Epidermal Growth Factor Receptor and Human Epidermal Growth Factor Receptor 2 Gene Polymorphisms in Endometrial Cancer in a Japanese Population

Abstract

Endometrial cancer is associated with both EGFR and HER2 receptor activation. The EGFR and HER2 genes could be disease susceptibility candidate genes for this cancer. This study was conducted to investigate a possible association between EGFR and HER2 gene polymorphisms and endometrial cancer and the influence of these polymorphisms on the clinical outcome of endometrial cancer patients in a Japanese population. The authors compare the genotype distributions and allele frequencies of the EGFR +2073 A/T and HER2 +655 A/G polymorphisms in 116 endometrial cancer patients and 213 controls using polymerase chain reaction—restriction fragment length polymorphism (RFLP) analysis. RFLP results were confirmed by direct DNA sequencing. Of the 116 patients, 76 (65.5%) could be followed up. Disease-free survival estimates were computed using the Kaplan-Meier method, and differences between survival periods were assessed using the log-rank test. No significant differences were observed in either genotype distributions or allele frequencies in the EGFR +2073 A/T and HER2 +655 A/G polymorphisms between endometrial cancer patients and controls. The stratification by histological types and staging failed to identify significant differences between endometrial cancer patients and controls. No statistical differences were noted between these polymorphisms and disease-free survival (Kaplan-Meier log-rank test P = .55 and .66, for the EGFR +2073 A/T and HER2 +655 A/G, respectively). These results suggest that the EGFR +2073 A/T and HER2 +655 A/G polymorphisms are not associated with endometrial cancer in a Japanese population. These conclusions are based on relatively small numbers and will require verification from additional independent studies.