Patient and tumor characteristics associated with breast cancer recurrence after complete pathological response to neoadjuvant chemotherapy

Breast cancer patients whose tumors achieve a pathological complete response (pCR) with neoadjuvant chemotherapy have a prognosis which is better than that predicted for the stage of their disease. However, within this subgroup of patients, recurrences have been observed. We sought to examine factors associated with recurrence in a population of breast cancer patients who achieved a pCR with neoadjuvant chemotherapy. A retrospective chart review was conducted of all patients with unilateral breast cancer treated with neoadjuvant chemotherapy from January 1, 2000 to December 31, 2010 at one comprehensive cancer center. A pCR was defined as no residual invasive cancer in the breast in the surgical specimen following neoadjuvant therapy. Recurrence was defined as visceral or bony reappearance of cancer after completion of all therapy. Of 818 patients who completed neoadjuvant chemotherapy, 144 (17.6 %) had pCR; six with bilateral breast cancer were excluded from further analysis. The mean time to follow-up was 47.2 months. Among the 138 patients with unilateral breast cancer, there were 14 recurrences (10.1 %). Using a binary multiple logistic regression model, examining types of chemotherapy and surgery, race, lymph node assessment, and lymph node status, breast cancer side, triple-negative status, and radiation receipt, only African-American patients (OR: 5.827, 95 % CI: 1.280-26.525; p = 0.023) were more likely to develop distant recurrence. The mean time to recurrence was 31.9 months. In our study, race was the only independent predictor of recurrence after achieving pCR with neoadjuvant chemotherapy. The reasons for this observation require further study.