A comparative analysis of radiotherapy use and patient outcome in males and females with breast cancer.

BACKGROUND: The aim was to determine whether gender was a significant prognostic factor for post-mastectomy relapse, after accounting for known prognostic factors and delivery of radiotherapy. PATIENTS AND METHODS: All patients diagnosed with invasive breast cancer between 1 January 1989 and 31 December 1998 who had undergone total mastectomy as primary therapy were identified from the British Columbia Cancer Agency's Breast Cancer Outcomes Unit database. Patients with pT4 or M1 disease were excluded. A comparison of patient, tumour and treatment factors was made between males and females. Outcomes were analysed in terms of locoregional-relapse free survival, breast cancer-specific survival and overall survival. RESULTS: Sixty males and 4181 females were identified. Multivariable analysis revealed increased tumour size, positive margin status, delivery of chemotherapy, positive nodal status and male gender to be significantly associated with the use of post-mastectomy radiotherapy. Multivariable analysis revealed tumour size, nodal status, tumour grade and presence of vascular space invasion to be significantly associated with locoregional recurrence. Gender was not a prognostic factor for locoregional recurrence, breast cancer-specific survival or overall survival on univariable or multivariable analysis. CONCLUSIONS: These data suggest that gender is not a prognostic factor in patients undergoing mastectomy for early stage breast cancer. Men having mastectomy for breast cancer should receive adjuvant radiotherapy following guidelines similar to those developed for females.