Concordance analysis of DNA and RNA profiling: The MD Anderson IMPACT2 study in precision oncology

Stephanie T Schmidt1,2, Mehmet A Baysal3, Siqing Fu3

  • 1Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.

Insights

RNA profiling shows potential for cancer treatment selection by revealing gene expression alterations. More than six altered genes correlate with shorter overall survival, highlighting RNA

Area of Science:

  • Oncology
  • Genomics
  • Molecular Biology

Background:

  • DNA profiling is standard for cancer treatment selection, but RNA profiling is still under investigation.
  • The IMPACT2 study (NCT02152254) evaluated molecular profiling for guiding cancer therapy across various tumor types.

Purpose of the Study:

  • To explore associations between DNA and RNA alterations in cancer patients.
  • To investigate the link between the number of genes with altered expression and overall survival (OS).
  • To assess the concordance between DNA and RNA profiling results.

Main Methods:

  • Molecular profiling, including DNA next-generation sequencing, was performed on 829 IMPACT2 study patients.
  • RNA profiling was conducted for 253 patients.
  • Concordance between DNA and RNA profiling was evaluated, and OS was analyzed in 217 treated patients.

Main Results:

  • Fifty patients showed 58 concordant DNA and RNA events, with 41 demonstrating statistically significant concordance.
  • 123 gene pairs exhibited significant associations between genomic and expression alterations (p < 0.05), including TP53 alterations with VEGFA overexpression.
  • Patients with ≥6 genes showing altered expression had a shorter median OS (6.7 months) compared to those with 0-2 (9.8 months) or 3-5 (11.9 months) altered genes (p = 0.03).

Conclusions:

  • RNA profiling demonstrates potential actionability in cancer treatment selection.
  • An increased number of genes with altered expression (≥6) is associated with poorer overall survival.
  • The observed concordance between TP53 alterations and VEGFA overexpression may inform bevacizumab response in TP53-mutant cancers.