Breast cancer with synchronous metastases: survival impact of exclusive locoregional radiotherapy.

Abstract

Several studies suggest that surgical excision of the primary tumor improves survival among patients with stage IV breast cancer at diagnosis. Exclusive locoregional radiotherapy (LRR) is an alternative form of locoregional treatment (LRT) in this setting. We retrospectively studied the impact of LRT on the survival of breast cancer patients with synchronous metastases. Among 18,753 breast cancer patients treated in our institution between 1980 and 2004, 598 patients (3.2%) had synchronous metastasis at diagnosis. Demographic data, tumor characteristics, metastatic sites, and treatments were prospectively recorded. The impact of LRT on overall survival (OS) was evaluated by multivariate analysis including known prognostic factors. Among 581 eligible patients, 320 received LRT (group A), and 261 received no LRT (group B). LRT consisted of exclusive LRR in 249 patients (78%), surgery of the primary tumor with adjuvant LRR in 41 patients (13%), and surgery alone in 30 patients (9%). With a median follow-up time of 39 months, the 3-year OS rates were 43.4% and 26.7% in group A and group B (P =.00002), respectively. The association between LRT and improved survival was particularly marked in women with visceral metastases. LRT was an independent prognostic factor in multivariate analysis (hazard ratio [HR] = 0.70; 95% CI, 0.58 to 0.85; P = .0002). The adjusted HR for late death (>or= 1 year) was 0.76 (95% CI, 0.61 to 0.96; P = .02). In our experience, LRT, consisting mainly of exclusive LRR, was associated with improved survival in breast cancer patients with synchronous metastases. Exclusive LRR may thus represent an active alternative to surgery.