P-308 PIK3CA and TP53 gene mutations in patients with metastatic colorectal cancer from Northeast Romania

In metastatic colorectal cancer (mCRC) PIK3CA and TP53 genes are biomarkers that are not currently used in daily practice. In the literature, there is little data that evaluated the correlations of these gene mutations with clinical, pathological, and molecular features of tumors. We performed a retrospective analysis of patients data diagnosed with mCRC who were tested with NGS for RAS, BRAF, PIK3CA, and TP53 mutations in Regional Institute of Oncology Iași from January 2018 to January 2021. We identified 208 patients in which the mutational status of RAS, BRAF, PIK3CA and TP53 was determined. PIK3CA mutations were detected in 14 (6.7%) and TP53 mutations in 152 (73.1%) patients. PIK3CA mutations were associated with N0 (P=0.006). Mutant TP53 tumors compared with wild-type tumors were associated with: absence of personal history of cancer (4.8% vs. 93.3%, P=0.007), ulcerated histopathological type (62.5% vs. 18.3%, P=0.04), moderate degree of differentiation (63.5% vs. 19.2%, P=0.01) and exon 2 KRAS mutations (34.6% vs. 4.8%, P=0.006). Comparing the results in our study group with data from literature, PIK3CA and TP53 mutations had a similar prevalence. This study completes the few data that exists in metastatic colorectal cancer regarding the clinical, pathological and molecular features of PIK3CA and TP53 mutations with a Northeast Romanian cohort of subjects.