Comparison of short-term surgical outcomes between men and women with breast cancer: a retrospective study using nationwide inpatient data in Japan.

Purpose Although long-term survival is similar between men and women, little is known about the short-term outcomes following breast cancer surgery in men. This study was performed to compare postoperative outcomes adjusted for background factors between men and women with breast cancer using a Japanese nationwide inpatient database. Methods This study included 2126 men and 363,468 women who underwent surgery for stage 0-III breast cancer from July 2010 to March 2017. We generated a 1:4 matched-pair cohort matched for age, institution, and fiscal year at admission. We then conducted multivariable regression analyses to compare postoperative complications, 30-day readmission, duration of anesthesia, length of hospitalization, and total hospitalization costs between the sexes. Results Men were older, more likely to have comorbidities and advanced cancer, and more likely to undergo total mastectomy and axillary dissection than women. There were no significant differences in postoperative complications between the sexes, but men showed a lower risk of 30-day readmission (odds ratio 0.74; 95% confidence interval [CI] 0.57-0.95), shorter duration of anesthesia (difference - 22.0 min; 95% CI - 2.1 to - 0.5), shorter length of hospitalization (difference - 1.3 days; 95% CI - 2.1 to - 0.5), and lower total hospitalization costs (difference - 506 US dollars; 95% CI - 668 to - 334) than women. Conclusions The matched-pair cohort analyses revealed no significant differences in postoperative complications between men and women with breast cancer. However, men showed better outcomes than women in terms of 30-day readmission, duration of anesthesia, length of hospitalization, and total hospitalization costs.