The polymorphisms on Igkappa gene are related to susceptibility of breast cancer and gastric cancer.

The phenomenon of immunoglobulin (Ig) expression in cancer cells has been discovered recently; the Ig protein expressed and secreted in cancer cells was found to be in favor of tumor growth. Two single-nucleotide polymorphism (SNP) loci rs232230 (5658C/G) and rs232228 (3635T/C) were identified on Igkappa gene previously, and we have demonstrated that they were associated with nasopharyngeal carcinoma susceptibility. In the present study, we further performed the study focused on these two SNPs in gastric and breast cancer, trying to demonstrate the association between the genotypes of the two SNPs and the susceptibility of gastric cancer and breast cancer. Our results suggested that the 5658-G allele and 3635-C allele were risk factors for both gastric cancer (odds ratio [OR]: 1.64 and 1.67, respectively) and breast cancer (OR: 1.94 and 1.56, respectively). Further, we also identified that they were related to other risk factors, including Helicobacter pylori (Hp) infection in gastric cancer and age in breast cancer.