Next-Generation Sequencing Finds Different Molecular Profiles of Pediatric, Adult Sarcomas

Next-generation sequencing (NGS) identified different molecular profiles of pediatric and adult sarcomas, including actionable gene mutations that can be targeted by FDA-approved drugs. Findings were reported in an abstract presented at the 2022 American Association of Cancer Research (AACR) Annual Meeting.

With over 100 subtypes, pediatric sarcomas represent approximately 12% of all pediatric cancers. Researchers highlighted that some molecular detection techniques can be used to assist the diagnosis and treatment of pediatric sarcoma, but this remains challenging due to overlapping morphological features and limited biopsy specimens.

Recent technological innovations in genomic profiling with NGS has shown its effectiveness in identifying biomarkers, prognosis, and response to therapy across various cancers. Moreover, findings reported in JAMA Oncology indicated that NGS located the primary site of cancer origin among patients with previously unknown disease status, and led to clinical benefit in some patients who were matched with targeted drugs based on findings.

Leveraging NGS to analyze the molecular profiles of pediatric and adult sarcomas, researchers recruited 700 Chinese patients who provided tumor tissue and matching blood specimens. The integrative DNA and RNA sequencing panel Onco Panscan plus at Genetronhealth was used to assess the collected tissue and specimen samples.

Of the study cohort, there were 224 children (32%) and 476 adults (68%) with sarcoma, in which a similar ratio of men to women was reported in adults and more males (n = 134) than females (n = 90) were included for the pediatric population.

Among children, rhabdomyosarcoma was the most common soft tissue tumor, accounting for 24.1% (n = 54), followed by Ewing's sarcoma (9.8%, n = 22) and osteosarcoma (8.5%, n = 34), whereas angiosarcoma (3.8%, n = 18) and fibrosarcoma (3.6%, n = 17) were the most common in adults.

A mean of 3 and 5 mutations per patient were identified in children and adults with sarcoma, respectively, with differing mutation types shown for both age groups:

• for children, frequent alterations were missense mutations (n = 326, 51.2%), fusions (n = 129, 20.3%), and copy number variants (n = 66, 10.4%)—TP53 (12.9%, n = 29), EWSR1 (8.9%, n = 20) and ALK mutations (6.7%, n = 15) were most common
• for adults, frequent alterations were missense mutations (n = 1438, 66.8%), fusions (n = 221, 10.3%), and truncating mutations (n = 215, 10.0%)—TP53 (29.4%, n = 140), NF1 (4.8%, n = 23), CTNNB1 (4.2%, n = 20) and RB1 (4.2%, n = 20) were most common
  

According to the NGS results, pathological subtypes could be confirmed in 40.2% (n = 90) and 48.1% (n = 229) of children and adult patients with sarcoma, respectively. Moreover, a total of 72 drug-targeted gene mutations were identified in 57 children with sarcoma, of which 35 (48.6%) gene mutations could be targeted by FDA-approved drugs. There were 256 drug-targeted gene mutations detected in adults, with the proportion of actionable mutations rising to 78.9% (n = 202).

“The genomic landscape of pediatric sarcomas is different from that of adults. NGS aids in the subtype classification and clinical guidance of pediatric sarcomas, providing evidence for personalized treatments with clinical benefit,” they concluded.

Reference

Cai W, Liu F, Liu X, et al. Next-generation sequencing (NGS) reveals different molecular profiles of pediatric sarcoma in children and adults. Presented at AACR 2022 Annual Meeting. Abstract: 5756.