Similarities found between breast cancers in men and women

A comparison study had found that although rare, breast cancer in men has similarities with the disease in women.

Specifically, researchers found: men and women had similar risk factors for breast cancer, the biology of the disease in men was similar to that of late-onset and ER–positive disease in women, and mortality and survival rates have improved in both sexes, although not as much in men as women.

The researchers sought to compare and contrast population-based incidence, mortality and survival in men and women with breast cancer. They examined data from this group from the National Cancer Institute’s SEER database from 1973 to 2005.

Men were more likely to be diagnosed with breast cancer later in life than women. In addition, their cancers were more often of a higher-stage, lower-grade and more likely to be estrogen-receptor positive.

High-risk stage-related variables were more common in men. Incidence rate ratios (IRRs) for tumor size greater than 2 cm vs. tumors 2.0 cm or less were higher in men (IRR=0.81; 95% CI, 0.76-0.86) than in women (IRR=0.54; 95% CI, 0.54-0.54).

Conversely, high-risk biologic variables were more common in women. IRRs for ER–negative vs. ER–positive disease were greater in women (IRR=0.29; 95% CI, 0.29-0.29) than in men (IRR=0.08; 95% CI, 0.07-0.09).

The rate of improvement in breast cancer survival throughout time was slower for men compared with women when adjusted for age, stage and grade. From the 1976-1985 period to the 1996-2005 period, the hazard rates for breast cancer mortality decreased by 28% among men (P=.03). Among women, the hazard rate for breast cancer death decreased by 42% during the same period.

Anderson WF. J Clin Oncol. 2009;doi:10.1200/JCO.2009.23.8162.