Primary prostate sarcomas (PPS) are rare. Outcomes for this cancer have not been well characterized.
Subjects with a PPS diagnosed between 1973 and 2014 were identified in the SEER database. Subjects were stratified by disease stage and types of therapies received. Disease-specific survival (DSS) and Overall survival (OS) was estimated by Kaplan-Meier analysis and cohorts were compared with a univariate and multivariable Cox regression.
The incidence of PPS among all prostate cancer diagnoses was 0.02%. Subjects younger than age 26 years at diagnosis represented 29% of cases, and 32% of primary prostate sarcomas were rhabdomyosarcoma histology.
The median age at diagnosis was 9 years. Between age 0-25 years rhabdomyosarcoma accounted for 96.4% of primary prostate sarcoma diagnoses, after age 25 rhabdomyosarcoma represented 15% of new diagnoses. The 10-year DSS and OS for rhabdomyosarcoma was 47% and 44%.
The median age at diagnosis was 71 years. The most common diagnoses were leiomyosarcoma (33%) and carcinosarcoma (28%). Localized, regional, or distant disease occurred in 40%, 34%, and 26% of cases. The 10-year DSS and OS were 26% and 14%. In locally advanced cases, RT added to surgery trended toward improved DSS (P = 0.10).
Disease-specific survival and OS for non-rhabdomyosarcoma histologies appear inferior to those of rhabdomyosarcoma. The addition of RT to surgical resection may improve DSS in locally advanced non-rhabdomyosarcoma. This is the largest report of the incidence, stage distribution, and survival for this extremely rare urologic malignancy providing valuable prognostic information.
Cancer medicine. 2018 Nov 19 [Epub ahead of print]
Jonathan D Tward, Matthew M Poppe, Ying J Hitchcock, Brock O'Neil, Daniel J Albertson, Dennis C Shrieve
Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, Utah., Department of Urology, University of Utah School of Medicine, Salt Lake City, Utah., Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah.