The Effect of Hospital Volume on Outcomes of Patients with Occult Breast Cancer.

Abstract

With limited data in regards to management, occult breast cancer (OBC) poses a challenging surgical scenario. Current surgical management includes axillary lymphadenectomy (ALND) with or without mastectomy. We sought to investigate the impact of hospital volume on surgical approach and survival outcomes of patients with OBC. Patients with cT0N+ breast cancer were selected from the National Cancer Data Base (NCDB, 2004-2014). Primary outcome was overall survival (OS), calculated using Kaplan-Meier methods compared according to hospital volume: community cancer center (CC), comprehensive community cancer center (COMP), and academic center (AC). Secondary outcome was the rate of modified radical mastectomy (MRM). We identified 574 patients with OBC, 11.1% were treated at a CC, 51.8% at a COMP, and 37.0% at an AC. Patients treated at CC had lower socioeconomic status compared with COMP or AC (23.1%, 14.1%, 19.3%; p = 0.005, respectively). There was no difference in access to radiation therapy (p = 0.888) or neoadjuvant chemotherapy (p = 0.221). Patients treated at CC had worse OS compared with COMP or AC (87.04, 105.29, 108.06 mo, p = 0.026, respectively). There was an increased rate of MRM at CC compared with COMP or AC (54.7%, 41.2%, 30.5%, p = 0.003, respectively). A direct association seems to exist between hospital volume and outcomes of patients with OBC. Patients with OBC treated at AC were more likely to undergo breast-conserving approaches and had better survival than those treated at CC.