COMT GENE POLYMORPHISM AND RADIATION REACTIONS OF NORMAL TISSUE IN BREAST CANCER PATIENTS
Introduction. The COMT gene encodes for a protein involved in deactivation of genotoxic estrogen species, and the protein product
encoded by the L (low activity) allele is 3–5-fold less active than its counterpart encoded by the H (high activity) allele.
The aim of the study. The study was designed to compare the severity of normal tissue reactions to radiation therapy in breast cancer
patients with different genotypes at the polymorphic site COMT*H/L.
Methods. The study group included 92 breast cancer patients, who received radiation therapy; total local doses were 50–60 Gy. Tissue
reactions were classified as three groups, namely expressed, moderate, and no reaction. Genotypes at the polymorphic site were determined
by PCR-RFLP technique.
Results. It was found that individual ray reaction was associated with the L allele frequency: 0,46 in patients without ray reactions, 0,52
– in patients with moderate reactions, and 0,64 – in patients with expressed ray reactions of normal tissues (p
Keywords:
breast cancer, radiation therapy, COMT gene, radiation reactions