Identification and clinical significance of somatic oncogenic mutations in epithelial ovarian cancer

Objective Epithelial ovarian cancer (EOC) is a heterogeneous disease with diverse clinicopathological features and behaviors, and its heterogeneity may be concerned with the accumulation of multiple somatic oncogenic mutations. The major goals of this study are to systematically perform the comprehensive mutational profiling in EOC patients, and investigate the associations between somatic mutations and clinicopathological characteristics. Methods A total of 80 surgical specimens were obtained from EOC patients who had previously undergone primary debulking surgery, and genomic DNAs were extracted from fresh-frozen tissues. We investigated mutational status in hot spot regions of 50 cancer-related genes by targeted next-generation sequencing using an Ion AmpliSeq Cancer Hotspot Panel v2 Kit. Results Validated mutations were detected in 66 of the 80 tumors (82.5%). The five most frequently mutated genes were TP53 (43.8%), PIK3CA (27.5%), KRAS (23.8%), PTEN (10%) and CTNNB1 (10%). PTEN and CTNNB1 mutations were associated with younger age. PIK3CA1, KRAS and CTNNB1 mutations were observed in early-stage, whereas TP53 mutations were more common in advanced stage. Significant associations were observed between TP53 mutation and serous carcinoma, and between KRAS mutation and mucinous carcinoma. Both PIK3CA mutation and CTNNB1 mutation were also significantly associated with endometrioid and clear cell carcinoma. The patients with PIK3CA and KRAS mutations were significantly associated with favorable progression free survival (PFS). In particular, PIK3CA mutations had more significant associations with favorable PFS than PIK3CA wild-type in the endometrioid subtype (P = 0.012). Patients with mutations only in TP53 were significantly associated with worse PFS. Conclusion EOCs were heterogeneous at the genomic level and harbored somatic oncogenic mutations. Our molecular profiling may have the potential for becoming a novel stratification within histological subtypes of EOC. Further studies are needed to define molecular classification for improved clinical outcomes and treatment of EOC patients in future.

Automated summary

The study aimed to comprehensively analyze mutational profiling in EOC patients and investigate the association between somatic mutations and clinicopathological characteristics. Validated mutations were detected in 82.5% of tumors, with TP53, PIK3CA, KRAS, PTEN, and CTNNB1 being the most frequently mutated genes. Mutations in PTEN and CTNNB1 were associated with younger age, while PIK3CA1, KRAS, and CTNNB1 mutations were observed in early-stage EOC. TP53 mutations were more common in advanced stage EOC. Significant associations were found between mutations and specific subtypes of EOC, with PIK3CA and KRAS mutations associated with favorable progression free survival (PFS). Mutations only in TP53 were associated with worse PFS. The study's molecular profiling may potentially be used for novel stratification within histological subtypes of EOC, with further research needed for improved clinical outcomes and treatment.