Breast
Sean Bennett, MD, MSc, FRCSC, FACS (he/him/his)
General Surgeon
Queen's University
Kingston, Ontario, Canada
Sean Bennett, MD, MSc, FRCSC, FACS (he/him/his)
General Surgeon
Queen's University
Kingston, Ontario, Canada
Sean Bennett, MD, MSc, FRCSC, FACS (he/him/his)
General Surgeon
Queen's University
Kingston, Ontario, Canada
Georgia Nelson, BSc
Medical Student
Queen's University, United States
Nouf AlMarzooqi, MD
Surgical Resident
McGill University, United States
Manisha Jogendran, MD
Resident
Queen's University, Ontario, Canada
Maya Djerboua, MSc
ICES Research Analyst
Queen's University, United States
Brooke E. Wilson, MD, MSc
Assistant Professor
Queen's University, United States
Jennifer A Flemming, M.D.
Gastroenterologist
Queen's University, United States
Shaila J. Merchant, MD
Associate Professor / Surgeon
Queen's University
Kingston, Ontario, Canada
Breast cancer in male patients is an uncommon diagnosis, the treatment of which is largely extrapolated from data in female patients. The objective of this study was to describe the epidemiology, treatment, and outcomes in a contemporary cohort of males diagnosed with breast cancer.
Methods:
We performed a retrospective cohort study of male patients diagnosed with breast cancer between 2007-2017 using linked administrative health data from Ontario, Canada. Descriptive statistics were reported. Trends in treatment, including systemic therapy, radiation, and surgery for the breast and axilla were reported using the Cochrane-Armitage test. Overall and cancer-specific survival was calculated from the time of diagnosis, using the Kaplan-Meier estimate.
Results:
A total of 868 males with breast cancer were identified, with a mean age of 68.6 years. At diagnosis, 26% were stage 1, 39% stage 2, 14% stage 3, and 7% stage 4, with 14% missing stage. Breast cancer subtype was missing in 55%. In those with available subtyping, 82% were ER+/PR+/HER2-, 10% were HER2+, and 3% were triple-negative. Breast surgery was performed in 78% of patients (70% mastectomy, 30% lumpectomy). Of those undergoing breast surgery, lymph node sampling was performed in only 55% [93% sentinel lymph node biopsy (SLNB), 7% axillary lymph node dissection (ALND)]. Use of lymph node surgery increased over time, with 73% undergoing either SLNB or ALND during the last three years of the cohort (p< 0.0001). Systemic therapy within 6 months after surgery was observed in 49% of patients, with increasing utilization over time (p< 0.0001). Radiation therapy was used in 36% of patients within 6 months after surgery with no significant change in frequency over time (p=0.2). Five-year cancer-specific survival by stage was 96%, 88%, 79%, and 16% for stages 1-4, respectively.
Conclusions:
Males with breast cancer have predominantly ER+/PR+/HER2- subtype. Mastectomy was the most commonly performed breast surgery, with increasing use of axillary staging over the study period. Cancer survival statistics in males with breast cancer are favourable for non-metastatic disease but are slightly inferior to those typically reported in females.