Impact of distance between tumor and nipple on survival outcomes in breast cancer.

Abstract

e12579 Background: Mastectomy is usually recommended surgical procedure for centrally located tumors regarding the increased risk of nipple invasion. Despite no difference in survival outcomes based on tumor locations, central tumor may have a higher chance of main lactiferous duct invasion, leading to tumor cell can migration to periphery of the breast. In this study, we investigated the relationship between locoregional recurrence (LRR) and the tumor-to-nipple distance (TND). Methods: We retrospectively analyzed the data of patients who underwent breast cancer surgery between 2004 and 2018 at two institutions. Patients who underwent neoadjuvant chemotherapy were excluded. TND was measured using preoperative MRI records. Results: A total of 9,014 patients were included, and median TND was 3.4 (0.0-15.0)cm. A restricted cubic spline curve showed that the hazard risk of LRR increased with shorter TND for all patients. While the risk of LRR appeared to apparently increase in the breast-conserving surgery (BCS) group, the mastectomy group showed the constant pattern. Thus, we conducted survival analysis for 5,455 patients who underwent BCS. We set the TND cutoff at 2.5 cm, which showed the lowest p-value for LRR rate. Compared to those with TND > 2.5cm, patients with TND≤2.5cm had significantly lower rates of LRR (HR,1.83; 95%CI,[1.37-2.46], p < 0.001) and distant metastasis (DM) (HR,1.53; 95%CI,[1.16-2.02], p = 0.002). However, overall survival was not different between the two groups (p = 0.405). Cox-regression analysis showed that TND still had a significant impact on LRR (HR,1.52; 95%CI,[1.11-2.09], p = 0.010) but not on DM. Importantly, TND still remained significant factor affecting LRR when analyzed as continuous variable (HR,1.04; 95%CI,[1.02-1.06], p < 0.001). The prognostic impact of shorter TND was more evident in patients with high mammographic density. Conclusions: BCS can be considered a safe option for central tumors, but mastectomy could be a better choice for patients who are concerned about recurrence or unwilling to undergo additional surgeries.