Sites of failure in breast cancer patients with extracapsular invasion of axillary lymph node metastases. No need for axillary irradiation?!

BACKGROUND AND PURPOSE: Extracapsular spread (ECS) is frequent, but the specific sites of relapse are seldom given in the literature. In this study it was evaluated, if ECS might be an indicator for axillary irradiation.

PATIENTS AND METHODS: After a retrospective review of pathology reports, the information about ECS was available in 254 lymph node-positive patients: ECS was absent in 34% (ECS-negative; n = 87) and present in 66% (ECS-positive; n = 167). All patients were irradiated locally, 78 patients got periclavicular and 74 axillary irradiation (median total dose: 50.4 Gy). 240/254 patients (94.5%) received systemic treatment/s. Mean follow-up was 46 months.

RESULTS: The regional relapse rate was 4.6% without ECS versus 9.6% with ECS. The 5-year axillary relapse-free survival was 100% in ECS-negative and 90% in ECS-positive patients (p = 0.01), whereas corresponding values for periclavicular relapse-free survival (with ECS: 91% +/- 4%; without ECS: 94% +/- 3%; p = 0.77) and local relapse-free survival (with ECS: 86% +/- 4%; without ECS: 91% +/- 3%; p = 0.69) were not significantly different. chi(2)-tests revealed a high correlation of ECS with T-stage, number of positive lymph nodes and progesterone receptor status, comparisons with estrogen receptor, grade, or age were not significant. In multivariate analysis number of positive lymph nodes was solely significant for regional failure. Dividing the patients into those with one to three and those with four or more positive lymph nodes, ECS lost its significance for axillary failure.

CONCLUSION: ECS was accompanied by an enhanced axillary failure rate in univariate analysis, which was no longer true after adjusting for the number of positive lymph nodes.