Is Breast-Conserving Therapy Appropriate for Male Breast Cancer Patients? A National Cancer Database Analysis

Abstract

Background: Current treatment guidelines for male breast cancer are predominantly guided by female-only clinical trials. With scarce research, it is unclear whether breast-conserving therapy (BCT) is equivalent to mastectomy in men. We sought to compare overall survival (OS) among male breast cancer patients who underwent BCT versus mastectomy.

Methods: We performed a retrospective analysis of 8445 stage I-II (T1-2 N0-1 M0) male breast cancer patients from the National Cancer Database (2004-2014). Patients were grouped according to surgical and radiation therapy (RT). BCT was defined as partial mastectomy followed by RT. Multivariable and inverse probability of treatment-weighted (IPTW) Cox proportional hazards models were used to compare OS between treatment groups, controlling for demographic and clinicopathologic characteristics.

Results: Most patients underwent total mastectomy (61.2%), whereas 18.2% underwent BCT, 12.4% underwent total mastectomy with RT, and 8.2% underwent partial mastectomy alone. In multivariable and IPTW models, partial mastectomy alone, total mastectomy alone, and total mastectomy with RT were associated with worse OS compared with BCT (p < 0.001 all). Ten-year OS was 73.8% for BCT and 56.3, 58.0 and 56.3% for other treatment approaches. Older age, higher T/N stage, histological grade, and triple-negative receptor status were associated with poorer OS (p < 0.05). Subgroup analysis by stage demonstrated similar results.

Conclusions: In this national sample of male breast cancer patients, BCT was associated with greater survival. The underlying mechanisms of this association warrant further study, because more routine adoption of BCT in male breast cancer appears to translate into clinically meaningful improvements in survival.

Figure 1.

A-B. Crude (A) and inverse probability of treatment weighted (B) overall survival for male breast cancer patients with breast conserving therapy (BCT), total mastectomy with (TM with RT) and without radiation therapy (TM no RT), and partial mastectomy alone (PM no RT).

Figure 2.

A-B. Univariate overall survival for breast conserving therapy (BCT) compared to partial mastectomy alone (PM no RT), total mastectomy alone (TM no RT) and total mastectomy with radiation therapy (TM with RT) by stage.

Figure 3.

A-B. Univariate overall survival for breast conserving therapy (BCT) compared to partial mastectomy alone (PM no RT), total mastectomy alone (TM no RT) and total mastectomy with radiation therapy (TM with RT) by T stage.