Gender differences in breast cancer: Analysis of 13,000 breast cancers in men from the national cancer data base

Purpose. To examine gender-specific differences in breast cancer utilizing the National Cancer Data Base (NCDB). Methods. Breast cancer patients entered in the NCDB from 1998 through 2007 were compared by gender for demographics, tumor characteristics, treatment, and outcomes. Results. A total of 13,457 men were compared to 1,439,866 women. Men were older, more often African American, less often Hispanic, had larger tumors, less often had low-grade disease, less often had stage 0 or I disease, and were more likely to have metastases to lymph nodes and/or distantly. Cancers in men were less likely lobular and more likely estrogen receptor and/or progesterone receptor positive. Men were more likely to have total mastectomy and less likely to receive radiotherapy. There was no difference in chemotherapy and little difference in hormone therapy rates. Differences in overall survival (OS) were highly significant (p<0.0001): 83 % 5-year OS for women with breast cancer (median survival 129 months) versus 74 % for men (median survival 101 months). Women had better 5-year OS (p<0.0001) for stage 0 (94 vs. 90 %), stage I (90 vs. 87 %), and stage II (82 vs. 74 %) breast cancer. There were no differences in 5-year OS for stage III (56.9 vs. 56.5 %, p = 0.99) or stage IV (19 vs. 16 %, p = 0.20) disease. Conclusions. At first glance, this large study demonstrated numerous gender-specific differences. However, after accounting for differences in presentation, absence of data on disease-specific survival, and inherent deficiencies in reporting cancer registry data, breast cancer in men and women appears more alike than different.