Breast-conservation Therapy After Neoadjuvant Chemotherapy Does Not Compromise 10-Year Breast Cancer–specific Mortality

Objectives: Neoadjuvant chemotherapy can increase the rate of breast-conserving surgery by downstaging disease in patients with breast cancer. The aim of this study was to determine whether patients who received neoadjuvant chemotherapy have equal survival after breast-conservation therapy compared with mastectomy. Material and Methods: Using the New Jersey State Cancer Registry (NJSCR) patients with a primary breast cancer diagnosed between 1998 and 2003 who underwent neoadjuvant chemotherapy were selected (n=1,468). Of those, only patients who received lumpectomy plus radiation (n=276) or mastectomy without radiation (n=442) were included in the analysis. The main outcome measured included 10-year breast cancer–specific mortality, with 90% of patients with known vital status through the end of 2011. Results: Baseline characteristics did not differ significantly between the breast-conservation and mastectomy without radiation groups except with respect to summary stage and lymph node involvement. After propensity score matching these differences were no longer statistically significant; however, both estrogen and progesterone status achieved statistical significance. The Kaplan-Meier survival curve showed that the breast-conservation group had significantly higher breast cancer–specific survival than the mastectomy group (P=0.0046). After adjusting for the propensity score in the regression model, the breast-conservation group continued to show significantly better survival than the mastectomy group (hazard ratios, 0.46; 95% confidence interval, 0.27-0.78). Conclusions: This study is consistent with previous research showing that breast-conserving surgery after neoadjuvant chemotherapy does not reduce breast cancer–specific survival. In fact, patients undergoing breast-conservation after neoadjuvant therapy appeared to have better survival than patients undergoing mastectomy without radiation. Cancer data used in this study were provided by the New Jersey State Cancer Registry, Cancer Epidemiology Services, New Jersey Department of Health, which is funded by the Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute under contract HHSN261201300021I, the National Program of Cancer Registries (NPCR), Centers for Disease Control and Prevention under grant 5U58DP003931-02 as well as the State of New Jersey and the Rutgers Cancer Institute of New Jersey. The authors declare no conflicts of interest. Reprints: Renee L. Arlow, MD, Department of Surgery, Rutgers Robert Wood Johnson Medical School, 51 French Street, MEB 596, P.O. Box 19, New Brunswick, NJ 08901. E-mails: renee.arlow@gmail.com; renee.arlow@uphs.upenn.edu. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

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