Radiat Oncol J.  2019 Jun;37(2):91-100. 10.3857/roj.2018.00451.

Radiotherapy for initial clinically positive internal mammary nodes in breast cancer

• Kim J
• Chang JS
• Choi SH
• Kim YB
• Keum KC
• Suh CO
• Yang G
• Cho Y
• Kim JW
• Lee IJ

• KMID: 2452569
• DOI: http://doi.org/10.3857/roj.2018.00451

Abstract

PURPOSE
Internal mammary lymph node (IMN) involvement is associated with poor prognosis in breast cancer. This study investigated the treatment outcomes of initial clinically IMN-positive breast cancer patients who received adjuvant radiotherapy (RT), including IMN irradiation, following primary breast surgery.
MATERIALS AND METHODS
We retrospectively reviewed data of 95 breast cancer patients with clinically detected IMNs at diagnosis treated with surgery and RT between June 2009 and December 2015. Patients received adjuvant RT to the whole breast/chest wall and regional lymph node (axillary, internal mammary, and supraclavicular) areas. Twelve patients received an additional boost to the IMN area.
RESULTS
The median follow-up was 43.2 months (range, 4.5 to 100.5 months). Among 77 patients who received neoadjuvant chemotherapy, 52 (67.5%) showed IMN normalization and 19 (24.6%) showed a partial response to IMN. There were 3 and 24 cases of IMN failure and any recurrence, respectively. The 5-year IMN failure-free survival, disease-free survival (DFS), and overall survival (OS) were 96%, 70%, and 84%, respectively. IMN failure-free survival was significantly affected by resection margin status (97.7% if negative, 87.5% for close or positive margins; p = 0.009). All three patients with IMN failure had initial IMN size ≥1 cm and did not receive IMN boost irradiation. The median age of the three patients was 31 years, and all had hormone receptor-negative tumors.
CONCLUSION
RT provides excellent IMN control without the support of IMN surgery. Intensity-modulated radiotherapy, including IMN boost for breast cancer patients, is a safe and effective technique for regional lymph node irradiation.

Keyword

Breast neoplasms; Internal mammary lymph node; Radiotherapy; Prognosis

MeSH Terms

Breast Neoplasms*
Breast*
Diagnosis
Disease-Free Survival
Drug Therapy
Follow-Up Studies
Humans
Lymph Nodes
Prognosis
Radiotherapy*
Radiotherapy, Adjuvant
Radiotherapy, Intensity-Modulated
Recurrence
Retrospective Studies