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Alterations of the p53 and PIK3CA/AKT/mTOR pathways in angiosarcomas: a pattern distinct from other sarcomas with

Antoine Italiano1, Chun-Liang Chen, Rachael Thomas

  • 1Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA. italiano@bergonie.org

Cancer
|June 1, 2012
PubMed
Abstract

Insights

Angiosarcomas show distinct genomic alterations compared to other sarcomas. While TP53 mutations and PTEN deletions are common in leiomyosarcoma and undifferentiated pleomorphic sarcoma, they are rare in angiosarcoma.

Area of Science:

  • Oncology
  • Genetics
  • Molecular Biology

Background:

  • Sarcomas like leiomyosarcoma (LMS) and undifferentiated pleomorphic sarcoma (UPS) often exhibit complex genomic alterations in the p53 and PIK3CA/AKT/mTOR pathways.
  • The genetic landscape of these pathways in angiosarcoma (AS) remains largely unexplored.

Purpose of the Study:

  • To investigate the status of key genes within the p53 and PIK3CA/AKT/mTOR signaling pathways in a cohort of angiosarcoma (AS) patients.
  • To determine if genetic alterations in these pathways differentiate AS from other sarcoma subtypes.

Main Methods:

  • Analysis of critical genes in the p53 and PIK3CA/AKT/mTOR pathways in 62 AS samples.
  • Utilized immunohistochemistry to assess p53 overexpression and evaluated gene mutations, deletions, and pathway activation markers (p-S6K, p-4eBP1).

Main Results:

  • TP53 mutations were infrequent (4%) in AS, and p53 overexpression was observed in 49% of cases, correlating with poorer disease-free survival.
  • PIK3CA/AKT/mTOR pathway activation, indicated by p-S6K and/or p-4eBP1 overexpression, was present in 42% of AS.
  • Unlike LMS and UPS, AS rarely showed TP53 mutations, PTEN deletions, or HDM2 alterations.

Conclusions:

  • Angiosarcomas represent a distinct molecular subgroup of sarcomas characterized by unique genomic alterations.
  • The pathogenesis of AS does not frequently involve TP53 mutations or PTEN deletions, which are common in other complex sarcoma types.

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