We performed a retrospective study of patients with breast cancer with ≥ 10 axillary LN metastases who had received standard surgery with postoperative RT, including limited SCRT (level III and supraclavicular area) and taxane-based adjuvant chemotherapy (except for neoadjuvant chemotherapy), from January 2000 to June 2012. ASR was defined as recurrence to levels I to III of the axillary or supraclavicular area.
The present study included 301 patients with breast cancer with ≥ 10 axillary LN metastases. The median follow-up period was 59.1 months (range, 7.4-167.9 months). Overall, 32 cases (10.6%) of locoregional recurrence were observed, and 27 patients (9.0%) exhibited ASR. Additionally, 16 patients (5.3%) developed recurrence in levels I or II of the axillary area, which are not included in the SCRT field. ASR-free survival was significantly related to the LN ratio (LNR) in both univariate and multivariate analysis.
ASR was the most prevalent locoregional recurrence pattern in patients with breast cancer with ≥ 10 axillary LN metastases, and LNR was a significant prognostic factor for the development of ASR. Modification of the SCRT field, including the full axilla, should be considered in patients with a greater LNR.