40MO - Targetable Gene Mutations in Mucinous Ovarian Cancer

Background

To characterize the mutational landscape of mucinous epithelial ovarian cancer (MOC).

Methods

Data were extracted from the American Association for Cancer Research’s (AACR) Project Genomics Evidence Neoplasia Information Exchange (GENIE) database version 12.1 via cBioPortal (http://genie.cbioportal.org). This publicly available, multi-institutional database provides next generation sequencing genomic profiles of tumors. We queried this database for MOC samples and descriptively report mutation frequencies of genes for which targeted therapies are either approved or in clinical trials for other cancer types. We include the following genes in our analysis: ERBB2 (HER2) amplifications, homologous recombination (HR) and mismatch repair (MMR) genes, BRAF, KRAS, NRAS, RNF43, ARID1A, PIK3CA, ERBB3, and PTEN mutations.

Results

Among 145 MOC samples, the most common somatic mutations were KRAS (98/145, 67.6%), ERBB2 (HER2) amplification (13/90, 14.4%), ARID1A (16/116, 13.8%), CDKN2A (17/141, 12.1%), PIK3CA (13/145, 9.0%), ERBB3 (10/120, 8.3%), RNF43 (7/102, 6.9%), BRAF (4/145, 2.8%), PTEN (4/145, 2.8%), and NRAS (2/145, 1.4%). Mutations in HR and MMR genes were relatively rare, with the most common HR mutations in BRIP 1 (5/114, 4.4%) and BRCA2 (5/122, 4.1%); and the most common MMR mutations in MLH3 (1/44, 2.3%) and MSH3 (1/48, 2.1%). Table: 40MO

Mutation frequencies of homologous recombination (HR) and mismatch repair (MMR) genes, as well as the TP53 gene in tumor samples from mucinous ovarian cancer

Conclusions

Advanced stage MOC carries a poor prognosis, with only platinum/taxane, anti-VEGF agents, and 5-fluouracil currently available as current standard of care therapies. Here, we demonstrate high mutation rates in targetable genes among MOC samples. Most commonly, these mutations were identified among KRAS/NRAS (targetable with MEK inhibitors), ERBB2 (HER2) (targetable with anti-HER2 agents), ARID1A (targetable with epigenetic modifiers and ATR inhibitors), and PI3CA (targetable with PI3-kinase and AKT inhibitors). Given the frequency of each mutation, genetically targeted clinical trials evaluating the clinical efficacy of their respective agents are warranted.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.