Purpose: The RAD51 gene plays an important role in homologous strand exchange in DNA repair. Two common single nucleotide polymorphisms in this gene, 135G>C and 172G>T, were associated with altered gene transcription. While 135G>C was already linked to breast and colorectal cancers in certain populations, 172G>T is far less investigated, although sporadic studies showed it could be a prognostic factor for some cancer lesions. The purpose of this study was to investigate RAD51 172G>T polymorphism in Serbian population, its association with colorectal carcinoma, as well as correlation with disease characteristics and response to neoadjuvant chemoradiotherapy.
Methods: The 172G>T polymorphism was evaluated by PCR-RFLP method in blood samples of 209 colorectal cancer patients and 43 healthy subjects who served as controls. The distribution of genotypes was also analyzed in respect to several tumor characteristics in cases where histopathological data were available.
Results: A significant association between the RAD51 172G>T polymoprhism and desmoplastic reaction of colorectal cancer was demonstrated. The 172G allele was found to be significantly more frequent in patients with more intensive desmoplastic response of the tumor tissue.
Conclusions: The results of our study suggest that the 172T allele of RAD51 may be a favorable prognostic factor in Serbian patients with colorectal cancer, although larger prospective studies are required to confirm this finding.