ERCC1 codon 118 C→T polymorphism associated with ERCC1 expression and outcome of FOLFOX-4 treatment in Asian patients with metastatic colorectal carcinoma

VEGF -460T → C polymorphism and its association with VEGF expression and outcome to FOLFOX-4 treatment in patients with colorectal carcinoma

The -460T → C polymorphism of vascular endothelial growth factor (VEGF) gene significantly increases its promoter activity. A pilot study was conducted to assess the influence of this polymorphism on clinicopathological features of patients with colorectal carcinoma. In total, 228 patients were enrolled, including 100 with stage II/III colorectal carcinoma receiving curative surgery and 128 with metastatic disease. An excellent correlation in VEGF -460 genotypes based on white blood cells and tumor tissues existed, but there was no between-group difference in patients with or without colorectal carcinoma. A marked increase in intratumor and circulating VEGF levels were observed in patients with the T/C or C/C genotypes (P < 0.01), which was associated with increased extent of invasion, nodal involvement, poor histological differentiation, subsequent metastasis and shorter survival in stage II/III patients treated with curative surgery (P < 0.01). For patients with metastatic disease, this polymorphism was associated with a lower response rate to FOLFOX-4 (P = 0.03) and shorter survival (P < 0.001). By multivariate analysis, this polymorphism was identified as an independent prognostic factor (P = 0.01). These data suggest that -460T → C polymorphism of VEGF gene, by increasing VEGF expression and subsequent angiogenesis, could be a key determinant for increased tumor recurrence and a poor prognosis of patients with colorectal carcinoma. However, this study is exploratory and is not adjusted for multiple comparisons, requiring independent replication.

Predictive effects of ERCC1 and XRCC3 SNP on efficacy of platinum-based chemotherapy in advanced NSCLC patients

OBJECTIVE

The purpose of the study was to investigate whether single-nucleotide polymorphisms of deoxyribonucleic acid repair gene excision repair cross-complementing group 1 at codon 118 and X-ray repair cross-complementing group 3 at codon 241 affected clinical outcomes in advanced non-small cell lung cancer patients receiving first-line platinum-based chemotherapy.

METHODS

A total of 130 patients treated with platinum-based doublets were examined for genotyping of excision repair cross-complementing group 1 118 and X-ray repair cross-complementing group 3 241 in peripheral blood lymphocytes with the method of the TaqMan assay plus the real-time polymerase chain reaction method. Multivariate logistic or Cox's regression analyses were used to adjust for possible confounding variables.

RESULTS

There were no differences in clinical characteristics among the different single-nucleotide polymorphisms. Overall response rate in the 130 patients was 20% with 85.4% of disease control rate. Followed up to 31 March 2008, there were 47 patients still alive. Overall survival was 15 months. No relationship was found between excision repair cross-complementing group 1 or X-ray repair cross-complementing group 3 single-nucleotide polymorphisms and tumor response to platinum-based chemotherapy. A significant correlation was found between excision repair cross-complementing group 1 118 C/T single-nucleotide polymorphisms and survival (P = 0.003). In the multivariate model, the survival was highly related with excision repair cross-complementing group 1 118 C/T or T/T genotypes and tumor response to chemotherapy.

CONCLUSIONS

Overall survival was significantly improved in the patients with excision repair cross-complementing group 1 118 T/T or C/T treated by platinum-based chemotherapy.

Influence of GSTP1 I105V polymorphism on cumulative neuropathy and outcome of FOLFOX-4 treatment in Asian patients with colorectal carcinoma

Glutathione S-transferase P1 (GSTP1) participates in detoxification of potentially genotoxic compounds that may alter the efficacy and toxicity of platinum-based chemotherapy. We analyzed the influence of I105V polymorphism of GSTP1 on clinico-pathological features and outcomes in 166 Chinese patients with metastatic colorectal carcinoma who had been treated with first-line FOLFOX-4. Combined analysis of GSTP1 I105V, ERCC1-118, and XPD-751 polymorphisms was also conducted. The results showed that, in comparison with Caucasian populations, a remarkably lower prevalence of Val105 allele variants was noted (24.7%). Patients with Val105 allele variants had a higher response to FOLFOX-4 (56.1%vs 37.6%, P = 0.04), and a longer progression-free (P < 0.01) as well as overall (P < 0.01) survival. By adjusted analysis, this polymorphism was identified as an independent prognostic factor (P = 0.01). In combined analysis, patients without any risk genotype, including GSTP1-105 Ile/Ile, ERCC1-118 C/T or T/T, and XPD-751 Lys/Gln, had significantly longer progression-free and overall survivals (P < 0.01). In addition, patients with Val105 allele variants had a higher incidence of grade 3/4 cumulative neuropathy after different cycles of treatment. These data suggest that Asian populations have a lower prevalence of I105V polymorphism in GSTP1. I105V polymorphism in GSTP1, by reducing its enzymatic activity and consequential detoxification to oxaliplatin, could be a key determinant for a better outcome, but more neurotoxicity, to FOLFOX-4 treatment.

Very low prevalence of XPD K751Q polymorphism and its association with XPD expression and outcomes of FOLFOX-4 treatment in Asian patients with colorectal carcinoma

Xeroderma pigmentosum group D (XPD) participates in DNA unwinding during nucleotide excision repair, which may alter the efficacy of platinum-based chemotherapy. We analyzed the influence of codon 751 Lys-->Gln polymorphism of XPD on its protein expression levels, clinico-pathological features, and outcome of 188 Chinese patients with metastatic colorectal carcinoma (CRC) that had been treated with first-line Oxaliplatin + Leucovorin + 5-Fluorouracil (FOLFOX-4) chemotherapy. The results showed that in comparison with Caucasian populations, a remarkably lower prevalence of Lys/Gln genotype was noted (16%, n = 30). No between-group difference in XPD protein expression of patients with or without this polymorphism was noted (56.5%vs 59.7%; P = 0.783). Patients with Gln751 allele have a significantly lower response to FOLFOX-4 treatment (36.7%vs 58.2%, P = 0.03), and shorter progression-free (7 vs 11 months; P < 0.01) and overall (14 vs 22 months; P < 0.01) survivals. The incidence of grade 3/4 oxaliplatin-neuropathies was very similar in both groups (13.3%vs 16.5%; P = 0.67). By adjusted analysis, this polymorphism was further identified as an independent prognostic factor (P = 0.03). These data suggest that Asian populations have a significantly lower prevalence of codon 751 Lys/Gln polymorphism in XPD, which could be a key determinant for good response to oxaliplatin-based treatment and favorable outcomes.