Predictors of survival and toxicity in patients on adjuvant therapy with 5-fluorouracil for colorectal cancer

The present study aimed at investigating whether the simultaneous evaluation of pharmacokinetic, pharmacogenetic and demographic factors could improve prediction on toxicity and survival in colorectal cancer patients treated with adjuvant 5-fluorouracil (5FU)/leucovorin therapy. One hundred and thirty consecutive, B2 and C Duke''s stage colorectal cancer patients were prospectively enrolled. 5FU pharmacokinetics was evaluated at the first cycle. Thymidylate synthase (TYMS) 5′UTR and 3′UTR polymorphisms and methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms were assessed in peripheral leukocytes. Univariate and multivariate analyses were applied to evaluate which variables could predict chemotherapy-induced toxicity, disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed that: (a) low 5FU clearance was an independent predictive factor for severe toxicity (OR=7.32; P<0.0001); (b) high-5FU clearance predicted poorer DFS (HR=1.96; P=0.041) and OS (HR=3.37; P=0.011); (c) advanced age was associated with shorter DFS (HR=3.34; P=0.0008) and OS (HR=2.66; P=0.024); (d) the C/C genotype of the MTHFR C677T polymorphism was protective against grade 3–4 toxicity (P=0.040); (e) none of the TYMS polymorphisms could explain 5FU toxicity or clinical outcome.     

Phase II trial of carboplatin and pemetrexed as first-line chemotherapy for non-squamous non-small cell lung cancer,and correlation between the efficacy/toxicity and genetic polymorphisms associated with pemetrexed metabolism: Hokkaido Lung Cancer Clinical Study Group Trial (HOT) 0902

Purpose

This phase II study evaluated the response rate (RR) and safety of combination therapy with carboplatin (CBDCA) and pemetrexed (PEM) in Japanese patients with non-squamous non-small cell lung cancer (non-sq NSCLC). Further, the relationship between therapy efficacy/toxicity and genetic polymorphisms associated with PEM metabolism was analyzed.

Methods

Forty-one patients received CBDCA at a dose targeting an area under the concentration–time curve of 5 mg/mL × min and PEM of 500 mg/m² on day 1 every 3 weeks. Single-nucleotide polymorphisms of the thymidylate synthase (TYMS) coding gene, the variable number of tandem repeat (VNTR) in the TYMS, and the methylenetetrahydrofolate reductase (MTHFR) coding gene were analyzed.

Results

The overall RR was 36.6 %. Median progression-free survival and median survival time were 4.7 months [95 % confidence interval (CI) 3.9–5.6 months] and 16.2 months (95 % CI 6.1–26.2 months), respectively. Epidermal growth factor receptor gene mutations were detected in 6 patients (14.6 %). The VNTR in the TYMS significantly correlated with anemia (p = 0.047) and thrombocytopenia (p = 0.038).

Conclusions

This combination therapy was effective and tolerable in patients with advanced non-sq NSCLC. The VNTR in the TYMS appears to be a predictive factor for anemia and thrombocytopenia in patients treated with this regimen.     

Association between dietary folate intake and clinical outcome in head and neck squamous cell carcinoma

BackgroundThe association between dietary folate intake, two polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and thymidylate synthase (TYMS), and survival in head and neck squamous cell carcinoma (HNSCC) patients is not clarified.Patients and methodsWe conducted a retrospective cohort study of 437 HNSCC patients treated at Aichi Cancer Center. We evaluated the survival impact of pretreatment dietary folate intake, which was estimated using a food-frequency questionnaire, and two polymorphisms, MTHFR C677T and a 6-bp insertion/deletion in the 3′-untranslated region of TYMS, using multivariate proportional hazard models.ResultsPatients with high folate intake (≥320 μg/day; n = 144) had significantly higher survival than patients with low or medium folate intake (<320 μg/day; n = 278; 79.1% versus 68.2%, respectively, P = 0.020). This association was consistent with multivariate analyses adjusted for established prognostic factors (hazard ratio 0.56; 95% confidence interval 0.37–0.84). MTHFR and TYMS polymorphisms did not show significant association with survival, although the TYMS 6-bp insertion allele showed potential association with a reduced risk of death. Notably, no significant interaction was observed between folate intake and the two examined polymorphisms.ConclusionsHigh pretreatment dietary folate intake was identified as an independent prognostic factor associated with improved clinical outcomes in HNSCC patients. Further study is warranted.     

Xenobiotic and folate pathway gene polymorphisms and risk of childhood acute lymphoblastic leukaemia in Javanese children

Xenobiotic and folate metabolic pathways are important for the maintenance of genetic stability and may influence susceptibility to the development of childhood acute lymphoblastic leukaemia (ALL). In this study, we investigated 10 polymorphisms in 6 genes (GSTM1‐present/null, GSTT1‐present/null, GSTP1 1578A > G, NQO1 609C > T, MTHFR 677C > T, MTHFR 1298A > C, MTHFD1 1958G > A, 3′‐TYMS 1494 6bp‐deletion/insertion, 5′‐TYMS 28bp‐tandem repeats, and SLC19A1 80G > A) in a cohort of 185 Javanese children with ALL and 177 healthy controls. In ALL patients, none of the polymorphisms demonstrated a statistically significant association with ALL after correcting for multiple comparisons. Gender‐stratified analysis showed that in girls, GSTT1‐null genotype was associated with increased ALL risk (OR = 2.20; p = 0.027), while GSTP1 1578AG genotype was associated with reduced risk (OR = 0.43; p = 0.031). Strong linkage disequilibrium between the MTHFR 677C > T and 1298A > C polymorphisms was observed (D′ = 1.0; r² = 0.072). The haplotypes 677C‐1298C and 677T‐1298A were associated with a reduced risk of ALL (OR = 0.68 and 0.64, respectively; gender‐adjusted global p = 0.028). Classification and regression tree (CART) analysis was employed to identify potential high‐order gene‐gene interactions and cluster subjects into susceptibility groups. SLC19A1 80G > A emerged as the predominant polymorphism associated with risk of ALL. Individuals simultaneously carrying MTHFR 1298AA, 3'‐TYMS 6bp deletion(s) and SLC19A1 80A‐allele(s) were at higher disease risk (OR = 2.21; p < 0.001). On the contrary, simultaneous possession of MTHFR 1298CC, 3'‐TYMS 6bp homozygosity and SLC19A1 80A‐allele(s) conferred lower risk (OR = 0.25; p = 0.004). Carriage of NQO1 609C‐allele amongst SLC19A1 80GG genotype was associated with lower risk (OR = 0.47; p = 0.003). In conclusion, our study has demonstrated the importance of gender and gene‐gene interaction within the xenobiotic and folate pathways in modulating childhood ALL susceptibility. Copyright © 2010 John Wiley & Sons, Ltd.     

Polymorphisms in folate pathway and pemetrexed treatment outcome in patients with malignant pleural mesothelioma

Introduction

A combination of pemetrexed and cisplatin has been shown to improve the outcome in patients with malignant pleural mesothelioma (MPM), however, there is a great heterogeneity in treatment response among patients. The aim of our study was to evaluate the influence of polymorphisms in folate pathway and transporter genes on pemetrexed treatment outcome in Slovenian patients with MPM.

Methods

MPM patients treated with pemetrexed in the course of a prospective randomized clinical trial were genotyped for nineteen polymorphisms in five genes of folate pathway and six transporter genes. Logistic regression was used to assess the influence of polymorphisms on treatment efficacy and toxicity, while Cox regression was used to determine their influence on progression-free and overall survival.

Results

Patients with at least one polymorphic MTHFD1 rs2236225 allele had a significantly lower response rate (p = 0.005; odds ratio [OR] = 0.12; 95% confidence interval [CI] = 0.03−0.54) and shorter progression-free survival (p = 0.032; hazard ratio [HR] = 3.10; 95% CI = 1.10−8.74) than non-carriers. Polymorphisms in transporter genes did not influence survival; however, several were associated with toxicity. Liver toxicity was significantly lower in carriers of polymorphic ABCC2 rs2273697 (p = 0.028; OR = 0.23; 95% CI = 0.06−0.85), SLCO1B1 rs4149056 (p = 0.028; OR = 0.23; 95% CI = 0.06−0.85) and rs11045879 (p = 0.014; OR = 0.18; 95% CI = 0.05−0.71) alleles compared to non-carriers, as well as in patients with SLCO1B1 GCAC haplotype (p = 0.048; OR = 0.17; 95% CI = 0.03−0.98). Gastrointestinal toxicity was much more common in patients with polymorphic ABCC2 rs717620 allele (p = 0.004; OR = 10.67; 95% CI = 2.15−52.85) and ABCC2 CAG haplotype (p = 0.006; OR = 5.67; 95% CI = 1.64−19.66).

Conclusions

MTHFD1 polymorphism affected treatment response and survival, while polymorphisms in ABCC2 and SLCO1B1 transporter genes influenced the risk for toxicity. These polymorphisms could serve as potential markers of pemetrexed treatment outcome in patients with MPM.     

Polymorphisms of methylenetetrahydrofolate reductase are associated with a high risk of nasopharyngeal carcinoma in a smoking population from southern China

Methylenetetrahydrofolate reductase (MTHFR) plays a central role in converting folate to a compound which serves as a methyl donor for DNA methylation, an epigenetic modification known to be dysregulated in carcinogenesis. This case–control study assessed the contribution of MTHFR polymorphisms to the risk of nasopharyngeal carcinoma (NPC). MTHFR genotypes C677T and A1298C in 529 NPC patients and 577 frequency‐matched controls were determined by PCR‐based restriction fragment length polymorphism. We found a 1.57‐fold increased risk of NPC in subjects with the MTHFR 1298AC genotype compared to subjects with the MTHFR 1298AA genotype. In addition, an elevated NPC risk was also found in subjects with both the MTHFR 677CT and 1298AC genotypes [odds ratio (OR) = 2.15, 95% confidence interval (CI) = 1.37–3.39] compared to subjects with the 677CC/1298AA genotypes. Furthermore, we observed an additive interaction between MTHFR polymorphisms and smoking status on the increased risk of NPC. The OR was 6.72 (95% CI = 1.85–24.48) among heavy smokers (pack‐years ≥15) carrying 677TT compared with nonsmokers carrying the 677CC genotype. The OR was 7.23 (95% CI = 4.22–12.38) or 12.75 (95% CI = 2.74–59.3) among subjects carrying the 1298AC or 1298CC genotype in heavy smokers (pack‐years ≥15) compared with 1298AA in nonsmokers. Our results provide the first molecular epidemiological evidence that MTHFR polymorphisms associate with the risk of NPC and this association is especially noteworthy in heavy smokers. © 2010 Wiley‐Liss, Inc.     

Variants in CDA and ABCB1 are predictors of capecitabine-related adverse reactions in colorectal cancer

Adverse reactions to capecitabine-based chemotherapy limit full administration of cytotoxic agents. Likewise, genetic variations associated with capecitabine-related adverse reactions are associated with controversial results and a low predictive value. Thus, more evidence on the role of these variations is needed. We evaluated the association between nine polymorphisms in MTHFR, CDA, TYMS, ABCB1, and ENOSF1 and adverse reactions, dose reductions, treatment delays, and overall toxicity in 239 colorectal cancer patients treated with capecitabine-based regimens. The ABCB1*1 haplotype was associated with a high risk of delay in administration or reduction in the dose of capecitabine, diarrhea, and overall toxicity. CDA rs2072671 A was associated with a high risk of overall toxicity. TYMS rs45445694 was associated with a high risk of delay in administration or reduction in the dose of capecitabine, HFS >1 and HFS >2. Finally, ENOSF1 rs2612091 was associated with HFS >1, but was a poorer predictor than TYMS rs45445694. A score based on ABCB1-CDA polymorphisms efficiently predicts patients at high risk of severe overall toxicity (PPV, 54%; sensitivity, 43%) in colorectal cancer patients treated with regimens containing capecitabine. Polymorphisms in ABCB1, CDA, ENOSF1,and TYMS could help to predict specific and overall severe adverse reactions to capecitabine.     

Polymorphisms of <Emphasis Type="Italic">MTHFR</Emphasis> C677T and A1298C associated with survival in patients with colorectal cancer treated with 5-fluorouracil-based chemotherapy

Background

This study examined the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms and survival of patients with colorectal cancer (CRC) treated with 5-fluorouracil (5-FU)-based chemotherapy in Taiwan.

Methods

We genotyped MTHFR polymorphisms C677T (rs1801133) and A1298C (rs1801131) for 498 CRC patients treated with 5-FU-based chemotherapy after receiving surgery. Survival analyses on MTHFR polymorphisms were performed using log-rank test and Kaplan–Meier curve. Cox proportional hazards models were used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between MTHFR genotypes and survival.

Results

Overall survival (OS) was significantly longer in CRC patients with MTHFR 677 CT+TT genotypes compared with those with 677 CC genotype (HR 0.77; 95% CI 0.60–0.98). Although the MTHFR A1298C polymorphism was not associated with OS in CRC, this polymorphism was associated with significantly shorter OS in rectal cancer. Among rectal cancer patients, OS was shorter for patients with AC+CC genotypes than for those with the AA genotype (HR 1.95; 95% CI 1.35–2.83). In haplotype analysis, better OS was found for colon cancer patients carrying the MTHFR 677T-1298A haplotype (HR 0.73; 95% CI 0.55–0.97), but worse survival was linked to rectal cancer patients carrying the MTHFR 677C-1298C haplotype (HR 1.53; 95% CI 1.08–2.18).

Conclusions

Our findings suggest that MTHFR genotypes provide prognostic information for CRC patients treated with 5-FU-based chemotherapy.

     

MTHFR polymorphisms and 5-FU-based adjuvant chemotherapy in colorectal cancer

BackgroundMethylenetetrahydrofolate reductase is a pivotal enzyme in folate metabolism and 5-fluorouracil (5-FU) cytotoxicity. Two common single-nucleotide polymorphisms (SNPs), MTHFR 677C>T (rs1801133) and 1298A>C (rs1801131), reduce enzyme activity. Initially, these SNPs were claimed to predict clinical efficacy, but further studies have yielded contradictory results. We tested whether these two polymorphisms are determinants of clinical outcome in a large patient group with a long follow-up time.Patients and methodsWe included 331 patients who had been treated with adjuvant 5-FU/leucovorin chemotherapy after intended curative resection between 1997 and 2003. Clinical data, including relapse rates, overall survival, and tumor stage, were collected. DNA was extracted from formalin-fixed tumor tissue and analyzed for the MTHFR 677C>T and 1298A>C SNPs with real-time PCR.ResultsThe MTHFR 677C>T and 1298A>C polymorphisms were not associated with survival or relapse-free survival (P > 0.2). The 677 CC genotype was associated to toxicity (odds ratio = 1.83, P = 0.01).ConclusionsThe MTHFR 677C>T and 1298A>C polymorphisms probably do not predict efficacy of adjuvant 5-FU treatment in colorectal cancer after complete resection; however, the 677C>T polymorphism may be associated with lower toxicity in 5-FU treatment. Implementation of SNP analysis for these polymorphisms for individualized treatment is premature.     

Pharmacogenetic analysis of adjuvant FOLFOX for Korean patients with colon cancer

Purpose

Ethnic diversity of genetic polymorphism can result in individual differences in the efficacy and toxicity of cancer chemotherapy.

Methods

We analyzed 20 germline polymorphisms in 10 genes (TS, MTHFR, ERCC1, XPD, XRCC1, ABCC2, AGXT, GSTP1, GSTT1 and GSTM1) from prospectively enrolled 292 Korean patients treated with adjuvant oxaliplatin plus leucovorin plus 5-fluorouracil (FOLFOX) for colon cancer.

Results

In contrast to previous studies in Caucasians, neutropenia (grade 3–4, 60.5 %) was frequently observed, whereas only 16.4 % experienced grade 2 or more sensory neuropathy. Neutropenia was more frequent in MTHFR 677TT [adjusted odds ratio (OR) 2.32, 95 % confidence interval (CI) 1.19–4.55] and ERCC1 19007TT (adjusted OR 4.58, 95 % CI 1.20–17.40) genotypes. Patients harboring XRCC1 23885GG experienced less grade 2–4 neuropathy [adjusted OR 0.52, 95 % CI 0.27–0.99]. MTHFR 677TT (p = 0.002) and XRCC1 23885GG (p = 0.146) genotypes were also more prevalent in Koreans compared to Caucasians. TS ‘low’ genotype (adjusted HR 1.83, 95 % CI 1.003–3.34) was significantly related to shorter disease-free survival. Overall survival was not significantly different according to the polymorphisms.

Conclusions

Polymorphisms in MTHFR, XRCC1 and TS are related to toxicities and disease-free survival in patients with colon cancer. The ethnic differences in frequencies of genotypes may explain the ethnic difference in toxicity profile following adjuvant FOLFOX chemotherapy.     

The role of pharmacogenetics in capecitabine efficacy and toxicity

Capecitabine is an oral prodrug of 5-fluorouracil (5-FU) and approved for treatment of various malignancies. Hereditary genetic variants may affect a drug’s pharmacokinetics or pharmacodynamics and account for differences in treatment response and adverse events among patients. In this review we present the current knowledge on genetic variants, commonly single-nucleotide polymorphisms (SNPs), tested in cohorts of cancer patients and possibly useful for prediction of capecitabine efficacy or toxicity. Capecitabine is activated to 5-FU by CES, CDA and TYMP, of which SNPs in CDA and CES2 were found to be associated with efficacy and toxicity. In addition, variants in genes of the 5-FU metabolic pathway, including TYMS, MTHFR and DPYD also influenced capecitabine efficacy and toxicity. In particular, well-known SNPs in TYMS and DPYD as well as putative DPYD SNPs had an association with clinical outcome as well as adverse events. Inconsistent findings may be attributable to factors related to ethnic differences, sample size, study design, study endpoints, dosing schedule and the use of multiple agents. Of the SNPs described in this review, dose reduction of fluoropyrimidines based on the presence of DPYD variants ^*2A (rs3918290), ^*13 (rs55886062), −2846A>T (rs67376798) and −1236G>A/HapB3 (rs56038477) has already been recommended. Other variants merit further validation to establish their definite role in explanation of interindividual differences in the outcome of capecitabine-based therapy.     

Increased risk of severe fluoropyrimidine‐associated toxicity in patients carrying a G to C substitution in the first 28‐bp tandem repeat of the thymidylate synthase 2R allele

The fluoropyrimidines act by inhibiting thymidylate synthase (TS). Recent studies have shown that patients' risk of severe fluoropyrimidine‐associated toxicity is affected by polymorphisms in the 5′‐untranslated region of TYMS, the gene encoding TS. A G>C substitution in the promoter enhancer region of TYMS, rs183205964 (known as the 2RC allele), markedly reduces TS activity in vitro, but its clinical relevance is unknown. We determined rs183205964 in 1605 patients previously enrolled in a prospective multicenter study. Associations between putative low TS expression genotypes (3RC/2RC, 2RG/2RC, and 2RC/2RC) and severe toxicity were investigated using univariable and multivariable logistic regression. Activity of TS and TYMS gene expression were determined in peripheral blood mononuclear cells (PBMCs) of a patient carrying genotype 2RC/2RC and of a control group of healthy individuals. Among 1,605 patients, 28 patients (1.7%) carried the 2RC allele. Twenty patients (1.2%) carried a risk‐associated genotype (2RG/2RC, n=13; 3RC/2RC, n=6; and 2RC/2RC, n=1), the eight remaining patients had genotype 3RG/2RC. Early severe toxicity and toxicity‐related hospitalization were significantly more frequent in risk‐associated genotype carriers (OR 3.0, 95%CI 1.04–8.93, p=0.043 and OR 3.8, 95%CI 1.19–11.9, p=0.024, respectively, in multivariable analysis). The patient with genotype 2RC/2RC was hospitalized twice and had severe febrile neutropenia, diarrhea, and hand‐foot syndrome. Baseline TS activity and gene expression in PBMCs of this patient, and a healthy individual with the 2RC allele, were found to be within the normal range. Our study suggests that patients carrying rs183205964 are at strongly increased risk of severe, potentially life‐threatening, toxicity when treated with fluoropyrimidines.     

The influence of platinum pathway polymorphisms on the outcome in patients with malignant mesothelioma

BackgroundPlatinum-based therapy is widely used in the treatment of malignant mesothelioma (MM); however, the efficacy and toxicity of platinum agents vary greatly between patients. The aim of our study was to evaluate the influence of platinum pathway polymorphisms on treatment outcome in patients with MM.Patients and methodsIn total, 133 patients with MM treated with (n = 97) or without (n = 36) platinum-based therapy were genotyped for common XPD, ERCC1, and GSTP1 polymorphisms, as well as for GSTM1 and GSTT1 gene deletion. Haplotype analysis was carried out to assess the combined effect of nucleotide excision repair (NER) polymorphisms.ResultsGST polymorphisms were not associated with treatment outcome in patients with MM. In the group of platinum-treated patients with MM, ERCC1 8092C/C wild-type genotype significantly influenced progression-free survival (PFS) in multivariable analysis accounting for clinical variables (P = 0.034). XPD 312Asp/Asp and ERCC1 8092C/C wild-type genotypes also increased the odds of treatment-related toxic effects in univariable as well as multivariable analysis. The association of wild-type NER genotypes with better PFS and higher susceptibility to treatment-related toxic effects was confirmed in haplotype analysis.ConclusionsOur results suggest that polymorphisms in NER pathway influence platinum-treatment efficacy and toxicity; therefore, these should be further evaluated as potential markers for the prediction of clinical outcome in patients with MM.     

Correlation Between TS,MTHFR, and ERCC1 Gene Polymorphisms and the Efficacy of Platinum in Combination With Pemetrexed First-Line Chemotherapy in Mesothelioma Patients

IntroductionThe combination of pemetrexed and platinum compound represents the standard regimen for first-line chemotherapy in malignant pleural mesothelioma patients. Pemetrexed is a multitarget antifolate agent that inhibits folate-dependent enzymes (eg, thymidylate synthase [TS]) and thus synthesis of nucleotides and DNA. Expression of TS and folate availability, regulated by gene polymorphisms, have implications for effectiveness of chemotherapy and the outcome of mesothelioma patients. The aim of this retrospective multicenter study was to assess the correlation between TS, 5,10-methylenetetrahydrofolate reductase (MTHFR) and excision repair cross-complementing group 1 (ERCC1) gene polymorphisms and the efficacy of pemetrexed-based first-line chemotherapy of mesothelioma patients.Patients and MethodsFifty-nine mesothelioma patients (31 men with a median age of 62 years) treated in first-line chemotherapy with platinum in combination with pemetrexed or pemetrexed monotherapy were enrolled. Genomic DNA was isolated from peripheral blood. Using polymerase chain reaction and high resolution melt methods, the variable number of tandem repeat, the G>C single nucleotide polymorphism (SNP) in these repeats, and 6-base pair (bp) insertion/deletion polymorphism of the TS gene, the SNP of 677C>T in MTHFR, and 19007C>T in the ERCC1 gene were analyzed and correlated with disease control rate, progression-free survival (PFS), and overall survival (OS) of mesothelioma patients.ResultsGreater risk of early disease progression (PD), and shortening of PFS and OS were associated with several clinical factors (eg, anemia for early PD and OS), weight loss (for PFS and OS), and previous surgical treatment (for early PD, PFS, and OS). Insertion of 6-bp in both alleles of the TS gene (1494del6) was the only genetic factor that increased the incidence of early progression (P = .028) and shortening of median PFS (P = .06) in patients treated with pemetrexed-based chemotherapy. In multivariate analysis, the 1494del6 in the 3′ untranslated region (UTR) of the TS gene also had a predictive role for PFS (P = .0185; hazard ratio, 2.3258 for +6/+6 homozygotes) in analyzed mesothelioma patients.ConclusionMost analyzed polymorphisms in TS, MTHFR, and ERCC1 genes failed to predict outcome in mesothelioma patients treated with pemetrexed-based chemotherapy. However, different variants of 1494del6 in the 3′ UTR of the TS gene were associated with differences in disease control rate and PFS of our patients.     

Methylenetetrahydrofolate reductase genetic polymorphisms and toxicity to 5-FU-based chemoradiation in rectal cancer

Background:

There is a large degree of variation in tumour response and host toxicities associated with neoadjuvant chemoradiation for rectal cancer patients. We performed a complimentary pharmacogenetic study to investigate germline polymorphisms of genes involved in 5-fluorouracil (5-FU) and irinotecan pathways and their potential association with clinical outcomes and toxicities from neoadjuvant chemoradiation in patients with rectal cancer treated in a prospective genotype-directed study.

Methods:

The germline DNA of 131 patients was genotyped for 10 variants in TYMS, MTHFR, DPYD, UGT1A1, ABCC1 and SLCO1B1 genes. Ninety-six patients were treated with 5-FU/radiotherapy (RT) and 35 received 5-FU/RT/irinotecan. Relationships between genetic variants and adverse events, tumour response, overall and disease-free survivals were assessed.

Results:

MTHFR 1298A>C and MTHFR diplotypes (for 677C>T and 1298A>C) were associated with chemoradiation-related toxicity when 5-FU was used alone. MTHFR haplotypes (677C–1298C) and diplotypes (CA–TA and TA–TA) showed, respectively, a protective and a negative effect on the incidence of severe diarrhoea or mucositis. No association was observed between genetic markers and drug response.

Conclusion:

MTHFR polymorphisms can potentially predict toxicity in patients treated with 5-FU as a single chemotherapeutic drug.     

Association of VEGF and VEGFR2 single nucleotide polymorphisms with hypertension and clinical outcome in metastatic clear cell renal cell carcinoma patients treated with sunitinib

PURPOSE:

Biomarkers that predict response or toxicity to antiangiogenic therapy are sought to favorably inform the risk/benefit ratio. This study evaluated the association of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2) genetic polymorphisms with the development of hypertension (HTN) and clinical outcome in metastatic clear cell renal cell carcinoma (MCCRCC) patients treated with sunitinib.

PATIENT AND METHODS:

Sixty‐three MCCRCC patients receiving sunitinib (50 mg 4/2) with available blood pressure (BP) data and germline DNA were retrospectively identified. A panel of candidate VEGF and VEGFR2 single nucleotide polymorphisms (SNPs) were evaluated for associations with the development of hypertension and clinical outcome.

RESULTS:

VEGF SNP ?634 genotype was associated with the prevalence and duration of sunitinib‐induced hypertension (as defined by systolic pressure ≥150 mmHg and/or diastolic pressure ≥90 mmHg) in both univariable analysis (P = .03 and .01, respectively) and multivariable analysis, which adjusted for baseline BP and use of antihypertension medication (P = .05 and .02, respectively). Patients with the GG genotype were estimated to have a greater likelihood of being hypertensive during treatment compared with patients with the CC genotype (odds ratio of 13.62, 95% confidence interval [CI] 3.71‐50.04). No single VEGF or VEGFR SNPs were found to correlate with clinical outcome. However, the combination of VEGF SNP 936 and VEGFR2 SNP 889 were associated with overall survival after adjustment for prognostic risk group (P = .03).

CONCLUSIONS:

In MCCRCC patients treated with sunitinib, VEGF SNP ?634 is associated with hypertension and a combination of VEGF SNP 936 and VEGFR2 SNP 889 genotypes is associated with overall survival. Cancer 2012;. © 2011 American Cancer Society.     

Molecular markers of response and toxicity to FOLFOX chemotherapy in metastatic colorectal cancer

Background:

To investigate three genetic alterations (TP53 mutation, Kras mutation and microsatellite instability (MSI)) and three polymorphisms (methylene tetrahydrofolate reductase (MTHFR) C677T, excision repair cross complementing group 1 (ERCC1)-118 and X-ray repair cross complementing group 1 (XRCC1)-399) for their ability to predict response, survival and toxicity to FOLFOX first line chemotherapy in the treatment of metastatic colorectal cancer (mCRC).

Methods:

Tumour tissues from 118 mCRC patients who underwent FOLFOX treatment from three successive phase II trials were evaluated for mutations in TP53 (exons 5–8) and Kras (codons 12 and 13) and for MSI using PCR-based analysis. Genotyping for common single nucleotide polymorphisms in the MTHFR (codon 677), ERCC1 (codon 118) and XRCC1 (codon 399) genes was also carried out using PCR techniques. These genetic markers were correlated with clinical response, survival and toxicity to treatment.

Results:

Patients with the T allele of ERCC1-118 showed significantly worse progression-free survival in univariate analysis (HR=2.62; 95% CI=1.14–6.02; P=0.02). None of the genetic alterations or polymorphisms showed significant association with clinical response to FOLFOX. The MTHFR, ERCC1 and XRCC1 polymorphisms showed no associations with overall haematological, gastrointestinal or neurological toxicity to FOLFOX, although MTHFR 677 TT genotype patients showed a significantly higher incidence of grade 3 or 4 diarrhoea (26%) compared with CC or CT genotype patients (6%, P=0.02).

Conclusions:

The ERCC1-118 and MTHFR C677T polymorphisms were associated with progression and severe diarrhoea, respectively, after FOLFOX treatment in mCRC. Although our findings require confirmation in large prospective studies, they reinforce the concept that individual genetic variation may allow personalized selection of chemotherapy to optimize clinical outcomes.     

Alterations in the expression pattern of MTHFR, DHFR, TYMS, and SLC19A1 genes after treatment of laryngeal cancer cells with high and low doses of methotrexate

Inter-individual variations to methotrexate (MTX) outcome have been attributed to different expression profiles of genes related to folate metabolism. To elucidate the mechanisms of variations to MTX outcome, we investigated MTHFR, DHFR, TYMS, and SLC19A1 gene expression profiles by quantifying the mRNA level of the genes involved in folate metabolism to MTX response in laryngeal cancer cell line (HEP-2). For this, three different concentrations of MTX (0.25, 25, and 75 μmol) were added separately in HEP-2 cell line for 24 h at 37 °C. Apoptotis quantification was evaluated with fluorescein isothiocyanate-labeled Bcl-2 by flow cytometry. Real-time quantitative PCR technique was performed by quantification of gene expression with TaqMan® Gene Expression Assay. ANOVA and Bonferroni’s post hoc tests were utilized for statistical analysis. The results showed that the numbers of apoptotic HEP-2 cells with 0.25, 25.0, and 75.0 μmol of MTX were 14.57, 77.54, and 91.58 %, respectively. We found that the expression levels for MTHFR, DHFR, TYMS, and SLC19A1 genes were increased in cells with 75.0 μmol of MTX (p?<?0.05). Moreover, SLC19A1 gene presented lower expression in cells treated with 0.25 μmol of MTX (p?<?0.05). In conclusion, our data suggest that MTHFR, DHFR, TYMS, and SLC19A1 genes present increased expression after the highest application of MTX dose in laryngeal cancer cell line. Furthermore, SLC19A1 gene also presents decreased expression after the lowest application of MTX dose in laryngeal cancer cell line. Significant alterations of expression of these studied genes in cell culture model may give support for studies in clinical practice and predict interesting and often novel mechanisms of resistance of MTX chemotherapy.     

Germline genetic polymorphisms may influence chemotherapy response and disease outcome in osteosarcoma: a pilot study

BACKGROUND:

Osteosarcoma is the most common malignant bone tumor in children and young people. Efficacy of multiagent MAP (methotrexate, doxorubicin [Adriamycin], cisplatin) chemotherapy may be influenced by multiple cellular pathways. This pilot study aimed to investigate the association of 36 candidate genetic polymorphisms in MAP pathway genes with histological response, survival, and grade 3‐4 chemotherapy toxicity in osteosarcoma.

METHODS:

Blood samples were obtained from 60 patients who had completed MAP chemotherapy. All patients were manually genotyped for 5 polymorphisms. The remaining 31 polymorphisms were genotyped in 50 patients using the Illumina 610‐Quad microarray. Associations between candidate polymorphisms and histological response, progression‐free survival, and toxicity were estimated using Pearson chi‐square and Fisher exact tests, the Kaplan‐Meier method, the log‐rank test, and the Cox proportional hazards model.

RESULTS:

Poor histological response was increased in variants of ABCC2 c.24C>T (P = .011) and GSTP1 c.313A>G p.Ile¹⁰⁵Val (P = .009), whereas MTHFD1 c.1958G>A p.Arg⁶⁵³Gln was protective (P = .03). Methotrexate toxicity was increased in variants of MTHFR c.1298A>C p.Glu⁴²⁹Ala (P = .038), ABCB1 c.3435T>C Ile¹⁴⁵Ile (P = .027), and ABCC2 c.3563T>A p.Val¹¹⁸⁸Glu (P = .028). Variants of GSTP1 c.313A>G p.Ile¹⁰⁵Val were at increased risk of myelosuppression (P = .024) and cardiac damage (P = .008).

CONCLUSIONS:

This pilot study represents the most comprehensive study to date examining the role of genetic polymorphisms in osteosarcoma. Although small and retrospective, it shows that several polymorphisms appear to significantly influence toxicity and clinical outcome. These deserve prospective validation in the hope of optimizing treatment for resistant disease and reducing the late effects burden. Cancer 2012. © 2011 American Cancer Society.     

Genotype-based selection of treatment of patients with advanced colorectal cancer (SETICC): a pharmacogenetic-based randomized phase II trial

BackgroundThere has been little progress toward personalized therapy for patients with metastatic colorectal cancer (mCRC). TYMS-3′untranslated region (UTR) 6 bp ins/del and ERCC1-118C/T polymorphisms were previously reported to facilitate selecting patients for fluoropyrimidine-based treatment in combination with oxaliplatin as first-line therapy. We assessed the utility of these markers in selecting therapy for patients with mCRC.Patients and methodsThis randomized, open-label phase II trial compared bevacizumab plus XELOX (control) versus treatment tailored according to TYMS-3′UTR 6 bp ins/del and ERCC1-118C/T polymorphisms. Patients randomized to the experimental treatment received bevacizumab plus FUOX, FUIRI, XELIRI, or XELOX depending on their combination of favorable polymorphisms for FUOX treatment (TYMS-3′UTR ins/del or del/del; ERCC1-118T/T). Progression-free survival (PFS) was the primary end point.ResultsOverall, 195 patients were randomized (control n = 65; experimental n = 130). The primary objective was not met: median PFS was 9.4 months in the control group and 10.1 months in the experimental group (P = 0.745). Median overall survival was similar in both groups (16.5 versus 19.1 months, respectively; P = 0.797). Patients in the experimental group had a significantly higher overall response rate (ORR; 65% versus 47% in the control group; P = 0.042) and R0 resection rate (86% versus 44%, respectively; P = 0.018). Neuropathy, hand–foot syndrome, thrombocytopenia, and dysesthesia were significantly less common in the experimental group.ConclusionsThis study did not show survival benefits after treatment personalization based on polymorphisms in mCRC. However, the improved ORR and R0 resection rate and fewer disabling toxicities suggest that tailoring therapy by TYMS-3′UTR and ERCC1-118 polymorphisms warrants further investigation in patients with mCRC.ClinicalTrials.govNCT01071655.