Parameningeal rhabdomyosarcoma- clinical profile, outcomes and
prognostic factors in children treated at a single center over a decade
Abstract
1 Background Parameningeal Rhabdomyosarcomas (PM-RMS) in
children are challenging to treat. While ten-year Event Free Survival
(EFS) of 62% have been reported from High-Middle Income Countries
(HMICs) for localized disease, data is limited from Low-Middle Income
Countries (LMICs). We studied the clinical profile, outcomes, and
prognostic factors in PM-RMS. 2 Materials and Methods
Children≤15 years with PM-RMS treated on a uniform chemotherapy protocol
from January 2013-December 2021 were retrospectively analysed. Local
therapy at 10-12weeks of induction was radiotherapy (RT)+/-surgery where
possible with early RT for intracranial extension (ICE). 3
Results Seventy-six patients with a median age of 6.7years
(range,3.2-15years), male to female ratio of 1.8:1 formed the study
cohort. Eleven patients (14.5%) had metastasis (lungs-8, bone-2, bone
marrow-1) and ICE seen in 46.1%(n=35). Twenty-five patients (49.0%)
had alveolar histology with PAX3/7 positive in 17/59 (28.8%). Median
tumor size(t size) at baseline was
5.2cm(range,1.2-12.8cm). Seventy-one patients received RT, 5 also
underwent surgery. At a median follow-up of 65months (range,53-76months)
4year EFS, OS of the whole cohort were 47.3%(95%CI:34.8%-58.8%),
51.7%(95%CI:38.0%-64.0%) respectively. Four-year EFS, OS of
localized and metastatic cohort were 54.7%(95%CI:41.3%-68.1%),
56.0%(95%CI:42.0%-70.0%) and 9.1%(95%CI:0%-26.5%),
18.2%(95%CI:0%-47.8%) respectively. Metastases
(HR-3.38,95%CI:1.57-7.26,p=0.002), t size
(HR-1.17,95%CI:1.02-1.34,p=0.026) were prognostic for survival on
multivariate analysis. 4 Conclusions Survival of children with
localized PM-RMS in our study is relatively fair compared to the
reported literature probably due to application of RT in all despite
higher proportion of larger tumors, unfavorable sites of primary and
intracranial extension. Identification of high-risk subsets and
optimizing current treatment strategies, both systemic and local therapy
may partly improve outcomes.