Trends in radiotherapy after breast-conserving surgery in elderly patients with early-stage breast cancer.

BACKGROUND

The benefit of adjuvant radiotherapy (RT) in elderly breast cancer patients is debatable. The purpose of this study was to evaluate trends in RT rates after breast-conserving surgery.

METHODS

Breast cancer patients ≥70 years treated from 2000 to 2009 were identified using the Surveillance, Epidemiology, and End Results (SEER) database. Patients were estrogen receptor positive with negative or unknown lymph node status. Trends in RT recommendation over years were evaluated with the Jonckheere-Terpstra test. Multiple logistic regression and Cox proportional hazard tests were used to determine factors associated with radiation recommendation and survival.

RESULTS

Of 46,581 patients, 31,989 (68.7 %) were recommended RT and 14,592 (31.3 %) were not. The recommendation for RT decreased from 70.3 % in 2000 to 67.4 % in 2009 (p < 0.0001). Seven of 18 registries exhibited decreased radiation recommendation rates, and 4 of 18 exhibited an increase. Recommendation of RT was associated with earlier year of diagnosis, younger age, Asian/Pacific Islander race, and negative lymph nodes. Predictors of worse survival were no radiation [hazard ratio (HR) 1.68, 95 % confidence interval (CI) 1.61-1.75], no nodes examined (HR 1.83, 95 % CI 1.75-1.91), large (>2-5 cm) tumor size (HR 2.02, 95 % CI 1.86-2.19), older age (80+, HR 2.38, 95 % CI 2.25-2.53), and black race (HR 1.13, 95 % CI1.03-1.23).

CONCLUSIONS

Rates of radiation recommendation in the elderly have been steadily decreasing without appreciable acceleration in this decline. This trend was not consistent across all registries. Continued research is necessary to assess differences in clinical practice and its impact on patient outcomes.