Assessing actionability and incidental findings of germline variants in two precision oncology trials

Eur J Cancer. 2024 Oct:210:114256. doi: 10.1016/j.ejca.2024.114256. Epub 2024 Aug 3.

Abstract

Introduction: High-throughput sequencing techniques have revolutionized oncology. Paired germline-tumor DNA analysis has emerged as a comprehensive strategy to uncover actionable alterations in advanced cancer patients (ACP) enrolled in precision oncology trials. However, challenges persist in variant interpretation and managing incidental germline findings.

Methods: We conducted a study involving 288 ACP from MOSCATO (NCT01566019) and MATCHR (NCT02517892) trials to assess germline variants impacting cancer-related genes. Germline DNA sequencing was performed using a panel of 250 cancer-related genes, and the results were discussed during tumor molecular board sessions.

Results: Germline pathogenic variants (PV) were classified according to the ESCAT classification. Lung cancer (36.8 %), followed by prostate (18.4 %) and breast cancer (17.7 %), comprised the most prevalent tumor types. PVs were found in 12.5 % of patients. Most PVs were classified as ESCAT X (63.9 %), highlighting limited therapeutic actionability. Notably,2 % of patients had actionable variants (ESCAT I-A/II-A). Incidental findings included 7.3 % of patients with PVs in cancer-predisposition genes, with 2.4 % having very high-risk potential, necessitating mandatory oncogenetic counseling. Nearly one in five patients (21.9 %) had at least one VUS.

Discussion: Our study underscores the significance of germline sequencing in identifying actionable alterations and the need for improved variant interpretation as well as pretest counseling plans in precision oncology trials.

Keywords: Basket trial; Germline DNA variants; Incidental variants; Precision oncology; Targeted therapy.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / genetics
  • Female
  • Genetic Predisposition to Disease
  • Genetic Testing / methods
  • Germ-Line Mutation*
  • High-Throughput Nucleotide Sequencing / methods
  • Humans
  • Incidental Findings*
  • Male
  • Middle Aged
  • Neoplasms* / genetics
  • Neoplasms* / therapy
  • Precision Medicine* / methods

Substances

  • Biomarkers, Tumor