Surgery for Men with Breast Cancer: Do the Same Data Still Apply?

Area of Science:

• Oncology
• Surgical Oncology
• Clinical Trials

Background:

• Male breast cancer is rare, and treatment guidelines are primarily based on female data due to trial exclusion.
• This study examines practice patterns in male and female breast cancer patients post-landmark surgical trials.

Purpose of the Study:

• To compare breast cancer treatment practices between men and women.
• To assess the impact of landmark clinical trials on treatment de-escalation in male breast cancer patients.
• To evaluate survival outcomes in men versus women following the adoption of trial findings.

Main Methods:

• Analysis of invasive breast cancer cases (2004-2015) from the National Cancer Data Base.
• Subcohort creation based on eligibility for NSABP-B06, CALGB 9343, and ACOSOG Z0011 trials.
• Gender-stratified comparison of practice patterns and Cox proportional hazards regression for overall survival (OS).

Main Results:

• Mastectomy rates remained stable (~80%) for eligible men in the NSABP-B06 cohort; OS was slightly worse (HR 1.19).
• Men were slower to adopt omission of radiation post-lumpectomy (CALGB 9343 eligible) but had similar OS (HR 0.92).
• De-escalation of axillary surgery (ACOSOG Z0011) occurred in both genders with comparable OS (HR 0.69 for men).

Conclusions:

• Adoption of clinical trial results in male breast cancer often parallels that in women, despite men's exclusion from trials.
• Men and women exhibit similar survival outcomes when study findings are applied to eligible patients.
• Observational studies are crucial for guiding treatment and improving clinical trial enrollment for male breast cancer patients.