Localized vaginal/uterine rhabdomyosarcoma-results of a pooled analysis from four international cooperative groups.

Minard-Colin V, Walterhouse D, Bisogno G, Martelli H, Anderson J, Rodeberg DA, Ferrari A, Jenney M, Wolden S, De Salvo G, Arndt C, Merks JHM, Gallego S, Schwob D, Haie-Meder C, Bergeron C, Stevens MCG, Oberlin O, Hawkins D; International Society of Pediatric Oncology Sarcoma Committee, the Children's Oncology Group, the Italian Cooperative Soft Tissue Sarcoma Group, and the European pediatric Soft tissue sarcoma Study Group. Pediatr Blood Cancer. 2018 Sep;65(9):e27096. DOI: 10.1002/pbc.27096.

Vaginal/uterine rhabdomyosarcoma (VU RMS) is one of the most favorable RMS sites. To determine the optimal therapy, the experience of four cooperative groups (Children's Oncology Group [COG], International Society of Pediatric Oncology (SIOP) Malignant Mesenchymal Tumor Group [MMT], Italian Cooperative Soft Tissue Sarcoma Group [ICG], and European pediatric Soft tissue sarcoma Study Group [EpSSG]) was analyzed.

From 1981 to 2009, 237 patients were identified. Median age (years) at diagnosis differed by tumor location; it was 1.9 for vagina (n = 160), 2.7 for uterus corpus (n = 26), and 13.5 for uterus cervix (n = 51). Twenty‐eight percent of patients received radiation therapy (RT) as part of primary therapy (23% COG, 27% MMT, 46% ICG, and 42% EpSSG), with significant differences in the use of brachytherapy between the cooperative groups (23% COG, 76% MMT, 64% ICG, and 88% EpSSG).

Ten‐year event‐free (EFS) and overall survival (OS) were 74% (95% CI, 67–79%) and 92% (95% CI, 88–96%), respectively. In univariate analysis, OS was inferior for patients with uterine RMS and for those with regional lymph node involvement. Although EFS was slightly lower in patients without initial RT (71% without RT vs. 81% with RT; P = 0.08), there was no difference in OS (94% without RT vs. 89% with RT; P = 0.18). Local control using brachytherapy was excellent (93%). Fifty‐one (51.5%) of the 99 survivors with known primary therapy and treatment for relapse were cured with chemotherapy with or without conservative surgery.

About half of all patients with VU RMS can be cured without systematic RT or radical surgery. When RT is indicated, modalities that limit sequelae should be considered, such as brachytherapy.