Abstract
Gastric cancer is the most common cancer and the most frequent cause of cancer death worldwide. Several studies have identified the role of thymidylate synthase (TS) 5′- and 3′-UTR and gastric cancer susceptibility; however, the results still remain inconclusive. The purpose of this meta-analysis was to reinvestigate this correlation. In the present study, online databases were searched to retrieve relevant articles published between January 2000 and 2016. The odds ratio (OR) and 95% confidence interval (CI) were employed to calculate the strength of association. Overall, a total of 13 articles were screened out, including 2382 gastric cancer patients and 3171 healthy controls. We found that polymorphisms of TS 5′-UTR 2R (double repeats)/3R (triple repeats) of a 28-bp sequence (11 articles) and 3′-UTR del6/ins6 (seven articles) were not significantly associated with increased risk of gastric cancer. Subgroup analysis by ethnicity showed that 2R allele and 2R/2R genotype in TS 5′-UTR were associated with gastric cancer susceptibility in Caucasian and African populations; del6 allele, del6/del6 and del6/ins6 genotypes were correlated with gastric cancer in Caucasian population. In conclusion, our result suggested that TS polymorphisms might be the risk factors for gastric cancer risk in Caucasian population, although this association needs further study, and future large-scale researches are still required.
Highlights
Gastric cancer is a disease in which malignant cells develop from the lining of the stomach [1].It remains a major health problem worldwide, and may spread from the stomach to other parts of the body, the liver, lung, bone, lining of the abdomen and lymph nodes [2,3]
Nine case-control studies were from Asian population, three studies were from Caucasian population, whereas only one study was from African population
Our result detected that 2R of thymidylate synthase (TS) 5 -untranslated enhanced region contributed to gastric cancer risk in non-Asian population under the allelic model (2R compared with 3R: odds ratio (OR) = 0.66, 95% confidence interval (CI) = 0.51–0.85, P = 0.001), homozygote model
Summary
Gastric cancer (or stomach cancer) is a disease in which malignant (cancer) cells develop from the lining of the stomach [1]. It remains a major health problem worldwide, and may spread from the stomach to other parts of the body, the liver, lung, bone, lining of the abdomen and lymph nodes [2,3]. Treatment of advanced gastric cancer is controversial and there is no standard regimen for first- or second-line chemotherapy (CT) [13]. Detection of this disease in its early stage is helpful to improve the treatment outcome.
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