Excision Repair Cross-complementation Group 1 Rs3212986 Research Articles

The Relationship between Single Nucleotide Polymorphism of ERCC1 Gene and the Response to Platinum Based Chemotherapy in Egyptian Non-Small Cell Lung Cancer Patients

Abstract Background Lung cancer (LC) is the second most common cancer diagnosed in both males and females. There are two subtypes of LC. Non-small cell lung cancer (NSCLC) is the major one. Treatment options for NSCLC depends mainly on the stage at diagnosis. The majority of the patients are diagnosed at advanced stages at time of presentation. Therefore, chemotherapy and radiotherapy play the dominant role in treatment of advanced NSCLC. The most commonly used chemotherapy is platinum-based chemotherapy as cisplatin and carboplatin and third generation drugs as vinorelbine and gemcitabine. The efficacy of platinum-based chemotherapy is limited by chemoresistance. The excision repair cross complementation group 1(ERCC1) gene is a member of nucleotide excision repair pathway that plays a critical role in the DNA repair by removing DNA covalent helix-distorting adducts. Aim of the Work In this study investigated the relationship between single nucleotide polymorphism of ERCC1 rs11615 and the response to platinum-based chemotherapy in Egyptian NSCLC patients in order to prevent the non-necessary exposure to the toxic effect of chemotherapy. Patients and Methods This is a cross-sectional study conducted on 50 NSCLC patients who were recruited from the Oncology Clinic in Ain Shams University Hospitals; twenty of them were responders to platinumbased chemotherapy and the other 30 were non-responders according to RECIST criteria. All subjects underwent full medical history focusing on tobacco smoking and family history of cancers, thorough clinical examination, histological diagnosis of NSCLC and TNM classification, radiological studies: computed tomography of chest and abdomen and laboratory investigations in the form of: complete blood picture (CBC), liver function tests and kidney function tests. Detection of the ERCC1 (T/C) polymorphism by realtime PCR was done for both the responders' and the non-responders' groups. Results There was no significant statistical difference observed between the responders’ and nonresponders’ groups regarding the genotype frequencies nor the allelic frequency (p > 0.05). Conclusion The present study did not confirm the presence of significant association between the genotypic frequencies nor the allelic frequencies of the ERCC1 rs 11615 among the responders' and the non-responders' groups. Further studies with higher sample size are needed to clarify the association.

Effect of ERCC1 polymorphisms on the response to platinum-based chemotherapy: A systematic review and meta-analysis based on Asian population.

Platinum-based chemotherapy is one of the most common treatments for many cancers; however, the effect of chemotherapy varies from individual to individual. Excision repair cross complementation group 1 (ERCC1) is widely recognized as a key gene regulating nucleotide excision repair (NER) and is closely associated with platinum response. Many studies have yielded conflicting results regarding whether ERCC1 polymorphisms can affect the response to platinum and overall survival (OS). Therefore, it is necessary to perform a meta-analysis of patients with specific races and cancer types. Eight databases (EMBASE, PubMed, Cochrane Library, Chinese National Knowledge Infrastructure, Scopus, VIP, China Biology Medicine disc and Wanfang databases) were searched. Results were expressed in terms of odds ratios (ORs), hazard ratios (HRs) and 95% CIs. In this study, rs11615, rs2298881 and rs3212986 SNPs were studied. In the comparison between CT and TT on the response to platinum, esophageal cancer [I2 = 0%, OR = 6.18, 95% CI(1.89,20.23), P = 0.003] and ovarian cancer [I2 = 0%, OR = 4.94, 95% CI(2.21,11.04), P<0.001] showed that the rs11615 CT genotype predicted a better response. In the comparison between CC and TT, ovarian cancer [I2 = 48.0%, OR = 6.15, 95% CI (2.56,14.29), P<0.001] indicated that the CC genotype predicted a better response. In the meta-analysis of OS, the CC genotype was related to longer OS than TT in ovarian cancer [TT vs CC: I2 = 57.7%, HR = 1.71, 95% CI (1.18, 2.49), P<0.001]. The ERCC1 rs11615 polymorphism was related to the response to platinum and OS, but the correlation is based on specific cancer types in the Asian population.

Association of ERCC1 and XPF polymorphisms with pediatric glioma susceptibility.

Association of ERCC1 and XPF polymorphisms with pediatric glioma susceptibility.

Association between ERCC1 Gene Polymorphism (rs11615) and Colorectal Cancer Susceptibility: A Meta-Analysis of Medical Image Fusion and Safety Applications.

Colorectal cancer (CRC) is a malignant tumor of the colorectal mucosa epithelial tissue transformed. The fusion of data for medical imaging has become a central issue in such biomedical applications as image-guided surgery and radiotherapy. Currently, CRC has been one of the most threatening tumors affecting people's health worldwide. The excision repair cross-complementation group 1 (ERCC1) is a key enzyme for nucleotide excision repair (NER). Emerging epidemiological studies have indicated that the presence of colorectal cancer (CRC) may be relevant to the ERCC1 rs11615 genetic polymorphism. However, the results of ERCC1 rs11615 on CRC in these studies are controversial. We searched PubMed, Web of Science, Embase, CNKI, and CBM databases for the effects of ERCC1 rs11615 variant on CRC development. There was no meta-analysis focused on the diagnosis of colorectal cancer with ERCC1 rs11615 variant. We creatively carried out a meta-analysis of nine case-control studies and used Stata (version 12.0) software to integrate the pooled odds ratios (ORs) corresponding to a 95% confidence interval (CI) of overall and subgroup analysis. Our results suggest that a significant correlation was observed between rs11615 and the susceptibility of CRC OR 95% CI = 1.13 (1.04-1.23) under an allele genetic model and OR 95% CI = 1.14 (1.01-1.30) under a dominant genetic model for overall CRC. Significant statistical difference was also noted in Asians rather than Caucasians based on the ethnicity subgroups. These results suggested that there is a certain association between rs11615 and the susceptibility of colorectal cancer in the Asian populations.

ERCC1 rs11615 polymorphism increases susceptibility to breast cancer: a meta-analysis of 4547 individuals.

Excision repair cross-complementation group 1 (ERCC1), a DNA repair protein, is vital for maintaining genomic fidelity and integrity. Despite the fact that a mounting body of case–control studies has concentrated on investigating the association of the ERCC1 rs11615 polymorphism and breast cancer risk, there is still no consensus on it. We conducted the current meta-analysis of all eligible articles to reach a much more explicit conclusion on this ambiguous association. A total of seven studies involving 2354 breast cancer cases and 2193 controls were elaborately selected for this analysis from the Embase, EBSCO, PubMed, WanFang, and China National Knowledge Infrastructure (CNKI) databases. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were estimated in our meta-analysis. We found that the ERCC1 rs11615 polymorphism was significantly associated with breast cancer risk under all genetic models. When excluded, the studies that deviated from Hardy–Weinberg equilibrium (HWE), the pooled results of what remained significantly increase the risk of breast cancer under the allele model (OR = 1.14, 95% CI = 1.02–1.27, P=0.02), heterozygote model (OR = 1.24, 95% CI = 1.06–1.44, P=0.007), and dominant model (OR = 1.21, 95% CI = 1.05–1.41, P=0.01). This increased breast cancer risk was found in Asian population as well as under the heterozygote model (OR = 1.24, 95% CI = 1.05–1.48, P=0.013) and dominant model (OR = 1.20, 95% CI = 1.02–1.42, P=0.03). Our results suggest that the ERCC1 rs11615 polymorphism is associated with breast cancer susceptibility, and in particular, this increased risk of breast cancer existence in Asian population.

Association between common polymorphisms in ERCC gene and prognosis of osteosarcoma in patients treated with chemotherapy: a meta-analysis.

PurposeSome previous studies have sought to investigate the roles of excision repair cross complementation group 1 (ERCC1), ERCC2, ERCC4, and ERCC5 gene polymorphisms in the prognosis of osteosarcoma patients. However, their results were inconclusive. Here, we performed a meta-analysis to determine the strength of the association between eight polymorphisms in the ERCC genes (rs11615, rs3212986, rs2298881, rs13181, rs1799793, rs1800067, rs2296147, and rs1047768) and prognosis of osteosarcoma patients treated with chemotherapy.Materials and methodsWe retrieved the relevant studies from PubMed, Embase, and Web of Science in human osteosarcoma published prior to July 2017. Primary outcomes included overall survival (OS) and event-free survival, expressed by hazard ratios (HRs) with their corresponding 95% CIs. STATA software (version 12.0) was utilized to perform data synthesis.ResultsA total of 13 eligible follow-up studies involving 2,303 patients met all the inclusion criteria, conducted in two populations of ethnic descent: 11 Asians and two Caucasians. In the present meta-analysis, we demonstrated that the homozygous variant genotypes in ERCC2 rs1799793 and ERCC5 rs2296147 were significantly associated with OS in osteosarcoma (TT vs GG for rs1799793: HR = 0.62, 95% CI = 0.41–0.93, Pheterogeneity = 0.310, I2 = 15.3%, P = 0.020; TT vs CC for rs2296147: HR = 0.42, 95% CI = 0.23–0.78, Pheterogeneity = 0.708, I2 = 0.0%, P = 0.006). In addition, no evidence of association was observed between prognosis in osteosarcoma and ERCC1 rs11615, ERCC1 rs3212986, ERCC1 rs2298881, ERCC2 rs13181, ERCC4 rs1800067, and ERCC5 rs1047768 polymorphisms.ConclusionOur meta-analysis indicated that TT genotype in the ERCC2 rs1799793 and ERCC5 rs2296147 might prolong the survival time of patients with osteosarcoma, suggesting that the rs1799793 and rs2296147 polymorphisms can be used as predictors for prognosis of osteosarcoma patients treated with chemotherapy.

ERCC1 rs3212986 A/C polymorphism is not associated with chemotherapy treatment outcomes in gastric cancer patients: evidence from 11 publications in Chinese populations.

BackgroundA number of studies have investigated the roles of excision repair cross-complementation group 1 (ERCC1) gene rs3212986 polymorphisms as potential biomarkers in gastric cancer (GC). However, the results were inconsistent. Here, we performed a meta-analysis to explore ERCC1 rs3212986 polymorphisms in the chemotherapy response and clinical outcome of GC.MethodsPubMed, Embase, and Web of Science were searched up to July 28, 2017, for studies on the association between ERCC1 rs3212986 A/C polymorphisms and response to chemotherapy as well as overall survival time of GC. A fixed-effect or random-effect model was used to calculate the pooled odds ratios (ORs) based on the results from the heterogeneity tests.ResultsThe result revealed that there was no significant association between the ERCC1 rs3212986 A/C polymorphism and response to chemotherapy in GC under comparison models (AA + CA versus CC, OR 0.95, P=0.80, AA versus CA, OR 0.85, P=0.55, AA versus CC, OR 0.74, P=0.47). Further identification suggested that ERCC1 rs3212986 A/C polymorphisms were not linked with the overall survival of GC (AA + CA versus CC, OR 1.09, P=0.52, AA versus CA, OR 1.05, P=0.85, AA versus CC, OR 1.43, P=0.23).ConclusionOur meta-analysis indicated that the ERCC1 rs3212986 A/C polymorphism was not associated with response to chemotherapy or overall survival time in GC. Well-designed studies with larger sample sizes and more ethnic groups should be performed to further validate our results.

Meta-analysis showing that ERCC1 polymorphism is predictive of osteosarcoma prognosis.

To investigate correlations between excision repair cross-complementation group 1 (ERCC1) and 2 (ERCC2) polymorphisms and osteosarcoma prognosis, we conducted a meta-analysis of studies published through October 2016. Studies were identified in the PubMed, ScienceDirect, Springer, and Web of Science databases using preferred reporting items for systematic reviews and meta-analyses (PRISMA). Odds ratios (ORs) or hazard ratios (HRs) and their 95% confidence intervals (CIs) for overall survival (OS), tumor response (TR), and event-free survival (EFS) were estimated. Our meta-analysis included eleven studies in which four SNPs (ERCC1 rs11615 and rs3212986, ERCC2 rs13181 and rs1799793) reportedly associated with osteosarcoma prognosis were investigated. Each of these studies scored > 6 on the Newcastle-Ottawa Scale (NOS). We found that only one SNP, ERCC1 rs11615, correlated with improved OS and TR. The HR of T vs. C for OS was 1.455 (T/C, 95% CI = 1.151–1.839, P = 0.002, I2 = 37.80%). The OR of T vs. C for good TR was 0.554 (T/C, 95% CI = 0.437–0.702, P < 0.001, I2 = 0%). Few significant outcome was observed in subgroup analyses stratified based on study characteristics with adjustments for potential confounders. Our results suggest that ERCC1 rs11615 CC is associated with a better clinical outcome. This suggests rs11615 may be a useful genetic marker for predicting osteosarcoma prognosis.

Association between common polymorphisms in ERCC gene and glioma risk: A meta-analysis of 15 studies.

Background:A number of studies have investigated the roles of excision repair cross complementation group 1 (ERCC1), ERCC2, and ERCC5 genes polymorphisms in the development of glioma; however, the results were inconsistent. Here, we performed a meta-analysis to investigate the association between 6 polymorphisms in the ERCC genes (rs3212986, rs11615, rs13181, rs1799793, rs238406, rs17655) and glioma risk.Methods:The PubMed, Embase, and Web of science were searched up to September 6, 2016, for studies on the association between ERCC polymorphisms and glioma risk. A fixed-effects or random-effects model was used to calculate the pooled odds ratios based on the results from the heterogeneity tests. Sensitivity and cumulative meta-analyses were also performed.Results:A total of 15 studies were eligible for the pooled analysis, conducted in 2 populations of ethnic descent: 8 Europeans and 7 Asians. The results showed that ERCC1 rs3212986 polymorphism was positively associated with glioma [AA vs CC: odds ratio (OR) = 1.298, 95% confidence interval (95% CI) = 1.043–1.230, P = .025]. Association of the ERCC2 rs13181 and rs1799793 polymorphisms was only observed in Asians (CC vs AA for rs13181: OR = 1.539, 95% CI = 1.122–2.109, P = .007; AA vs GG for rs1799793: OR = 1.474, 95% CI = 1.090–1.994, P = .012). However, no association was observed between glioma risk and ERCC1 rs11615, ERCC2 rs238406, and ERCC5 rs17655 polymorphisms. Moreover, sensitivity and cumulative meta-analyses confirmed the stability of the results.Conclusions:Our meta-analysis indicated that the ERCC1 rs3212986 polymorphism and 2 polymorphisms in ERCC2 gene (rs13181 and rs1799793) contributed to the susceptibility of glioma.

Genetic Polymorphisms in XRCC1, CD3EAP, PPP1R13L, XPB, XPC, and XPF and the Risk of Chronic Benzene Poisoning in a Chinese Occupational Population.

ObjectivesIndividual variations in the capacity of DNA repair machinery to relieve benzene-induced DNA damage may be the key to developing chronic benzene poisoning (CBP), an increasingly prevalent occupational disease in China. ERCC1 (Excision repair cross complementation group 1) is located on chromosome 19q13.2–3 and participates in the crucial steps of Nucleotide Excision Repair (NER); moreover, we determined that one of its polymorphisms, ERCC1 rs11615, is a biomarker for CBP susceptibility in our previous report. Our aim is to further explore the deeper association between some genetic variations related to ERCC1 polymorphisms and CBP risk.MethodsNine single nucleotide polymorphisms (SNPs) of XRCC1 (X-ray repair cross-complementing 1), CD3EAP (CD3e molecule, epsilon associated protein), PPP1R13L (protein phosphatase 1, regulatory subunit 13 like), XPB (Xeroderma pigmentosum group B), XPC (Xeroderma pigmentosum group C) and XPF (Xeroderma pigmentosum group F) were genotyped by the Snapshot and TaqMan-MGB® probe techniques, in a study involving 102 CBP patients and 204 controls. The potential interactions between these SNPs and lifestyle factors, such as smoking and drinking, were assessed using a stratified analysis.ResultsAn XRCC1 allele, rs25487, was related to a higher risk of CBP (P<0.001) even after stratifying for potential confounders. Carriers of the TT genotype of XRCC1 rs1799782 who were alcohol drinkers (OR = 8.000; 95% CI: 1.316–48.645; P = 0.022), male (OR = 9.333; 95% CI: 1.593–54.672; P = 0.019), and had an exposure of ≤12 years (OR = 2.612; 95% CI: 1.048–6.510; P = 0.035) had an increased risk of CBP. However, the T allele in PPP1R13L rs1005165 (P<0.05) and the GA allele in CD3EAP rs967591 (OR = 0.162; 95% CI: 0039~0.666; P = 0.037) decreased the risk of CBP in men. The haplotype analysis of XRCC1 indicated that XRCC1 rs25487A, rs25489G and rs1799782T (OR = 15.469; 95% CI: 5.536–43.225; P<0.001) were associated with a high risk of CBP.ConclusionsThe findings showed that the rs25487 and rs1799782 polymorphisms of XRCC1 may contribute to an individual’s susceptibility to CBP and may be used as valid biomarkers. Overall, the genes on chromosome 19q13.2–3 may have a special significance in the development of CBP in occupationally exposed Chinese populations.

Systematic review on the association between ERCC1 rs3212986 and ERCC2 rs13181 polymorphisms and glioma risk.

Several studies have examined the association between excision repair cross-complementation group 1 (ERCC1) C8092A and ERCC2 Lys751Gln polymorphisms and glioma risk, but the results have been inconclusive. We conducted a meta-analysis of 12 studies to determine the association between ERCC1 rs3212986 and ERCC2 rs13181 genes and glioma susceptibility. We searched for relevant studies in both Chinese and English in PubMed, Web of Science, Cochrane Library, and EMBASE through January 1, 2014, and identified 3939 cases and 5407 controls. The results showed that individuals carrying the ERCC1 rs3212986 AA genotype had higher risk of glioma compared with the CC genotype, with a pooled odds ratio = 1.29, 95% confidence interval = 1.07-1.55. Subgroup analysis showed that the ERCC1 rs3212986 AA genotype was significantly associated with an increased risk of glioma in the Chinese population (odds ratio = 1.37, 95% confidence interval = 1.07-1.55), but no association in Caucasian Chinese. No significant association was observed between ERCC2 rs13181 polymorphisms and glioma risk. The results of our meta-analysis strongly suggested that the ERCC1 rs3212986 polymorphism was associated with a higher susceptibility to glioma, particularly in the Chinese population. Studies including a larger sample size and more specified information regarding pathological types of glioma are needed to confirm our results.

Associations of polymorphisms in DNA repair genes and MDR1 gene with chemotherapy response and survival of non-small cell lung cancer.

ObjectivesWe aimed to determine the associations of genetic polymorphisms of excision repair cross-complementation group 1 (ERCC1) rs11615, xeroderma pigmentosum group D (XPD/ERCC2) rs13181, X-ray repair cross complementing group 1 (XRCC1) rs25487, XRCC3 rs1799794, and breast cancer susceptibility gene 1 (BRCA1) rs1799966 from the DNA repair pathway and multiple drug resistance 1 (MDR1/ABCB1) rs1045642 with response to chemotherapy and survival of non-small cell lung cancer (NSCLC) in a Chinese population.Materials and MethodsA total of 352 NSCLC patients were enrolled to evaluate the associations of the six SNPs with response to chemotherapy and overall survival. Logistic regressions were applied to test the associations of genetic polymorphisms with response to chemotherapy in 161 advanced NSCLC patients. Overall survival was analyzed in 161 advanced and 156 early stage NSCLC patients using the Kaplan-Meier method with log-rank test, respectively. Multivariate Cox proportional hazards model was performed to determine the factors independently associated with NSCLC prognosis.Results BRCA1 rs1799966 minor allele C (TC+CC vs. TT, OR = 0.402, 95%CI = 0.204−0.794, p = 0.008) and MDR1/ABCB1 rs1045642 minor allele A (GA +AA vs. GG, OR = 0.478, 95%CI = 0.244−0.934, p = 0.030) were associated with a better response to chemotherapy in advanced NSCLC patients. Survival analyses indicated that BRCA1 rs1799966 TC+CC genotypes were associated with a decreased risk of death (HR = 0.617, 95% CI = 0.402−0.948, p = 0.028) in advanced NSCLC patients, and the association was still significant after the adjustment for covariates. Multivariate Cox regression analysis showed that ERCC1 rs11615 AA genotype (P = 0.020) and smoking (p = 0.037) were associated with increased risks of death in early stage NSCLC patients after surgery.ConclusionsPolymorphisms of genes in DNA repair pathway and MDR1 could contribute to chemotherapy response and survival of patients with NSCLC.

Association of single nucleotide polymorphisms of ERCC1 and XPF with colorectal cancer risk and interaction with tobacco use.

We investigated the association between polymorphisms in excision repair cross-complementation group 1 (ERCC1) (rs3212986, rs2298881 and rs11615) and xeroderma pigmentosum-complementation group F (XPF) (rs2276466 and rs6498486) and risk of colorectal cancer. A 1:1 matched case-control study was conducted. Conditional regression analysis indicated that individuals carrying the ERCC1 rs3212986 TT genotype and T allele had a marginally increased risk of colorectal cancer when compared with subjects with the GG genotype. Similarly, subjects carrying the rs11615 TT genotype and T allele had a marginally increased risk of colorectal cancer when compared with those with the CC genotype. Stratified analysis revealed that individuals with rs3212986 TT who were current or former smokers had a significantly increased risk of colorectal cancer, and a significant interaction was found between this SNP and cigarette smoking. In conclusion, our study suggests that rs3212986 and rs11615 polymorphisms are associated with risk of colorectal cancer in a Chinese population, particularly in smokers. This finding could be useful in revealing the genetic characteristics of colorectal cancer, and suggests more effective strategies for prevention and treatment.

Effect of ERCC1 polymorphism on the response to chemotherapy and clinical outcome of non-small cell lung cancer.

We conducted a cohort study to investigate the role of 3 single-nucleotide polymorphisms of the excision repair cross-complementation group 1 (ERCC1) gene on the response to chemotherapy and clinical outcomes of non-small cell lung cancer (NSCLC). A total of 163 patients with newly diagnosed and histopathologically confirmed primary NSCLC were examined in our study and were followed up until December 2012. ERCC1 rs11615, rs3212986, and rs2298881 were selected and genotyped. Of the 163 patients, 86 patients showed a complete response and partial response to chemotherapy (52.76%), while 91 patients (55.83%) died from NSCLC during the follow-up period with a median survival time of 19.3 months (range, 2-60 months). Multivariate regression analysis showed that individuals carrying the rs11615 TT genotype and T allele had a significantly lower response rate to chemotherapy using the rs11615 CC genotype as the reference. For rs3212986, carriers of the rs3212986 AA genotype and A allele had a significantly lower response rate to chemotherapy when compared with the CC genotype. In the Cox proportional hazards model, patients carrying the rs11615 TT genotype and T allele and the rs3212986 AA genotype and A allele were significantly associated with increased risk of death from NSCLC. We found that polymorphisms in ERCC1 rs11615 and rs3212986 were associated with poor response to chemotherapy and shorter survival time of advanced NSCLC.

Role of ERCC1 variants in response to chemotherapy and clinical outcome of advanced non-small cell lung cancer

Excision repair cross-complementation group 1 (ERCC1) and xeroderma pigmentosum-F (XPF) in the nucleotide excision repair pathway have been effectively repairing DNA damage induced by chemotherapeutic agents. We conducted a cohort study to assess the associations of ERCC1 and XPF polymorphisms with response to platinum-based chemotherapy and clinical outcome of non-small-cell lung cancer (NSCLC). One hundred eighty-seven NSCLC cases treated with platinum-based chemotherapy were prospectively analyzed. The predictive value of four SNPs in ERCC1 and two SNPs in XPF in patient's response and survival related to platinum-based chemotherapy were analyzed using χ(2) tests, Kaplan-Meier method, log-rank test, and Cox proportional hazards regression. The overall chemotherapy response rate for treatment was 51.18%. One hundred eighty-seven patients were followed up, and the median survival time is 17.6 months (ranged from 1 to 50 months). A total of 106 patients (56.68%) died from NSCLC during the follow-up period. Carriers of the rs3212986 AA and A allele had a borderline significantly lower response rate to the chemotherapy. In the Cox proportional hazards model, patients carrying the ERCC1 rs3212986 AA genotype were significantly associated with increased risk of death from NSCLC when compared with those with CC genotype as a reference variable. This study reported that variants in ERCC1 can be used as a prognostic maker to platinum-based chemotherapy in NSCLC patients.

CYP2A6 and ERCC1 polymorphisms correlate with efficacy of S-1 plus cisplatin in metastatic gastric cancer patients

Background:We evaluated the association between polymorphisms of cytochrome P450 2A6 (CYP2A6)/excision repair cross-complementation group 1 (ERCC1)/X-ray repair cross-complementing group 1(XRCC1) and treatment outcomes of metastatic gastric cancer (MGC) patients treated with S-1/cisplatin.Methods:Among MGC patients (n=108), who received S-1 (40 mg m−2 b.i.d., days 1–14) and cisplatin (60 mg m−2, day 1) every 3 weeks, we analysed the wild-type allele (W) and variants (V) of CYP2A6 (*4, *7, *9, *10), and the polymorphisms of ERCC1 (rs11615, rs3212986) and XRCC1 (rs25487).Results:Patients having fewer CYP2A6 variants had better response rates (W/W vs W/V other than *1/*4 vs V/V or *1/*4=66.7 vs 58.3 vs 32.3% P=0.008), time to progression (TTP) (7.2 vs 6.1 vs 3.5 months, P=0.021), and overall survival (23.2 vs 15.4 vs 12.0 months, P=0.004). ERCC1 19442C>A (rs3212986) was also associated with response rate (C/C, 46.7% vs C/A, 55.3% vs A/A, 87.5%) (P=0.048) and TTP (4.4 vs 7.6 vs 7.9 months) (P=0.012). Patients carrying both risk genotypes of CYP2A6 (V/V or 1/*4) and ERCC1 19442C>A (C/C) vs those carrying none showed an adjusted odds ratio of 0.113 (P=0.004) for response, and adjusted hazard ratios of 3.748 (P=0.0001) for TTP and 2.961 (P=0.006) for death.Conclusion:Polymorphisms of CYP2A6 and ERCC1 19442C>A correlated with the efficacy of S-1/cisplatin.