Author: Lynda Williams
medwireNews: Considering FOXO1 fusion status improves the risk assessment of children with localised rhabdomyosarcoma (RMS), suggest study findings published in Cancer.
Recognising that the PAX3/7-FOXO1 translocation has been associated with a poor prognosis, the authors investigated the potential role of the alteration in the risk stratification of 1661 patients who participated in the European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) RMS 2005 study between 2005 and 2016.
During this time, risk stratification was based on six factors: histology, Intergroup Rhabdomyosarcoma Studies (IRS) Group postoperative staging, primary tumour site, tumour size, nodal status and patient age, explain Gian Luca De Salvo, from Veneto Institute of Oncology-IRCCS in Padua, Italy, and colleagues.
The patients were aged a median 5.3 years at diagnosis, 61% were boys, the most common tumour sites were parameningeal (24%) and within the genitourinary tract excluding the bladder and prostate (19%) and 77% had favourable histology. Overall, 84% were negative for the FOXO1 fusion.
Over a median follow-up of 6.3 years, 50% of patients had a locoregional relapse, 26% metastatic progression and 1% died. The 5-year event-free survival (EFS) and overall survival rates were 71% and 81%, respectively.
Initial analysis found that children younger than 3 years old were more likely to experience a local event than those aged 3–10 years or older than 10 years. The risk of events was also higher with a tumour size greater than 5 cm and differed between three clusters of primary RMS sites. The lowest risk tumours affected the bile ducts and nonbladder/prostate genitourinary tract, the intermediate risk tumours were orbit and nonparamengineal head and neck and the highest risk tumours were parameningeal, extremities and bladder/prostate.
De Salvo et al created a nomogram to assess the likelihood of achieving 5-year EFS based on scoring for age, tumour size, primary tumour site, IRS Group staging and fusion status.
This classified patients as being at low (11%), intermediate (42%), high (26%) or very high risk (22%) for events, with 5-year EFS rates in these groups of 94%, 78%, 65% and 52%, respectively. The corresponding 5-year OS rates were 97%, 92%, 74% and 61%.
The researchers note that the nomogram requires external validation but say that “the results presented provide the rationale to modify the EpSSG stratification for adoption in the current FaR‐RMS trial, confirming the adverse prognostic value of an age of 10 years and a tumor size of 5 cm.”
They continue: “It also supports reconsideration of the role of primary tumor site”, adding that “[b]ladder/prostate and biliary tree RMS are now included in the favorable category in the FaR‐RMS trial”, a new international study by the EpSSG.
The team concludes: “The most significant change is probably represented by the replacement of histology with fusion status. This makes the EpSSG stratification more similar to that of the [Children’s Oncology Group] system and will facilitate data comparison in the future.”
News stories are provided by medwireNews, which is an independent medical news service provided by Springer Healthcare Ltd. © 2024 Springer Healthcare Ltd, part of the Springer Nature Group
Cancer 2024; doi:10.1002/cncr.35258
Image credit: © FatCamera / Getty Images / iStock
