Clinical trial NCT05126667: Analysis of Breast-Conserving Surgery Plus Whole-Breast Irradiation Versus Mastectomy
Official title: A Propensity Score-Matched Analysis of Breast-Conserving Surgery Plus Whole-Breast Irradiation Versus Mastectomy in Breast Cancer
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Breast Cancer
Lead sponsor: European Institute of Oncology
Sponsor class: OTHER
First posted: 2021-11-19
Enrollment: 9710
Sex: FEMALE
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Retrospectively analysis of patients who received treatment for invasive breast cancer at the European Institute of Oncology between January 1, 2000, and December 31, 2008.

The original cohort comprised 9710 eligible patients with breast cancer, of whom 2289 (23.6%) underwent breast conserving surgery + whole breast irradiation and 7421 (76.4%) underwent mastectomy alone.

After propensity score matching, 1970 of the 2289 patients who underwent mastectomy (86.1%) were successfully matched to 1970 patients who underwent breast conserving surgery.

Brief summary: This is a retrospective propensity score-matched analysis of a large institutional cohort of patients in order to compare long-term outcomes and clinicopathologic characteristics between patients treated with breast conserving surgery or mastectomy for breast cancer.

Detailed description: The aim of the study is to compare long-term outcomes and clinicopathologic characteristics between patients treated with breast conserving surgery + whole breast irradiation or mastectomy for breast cancer.

Recent observations regarding long-term outcomes among patients with early-stage breast cancer who underwent breast-conserving surgery plus whole-breast irradiation or mastectomy are from a small number of registry-based studies.

Therefore, these findings may overestimate differences in survival between the two groups, compared with randomized controlled trials conducted in the 1980s.

This study performed a propensity score-matched analysis in a cohort of 9710 patients aged \<70 years who underwent breast conserving surgery + whole breast irradiation or mastectomy without external radiotherapy for a first primary breast cancer (pT1-2, N0-3a) at the European Institute of Oncology between 2000 and 2008.

Patients were matched by propensity score.

Eligibility criteria: Inclusion Criteria:

* First primary breast cancer
* pT1-2
* pN0-3a
* Surgery performed at European Institute of Oncology between 2000 and 2008

Exclusion Criteria:

* pT\>=3
* Neoadjuvant treatment
* Presence of metastatic breast disease at the time of admission or within 3 months

Primary outcomes:
measure: Cumulative incidence of ipsilateral breast tumor recurrence
timeFrame: 10 years
measure: Cumulative incidence of axillary lymph node recurrence
timeFrame: 10 years
measure: Cumulative incidence of contralateral breast cancer
timeFrame: 10 years
measure: Rate of distant metastasis
timeFrame: 10 years
measure: Cumulative incidence of breast cancer specific survival
timeFrame: 10 years
measure: Rate of overall survival
timeFrame: 10 years
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: European Institute of Oncology
name: Francesca Magnoni, MD
role: PRINCIPAL_INVESTIGATOR
References: