Pathogenic EGFR mutations occur in only 0.08% of ovarian cancers but represent actionable targets for EGFR-directed therapy, with one patient achieving durable response (>17 months) to osimertinib. This rare finding supports comprehensive next-generation sequencing in ovarian cancer to identify uncommon but treatable molecular alterations.
Study Design & Population:
- Retrospective analysis of 33,850 molecularly profiled ovarian cancer samples
- Real-world patient cohort undergoing NGS DNA testing between 2016-2025
- Patients identified through Caris molecular profiling database
- Focus on pathogenic or likely pathogenic EGFR mutations
Key Findings:
- 0.08% prevalence: 27 of 33,850 patients harbored pathogenic EGFR mutations
- Mutation distribution: EGFR exon 20 mutations (n=12, including 5 T790M), L858R (n=3), exon 19 deletions (n=2)
- Clinical response: One patient treated with osimertinib achieved objective response lasting >17 months
- Treatment utilization: Only 1 of 27 EGFR-positive patients received targeted therapy
Clinical Implications:
- Supports routine comprehensive NGS testing in ovarian cancer for rare actionable mutations
- EGFR-mutated ovarian cancers may respond to established EGFR inhibitors like osimertinib
- Highlights potential underutilization of targeted therapy in rare molecular subsets
- Expands therapeutic options beyond traditional chemotherapy in select ovarian cancer patients
Limitations:
- Single case of clinical response limits generalizability of treatment efficacy
- Retrospective design with potential selection bias in molecular testing
- Limited clinical outcome data for majority of EGFR-positive cases
- No comparison of outcomes between EGFR-positive and EGFR-negative cohorts
