Breast conservation therapy (BCT) is standard treatment for breast cancer, but few clinical trials have compared BCT with mastectomy in patients with larger tumors (more than 5 cm).
Survival after BCT and mastectomy is similar in women whose tumors measured more than 5 cm, according to a study published online ahead of print in Cancer.
Although BCT is standard treatment for breast cancer, clinical trials exclude patients with tumors larger than 5 cm. In this study, researchers from Fox Chase Cancer Center, in Philadelphia, Pennsylvania, sought to determine if survival is similar for BCT vs mastectomy in these patients.
Reviewing Surveillance, Epidemiology, and End Results (SEER)-Medicare data, the researchers identified 5,685 patients age 66 years and older who underwent breast surgery for invasive, noninflammatory, nonmetastatic breast cancer between 1992 and 2009. Demographics and tumor and treatment factors were accounted for via propensity score-based adjustment.
The patients in this study underwent breast surgery for tumors measuring more than 5 cm, with BCT used in 15.6% of the patients.
Factors that predicted BCT included neoadjuvant chemotherapy and postoperative radiotherapy, higher income, breast cancer as a first malignancy, and a higher Charlson Comorbidity Index.
Factors that predicted mastectomy included younger age, nonductal histology, higher grade, numbers of lymph nodes examined and found to be positive, stage 3 disease per the American Joint Committee on Cancer, postoperative chemotherapy use, and residential region of the country.
Patients were followed for a median 7.0 years. Adjusted overall survival (hazard radio, 0.934; 95% confidence interval, 0.791-1.103 [P=.419]) and breast cancer-specific survival (subdistribution hazard ratio, 1.042; 95% confidence interval, 0.793-1.369 [P=.769]) were similar between those treated with BCT and mastectomy.
The researchers conclude that BCT may be an option for patients whose tumors measure more than 5 cm, despite a lack of clinical trial data supporting BCT in these patients.
1. Bleicher RJ, Ruth K, Sigurdson ER, et al. Breast conservation versus mastectomy for patients with T3 primary tumors (>5 cm) a review of 5685 medicare patients [published online ahead of print October 19, 2015]. Cancer. doi:10.1002/cncr.29726.