PAX3

Overview

PAX3 is a paired-box transcription factor. PAX3::FOXO1 fusions define the adverse-prognosis subset of alveolar rhabdomyosarcoma.

Alterations observed in the corpus

  • PAX3::FOXO1 fusion present in 70% of extremity alveolar RMS cases in the 61-patient MSK cohort; detected by Archer FusionPlex or FISH PMID:37315267.
  • PAX3::FOXO1 ARMS had worse prognosis and affected older children than PAX7::FOXO1 (HR 3.45, P=.016) PMID:37315267.
  • PAX3::FOXO1 fusion — pathognomonic driver in FP-RMS; detected in 16/18 FP-RMS patients in a multi-institutional sequential genomic study (MSKCC + Institut Curie); detected in ctDNA at diagnosis in 100% of cases and at relapse in 86% of cases; fusion read counts quantified by UMIs correlate with disease burden and predict relapse PMID:37730754.
  • Defining translocation partner in ARMS rhabdomyosarcoma: t(2;13) produces PAX3-FOXO1 fusion (n=35); alternative fusions PAX3-NCOA1 (RMS235, RMS2031) and PAX3-INO80D (RMS2046) identified in tumors classified as fusion-negative by RT-PCR PMID:24436047

Cancer types (linked)

  • Alveolar rhabdomyosarcoma (ARMS) — dominant fusion partner; adverse prognosis PMID:37315267.
  • RMS (FP-RMS) — PAX3::FOXO1 ctDNA detection enables non-invasive disease burden monitoring; patients with secondary CDKN2A/MYCN/CDK4 co-alterations have the worst survival outcomes PMID:37730754.

Co-occurrence and mutual exclusivity

Therapeutic relevance

  • Fusion-partner-aware risk stratification is proposed; no direct targeted therapy reported PMID:37315267.

Open questions

Sources

This page was processed by crosslinker on 2026-05-09. - PMID:24436047

This page was processed by crosslinker on 2026-05-09.