Concerning the dismal prognosis of chemoresistant patients with epithelial ovarian carcinoma (EOC), we aimed to follow up the findings of a previous whole-exome sequencing study using an orthogonal Sanger sequencing on the same patients and a separate set of 127 EOC patients (N = 177, all fresh frozen tumor samples). We focused on TP53 as a frequently mutated gene relevant for chemosensitivity, included KRAS as an additional therapeutically relevant target, complemented the study with transcript levels of both genes, and compared results with clinical parameters. All variants in TP53 and KRAS detected by exome sequencing were confirmed. KRAS mutated patients had significantly more frequent FIGO stages I or II (p = .002) and other than high-grade serous tumor subtypes (nonHGSCs) (p < .001), which was connected with lower KRAS transcript levels (p = .004). Patients with nonHGSC subtypes had less frequent TP53 mutations (p = .002). Carriers of TP53 variants disrupting the DNA binding loop had significantly longer platinum-free intervals than the rest (p = .037). Tumors bearing nonsense, frameshift, or splice site TP53 variants had a significantly lower TP53 transcript level, while those with missense variants had significantly higher levels than wild types (p < .001). The normalized intratumoral TP53 and KRAS transcript levels were correlated, and patients with co-mutated genes had poorer overall survival than others (p = .015). Protein levels of both genes significantly correlated with their respective transcripts (p = .028 and p = .001, respectively). Our study points to KRAS as a target for future therapy of nonHGSCs and reveals the prognostic value of TP53 variants in the DNA binding loop.

• Keywords
• Epithelial ovarian carcinoma, KRAS, TP53, platinum sensitivity, transcript expression, variant,
• MeSH
• Drug Resistance, Neoplasm genetics   MeSH
• Adult MeSH
• Carcinoma, Ovarian Epithelial * genetics   drug therapy   pathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Mutation MeSH
• Tumor Suppressor Protein p53 * genetics   metabolism   MeSH
• Ovarian Neoplasms * genetics   drug therapy   pathology   mortality   MeSH
• Platinum * therapeutic use   pharmacology   MeSH
• Prognosis MeSH
• Proto-Oncogene Proteins p21(ras) * genetics   metabolism   MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• KRAS protein, human MeSH Browser
• Tumor Suppressor Protein p53 * MeSH
• Platinum * MeSH
• Proto-Oncogene Proteins p21(ras) * MeSH
• TP53 protein, human MeSH Browser

BACKGROUND: Colorectal cancer is a highly prevalent and deadly. The most common metastatic site is the liver. We performed a whole exome sequencing analysis of a series of metachronous colorectal cancer liver metastases (mCLM) and matched non-malignant liver tissues to investigate the genomic profile of mCLM and explore associations with the patients' prognosis and therapeutic modalities. METHODS: DNA samples from mCLM and non-malignant liver tissue pairs (n = 41) were sequenced using whole exome target enrichment and their germline and somatic genetic variability, copy number variations, and mutational signatures were assessed for associations with relapse-free (RFS) and overall survival (OS). RESULTS: Our genetic analysis could stratify all patients into existing targeted therapeutic regimens. The most commonly mutated genes in mCLM were TP53, APC, and KRAS together with PIK3CA and several passenger genes like ABCA13, FAT4, PCLO, and UNC80. Patients with somatic alterations in genes from homologous recombination repair, Notch, and Hedgehog pathways had significantly prolonged RFS, while those with altered MYC pathway genes had poor RFS. Additionally, alterations in the JAK-STAT pathway were prognostic of longer OS. Patients bearing somatic variants in VIPR2 had significantly shorter OS and those with alterations in MUC16 prolonged OS. Carriage of the KRAS-12D variant was associated with shortened survival in our and external datasets. On the other hand, tumor mutation burden, mismatch repair deficiency, microsatellite instability, mutational signatures, or copy number variation in mCLM had no prognostic value. CONCLUSIONS: The results encourage further molecular profiling for personalized treatment of colorectal cancer liver metastases discerning metachronous from synchronous scenarios.

• Keywords
• Colorectal cancer, Exome, Liver Metastasis, Metachronous, Prognosis, Therapy,
• Publication type
• Journal Article MeSH