Genetic polymorphism of GSTP1 and ERCC1 correlated with response to platinum-based chemotherapy in non-small cell lung cancer

Multi-index comprehensive evaluation of the efficacy and response mechanism of immunotherapy in non-small cell lung cancer

OBJECTIVE

This research conducted multi-index comprehensive evaluations of the immunotherapeutic efficacy and response in non-small cell lung cancer (NSCLC).

METHODS

Forty-five patients with epidermal growth factor receptor (EGFR)/anaplastic lymphoma kinase (ALK) wild-type advanced NSCLC who received immunotherapy were included. Immunohistochemistry was adopted to detect the expression levels of programmed death ligand 1 (PD-L1) with X-ray cross-complementing protein 1 (XRCC1) and excision repair cross-complementing group 1 (ERCC1) proteins in tumor tissues. Flow cytometry was utilized to measure the levels of T-cell subsets in peripheral blood before and after treatment. PCR-RELP method was employed to evaluate XRCC1 and ERCC1 gene polymorphisms in peripheral blood. According to the treatment effect, patients evaluated as complete response (CR), partial response (PR), and stable disease (SD) were categorized into the immune response group, and patients evaluated as progressive disease (PD) were categorized into the immune unresponsive group. The correlation between PD-L1 protein expression, XRCC1 and ERCC1 protein expression, gene polymorphisms, T-cell subpopulation levels, and treatment efficacy was analyzed.

RESULTS

The therapeutic efficacy of patients with positive PD-L1 expression was better than that of patients with negative PD-L1 expression (P < 0.05). After treatment, peripheral blood CD3+ and CD4+ cell levels and Thl/Th2 cell levels were higher and CD8+ T cells were lower in the immune response group than in the immune unresponsive group (P < 0.05). Among the patients in the immune response group, peripheral blood CD3+ and CD4+ cell levels were higher and CD8+ T cells were lower in patients with positive PD-L1 expression than in patients with negative PD-L1 expression (P < 0.05). In the XRCC1 gene, the proportion of patients in the immune response group carrying the Arg/Trp + Trp/Trp genotype was higher than that of patients in the immune unresponsive group (P < 0.05). In the ERCC1 gene, the proportion of patients in the immune response group carrying the C/T + T/T genotype was higher than that of patients in the immune unresponsive group (P < 0.05). The positive expression rates of XRCC1 and ERCC1 in patients in the immune unresponsive group were higher than those in the immune response group (P < 0.05).

CONCLUSION

PD-L1 protein expression, XRCC1 and ERCC1 protein expression, and gene polymorphisms are associated with immunotherapy outcome in EGFR/ALK wild-type advanced NSCLC patients, and may be biological indicators for predicting immunotherapy outcome in EGFR/ALK wild-type advanced NSCLC patients.

Genetic polymorphisms as potential pharmacogenetic biomarkers for platinum-based chemotherapy in non-small cell lung cancer

Platinum-based chemotherapy (PBC) is a widely used treatment for various solid tumors, including non-small cell lung cancer (NSCLC). However, its efficacy is often compromised by the emergence of drug resistance in patients. There is growing evidence that genetic variations may influence the susceptibility of NSCLC patients to develop resistance to PBC. Here, we provide a comprehensive overview of the mechanisms underlying platinum drug resistance and highlight the important role that genetic polymorphisms play in this process. This paper discussed the genetic variants that regulate DNA repair, cellular movement, drug transport, metabolic processing, and immune response, with a focus on their effects on response to PBC. The potential applications of these genetic polymorphisms as predictive indicators in clinical practice are explored, as are the challenges associated with their implementation.

Predictive role of polymorphic variants of phase II drug metabolising enzyme in modulating toxicity in North Indian lung cancer patients undergoing chemotherapy

Genetic polymorphism of drug-metabolizing enzymes such as NQO1, SULT1A1, EPHX1, and NAT2 alters its activity which hampers the detoxification and disposal of chemotherapeutic compounds. Thus, in the present study, we have comprehensively investigated the associations between SNPs of the Phase II detoxifying genes and its relationship towards platinum-induced toxicity of lung cancer patients.A total of 273 samples were enrolled in this study and polymorphisms of gene NQO1 (609C > T), SULT1A1 (Arg²¹³ His), EPHX1 (Tyr¹¹³His, His¹³⁹Arg), and NAT2 (481C > T, 803A > G, 590 G > A, 857 G > A) were evaluated in our study for their associated adverse events caused due to the administration of platinum-based chemotherapy to the lung cancer patients.For NQO1 609C > T polymorphism, the TT genotype showed reduced risk of constipation (OR =0.10, p=0.04) and anorexia (OR =0.15, p=0.03). For SULT1A1 Arg²¹³His, heterozygous genotype (Arg/His) (AOR =0.38, p=0.006) and combined genotype (Arg/His + His/His) were not associated with increased risk of nephrotoxicity (AOR =0.38, p= 0.004). For NAT2, heterozygous (NAT2*4/*6) and combined genotypes (NAT2*4/*4 + *4/*6) for NAT2*6 polymorphism exhibit 2.4 folds (p=0.005), and two-folds (p=0.01) increased risk of hematological toxicity. The heterozygous (AOR =0.45, p=0.004) and variant genotype (AOR =0.39, p=0.02) for NAT2*5C had decreased risk for hematological toxicity. The heterozygous genotype for NAT2*7 polymorphism showed two-fold increased risk for developing thrombocytopenia.This study provides association of NAT2 polymorphic variants in predicting haematological toxicity.

Influence of GSTP1 Polymorphism on the Clinical Outcomes of Patients With Advanced NSCLC Receiving First-Line Bevacizumab-Based Regimen: A Real-World Retrospective Study

Background:

This study was to investigate the influence of GSTP1 gene polymorphism on the clinical outcomes of patients with advanced non-small-cell lung cancer (NSCLC) receiving first-line bevacizumab plus chemotherapy regimen.

Methods:

A total of 128 patients with advanced NSCLC who were administered with bevacizumab-based first-line regimens were recruited in this study. Available blood specimen and peripheral blood mononuclear cells (PBMCs) of the patients were obtained for the analysis of polymorphism and GSTP1 gene mRNA expression, respectively. The association between genotype status and clinical outcomes and other variates was analyzed and presented.

Results:

The prevalence of rs1695 were in accordance with Hardy-Weinberg Equilibrium (P = .978). Patients with GG and AG genotypes were merged in a pattern of dominant inheritance to seek for the potentially clinical significance. Analysis of efficacy exhibited that the objective response rate (ORR) of patients with AA genotype and AG/GG genotypes were 62.1% (54/87) and 51.2% (21/41) (P = 0.245). Prognosis demonstrated that the median progression-free survival (PFS) of patients with AA genotype and AG/GG genotypes were 9.5 and 5.6 months, respectively (P = .007). Furthermore, the median overall survival (OS) of the two genotypes were 22.0 and 16.6 months, respectively (P = .003). In addition, adjusted in multivariate Cox analysis for OS, AG/GG genotype was an independent factor for OS. Interestingly, mRNA analysis suggested that the mRNA expression of GSTP1 in PBMC of the patients with AG/GG genotypes of rs1695 polymorphism was significantly higher than those of patients with AA genotype (P < .001).

Conclusion:

GSTP1 polymorphism rs1695 could be used for the prognostic evaluation of patients with advanced NSCLC receiving bevacizumab combined chemotherapy regimen.

Influence of GSTP-1 Polymorphism on the Prognosis of Patients with High-Grade Glioma Who Received Temozolomide Plus Radiotherapy Adjuvant Treatment

Background

Glutathione S-Transferase P 1 (GSTP-1) gene plays an important physiological role in the body. The present study was conducted to identify the clinical implication of GSTP-1 gene polymorphism on the prognosis of patients with high-grade glioma (HGG) who received temozolomide plus radiotherapy adjuvant treatment.

Methods

This study recruited a total of 186 patients with HGG who were treated with temozolomide plus radiotherapy adjuvant regimen (retrospectively). Baseline clinical characteristics were obtained and the prognostic data of the patients were collected. Peripheral blood specimen of patients was preserved for genotyping of GSTP-1 polymorphism during hospitalization. Correlation analysis was carried out accordingly. Additionally, fresh peripheral blood specimens that were available for mRNA expression analysis were collected for the mRNA expression analysis.

Results

The median progression-free survival (PFS) and overall survival (OS) of the 186 patients with HGG who received temozolomide plus radiotherapy regimen was 8.5 months (95% CI: 5.95–11.05) and 15.5 months (95% CI: 11.49–19.51), respectively. The prevalence of 313A>G among 186 patients with glioma was AA genotype: 126 cases (67.7%), AG genotype: 54 cases (29.1%), GG genotype: 6 cases (3.2%), minor allele frequency of 313A>G was 0.18. Association analysis suggested that the median PFS of patients with AA and AG/GG genotypes was 11.2 and 5.0 months, respectively (χ²=11.17, P=0.001). Furthermore, the median OS of patients with AA and AG/GG genotypes was 18.9 and 10.5 months, respectively (χ²=12.684, P<0.001). Besides, when adjusted for PFS in multivariate Cox regression analysis, AG/GG genotype was an independent factor for PFS (HR=0.48, P=0.006). The mRNA expression results indicated that mRNA expression of GSTP-1 in patients with AG/GG genotypes of 313A>G was significantly higher than that of patients with AA genotype (P<0.001).

Conclusion

GSTP-1 polymorphism 313A>G might be used as a potential biomarker to predict the prognosis of patients with HGG who received temozolomide plus radiotherapy adjuvant treatment.

GSTP1 Ile105Val polymorphism among North Indian lung cancer patients treated using monotherapy and poly-pharmacy

BACKGROUND

Genetic polymorphism within the P1 isoenzyme of the Glutathione-S-Transferase (GST) family is found to modulate and alter the enzyme activity of GSTP1 protein and thus may result in a change of sensitivity to platinum-based chemotherapy. We investigated the relationship between GSTP1 Ile¹⁰⁵Val polymorphisms and overall survival, treatment response, and for both hematological and non-hematological toxicity of advanced North Indian lung cancer patients undergoing platinum-based double chemotherapy.

METHODS

The polymorphism of GSTP1 Ile¹⁰⁵Val in North Indian lung cancer patients was assessed by polymerase chain reaction-restriction fragment length polymorphism. A total of 682 lung cancer patients were enrolled in the study, and it was observed that patients who were carrying both the mutant alleles (Val/Val) for the GSTP1 polymorphism showed a higher trend of median survival time (MST) as compared to the patients bearing the wild type of genotype (Ile/Ile) (MST = 8.30 vs. 7.47, p = 0.56). Based on toxicity profiling, we observed that lung cancer patients with the mutant genotype of GSTP1 (Val/Val) had an increased risk of leukopenia (OR = 2.41; 95% CI = 1.39-4.18, p = 0.001) as compared to subjects carrying both copies of the wild alleles (Ile/Ile). Our data suggested that patients with heterozygous genotype (Ile/Val) had a 2.14-fold increased risk of developing severe anemia (OR = 2.14, 95% CI = 0.97-4.62, p = 0.03). Our data also showed that in small cell lung carcinoma (SCLC) patients' polymorphism of GSTP1 was associated with thrombocytopenia (χ2 test = 7.32, p = 0.02).

CONCLUSIONS

Our results suggest that GSTP1 Ile¹⁰⁵Val polymorphism could be a predictive biomarker for hematological toxicity, like leukopenia and anemia, but not thrombocytopenia or neutropenia.

Expression and Genetic Polymorphisms of ERCC1 in Chinese Han Patients with Oral Squamous Cell Carcinoma

The aim of this study was to investigate the expression of the excision repair cross-complementation group 1 (ERCC1) in oral squamous cell carcinoma (OSCC) and the possible association of ERCC1 polymorphisms with susceptibility and response to chemotherapy of OSCC in a Chinese Han population. The expression of ERCC1 was determined by real-time PCR in eight patients. Four single-nucleotide polymorphisms (SNPs) rs11615, rs3212948, rs3212961, and rs735482 of ERCC1 were genotyped in 113 OSCC patients and 184 healthy controls using a PCR restriction matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) assay. We found that a higher gene expression of ERCC1 was observed in tumor tissue as compared to pericarcinomatous tissue in OSCC patients. All genotypic and allelic frequencies of the tested ERCC1 polymorphisms were in Hardy-Weinberg equilibrium. The genotypic and allelic frequencies of rs11615, rs3212948, rs3212961, and rs735482 of ERCC1 were not different between OSCC patients and controls. No correlation was observed between ERCC1 polymorphisms and the response to chemotherapy. Our results show that ERCC1 is increased in the tumor tissue of OSCC patients. The investigated ERCC1 gene polymorphisms (rs11615, rs3212948, rs3212961, and rs735482) are not associated with the susceptibility and response to chemotherapy of OSCC in our investigated Chinese Han population.

Genetic Variations and Cisplatin Nephrotoxicity: A Systematic Review

Background: Nephrotoxicity is a notable adverse effect in cisplatin treated patients characterized by tubular injury and/or increased serum creatinine (SCr) with incidence varying from 20 to 70%. Pharmacogenomics has been shown to identify strongly predictive genetic markers to help determine which patients are more likely to experience, for example, a serious adverse drug reaction or receive optimal benefit through enhanced efficacy. Genetic variations have been reported to influence the risk of cisplatin nephrotoxicity; however, a comprehensive overview is lacking. Methods: A systematic review was performed using Pubmed, Embase and Web of Science on clinical studies that used cisplatin-based chemotherapy as treatment, had available genotyping data, and evaluated nephrotoxicity as an outcome. The quality of reporting was assessed using the STrengthening the REporting of Genetic Association Studies (STREGA) checklist. Results: Twenty-eight eligible studies were included; all were candidate gene studies. Over 300 SNPs across 135 genes were studied; 29 SNPs in 14 genes were significantly associated with cisplatin-induced nephrotoxicity. A variation in SLC22A2 rs316019, a gene involved in platinum uptake by the kidney, was associated with different measures of nephrotoxicity in four independent studies. Further, variants of ERCC1 (rs11615 and rs3212986) and ERCC2 (rs13181), two genes involved in DNA repair, were found to be positively associated with increased risks of nephrotoxicity in two independent studies. Conclusion: Three genes consistently associated with cisplatin-induced nephrotoxicity. Further research is needed to assess the biological mechanism and the clinical value of modifying treatment based on SLCC22A2 and ERCC1/2 genotypes.

Pharmacogenomics of platinum-based chemotherapy response in NSCLC: a genotyping study and a pooled analysis

Published data showed inconsistent results about associations of extensively studied polymorphisms with platinum-based chemotherapy response. Our study aimed to provide reliable conclusions of these associations by detecting genotypes of the SNPs in a larger sample size and summarizing a comprehensive pooled analysis. 13 SNPs in 8 genes were genotyped in 1024 NSCLC patients by SequenomMassARRAY. 39 published studies and our study were included in meta-analysis. Patients with GA or GG genotypes of XRCC1 G1196 had better response than AA genotype carriers (Genotyping study: OR = 0.72, 95%CI: 0.53-0.96, P = 0.028; Meta-analysis: OR = 0.74, 95%CI: 0.62-0.89, P = 0.001). Patients carrying CT or TT genotypes of XRCC1 C580T could be more sensitive to platinum-based chemotherapy compared to patients with CC genotype (OR = 0.54, 95%CI: 0.37-0.80, P = 0.002). CC genotype of XRCC3 C18067T carriers showed more resistance to platinum-based chemotherapy when compared to those with CT or TT genotypes (OR = 0.69, 95%CI: 0.52-0.91, P = 0.009). Our study indicated that XRCC1 G1196A/C580T and XRCC3 C18067T should be paid attention for personalized platinum-based chemotherapy in NSCLC patients.

Pharmacogenetics of platinum-based chemotherapy in non-small cell lung cancer: predictive validity of polymorphisms of ERCC1

INTRODUCTION

The efficacy of platinum-based chemotherapy for patients with non-small cell lung cancer (NSCLC) is limited by chemoresistance. Platinum drugs damage DNA by introducing intrastrand and interstrand crosslinks which result in cell death. Excision repair cross-complementing 1 (ERCC1) is a member of the nucleotide excision repair (NER) pathway which erases such defects. Single nucleotide polymorphisms (SNPs) in ERCC1 impair this activity and have been suggested to predict the response to chemotherapy. Area covered: Among the polymorphisms of proteins involved in uptake, metabolism, cytotoxicity and efflux of platinum drugs, codon 118 C/T and C8092A in ERCC1 are the best characterized SNPs studied for their predictive power. Here, the divergent results for studies of these markers in NSCLC are summarized and the reasons for this contradictory data discussed. Expert opinion: Cytotoxicity of platinum compounds comprise complex cellular processes for which DNA repair may not constitute the rate limiting step. These drugs are administered as doublets to histologically diverse patients and, furthermore, the NER pathway in ERCC1 wildtype cohorts may be still impaired by the chemotherapeutics applied. At present, assessment of a limited number of polymorphism in DNA repair proteins is not reliably associated with response to treatment in NSCLC patients.

Genetic Polymorphisms and Platinum-based Chemotherapy Treatment Outcomes in Patients with Non-Small Cell Lung Cancer: A Genetic Epidemiology Study Based Meta-analysis

Data regarding genetic polymorphisms and platinum-based chemotherapy (PBC) treatment outcomes in patients with NSCLC are published at a growing pace, but the results are inconsistent. This meta-analysis integrated eligible candidate genes to better evaluate the pharmacogenetics of PBC in NSCLC patients. Relevant studies were retrieved from PubMed, Chinese National Knowledge Infrastructure and WANFANG databases. A total of 111 articles comprising 18,196 subjects were included for this study. The associations of genetic polymorphisms with treatment outcomes of PBC including overall response rate (ORR), overall survival (OS) and progression-free survival (PFS) were determined by analyzing the relative risk (RR), hazard ration (HR), corresponding 95% confidence interval (CI). Eleven polymorphisms in 9 genes, including ERCC1 rs11615 (OS), rs3212986 (ORR), XPA rs1800975 (ORR), XPD rs1052555 (OS, PFS), rs13181 (OS, PFS), XPG rs2296147 (OS), XRCC1 rs1799782 (ORR), XRCC3 rs861539 (ORR), GSTP1 rs1695 (ORR), MTHFR rs1801133 (ORR) and MDR1 rs1045642 (ORR), were found significantly associated with PBC treatment outcomes. These variants were mainly involved in DNA repair (EXCC1, XPA, XPD, XPG, XRCC1 and XRCC3), drug influx and efflux (MDR1), metabolism and detoxification (GSTP1) and DNA synthesis (MTHFR), and might be considered as potential prognostic biomarkers for assessing objective response and progression risk in NSCLC patients receiving platinum-based regimens.

Predictive assessment in pharmacogenetics of Glutathione S-transferases genes on efficacy of platinum-based chemotherapy in non-small cell lung cancer patients

The influences of glutathione s-transferase P1, M1, and T1 variants on the efficacy of platinum-based chemotherapy in non-small cell lung cancer (NSCLC) patients were inconsistent in previous studies. Our meta-analysis enrolled 31 publications including 5712 patients and provided more convincing and reliable conclusions. Results showed that GSTP1 IIe105Val IIe/Val and Val/Val Asian patients were more likely to have better response rates compared to IIe/IIe patients (odds ratio (OR) = 1.592, 95% confidence intervals (CIs), 1.087-2.332, P = 0.017). The Asian patients bearing the favorable GSTM1 null genotype were more likely to have better response rates to platinum-based chemotherapy compared to those patients with the unfavorable GSTM1 present genotype (OR = 1.493 (1.192-1.870), P < 0.001). Caucasian lung cancer patients bearing GSTT1 null genotype might be more closely associated with shorter survival time and higher risks of death than the GSTT1 present patients (hazard ratio (HR) = 1.423, CI = 1.084-1.869, P = 0.011). Our meta-analysis suggested that the GSTP1 IIe105Val, GSTM1 and GSTT1 null variants might be predictive factors for the efficacy of platinum-based chemotherapy to NSCLC patients. The use of GSTP1 IIe105Val, GSTM1 and GSTT1 null polymorphisms as predictive factors of efficacy of personalized platinum-based chemotherapy to NSCLC patients requires further verification with multi-center, multi-ethnic and large-sample-size pharmacogenetic studies.

Prevalence of CTR1 and ERCC1 Polymorphisms and Response of Biliary Tract Cancer to Gemcitabine-Platinum Chemotherapy

Purpose:

Biliary tract cancer (BTC)is an aggressive disease with a poor prognosis. Most patients are diagnosed at an advanced stage for which curative surgery is not possible and gemcitabine-platinum chemotherapy is the treatment of choice for advanced cases. Several studies had focused on biomarkers to predict response from platinum drugs in lung cancer, but information is limited for BTC. In this study, two single nucleotide polymorphisms (SNPs) in the copper transporter (CTR1) and excision repair cross-complementary group 1 (ERCC1) genes were investigated as predictive biomarkers of objective response to gemcitabine-platinum.

Methods:

This cohort study aimed to assess any associations of genetic polymorphisms of these proteins active in drug pathway with treatment response in advanced BTC patients. Twenty six patients were enrolled. DNA was extracted from peripheral blood and genetic polymorphisms were assessed by Taqman allelic discrimination assay. Response was evaluated according to RECIST version 1.1. Results: For the CTR1 polymorphism, GT was the most common genotype (61.5%) followed by GG (34.6%), and TT (3.8%). For the ERCC1 polymorphism, only 2 genotypes were found, CC and CT at 57.7% and 42.3%, respectively. Genetic polymorphisms were not found to be singly associated with response. However, when the 2 genetic polymorphisms were combined, GG/CC showed a higher response rate than the others (p=0.018, Fisher’s Exact Test).

Conclusion:

This is the first study to show an association between CTR1 and ERCC1 polymorphisms and response to gemcitabine-platinum in advanced BTC patients. These polymorphisms might be used as biomarkers to predict response in such cases in the future.

Pharmacogenomics of platinum-based chemotherapy sensitivity in NSCLC: toward precision medicine

Lung cancer is one of the leading causes of cancer-related death in the world. Platinum-based chemotherapy is the first-line treatment for non-small-cell lung cancer (NSCLC), however, the therapeutic efficiency varies remarkably among individuals. A large number of pharmacogenomics studies aimed to identify genetic variations which can be used to predict platinum response. Those studies are leading NSCLC treatment to the new era of precision medicine. In the current review, we provided a comprehensive update on the main recent findings of genetic variations which can be used to predict platinum sensitivity in the NSCLC patients.

Cisplatin resistance and opportunities for precision medicine

Cisplatin is one of the most commonly used chemotherapy drugs, treating a wide range of cancer types. Unfortunately, many cancers initially respond to platinum treatment but when the tumor returns, drug resistance frequently occurs. Resistance to cisplatin is attributed to three molecular mechanisms: increased DNA repair, altered cellular accumulation, and increased drug inactivation. The use of precision medicine to make informed decisions on a patient's cisplatin resistance status and predicting the tumor response would allow the clinician to tailor the chemotherapy program based on the biology of the disease. In this review, key biomarkers of each molecular mechanism will be discussed along with the current clinical research. Additionally, known polymorphisms for each biomarker will be discussed in relation to their influence on cisplatin resistance.

A Significant Statistical Advancement on the Predictive Values of ERCC1 Polymorphisms for Clinical Outcomes of Platinum-Based Chemotherapy in Non-Small Cell Lung Cancer: An Updated Meta-Analysis

Background. There is no definitive conclusion so far on the predictive values of ERCC1 polymorphisms for clinical outcomes of platinum-based chemotherapy in non-small cell lung cancer (NSCLC). We updated this meta-analysis with an expectation to obtain some statistical advancement on this issue. Methods. Relevant studies were identified by searching MEDLINE, EMBASE databases from inception to April 2015. Primary outcomes included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). All analyses were performed using the Review Manager version 5.3 and the Stata version 12.0. Results. A total of 33 studies including 5373 patients were identified. ERCC1 C118T and C8092A could predict both ORR and OS for platinum-based chemotherapy in Asian NSCLC patients (CT + TT versus CC, ORR: OR = 0.80, 95% CI = 0.67–0.94; OS: HR = 1.24, 95% CI = 1.01–1.53) (CA + AA versus CC, ORR: OR = 0.76, 95% CI = 0.60–0.96; OS: HR = 1.37, 95% CI = 1.06–1.75). Conclusions. Current evidence strongly indicated the prospect of ERCC1 C118T and C8092A as predictive biomarkers for platinum-based chemotherapy in Asian NSCLC patients. However, the results should be interpreted with caution and large prospective studies are still required to further investigate these findings.

Germline TYMS genotype is highly predictive in patients with metastatic gastrointestinal malignancies receiving capecitabine-based chemotherapy

PURPOSE

This work was initiated to extend data on the effect of pharmacogenetics and chemotherapy pharmacokinetics (PK) on clinical outcome in patients with gastrointestinal malignancies.

METHODS

We assessed 44 gene polymorphisms in 16 genes (TYMS, MTHFR, GSTP1, GSTM1, GSTT1, DPYD, XRCC1, XRCC3, XPD, ERCC1, RECQ1, RAD54L, ABCB1, ABCC2, ABCG2 and UGT2B7) in 64 patients with metastatic colorectal cancer (CRC) receiving capecitabine/oxaliplatin and 76 patients with advanced gastroesophageal cancer (GEC) receiving epirubicin/cisplatin/capecitabine, respectively. Plasma concentrations of anticancer drugs were measured for up to 24 h, and results were submitted to population PK analysis. We calculated the association between gene polymorphisms, chemotherapy exposure, tumor response, progression-free survival (PFS), overall survival (OS) and chemotherapy-related toxicity using appropriate statistical tests.

RESULTS

Patients with a low clearance of 5FU were at increased risk of neutropenia (P < 0.05) and hand-foot syndrome (P = 0.002). DPYD T85C, T1896C and A2846T mutant variants were associated with diarrhea (P < 0.05) and HFS (P < 0.02), and IVS14+1G>A additionally with diarrhea (P < 0.001). The TYMS 2R/3G, 3C/3G or 3G/3G promoter variants were associated with worse PFS in the CRC (HR = 2.0, P < 0.01) and GEC group (HR = 5.4, P < 0.001) and worse OS in the GEC group (HR = 4.7, P < 0.001). The GSTP1 A313G mutant variant was associated with a higher PFS (HR = 0.55, P = 0.001) and OS (HR = 0.60, P = 0.002) in the CRC group.

CONCLUSIONS

Germline polymorphisms of DPYD, TYMS and GSTP1 have a significant effect on toxicity and clinical outcome in patients receiving capecitabine-based chemotherapy for advanced colorectal or gastroesophageal cancer. These data should further be validated in prospective clinical studies.

Elevated expression of CRYAB predicts unfavorable prognosis in non-small cell lung cancer

Alpha B-crystallin (CRYAB) is one of the principal members of the small heat-shock protein family, and several studies described the CRYAB expression in human cancers. However, the association between CRYAB expression and the clinical features of non-small cell lung cancer (NSCLC) is rarely elucidated. In this present study, one-step quantitative reverse transcription-polymerase chain reaction with 12 fresh-frozen NSCLC samples and Western blotting as well as immunohistochemistry (IHC) analyses in 101 NSCLC cases were conducted to investigate the relationship between CRYAB expression and the clinicopathological attributes of NSCLC. The results showed that CRYAB mRNA and protein expression levels were significantly higher in NSCLC than in matched non-cancerous tissues (p < 0.05). The IHC data indicated that the CRYAB protein expression in NSCLC was significantly correlated with TNM stage (p = 0.043), and overall survival (p = 0.029). Kaplan-Meier method and Cox multifactor analysis suggested that higher CRYAB protein level (p = 0.032) and TNM stage (p = 0.048) were statistically associated with the poor survival of patients with NSCLC. The data suggested that CRYAB may be identified as a novel prognostic marker and targeting CRYAB may provide a promising strategy for NSCLC treatment.