Phase II study of pharmacogenetic-tailored therapy in elderly colorectal cancer patients.

BACKGROUND: Retrospective analyses suggested that a pharmacogenetic approach may allow a tailored selection of chemotherapy for metastatic colorectal cancer. AIM: We conducted a phase II study of pharmacogenetic-selected first-line chemotherapy in elderly patients with advanced colorectal cancer, with the aim to improve efficacy and to reduce toxicity in this group of patients. METHODS: 24 patients were enrolled in this study. Chemotherapy regimen was prospectively assigned based on TS, DPD, ERCC-1 and UGT1A1 genotyping results. Twelve patients (50%) were treated with modified FOLFIRI, 11 patients (46%) with modified FOLFOX6 and 1 (4%) with De Gramont regimen. RESULTS: A partial remission was obtained in 4 cases (17%), stable disease in 8 cases (33%) and progressive disease in 12 cases (50%). Grade 3-4 neutropenia was observed in 7 patients (29%) and diarrhoea in 3 cases (12%). The trial was then interrupted according to study design requiring 13 partial remissions out of the first 24 patients enrolled as the necessary response rate level in order to continue. CONCLUSION: Prospective selection of chemotherapy based on TS, DPD, ERCC-1 and UGT1A1 expression in elderly advanced colorectal cancer patients failed to confirm previous results. A more accurate validation of retrospective findings is warranted before these molecular markers can be used for treatment selection in the clinical practice.

Polymorphisms in genes involved in DNA repair and metabolism of xenobiotics in individual susceptibility to sporadic diffuse gastric cancer.

BACKGROUND: Gastric cancer is the second highest cause of cancer mortality in the world, despite declining rates of incidence in many industrialized countries. We carried out a case-control study to evaluate whether polymorphisms of DNA repair and glutathione S-transferase (GST) genes modulate the risk of developing diffuse gastric cancer. METHODS: ERCC1 118 T/C, XRCC1 399 G/A, XPD 312 G/A, XPD 751 A/C, XRCC3 241 C/T, MS 919 A/G, GSTP1 105 A/G, GSTM1-null/positive and GSTT1-null/positive genotypes were obtained for a series of 126 Helicobacter pylori-negative diffuse gastric cancer patients and 144 Helicobacter pylori-negative controls sampled from the population of Marche, an area with high gastric cancer risk in central Italy. RESULTS: GSTP1 105 A/G and GSTP1 105 G/G genotypes were identified as protective factors, with odds ratio (OR) of 0.4 (95% CI 0.17-0.81, p=0.01) and OR=0.58 (95% CI 0.33-1, p=0.05), respectively. GSTT1-null genotype was identified as a protective factor, with OR=0.48 (95% CI 0.22-0.99, p=0.04). There was no significant difference between cases and controls for XPD 751 A/C, ERCC1 118 T/C, XRCC3 241 C/T, XRCC1 399 G/A, XPD 312 G/A, GSTM1-null/positive and MS 919 A/G polymorphisms. CONCLUSIONS: This study suggests that GSTP1 105A/G and GSTT1-null/positive genotypes might be associated with a reduced risk for sporadic diffuse gastric cancer. Clin Chem Lab Med 2007;45:822-8.

Pharmacogenetic profiling and clinical outcome of patients with advanced gastric cancer treated with palliative chemotherapy.

PURPOSE: To investigate whether polymorphisms with putative influence on fluorouracil/cisplatin activity are associated with clinical outcomes of patients with advanced gastric cancer (AGC). PATIENTS AND METHODS: Peripheral blood samples from 175 prospectively enrolled AGC patients treated with fluorouracil/cisplatin palliative chemotherapy were used for genotyping 13 polymorphisms in nine genes (TS, MTHFR, XPD, ERCC1, XRCC1, XRCC3, GSTPI, GSTTI, GSTMI). Genotypes were correlated to response and survival. RESULTS: The overall response rate was 41%, the median progression-free survival (PFS) was 24 weeks (range, 4 to 50 weeks), and the median overall survival (OS) was 39 weeks (range, 8 to 72+ weeks). Chemoresistance and poor survival were significantly associated with TS 5'-UTR 3G-genotype (2R/3G, 3C/3G, 3G/3G) and GSTP1 105 A/A homozygous genotype. Sixty-one patients (35%) did not show any of these risk genotypes (group 0), 57 patients (32.5%) showed one of the two risk genotypes (group 1), and 57 patients (32.5%) showed both risk genotypes (group 2). Median PFS and OS in group 0 patients were 32 weeks (range, 8 to 50 weeks) and 49 weeks (range, 18 to 72+ weeks), respectively. Group 1 and group 2 patients showed significantly worse PFS (median, 26 weeks [range, 6 to 44 weeks] and 14 weeks [range, 4 to 38 weeks], respectively) and worse OS (median, 39 weeks [range, 10 to 58 weeks] and 28 weeks [range, 8 to 56 weeks]), respectively, than group 0 patients. This adverse effect was retained in multivariate analysis. CONCLUSION: Specific polymorphisms may influence clinical outcomes of AGC patients. Selecting palliative chemotherapy on the basis of pretreatment genotyping may represent an innovative strategy that warrants prospective studies.

Methylenetetrahydrofolate reductase 677C/T gene polymorphism, gastric cancer susceptibility and genomic DNA hypomethylation in an at-risk Italian population.

We performed a case-control study to examine the relationship between MTHFR C677T gene polymorphism (MTHFR677C/T) and gastric cancer susceptibility in at-risk populations in central Italy. To explore genomic DNA hypomethylation as a potential etiologic mechanism, this phenomenon was evaluated in carriers of the MTHFR677T/T genotype and carriers of the wild-type MTHFR677C/C genotype. Lymphocyte genomic DNA from 162 gastric cancer patients and 164 controls was used for MTHFR677C/T genotyping. Unconditional regression analysis with ORs and 95% CIs was used to investigate the association of the polymorphism with disease. Genomic DNA methylation status by an established enzymatic assay that measures the DNA accepting capacity of methyl groups (inversely related to endogenous methylation) was assessed in a random sample of 40 carriers of the wild-type MTHFR677C/C genotype and 40 carriers of the MTHFR677T/T genotype. The global allelic distribution was in Hardy-Weinberg equilibrium. The MTHFR677T allele was significantly associated with gastric cancer risk with an OR of 2.49 (95% CI 1.48-4.20) in heterozygous MTHFR677C/T carriers and an OR of 2.85 (95% CI 1.52-5.35) in homozygous MTHFR677T/T carriers. This risk association was retained in subgroup analyses by tumor histotype and location. Genomic DNA hypomethylation status in MTHFR677T/T carriers was significantly higher than in subjects with wild-type MTHF677C/C genotype (p = 0.012). In the studied population, MTHFR677T played the role of a moderate-penetrance gastric cancer susceptibility allele. Possession of the MTHFR677T/T genotype was significantly associated with genomic DNA hypomethylation. These findings deserve further investigation in the context of novel strategies for gastric cancer prevention.

Elderly patients with advanced colorectal cancer: tolerability and activity of chemotherapy.

AIMS AND BACKGROUND: Colorectal cancer is the most common gastrointestinal tumor in Western countries and is increasing in elderly patients. In recent years, new treatments based on the use of 5-fluorouracil associated with oxaliplatin or CPT-11 have shown promising activity. The aim of the present study was to analyze the tolerability and activity of chemotherapy with 5-fluorouracil plus oxaliplatin or CPT-11 in elderly patients with advanced colorectal cancer. METHODS: Patients aged 70 years or older with advanced colorectal cancer were treated with 5-fluorouracil (400 mg/m2 in bolus and 600 mg/m2 in a 22-hr continuous infusion on days 1-2) plus folinic acid (100 mg/m2) associated to oxaliplatin (85 mg/m2 on day 1, FOLFOX regimen) or CPT-11 (180 mg/m2 on day 1, FOLFIRI regimen), every 14 days. RESULTS: Twenty-nine patients with a median age of 76 years (range, 70-82) were treated with FOLFOX or FOLFIRI as first-line chemotherapy for metastatic disease. We observed a partial response in 8/29 (27.6%), stable disease in 11/29 (37.9%) and progressive disease in 10/29 (34.5%). Median survival was 21 months; 1-year survival probability was 89.8%. Grade III leukopenia was observed in 2/29 (7%) patients and grade III diarrhea in 1/29 patients. No other grade III-IV toxicity was observed. CONCLUSIONS: FOLFOX and FOLFIRI appear to be active and well tolerated regimens for elderly patients with advanced colorectal cancer.

Predictive and prognostic role of E-cadherin protein expression in patients with advanced gastric carcinomas treated with palliative chemotherapy.

Loss of E-cadherin expression has been related with an adverse outcome in patients with resected gastric cancer. More recently, experimental models with cancer cell lines showed that chemosensitivity may be affected by the E-cadherin expression status. We investigated whether E-cadherin expression is correlated with the response to chemotherapy and the survival of patients with advanced gastric cancer. Consecutive patients with advanced gastric cancer who underwent palliative chemotherapy were considered eligible for study entry. Measurable disease, complete follow-up information and availability of tumor specimens for immunohistochemistry were mandatory inclusion criteria. In 70 assessable patients, 30 patients had locoregional disease and 40 patients had visceral metastases. Chemotherapy consisted of cisplatin/fluorouracil/folinic acid in 33 patients and cisplatin/fluorouracil/epirubicin/folinic acid in 37 patients. There were 13 patients with complete response, 20 with partial response, 20 with stable disease and 17 patients progressed. Thirty-eight patients had > 80% E-cadherin-positive cancer cells (positive E-cadherin expression); 15 cases showed 25-70% (reduced E-cadherin expression), and in the remaining 17 cases E-cadherin expression was < 10% (negative E-cadherin expression). The response to chemotherapy was unrelated to the E-cadherin expression status. Conversely, survival in the 32 patients with reduced/negative E-cadherin expression (25 weeks) was significantly worse than that observed in the 38 patients with preserved E-cadherin expression (36 weeks) (p < 0.01). E-cadherin expression retained its independent prognostic role in the multivariate analysis. E-cadherin expression may give prognostic information in patients with advanced gastric cancer, but it does not seem to possess a predictive role in vivo. Some of the mechanisms inducing E-cadherin downregulation, like hypermethylation, may be potentially reversible, and they deserve further investigation as the target of novel therapeutic strategies.

Prognostic analysis of E-cadherin gene promoter hypermethylation in patients with surgically resected, node-positive, diffuse gastric cancer.

PURPOSE: Recent investigations have demonstrated that hypermethylation is a frequent mechanism for silencing tumor suppressor genes. This is a potentially reversible epigenetic change, and it is the target of a novel class of anticancer compounds with demethylating activity. Better understanding of the clinical implications of hypermethylation will allow the optimal planning of future trials with demethylating drugs. In this perspective, we investigated whether hypermethylation in the CDH1 promoter region is correlated with poor prognosis of patients with surgically resected, node-positive, diffuse gastric cancer. EXPERIMENTAL DESIGN: Consecutive cases of diffuse gastric cancer were considered eligible for study entry. Additional inclusion criteria were radical surgery with a minimum of D1 lymphadenectomy, complete follow-up information, and availability of tumor specimens for methylation-specific PCR and immunohistochemistry analyses. RESULTS: CDH1 promoter hypermethylation was found in 40 of 73 cases (54%), and it was significantly associated with worse prognosis. In patients with and without hypermethylation, the 5-year event-free survival rate was 30% and 62%, respectively, and the 5-year overall survival rate was 35% and 67%, respectively. CDH1 promoter hypermethylation retained its prognostic role for disease-free survival (P < 0.001) and overall survival (P < 0.001) in multivariate analysis. Immunohistochemistry showed a significant association between CDH1 methylation and E-cadherin expression (P < 0.001). CONCLUSIONS: This study shows adverse prognostic effect of CDH1 promoter hypermethylation in patients with diffuse gastric cancer. This form of cancer, and other types with frequent hypermethylation and silencing of critical tumor suppressor genes, would make appropriate targets for the testing of novel compounds with demethylating activity.