Retrospective study of neoadjuvant versus adjuvant radiochemotherapy in locally advanced noninflammatory breast cancer : survival advantage in cT2 category by neoadjuvant radiochemotherapy

Abstract

Purpose: This retrospective study compares patients treated between 1991 and 1998 with neoadjuvant radiotherapy +/- chemotherapy (RCT) or adjuvant RCT for locally advanced noninflammatory breast cancers (LABC) in terms of pathologic complete response (pCR), 10-year relapse-free (RFS), and overall survival (OS).

Patients and methods: Preoperative RCT in 315 and adjuvant RCT in 329 cases consisted in 50 Gy (5 x 2 Gy/week) to the breast and the supra-/infraclavicular lymph nodes. 101 neoadjuvant patients received - in case of breast conservation - a 10-Gy interstitial boost with (192)Ir afterloading before and 214 neoadjuvant patients a preoperative electron boost after external-beam radiotherapy. In the neoadjuvant RCT group, chemotherapy was applied prior to radiotherapy in 192 patients, and simultaneously in 113; ten had no chemotherapy. In the adjuvant RCT group, chemotherapy was applied to 44 patients before surgery and to 166 after surgery; 119 had no chemotherapy.

Results: Breast conservation became possible in 50.8% after neoadjuvant RCT for LABC with a pCR rate at surgery of 29.2%. A complete nodal remission (pN0) after RCT was observed in 56% (89/159) of the cN+ (clinically node-positive) neoadjuvant patients. There were trends in favor of preoperative RCT for RFS and OS (hazard ratio [HR] = 0.85; p = 0.09 for RFS; HR = 0.8130; p = 0.1037 for OS). For patients with cT2 tumors the RFS and OS were statistically significantly better (HR = 0.5090; p = 0.0130 for RFS; HR = 0.4390; p = 0.0026 for OS) after neoadjuvant compared to adjuvant RCT.

Conclusion: Neoadjuvant RCT achieved a pCR rate of 29.2% and a statistically significantly better RFS and OS in patients with cT2-category breast cancer.