Predictive Value of Primary Tumor Site for Loco-regional Recurrence in Early Breast Cancer Patients with One to Three Positive Axillary Lymphadenophy

Introduction: It remains controversial on high risks for early breast cancer patients with one to three axillary nodes after mastectomy who is predisposition to locoregional recurrence. The present study is to investigate the relationship between primary tumor site and loco-regional recurrence (LRR) and explore the predictive value of clinicopathological characteristics in LRR for early breast cancer patients with one to three positive axillary lymph nodes after mastectomy. Methods: We reviewed the clinical data of 656 consecutively diagnosed patients with pT(1-2)N(1)M(0) breast cancer who were treated in Sun Yat-sen University Cancer Center with radical operation without postoperative radiotherapy between March 1998 and December 2010. The primary tumor sites included outer quadrant in 455 patients (69.36%), inner quadrant in 156 patients (23.78%)and central quadrant in 45 patients (6.86%). LRR and LRR-free survival (LRFS) in combination with clinical and pathological features were analyzed to screen out patients with higher risk of LRR. Results: The median follow-up time was 64.9 months. The 5-, 10-year LRR for the cohort was 8.6% and 12.9%, respectively; the 5-, 10-year LRFS was 86.2% and 76.4%, respectively. Multivariate analyses showed that age of ≤35 years, inner quadrant tumor and non-luminal subtype were independent risk factors for LRR and LRFS. Patients with primary tumor in inner quadrant showed higher LRR and poorer LRFS when risk factors are ≥2 than those with tumors in other sites. Conclusions: Inner quadrant tumor was an independent predictor for LRR and LRFS in patients with early breast cancer and one to three positive axillary lymph nodes, which would be more accurate in combination with other prognostic indexes including patients' age, pathological T stage, Ki67 status, molecular subtypes.