BACKGROUNDThe surgical management of occult breast cancer is controversial. We compared the outcomes of different treatments of occult breast cancer and evaluated the potential prognostic factors for overall survival and recurrence.

METHODSWe retrospectively reviewed 77 patients who presented to our hospital from 1968 to 2011 with a diagnosis of occult breast cancer. Patients were divided into three groups: 42 patients (63%) were treated with modified radical mastectomy+axillary lymph node dissection (ALND), 16 patients (24%) were treated with ALND + postoperative radiotherapy, and 9 patients (13%) with only ALND. Survival analyses were undertaken to compare the efficacy of these three treatments.

RESULTSOf the 77 patients with occult breast cancer, 2 patients were lost to follow-up and 8 patients refused surgical treatment: 67 patients (90.4%) were included in this analysis. The median follow-up was 62.2 (0.6-328.0) months. Kaplan-Meier analyses showed no significant difference in overall survival and recurrence-free survival between the three groups (P = 0.494 and 0.397, respectively). The prevalence of local recurrence was 11.9% for the mastectomy + ALND, 18.8% for ALND + radiotherapy, and 11.1% for ALND-only groups, and those for distant recurrence were 2.4%, 12.5%, and 11.1%, respectively. Compared with progesterone receptor-negative subjects, progesterone receptor-positive patients had better overall survival and lower recurrence rates (P = 0.057 and 0.062, respectively).

CONCLUSIONSThere was no significant difference in outcomes between mastectomy and breast-preserving surgery. Expression of the progesterone receptor should be taken into account when evaluating the prognosis of occult breast cancer.