Outcome of 449 adult patients with rhabdomyosarcoma: an observational ambispective nationwide study

Abstract

Five‐year overall survival (OS) of localized RMS exceeds 70% in children (<18) but is very poor in adult patients. We analyzed the outcome and prognostic factors (PF) of a national series of adult patients with RMS in a large study. The study population consisted of two different cohorts: a retrospective cohort (157 adult patients treated in 13 reference centers between 05/1981 and 02/2010) and the prospective cohort (292 patients with RMS diagnosed and treated between 01/2010 and 12/2014 in France) included in the NetSarc database. A descriptive analysis of patients’ characteristics and prognostic factors was conducted on both series which were compared. In the retrospective series, histological subtypes were embryonal (E‐RMS) for 21% of patients, alveolar (A‐RMS) for 35% of patients, and “adult‐type” P‐RMS (pleomorphic, spindle cell RMS, not otherwise specified) (P) for 44% patients. This distribution significantly differed in the prospective cohort: A‐RMS: 18%; E‐RMS: 17%; and P‐RMS 65%. With a median follow‐up of 8.5 years, 5‐year OS for localized RMS and advanced RMS (with nodes and/or metastases) was 43% and 5%, respectively, (P < 0.0001), and median OS was 51, 33, and 16 months for E‐RMS, A‐RMS, and P‐RMS, respectively, in the retrospective cohort. The median OS was less than 40 months for the prospective nationwide cohort for the entire population. In a multivariate analysis of the retrospective study, independent prognostic factors for OS were A‐RMS, R0 resection, and adjuvant radiotherapy (RT). For localized RMS, age and use of pediatric chemotherapy (CT) regimen are independent prognostic factors. Adult patients with RMS have a poorer overall survival than pediatric patients, and survival varies considerably across histological subtypes.

The VAC regimen for adult rhabdomyosarcoma: Differences between adolescent/young adult and older patients

“…The median OS of the adult RMS patients treated with the VAC regimen in our analyses was approximately 2 years, which is similar to the prognoses of adult RMS patients in previous studies . The VAC regimen could be a feasible treatment option for adult RMS, but the efficacy of the VAC regimen for adult RMS was inferior to those in pediatric RMS patients, regardless of whether the patient is an adolescent/young adult or older, and thus more effective treatment strategies for adult RMS are necessary.…”

“…However, most prospective clinical trials of RMS with or without the VAC regimen were designed for the evaluation of pediatric patients, and when adult patients were enrolled in the trials their numbers were low . In large‐scale data of adult RMS including patients older than AYA, the chemotherapy regimens were not limited to a specific regimen, and many patients were treated with combination chemotherapies including doxorubicin and/or ifosfamide . This could be because pleomorphic RMS shows a high rate of adult RMS.…”

“…The prognoses of pediatric RMS patients are improving as the treatment protocols improve; the 5‐year overall survival (OS) of non‐metastatic pediatric RMS has reached 71% . Adult RMS, which is a more rare component of adult soft tissue sarcoma than the pediatric cases, have poorer prognoses than those of pediatric RMS; the reported 5‐year OS of adult RMS is 27–43% …”

“…There is a clinical report noting that adult RMS patients tended to have a low dose density of the VAC regimen compared to pediatric RMS patients . The age distribution of adult RMS patients is broad and includes many adolescent/young adult (AYA) patients under 40 years old . Differences between pediatric and AYA patients with RMS and between pediatric and adult RMS patients have been examined, but clinical data comparing AYA and older patients with RMS are lacking.…”

Establishment and Characterization of a Sclerosing Spindle Cell Rhabdomyosarcoma Cell Line with a Complex Genomic Profile

“…The worldwide age standardized RMS incidence rate is 0.3/100,000 [ 3 ]. Several distinct histopathological RMS subtypes have been defined: young children are most often affected by the embryonal RMS (ERMS) subtype, the proportion of alveolar RMS (ARMS) increases in older children and adolescents [ 4 ], whereas, in adults, the pleomorphic (PRMS) subtype is most frequently diagnosed [ 5 ].…”