MLH1 rs1800734 Pathogenic Variant among Patients with Colorectal Cancer in the Lower Northeastern Region of Thailand.

BACKGROUND: The -93G > A (rs1800734) polymorphism within the core promoter region of MLH1 gene is associated with MLH1 CpG island hypermethylation. This polymorphism has recently been proposed as a low penetrance variant for colorectal cancer. Many published studies have evaluated the association between the MLH1 -93G > A polymorphism and colorectal cancer risk. However, the results remain conflicting rather than conclusive. The aim of this study was to assess the association between the MLH1 -93G > A polymorphism and the risk of colorectal cancer in patients with colorectal cancer in the lower northeastern region of Thailand. METHODS: One hundred fifty one samples from colorectal cancer patients and 100 samples from healthy control group were analyzed. Genomic DNA was extracted from white blood cell of all samples. The real-time polymerase chain reaction (qPCR) was used to demonstrate genetic polymorphism of MLH1 rs1800734. RESULTS: This study demonstrated that the frequency of MLH1 rs1800734 in patients with colorectal cancer was higher than healthy control group. The MLH1 rs1800734 polymorphism variant AA was associated with an increased risk of colorectal cancer (p < 0.05). The MLH1 polymorphism variant AA carriers presented 1.36-folds high risk of colorectal cancer and the alcohol consumption was linked to their likelihood of developing colorectal cancer and their tumor's grade. CONCLUSION: This study showed that MLH1 rs1800734 genotype AA was associated with colorectal cancer risk in the lower northeastern region of Thailand.

ERCC5 rs751402 polymorphism is the risk factor for sporadic breast cancer in Thailand.

Breast cancer is a complex disease. Single Nucleotide Polymorphisms (SNPs) can modify the risk of cancer. They may be regarded as potential markers of carcinogenesis. Currently, the diversity or polymorphism of ERCC5 gene (excision repair cross-complementary group 5 gene or ERCC5) was reported to associate with an increased risk of breast cancer. This study aims to investigate the relationship between ERCC5 polymorphism and the breast cancer risk in the lower northeastern region women of Thailand. One hundred fifty five samples from breast cancer patients and 122 samples from healthy control group were analysed. Genomic DNA was extracted from white blood cell of all samples. The real-time polymerase chain reaction (qPCR) was used to demonstrate genetic polymorphism of ERCC5. The results showed that the ERCC5 rs751402 polymorphism variant AG was associated with an increased risk of breast cancer. The frequency of ERCC5 rs751402 in patients with breast cancer was higher than healthy control group. The ERCC5 rs751402 variant AG carrier was associated with increased breast cancer risk to 2.3 folds, with OR = 2.30, 95% CI = 1.22-4.35, P = 0.01, when age, menopause period, number of child, smoking and alcohol drinking were adjust. This study demonstrated that ERCC5 rs751402 genotype AG was associated with breast cancer risk in the lower northeastern region women of Thailand.

Association between ERCC1 Polymorphism and the Risk and Clinicopathological Features of Breast Cancer in Thai Women in the Lower Northeastern Region

Background: Breast cancer is a major public health problem around the world, including Thailand and it has the highest ranking among female cancer. Currently, the diversity or polymorphism of ERCC1 gene (excision repair cross-complementary group 1 gene or ERCC1) was reported to associate with an increased risk of breast cancer. This study aims to investigate the relationship between ERCC1 polymorphism and the breast cancer risk in the lower northeastern region women of Thailand. Materials and Methods: One hundred fifty one samples from breast cancer patients and 120 samples from healthy control group were analysed. Genomic DNA was extracted from white blood cell of all samples. The real-time polymerase chain reaction (qPCR) was used to demonstrate genetic polymorphism of ERCC1. Results: The results showed that the ERCC1 rs11615 polymorphism variant AG was associated with an increased risk of breast cancer. This study demonstrated that the frequency of ERCC1 rs11615 in patients with breast cancer was higher than healthy control group. The ERCC1 polymorphism variant AG carrier presented 3.53-folds high risk of breast cancer [odds ratio (OR) = 3.53, 95% CI = 1.61-7.74, P = 0.001]. In addition, when age, menopause period, number of child, smoking and alcohol drinking were adjusted, the ERCC1 rs11615 variant AG carrier was associated with increased breast cancer risk to 3.97 folds, with OR = 3.79, 95% CI = 1.62-8.84, P = 0.002. Conclusions: This study showed that ERCC1 rs11615 genotype AG was associated with breast cancer risk in the lower northeastern region women of Thailand.