Abstract P4-14-02: National Trends and Indications for Nipple-Sparing Mastectomy: An Analysis Using the Surveillance, Epidemiology, and End Results (SEER) Database

Abstract

Abstract Introduction: Nipple-sparing mastectomy (NSM) is an evolving procedure occasionally used for breast cancer treatment. However, indications for NSM are institution-specific and lack consensus in the literature. This study uses the Surveillance, Epidemiology, and End Results (SEER) database to investigate the oncologic and demographic characteristics of breast cancer patients treated with NSM in the United States from 2005–2009. Methods: Female breast cancer patients treated from 2005–2009 with nipple-sparing/subcutaneous mastectomy (SEER code 30), defined as removal of breast tissue with preservation of nipple-areolar complex and overlying skin, were included. Variables analyzed included patient age, race, tumor stage, tumor size, lymph node status, and radiotherapy delivery. Results: A total of 449 female breast cancer patients who underwent NSM were isolated from the SEER database. The number of patients in the SEER database who underwent NSM increased steadily each year, from 66 in 2005 to 133 in 2009. Mean age was 52 years (s.d. 12 years). Breakdown by race showed that 369 (82%) patients were White women, 42 (9%) were Black women, 36 (8%) were of Asian descent. A majority of patients (402) were documented to have ductal or lobular carcinoma. Documented tumor diameter was less than 3 cm in 63% (284) of patients. Invasive cancer was documented in 283 (63%) patients; in situ cancer was documented in 166 (37%) patients. Lymph node involvement was negative in 374 (83%) patients. Radiation therapy was delivered to 91 (20%) patients; however, 64 patients receiving radiation therapy were node-negative. Radiation was delivered to 6% (10) of patients with in situ cancer and 27% (77) of patients with invasive cancer (p < 0.0001). Conclusions: The number of NSM procedures reported in SEER for breast cancer has increased from 2005–2009. However, there is a lack of consensus in the literature as to which patients may be candidates for NSM. By utilizing a national database, we are able to aggregate and report on the national experience with therapeutic NSM, to date. Patients undergoing NSM for breast cancer were characterized predominantly by tumors less than 3 cm in diameter and with negative lymph node involvement. Patients with both invasive and in situ tumors were considered suitable candidates for NSM. A majority of patients had either ductal or lobular carcinomas. A minority of patients received radiation therapy, although there was a tendency towards providing patients with invasive tumors with radiation therapy. This national data should help guide patient selection for NSM, although future studies are needed to report on the long-term oncologic safety of this procedure. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-14-02.