Abstract: Background and purpose: CD44 is a biomarker for many human malignant tumors, and the expression level of CD44 might be associated with malignancy of cancers. Thus, in the current study, we investigated the association between single nucleotide polymorphisms (SNP) in CD44 gene and cervical cancer and non-small cell lung cancer (NSCLC) in a Yunnan Han population. Methods: For cervical cancer, 497 patients and 500 healthy individuals were recruited. For NSCLC, 483 patients and 471 healthy individuals were recruited. Two SNP in CD44 gene (rs13347, rs8193) were genotyped using TaqMan assay. And the association between the two SNP and the tumors was analyzed. Results: For cervical cancer, the allelic and genotypic frequencies of rs13347 and rs8193 were not significantly different between patients with cervical cancer and control groups (P>0.05). For NSCLC, the allelic frequencies of rs13347 and rs8193 were significantly different between NSCLC and control groups (P=0.020 and P=0.004). The C allele of rs13347 occurred more frequently in NSCLC group than in control group and might be the risk factor for NSCLC (OR=1.250, 95% CI: 1.035-1.509). The C allele of rs8193 occurred significantly more frequently in control group compared with NSCLC group, and might be a protective factor for NSCLC (OR=0.768, 95% CI: 0.641-0.921). The genotypic frequencies of rs13347 and rs8193 were significantly different between NSCLC and control groups (P=0.027 and P=0.020). Additionally, the results of haplotype analysis showed that rs13347C-rs8193T haplotype might be associated with higher risk of NSCLC (P=0.003, OR=1.316, 95% CI: 1.096-1.579). Conclusion: The two SNP in the CD44 gene (rs13347, rs8193) might be only associated with the risk of NSCLC, but not cervical cancer in the Yunnan Han population.

Key words: Cervical cancer, Non-small cell lung cancer, Malignant tumor, CD44, Single nucleotide polymorphisms, Genetic susceptibility, Yunnan Han population