Disparities in Perioperative Radiation Therapy Use in Elderly Patients With Soft-Tissue Sarcoma

Abstract

The benefit of perioperative radiation therapy in elderly patients with soft-tissue sarcoma (STS) is unclear due to the underrepresentation of elderly patients in clinical trials. We assessed patterns of care and overall survival (OS) associated with perioperative radiation therapy use in this population. Elderly patients (≥70 years) with high-grade STS who underwent surgery with or without perioperative radiation therapy from 2004 to 2013 were identified from the National Cancer Database. A nonelderly cohort (<70 years) was also identified for secondary comparative analyses. The association between perioperative radiation therapy use and OS was assessed using propensity score-weighted Cox proportional hazards analyses. Relative survival was calculated using national life tables to assess the impact of radiation therapy on estimated sarcoma-specific survival in elderly and nonelderly patients. Patterns of care were assessed using multivariable logistic regression analyses. Of 6978 elderly patients, 3549 (51%) underwent surgery alone, and 740 (11%) and 2,679 (38%) received pre- and postoperative radiation therapy, respectively. Elderly patients received radiation therapy less commonly than did nonelderly patients (49% vs 52%, P < .001) despite presenting with higher grade tumors (grade 3, 86% vs 80%, P < .001) and experiencing more frequent positive surgical margins (23% vs 16%, P < .001). On propensity score-weighted analyses, preoperative (hazard ratio = 0.64, 95% confidence interval: 0.54-0.77, P < .001) and postoperative (hazard ratio = 0.72, 95% confidence interval: 0.67-0.77, P < .001) radiation therapy use was associated with improved OS compared with surgery alone. These associations were robust to landmark analyses of patients surviving at least 12 months. Radiation therapy use resulted in a greater magnitude of 5-year relative survival improvement in elderly than nonelderly patients. There is an overall and an age-disparate underuse of perioperative radiation therapy in elderly patients with high-grade STS despite radiation therapy being associated with improved OS. Further research is warranted to minimize gaps in care for elderly patients.