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Medline ® Abstract for Reference 78

of 'Adjuvant radiation therapy for women with newly diagnosed, non-metastatic breast cancer'

Ten-year survival results of a randomized trial of irradiation of internal mammary nodes after mastectomy.
Hennequin C, Bossard N, Servagi-Vernat S, Maingon P, Dubois JB, Datchary J, Carrie C, Roullet B, Suchaud JP, Teissier E, Lucardi A, Gerard JP, Belot A, Iwaz J, Ecochard R, Romestaing P
Int J Radiat Oncol Biol Phys. 2013 Aug;86(5):860-6. Epub 2013 May 9.
PURPOSE: To evaluate the efficacy of irradiation of internal mammary nodes (IMN) on 10-year overall survival in breast cancer patients after mastectomy.
METHODS AND PATIENTS: This multicenter phase 3 study enrolled patients with positive axillary nodes (pN+) or central/medial tumors with or without pN+. Other inclusion criteria were age<75 and a Karnofsky index≥70. All patients received postoperative irradiation of the chest wall and supraclavicular nodes and were randomly assigned to receive IMN irradiation or not. Randomization was stratified by tumor location (medial/central or lateral), axillary lymph node status, and adjuvant therapy (chemotherapy vs no chemotherapy). The prescribed dose of irradiation to the target volumes was 50 Gy or equivalent. The first 5 intercostal spaces were included in the IMN target volume, and two-thirds of the dose (31.5 Gy) was given by electrons. The primary outcome was overall survival at 10 years. Disease-free survival and toxicity were secondary outcomes.
RESULTS: T total of 1334 patients were analyzed after a median follow-up of 11.3 years among the survivors. No benefit of IMN irradiation on the overall survival could be demonstrated: the 10-year overall survival was 59.3% in the IMN-nonirradiated group versus 62.6% in the IMN-irradiated group (P=.8). According to stratification factors, we defined 6 subgroups (medial/central or lateral tumor, pN0 [only for medial/central]or pN+, and chemotherapy or not). In all these subgroups, IMN irradiation did not significantly improve overall survival.
CONCLUSIONS: In patients treated with 2-dimensional techniques, we failed to demonstrate a survival benefit for IMN irradiation. This study cannot rule out a moderate benefit, especially with more modern, conformal techniques applied to a higher risk population.
Hôpital Saint-Louis, AP-HP et Universitéde Paris VII, France. Electronic address: christophe.hennequin@sls.aphp.fr.