Comparison of Preoperative Chemoradiation With Radiation or Chemotherapy Alone in Patients with Non-Metastatic, Resectable Retroperitoneal Sarcoma

PURPOSE/OBJECTIVE(S) Optimal preoperative therapy regimen in the treatment of resectable retroperitoneal sarcoma remains unclear. This study compares the impact of preoperative radiation, chemoradiation, and chemotherapy on overall survival. MATERIALS/METHODS The National Cancer Database (NCDB) was queried for patients diagnosed between 2006 and 2015 with non-metastatic, resectable RPS with follow up through 2017, treated with preoperative therapies followed by surgery. Primary endpoint was overall survival (OS), evaluated by Kaplan-Meier method, log-rank test, and Cox multivariable analysis. Propensity score matching was used to address selection bias. RESULTS A total of 1253 patients met the inclusion criteria, with 210 patients (17%) receiving chemoradiation, 850 patients (68%) receiving radiation, and 193 patients (15%) receiving chemotherapy. On Cox multivariable analysis compared to preoperative chemoradiation, preoperative radiation was not associated with improved OS (hazards ratio [HR] 0.98, 95% CI 0.76-1.25, P = 0.84), while preoperative chemotherapy was associated with worse OS (HR 1.64, 95% confidence interval [CI] 1.24-2.18, P < 0.001). Recent years of diagnosis (HR 1.30, 95% CI 1.08-1.58, P = 0.007), elderly age (HR 1.32, 95% CI 1.10-1.59, P = 0.003), male gender (HR 1.20, 95% CI 1.00-1.43, P = 0.047), lower income (HR 1.19, 95% CI 1.00-1.43, P = 0.049), poorly differentiated (HR 2.53, 95% CI 1.84-3.48, P < 0.001) or other tumor grade (HR 2.44, 95% CI 1.75-3.40, P < 0.001), and positive surgical margin (HR 1.37, 95% CI 1.12-1.68, P = 0.002) were associated with worse OS. Similar findings were observed in 199 and 128 matched pairs for preoperative radiation and chemotherapy respectively when compared to preoperative chemoradiation. CONCLUSION Our study suggested an OS benefit in using preoperative chemoradiation compared to chemotherapy alone, but OS outcomes were comparable between preoperative chemoradiation and radiation alone. Further studies are warranted to optimize preoperative therapies.