Genetic Analysis Using a Gene Panel in 87 Caucasian Patients With Colorectal Cancer: Own Results and Review of Literature

Abstract

Background/aim: Colorectal cancer (CRC) is the third most common cancer worldwide. The prognosis between left- and right-sided CRC differs, partly due to baseline differences as vascular supply. The purpose of the present study was to investigate whether there are genetic differences between left- and right-sided CRC.

Patients and methods: Eighty-seven patients with CRC (mean age: 61 years) were retrospectively included in the study. Blood samples were used for genetic analysis, by applying the sequencing research panel Ion AmpliSeq Colon and Lung Cancer Research Panel V2. Statistical analyses included Chi-square tests, Kaplan-Meier survival curves, and univariate/multivariate Cox-regression analyses.

Results: By testing the sequence of 22 genes included in the panel, a significant difference was detected between left- and right-sided CRC regarding the expression of BRAF and DDR2 genes, with mutations occurring more often in the right-sided CRC. In the multivariate setting, left-sided CRC only turned out as a significant positive prognostic parameter regarding progression-free survival, irrespective of the type of chemotherapy or BRAF and NRAS mutations.

Conclusion: Tumour location was the only parameter proven to be an independent prognostic factor for CRC in the present study.

Keywords: BRAF gene; Colorectal cancer; DDR2 gene; genetic analysis; left-sided CRC; prognostic markers; right-sided CRC.