The prognostic factors on survival outcome following locoregional recurrence after mastectomy for breast cancer – A retrospective study in single medical centre in lower incidence and young age area

Background: Women of breast cancer with locoregional recurrence is a ‘high risk’ subgroup with respect to systemic recurrence and mortality after mastectomy. It is important to early identify the prognostic factors on survival outcome following locoregional recurrence after mastectomy, especially in low incidence and young age area. Methods. Of 3,364 patients undergoing mastectomy for breast cancer from 2002 to 2020, total 68 patients (2.02%) with the age of 32 to 81 years, had locoregional recurrence as the first event. We analysed prognostic factors on overall and post-relapse survival outcomes, like as age at primary diagnosis, intrinsic molecular subtypes, initial diagnosis stage, prior neoadjuvant chemotherapy, and time to relapse, by Kaplan-Meier Estimate Method and Cox proportional hazards regression models. Statistical significance was accepted at P < 0.05. Results. Of 68 patients with locoregional recurrence, 37 patients are alive and 31 patients died on the end of study. The survival group has longer time to relapse (mean, 77.87 vs. 33.28 months), compared to the mortality group. Among all collected factors, age at primary diagnosis (age ≦ 55 vs. >55 y/o) is one important prognostic factor on overall (p = 0.044) and post-relapse survival outcomes (p = 0.046), after controlled all confounding factors of initial diagnosis stage, prior neoadjuvant chemotherapy condition, and time to relapse after initial therapy by cox proportional hazard model. Conclusions. The patients with the age > 55 years at primary diagnosis is a significantly poor prognostic factor on survival outcome following locoregional recurrence after mastectomy, so they need more aggressive treatment when encountering locoregional recurrence.