identify high-risk individuals for

prevention, early diagnosis, and reduced disease burden.
Current research on hereditary ovarian cancer in China is scarce, and clinical practice
relies heavily on foreign data. However, hereditary cancers exhibit distinct geographic
and ethnic variations. There is an urgent need for China-specific clinical data to guide
local practice. Studies indicate that 50%–60% of hereditary ovarian cancers are
closely associated with BRCA1/2 germline mutations. Accurate assessment of ovarian
cancer risk in BRCA1/2 mutation carriers is critical for prevention and early
intervention.
Study Purpose
This study aims to establish a bidirectional cohort of BRCA1/2 mutation carriers to
comprehensively collect genetic, familial, and lifestyle data. Using statistical
modeling and machine learning, we will develop a risk prediction model to:
1.
accurately predict individual ovarian cancer risk in BRCA1/2 mutation carriers.
2.
provide clinical decision support for optimal intervention timing.
3.
reduce ovarian cancer incidence and improve quality of life.
Study Design
A cohort study design will be used to analyze germline mutation profiles, family
characteristics, and lifestyle data of BRCA1/2 mutation carriers.
Figure 1: Study Flowchart

Study population
Family members of ovarian cancer patients with BRCA1/2 mutations.
1.
Ovarian cancer patients with BRCA1/BRCA2 germline mutations
Inclusion criteria:
①Pathologically confirmed epithelial ovarian cancer.
②Confirmed BRCA1/2 germline pathogenic/likely pathogenic mutation per ACMG
guidelines (2015).
③Age ≥18 years.
④Voluntary participation with signed informed consent.
Exclusion criteria:
①Unwillingness to provide necessary information.
2.
Female first-degree relatives with BRCA1/BRCA2 germline mutations
Inclusion criteria:
①Female first-degree relative (daughter, mother, sister) of an enrolled patient.
②Age ≥18 years.
③Voluntary participation with signed informed consent.
Exclusion criteria:
①Non-biological first-degree relatives (e.g., adopted daughters, stepmothers).
3.
Withdrawal Criteria
①Participants may withdraw at any time without penalty or impact on medical care.
Sample Size & Duration
This 3-year study plans to enroll 2,000 participants (probands and female first-degree
relatives).

Procedures
Blood Collection: 4 mL peripheral blood for genetic testing.
Study Timeline & Follow-up
Patients with cancer: Follow-up every 6 months (via phone/clinic).
Relatives: Annual follow-up.
Data Collected: Lifestyle, menstrual/reproductive history, personal/family cancer
history.
Risks
1.
Genetic Testing Limitations: Results are for research only. Clinical decisions
require confirmatory clinical genetic testing.
2.
Blood Draw Risks: Minor discomfort, bruising, or rare risks including infection
or excessive bleeding.
Reporting Adverse Events: Notify the study physician immediately if you experience
discomfort or health changes. Urgent medical issues will be communicated to
you/family for prompt clinical evaluation. You will be informed of new findings
affecting your participation.
Prohibited Medications
Immunosuppressants, substance abuse, or alcohol misuse during sample collection.
Costs & Compensation
Genetic testing and blood shipment costs for relatives (non-probands) are covered by
the study.
Benefits
You will receive BRCA1/2 genetic results for early screening and family planning
guidance. Findings may aid other families with hereditary ovarian cancer.
Note: No direct therapeutic benefit is guaranteed.

Voluntary Participation & Withdrawal
Participation is voluntary. You may withdraw anytime without affecting your medical
care. The investigator may withdraw you if continuing is not in your best interest.
New Information Disclosure
New findings about your genetic results or emerging therapies will be shared with
you.
Privacy & Confidentiality
Identifiers (e.g., name, gender) will be replaced with codes. Only authorized
researchers will access your data. Regulatory/ethics committees may audit records per
protocol. Published results will not disclose your identity.
Contact Information
Study Questions: Dr. Yuan Li, Phone: +86 15611908183
Rights Concerns: IRB Office, Peking University Third Hospital, Phone: +86 (010)
82265571 / 82265176

Investigator’s Statement
“I have explained the study background, purpose, procedures, risks, and benefits to
the participant. I provided time to review this form, discuss with others, and answered
all questions. I informed the participant of their right to contact the investigator or
IRB with concerns and to withdraw anytime without penalty. A copy of this signed
consent form will be provided.”
Investigator’s Signature: ________________________
Phone: ________________________ Date: ________________________
Subject’s Consent Statement
“I understand the study’s background, purpose, procedures, risks, and benefits. I had
sufficient time to ask questions and received satisfactory answers. I know whom to
contact with concerns. I voluntarily agree to participate and confirm that all provided
information is accurate. I understand I may withdraw at any time without penalty. I
will receive a copy of this signed consent form.”
Subject’s Signature: ________________________
Phone: ________________________ Date: ________________________
(For subjects lacking legal capacity, complete below)
Legally Authorized Representative Signature: ________________________
Relationship to Subject: ________________________
Date:________________________
(For subjects unable to read this form)
Witness Signature: ________________________ Date: ________________________
END OF DOCUMENT