Expression profiles of MGMT, p16, and APC genes in tumor and matching surgical margin from patients with oral squamous cell carcinoma

The aim of the study was to assess the expression of MGMT, p16, and APC genes in tumors and matching surgical margin samples from 56 patients with primary OSCC. We also analyzed the association of the clinical variables with the expression of the studied genes. After RNA isolation and cDNA synthesis gene expression levels were assessed by quantitative reverse transcription (qRT)-PCR. Two-sided parametrical Student's t-test for independent groups with equal/unequal variances showed no statistically significant differences in genes' expression in tumor compared to margin samples. No association was found between the genes' expression and clinical parameters, except for MGMT, whose low expression was probably associated with smoking (0.87 vs 1.34, p=0.065). 'Field cancerization' is an area with genetically or epigenetically altered cells and at the same time a risk factor for cancer. Disturbances in gene expression could also be the source of damages leading to cancerization. In conclusion, it is important to mention that the field remaining after a surgery may pose an increased risk of cancer development. It may be suggested that the diagnosis and treatment of cancers should not be concentrated only on the tumor itself, but also on the cancer field effect. Therefore, further molecular analysis on surgical margins and additional research regarding their assessment are required.