The poor prognosis of lower-inner quadrant breast cancer in patients who received neoadjuvant chemotherapy

Background The elevated risk for recurrence in breast cancer patients after receiving neoadjuvant chemotherapy (NAC) is still controversial. The purpose of this paper was to investigate the prognostic significance of tumor location concerning the survival of patients with breast cancer treated with NAC. Methods The clinical information of 676 patients with stage II-III breast carcinoma who were being treated with NAC between March 2009 and 2014 was investigated. The primary tumor sites were categorized into three groups: outer quadrant, upper-inner quadrant, and lower-inner/central quadrant. Results According to the results of multivariate analyses, the number of tumor locations, nuclear grade, and the initial clinical stage was associated with disease-free survival (DFS), distant metastasis-free survival (DMFS), and overall survival (OS). When stratified into subgroups, tumors in the lower-inner/central quadrant were associated with a significantly worse prognosis in patients not treated with postmastectomy radiation therapy (PMRT) and in patients in the human epidermal growth factor receptor 2 (HER-2)-enriched and triple-negative subgroups. Conclusions The primary tumor site is likely to be a critical feature that affects the prognosis of breast cancer tumors treated with NAC. To address the poor prognosis related to inner-quadrant participation in breast carcinoma, more aggressive NAC with internal mammary node radiotherapy (IMN-RT) should be conducted.