Clinical group and modified TNM stage for rhabdomyosarcoma: A review from the Children’s Oncology Group

Crane JN, Xue W, Qumseya A, Gao Z, Arndt CAS, Donaldson SS, Harrison DJ, Hawkins DS, Linardic CM, Mascarenhas L, Meyer WH, Rodeberg DA, Rudzinski ER, Shulkin BL, Walterhouse DO, Venkatramani R, Weiss AR. Clinical group and modified TNM stage for rhabdomyosarcoma: A review from the Children’s Oncology Group. Pediatr Blood Cancer. 2022 Jun;69(6):e29644. doi: 10.1002/pbc.29644. Epub 2022 Mar 6. Review. PubMed PMID: 35253352; PubMed Central PMCID: PMC9233945.

The Children’s Oncology Group (COG) uses Clinical Group (CG) and modified Tumor Node Metastasis (TNM) stage to classify rhabdomyosarcoma (RMS). CG is based on surgicopathologic findings and is determined after the completion of initial surgical procedure(s) but prior to chemotherapy and/or radiation therapy. The modified TNM stage is based on clinical and radiographic findings and is assigned prior to any treatment. These systems have evolved over several decades. We review the history, evolution, and rationale behind the current CG and modified TNM classification systems used by COG for RMS. Data from the seven most recently completed and reported frontline COG trials (D9602, D9802, D9803, ARST0331, ARST0431, ARST0531, ARST08P1) were analyzed and confirm that CG and modified TNM stage remain relevant and useful for predicting prognosis in RMS. We propose updates based on recent data and discuss factors warranting future study to further optimize these classification systems.