Rhabdomyosarcoma Outcomes in Adolescents and Young Adults Worse Than in Children

By Reuters Staff

June 27, 2022

NEW YORK (Reuters Health) - New data from rhabdomyosarcoma patients confirm poorer outcomes in adolescents and young adults compared with those in children, despite similar treatment, suggesting that a "tailored and intensive" treatment strategy might be warranted in adolescents and young adults, researchers say.

While rare, rhabdomyosarcoma is the most common soft-tissue sarcoma in children and adolescents, Dr. Andrea Ferrari with IRCCS National Cancer Institute Foundation, in Milan, Italy, and colleagues note in The Lancet Child & Adolescent Health.

They report new data on the outcome of adolescent and young adult patients (15-21 years) compared with children under 15 in the European pediatric Soft tissue sarcoma Study Group (EpSSG) rhabdomyosarcoma 2005 trial for localized disease and the EpSSG MTS 2008 study on metastatic disease.

To their knowledge, this is the first study to determine whether the outcomes of adolescent and young adult patients were "persistently worse than in children when enrolled in the same clinical trials and receiving similar treatments," they point out.

Adolescent and young adult patients were more likely than children to have metastatic tumors, unfavorable histological subtypes, large tumors (>5 cm) and regional lymph-node involvement.

The data confirm worse survival in adolescents and young adult patients than in younger children, with five-year event-free survival of 52.6% and five-year overall survival of 57.1% versus 67.8% and 77.9%, respectively, in children (both P<0.0001).

Multivariable analysis also confirmed the inferior prognosis of adolescent and young adult patients, with a hazard ratio 1.48 for poorer event-free survival (P=0.0002) and 1.73 for poorer overall survival (P<0.0001).

"A new insight from the study was that a significantly higher proportion of adolescents and young adults developed metastatic relapse than did younger children," Dr. Monika Sparber-Sauer of Hospital of the State Capital Stuttgart, in Germany, notes in a linked comment.

"Notably, Ferrari and colleagues report no differences in major toxicity or protocol modifications in adolescents and young adults compared with younger children," she adds.

"For adolescents and young adults, a multidisciplinary approach is necessary and should involve pediatric and adult sarcoma experts, pathologists, radiologists, surgeons, and radiotherapists," Dr. Sparber-Sauer writes.

"As rhabdomyosarcoma is a rare disease with small numbers of patients within newly defined molecular subgroups, international collaboration in future trials is warranted. Future trials including new diagnostic tests and targeted treatments should address the unique needs of the adolescent and young adult population, in addition to the needs of younger children, on an international level to improve prognosis of rhabdomyosarcoma," she concludes.

SOURCE: https://bit.ly/3Nh0JbC and https://bit.ly/3OiViKM Lancet Child & Adolescent Health, online June 8, 2022.

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