Paratesticular rhabdomyosarcoma-Impact of Locoregional Approach on Patient Outcome: A Report From the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG)

Rogers T, De Corti F, Guillén Burrieza G, Guérin F, van Scheltinga ST, Smeulders N, Craigie R, Jenney M, Kelsey A, Zanetti I, Coppadoro B, De Salvo GL, Bisogno G, Martelli H. Pediatr Blood Cancer. 2020 Jun 23:e28479. doi: 10.1002/pbc.28479.

Background: Paratesticular rhabdomyosarcoma (PT RMS) is rare compared to benign scrotal pathology. Inappropriate first surgery (InFS) required supplementary treatment to maintain excellent outcomes. Initial staging of regional lymph nodes is important. The aim of this study was to determine to what extent the quality of locoregional approach impacted on patient morbidity and survival.

Design/methods: Analysis was performed on all nonmetastatic PT RMS patients enrolled in the European paediatric Soft tissue sarcoma Study Group (EpSSG) RMS 2005 protocol. Aspects assessed were adherence to surgical guidelines and impact of protocol violations, relapse analysis, and survival outcomes.

Results: Analysis was performed on 237 patients, with median follow up of 67.1 months. Median age was 9.0 years. InFS occurred in 75 of 237 (32%) patients. InFS required intensified chemotherapy (10) and local therapy. After InFS, 61 required primary reexcision and five delayed surgery. Of 26 recurrences, the risk of relapse was higher in patients ≥10 years (21/26) and was mainly locoregional in 16 of 26 recurrences (± metastatic). Sixteen of 26 died with 14 of 16 patients ≥10 years. Nodal relapse neither occurred when N1 nodes were identified at diagnosis, nor after surgical staging. Five-year overall survival (OS) at age <10 years versus ≥10 years was 98.1 and 86.7%, respectively (P = .0013). Event-free survival (EFS) at age <10 years versus ≥10 years was 95.8 and 79.6%, respectively (P = .0004). OS and EFS did not highlight a significant difference in patients undergoing appropriate versus InFS (P = .8479, P = .2780, respectively).

Conclusions: InFS required intensified therapy to maintain excellent OS and EFS, so better anticipation of malignancy is required. Surgical staging of the retroperitoneal lymph nodes should be performed in patients ≥10 years old.

Keywords: paratesticular; pediatric; rhabdomyosarcoma.