Radiation therapy and patient age in the survival from early-stage breast cancer.

PURPOSE: To analyze the use of radiation therapy following local excision of invasive localized breast cancer and subsequent survival by 5-year age category.
METHODS: Data for 27, 399 women diagnosed with localized stage of breast cancer and treated with local excision surgery from 1983 through 1992 were collected and provided by the national Surveillance, Epidemiology, and End Results (SEER) program. Use of radiation therapy was analyzed by race, ethnic background, geographic location, and age at diagnosis. Survival for women treated with local excision plus radiation therapy was compared to that of women treated with local excision alone for each 5-year age category.
RESULTS: Subjects in older age groups were significantly less likely (p < 0.001) to receive radiation following local excision compared to younger age groups. Statistically significant survival advantages were conferred on women receiving radiation therapy in each 5-year age category from age 35 to 84 years (ranging from p = 0.02 to p < 0.0001).
CONCLUSION: While the use of radiation therapy following local excision of early-stage breast tumors drops significantly in older age groups, women aged 35-84 years receiving radiation therapy had significant reductions in mortality. These results did not appear to be influenced by the presence of mortal comorbid conditions. These results strongly suggest the need to consider carefully patient characteristics other than age in deciding the course of treatment for early-stage breast cancer.