Real-World Data on Clinical Characteristics, Demographics, and Outcomes of Patients With Metastatic Breast Cancer in Turkey

Study Overview
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Brief Summary
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This study is planned as a secondary data use (SDU) study and the data collection will be performed retrospectively. Patients who presented to the participating sites with metastatic breast cancer will be defined, and patients' data will be recorded into a database.

Detailed Description
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This study is planned as a secondary data use (SDU) study and the data collection will be performed retrospectively. Patients who presented to the participating sites with metastatic breast cancer will be defined and patients' data will be recorded into a database. The study will be performed at clinical centers located in the populated cities with high clinical and diagnostic standards including patients presented with metastatic disease will be recorded. It is also planned to collect data on the treatment of metastatic breast cancer in line with institutional guidelines at academic and private centers which has implemented high quality clinical and pathologic standards. This retrospective study is designed to record, define and evaluate the changes in the presentation patterns, pathological subtypes and outcomes of metastatic breast cancer patients in relation with the evolution of overall and progression-free survival rates following the changes in treatment approaches over the last decade based on the evolving/different treatment regimens of metastatic breast cancer. These findings will shed light on how changes in metastatic patterns have influenced practice patterns, as well as the generalizability of this data to the current knowledge and physician's adherence to adopt contemporary treatment options which have been integrated within standard treatment algorithms. Demographic characteristics of metastatic breast cancer patients, diagnosis of disease and treatments initiated for all patients receiving first line (1L) and second line (2L) treatment who were admitted to the clinical centers starting from year 2010 will be retrospectively collected for this study. Data of patients who previously consented for institutional data sharing will be retrieved from patient charts and recorded in a secure electronic registry. The study data will be categorized on two different patient characteristics: Metastatic pattern at presentation [recurrent metastatic breast cancer (rMBC) or de-novo metastatic breast cancer (dnMBC)] of patient and date of initial presentation for diagnosis and treatment. The study is planning to analyze patients with follow-up data of minimum 3 years and the data recording will eventually plan to construct two cohorts based on the initial diagnosis date; patient diagnosed during Jan 2010-Dec 2014 and Jan 2015-Dec 2019. The main goal of the study is to define whether if any changes in the treatment practices occurred during the period of data record in line changes occurred with the availability of novel diagnostic methods and treatments for metastatic breast cancer.

Official Title
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Demographic Data and Outcomes Of Metastatic Breast Cancer Patients Treated Over The Last Decade At Tertiary Oncology Clinics In Highly Populated Cities In Turkey: A Turkish Oncology Collaborative Group Analysis

Conditions
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Metastatic Breast Cancer

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 18 years, no upper age limit. Must have a definite diagnosis of metastatic breast cancer at the time of initial application at any of the participating clinical centers. Patients who were initiated their first treatment at the center where the initial mBC diagnosis was made and whose follow-up and treatment period have continued at the current center. Patients must have signed an informed consent that allow collection of personal data and protection of patient confidentiality according to the standard procedures of each participating center. Exclusion Criteria: Patients who were referred to the participating centers for further treatment for a second opinion.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Time period 2010-2014<br>Data from Turkish participants with metastatic breast cancer diagnosed January 2010-December 2014 will be retrospectively collected. | |
| Time period 2015-2019<br>Data from Turkish participants with metastatic breast cancer diagnosed January 2015-December 2019 will be retrospectively collected. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Treatment outcome data: Overall survival (OS) | OS: it is defined as the time from the date of initial breast cancer diagnosis to the date of death due to any cause. OS data: number (%) patients receiving first-line, second-line, third-line chemotherapy | Up to 10 years | 
| Treatment outcome data: Progression-free survival (PFS) | PFS: it is defined as the time from the start date of a specific treatment to the documentation of disease progression on such treatment, or death due to any cause, whichever occurs first. In the event that none of the previous events were observed, censoring the last contact date will be considered. PFS data: number (%) patients receiving first-line, second-line, third-line chemotherapy | Up to 10 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to progression (TTP) | Time to progression is measured as the time from study entry to the development of disease progression. | Up to 10 years | 
| Demographic characteristics at baseline | Patient demographics: age and gender. Type of insurance (social security system, private insurance) [if available] | Up to 10 years | 
| Clinical and pathological characteristics: Diagnosis | Date and stage of diagnosis | Up to 10 years | 
| Clinical and pathological characteristics: Clinical and/or pathological stage | Tumor clinical and/or pathological stage will be collected through the tumor-node-metastasis (TNM) staging system | Up to 10 years | 
| Clinical and pathological characteristics: Lymph nodes | Number (N) of lymph nodes involved / retrieved | Up to 10 years | 
| Clinical and pathological characteristics: Tumor size | Measured by a pathologist from the tumor surgical specimen at breast surgery [unifocal, multifocal, multicentric] | Up to 10 years | 
| Clinical and pathological characteristics: Pathological subtype | Number of patients with different pathological subtypes [HER2+/HR- , HER2+/HR+, HER2-/HR+, TNBC] | Up to 10 years | 
| Clinical and pathological characteristics: Hormone-receptor expression | Estrogen Receptor positivity [%] Progesterone Receptor positivity [%] | Up to 10 years | 
| Clinical and pathological characteristics: Human Epidermal Growth Factor Receptor 2 (HER-2) expression | HER2 status will be determined by immunohistochemistry (IHC) [scoring: 0, 1+, 2+, 3+] In situ hybridization (ISH) will be used to confirm IHC results [positive/negative and amplification ratio (%)] Progesteron Receptor positivity [%] | Up to 10 years | 
| Clinical and pathological characteristics: Histological type | Histological type: Invasive ductal, invasive lobular, other. | Up to 10 years | 
| Clinical and pathological characteristics: Histological grade | Histological grade with using Modified Bloom Richardson grading system: Grade 1, Grade 2, Grade 3 | Up to 10 years | 
| Clinical and pathological characteristics: Nuclear grade | Nuclear grade: Grade 1, Grade 2, Grade 3 | Up to 10 years | 
| Anatomopathological characteristics of the tumor: Ki-67 | Tumor Ki-67 proliferation index will be collected | Up to 10 years | 
| Treatment data: type of chemotherapy | Number (%) patients receiving neoadjuvant or adjuvant chemotherapy | Up to 10 years | 
| Treatment data: adjuvant hormonotherapy | Number (%) patients receiving adjuvant hormonotherapy | Up to 10 years | 
| Treatment data: radiotherapy | Number (%) patients receiving radiotherapy [Stereotactic Body Radiation Therapy (SBRT), conventional radiotherapy or other] | Up to 10 years | 
| Treatment data: surgery | Number (%) patients underwent surgery [by regions] | Up to 10 years | 
| Treatment data: locally ablative treatment | Number (%) patients had locally ablative treatment [by regions] | Up to 10 years | 
| Follow-up data: initial recurrence | Date and site of recurrence [visceral, non-visceral, central nervous system (CNS) and oligometastatic] | Up to 10 years | 
| Follow-up data: current condition | The date of the last review and current clinical condition will be recorded. | Up to 10 years | 
| Follow-up data: date and cause of death | Date and cause of death, when applicable. | Up to 10 years |