A retrospective study of optimal surgical management for occult breast carcinoma: Mastectomy or quadrantectomy?

The diagnosis and treatment for occult breast carcinoma (OBC) remain controversial because of no detectable primary lesions. We aimed to analyze optimal surgical management for OBC. A total of 26 female patients diagnosed with OBC, which were based on available criteria, were collected at a single clinic center from January 2005 to May 2016. We classified all patients into 4 groups: group A1, mastectomy with axillary lymph node dissection (ALND) + radiotherapy (RT); group A2, mastectomy with ALND; group B1, quadrantectomy with ALND + RT; group B2, quadrantectomy with ALND. Patient characteristics, disease-free survival, and overall survival were compared between groups. There were 14 cases in group A1, 5 cases in group A2, 4 cases in group B1, and 3 cases in group B2. Baseline characteristics were similar among groups. Compared with OBC patients treated with quadrantectomy, the disease-free survival (DFS) and overall survival (OS) rate of those treated with mastectomy had significantly improved (A1 vs. B1, DFS: hazard ratio [HR] 0.018, 95% confidence interval [CI] 0.001–0.241, P = .002; OS: HR 0.002, 95% CI 0.000–0.102, P = .002). Patients treated with radiotherapy had higher local recurrence and OS rate compared with patients treated with no radiotherapy on univariate survival analysis (A1 vs. A2, DFS: HR 0.018, 95% CI 0.001–0.240, P = .002; OS: HR 0.005, 95% CI 0.000–0.170, P = .003). The diagnosis of OBC will need continuous improvement with advances of diagnostic breast imaging. Modified radical mastectomy + RT is still a safe and effective choice.