title: Variable effects of post-operative radiotherapy on disease-free survival in subgroups of patients with node-negative breast carcinoma.
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008875:Middle Aged; D008962:Models, Theoretical; D011184:Postoperative Period; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies