Limited Supraclavicular Radiation Field in Breast Cancer With ≥ 10 Positive Axillary Lymph Nodes.

Purpose: The present study was conducted to evaluate the patterns of recurrence and factors related to axillary or supraclavicular recurrence (ASR) and to suggest the probable indications of supraclavicular radiotherapy (SCRT) field modification for breast cancer patients with ≥ 10 axillary lymph node (LN) metastases who had received the current standard systemic management and limited-field SCRT.

Materials And Methods: 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.

Results: 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.

Conclusion: 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.