title: Ten-year survival results of a randomized trial of irradiation of internal mammary nodes after mastectomy.
abstract: OBJECTIVE
  To evaluate the efficacy of irradiation of internal mammary nodes (IMN) on 10-year overall survival in breast cancer patients after mastectomy.
  
  
  METHODS
  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.
authors.affiliation: Hôpital Saint-Louis, AP-HP et Université de Paris VII, France. christophe.hennequin@sls.aphp.fr
authors.forename: Christophe
authors.initials: C
authors.lastname: Hennequin
authors.forename: Nadine
authors.initials: N
authors.lastname: Bossard
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Servagi-Vernat
authors.forename: Philippe
authors.initials: P
authors.lastname: Maingon
authors.forename: Jean-Bernard
authors.initials: JB
authors.lastname: Dubois
authors.forename: Jean
authors.initials: J
authors.lastname: Datchary
authors.forename: Christian
authors.initials: C
authors.lastname: Carrie
authors.forename: Bernard
authors.initials: B
authors.lastname: Roullet
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Suchaud
authors.forename: Eric
authors.initials: E
authors.lastname: Teissier
authors.forename: Audrey
authors.initials: A
authors.lastname: Lucardi
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Gerard
authors.forename: Aurélien
authors.initials: A
authors.lastname: Belot
authors.forename: Jean
authors.initials: J
authors.lastname: Iwaz
authors.forename: René
authors.initials: R
authors.lastname: Ecochard
authors.forename: Pascale
authors.initials: P
authors.lastname: Romestaing
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001365:Axilla; D001943:Breast Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D017024:Chemotherapy, Adjuvant / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D005602:France; D006801:Humans; D015182:Lymphatic Irradiation / Q000009:adverse effects / Q000379:methods / Q000401:mortality*; D008408:Mastectomy / Q000379:methods / Q000401:mortality; D008875:Middle Aged; D011879:Radiotherapy Dosage; D015996:Survival Rate