Utilization of radiation therapy and impact on outcomes in spermatic cord sarcomas in the United States.

Abstract

419 Background: Spermatic cord sarcomas are a rare entity with management consisting of radical orchiectomy and the value of adjuvant radiation being unclear, as the literature consists of heterogeneous case series spanning multiple decades with limited numbers of patients. Methods: The National Cancer Data Base was queried for men who underwent orchiectomy for spermatic cord sarcomas between 2004 and 2018 with known surgical margin status. Kaplan-Meier with log-rank test and Cox proportional hazards tests were utilized for overall survival (OS) calculations. Associations were determined with bivariate regression analysis. Results: A total of 912 men were identified who met inclusion criteria. Six hundred seventeen (67.7%) had liposarcomas (LS) while 32.3% had non-lipsarcomatous (NLS) histologies. 5/10-year OS for men with LS was 85.1%/67.4% and 74.1%/58.4% for NLS, respectively (p < 0.001). 238 (26.1%) men were treated with adjuvant radiation therapy with similar distributions between LS and NLS. Utilization of radiation was significantly associated with moderate-poorly differentiated histology (HR 3.228 [95%CI 2.241-4.649] p < 0.001), radical orchiectomy (HR 1.477 [1.062-2.054] p = 0.020), positive surgical margins (HR 1.826 [95%CI 1.257-2.652] p = 0.002), but not histologic subtype or tumor size. There was no difference in OS for LS nor NLS with respect to the application of adjuvant radiation, but in men with moderately-poorly differentiated LS treated with adjuvant radiation, 5-year OS was 86.8% vs. 68.6% (p = 0.148). In men with well-differentiated LS, 5-year OS was 93.6% with XRT vs 89.5% (p = 0.623). Adjuvant XRT did not impact OS in men with positive surgical margins, nor did it have an impact on OS for NLS regardless of disease grade or margins. Conclusions: Adjuvant radiation therapy is utilized for approximately one quarter of men diagnosed with spermatic cord sarcomas. XRT may impact OS for men with moderately-poorly differentiated liposarcomas; further research with patient-level data is required.