To evaluate survival outcomes of young women with early-stage breast cancer treated with breast conservation therapy (BCT) or mastectomy, using a large, population-based database.

Using the Surveillance, Epidemiology, and End Results (SEER) database, information was obtained for all female patients, ages 20 to 39 years old, diagnosed with T1-2 N0-1 M0 breast cancer between 1990 and 2007, who underwent either BCT (lumpectomy and radiation treatment) or mastectomy. Multivariable and matched pair analyses were performed to compare overall survival (OS) and cause-specific survival (CSS) of patients undergoing BCT and mastectomy.

A total of 14,764 women were identified, of whom 45% received BCT and 55% received mastectomy. Median follow-up was 5.7 years (range, 0.5-17.9 years). After we accounted for all patient and tumor characteristics, multivariable analysis found that BCT resulted in OS (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.83-1.04; p = 0.16) and CSS (HR, 0.93; CI, 0.83-1.05; p = 0.26) similar to that of mastectomy. Matched pair analysis, including 4,644 BCT and mastectomy patients, confirmed no difference in OS or CSS: the 5-, 10-, and 15-year OS rates for BCT and mastectomy were 92.5%, 83.5%, and 77.0% and 91.9%, 83.6%, and 79.1%, respectively (p = 0.99), and the 5-, 10-, and 15-year CSS rates for BCT and mastectomy were 93.3%, 85.5%, and 79.9% and 92.5%, 85.5%, and 81.9%, respectively (p = 0.88).

Our analysis of this population-based database suggests that young women with early-stage breast cancer have similar survival rates whether treated with BCT or mastectomy. These patients should be counseled appropriately regarding their treatment options and should not choose a mastectomy based on the assumption of improved survival.