Prognostic Factors for Distant Metastasis in Patients with Locoregional Recurrence after Mastectomy

The purpose of this study was to identify patients with high risk of distant metastasis (DM) after salvage treatment for postmastectomy locoregional recurrence (LRR).

We retrospectively reviewed 142 patients who received salvage radiotherapy with or without wide excision for isolated LRR after mastectomy between January 1999 and December 2012. Distant metastasis-free survival (DMFS) was estimated from the date of diagnosis of isolated LRR to the date of DM or last follow-up using the Kaplan-Meier method, and Cox regression analysis was performed to identify prognostic factors for DM.

The median follow-up period was 54 months. The major failure pattern was DM (56%) and the 5-year DMFS was 43%. In multivariate analysis, initial N (iN) stage, recurrent N (rN) stage, and hormone receptor (HR) status were significant prognostic factors for DM (5-year DMFS: iN0 vs. iN1-3, 73% vs. 25%, p<0.001; rN0 vs. rN1-3, 61% vs. 29%, p<0.001; HR+ vs. HR-, 49% vs. 21%, p<0.001).

Patients with lymph node involvement and/or HR- specimens seem to experience more DM than patients with chest wall-only recurrence and HR+ specimens. Further studies are needed to investigate the role of chemotherapy in these patients.