Randomized Clinical Trial of Breast Irradiation Following Lumpectomy and Axillary Dissection for Node-Negative Breast Cancer: an Update

摘要: Background: Breast-conservation surgery is now commonly used to treat breast cancer. Postoperative irradiation reduces cancer recurrence in the breast. There still controversy concerning necessity of all patients. Purpose: We present an update results from a randomized clinical trial designed examine efficacy following conservation treatment women with axillary lymph node-negative The patients were enrolled April 1984 through February 1989. Initial published 1992 after median follow-up time 43 months. It was reported that occurred 5.5% who received compared 25.7% those did not. No difference survival detected between two groups. Now patient has reached 7.6 years, end points have been re-examined and attempt again made identify group at low risk for Methods: Eight hundred thirty-seven randomly assigned receive either radiation therapy (n = 416) or no 421) lumpectomy node dissection. cumulative local rate as first event, distant (i.e., occurrence metastasis) rate, overall mortality groups described by Kaplan—Meier method use logrank test Cox proportional hazards model adjust observed effect influence various prognostic factors (patient age, tumor size, estrogen receptor level, histology) study entry on outcomes recurrence, mortality. All P values resulted twotailed statistical tests. Results: One forty eight (35%) nonirradiated 47 (11%) irradiated developed recurrent (relative former versus latter 4.0; 95% confidence interval 2.83-5.65; 2 cm), nuclear grade (poor) continued be important predictors relapse. On basis these factors, we unable subgroup very recurrence. Tumor grade, previously reported, size Conclusions: Breast shown reduce breast, but there statistically significant reduction A might not require identified. [J Natl Cancer List 1996;88:1659-64]