Alfredo Carrato

NAT2 slow acetylation, GSTM1 null genotype, and risk of bladder cancer: results from the Spanish Bladder Cancer Study and meta-analyses

BACKGROUND Many reported associations between common genetic polymorphisms and complex diseases have not been confirmed in subsequent studies. An exception could be the association between NAT2 slow acetylation, GSTM1 null genotype, and bladder-cancer risk. However, current evidence is based on meta-analyses of relatively small studies (range 23-374 cases) with some evidence of publication bias and study heterogeneity. Associations between polymorphisms in other NAT and GST genes and bladder-cancer risk have been inconsistent. METHODS We investigated polymorphisms in NAT2, GSTM1, NAT1, GSTT1, GSTM3, and GSTP1 in 1150 patients with transitional-cell carcinoma of the urinary bladder and 1149 controls in Spain; all the participants were white. We also carried out meta-analyses of NAT2, GSTM1, and bladder cancer that included more than twice as many cases as in previous reports. FINDINGS In our study, the odds ratios for bladder cancer for individuals with deletion of one or two copies of the GSTM1 gene were 1.2 (95% CI 0.8-1.7) and 1.9 (1.4-2.7) respectively (p for trend <0.0001). Compared with NAT2 rapid or intermediate acetylators, NAT2 slow acetylators had an increased overall risk of bladder cancer (1.4 [1.2-1.7]) that was stronger for cigarette smokers than for never smokers (p for interaction 0.008). No significant associations were found with the other polymorphisms. Meta-analyses showed that the overall association for NAT2 was robust (p<0.0001), and case-only meta-analyses provided support for an interaction between NAT2 and smoking (p for interaction 0.009). The overall association for GSTM1 was also robust (p<0.0001) and was not modified by smoking status (p=0.86). INTERPRETATION The GSTM1 null genotype increases the overall risk of bladder cancer, and the NAT2 slow-acetylator genotype increases risk particularly among cigarette smokers. These findings provide compelling evidence for the role of common polymorphisms in the aetiology of cancer. RELEVANCE TO PRACTICE Although the relative risks are modest, these polymorphisms could account for up to 31% of bladder cancers because of their high prevalence.

Randomized Phase III Study of Gemcitabine-Cisplatin Versus Etoposide-Cisplatin in the Treatment of Locally Advanced or Metastatic Non–Small-Cell Lung Cancer

PURPOSE We conducted a randomized trial to compare gemcitabine-cisplatin with etoposide-cisplatin in the treatment of patients with advanced non-small-cell lung cancer (NSCLC). The primary end point of the comparison was response rate. PATIENTS AND METHODS A total of 135 chemotherapy-naive patients with advanced NSCLC were randomized to receive either gemcitabine 1,250 mg/m2 intravenously (IV) days 1 and 8 or etoposide 100 mg/m2 IV days 1 to 3 along with cisplatin 100 mg/m2 IV day 1. Both treatments were administered in 21-day cycles. One hundred thirty-three patients were included in the intent-to-treat analysis of response. RESULTS The response rate (externally validated) for patients given gemcitabine-cisplatin was superior to that for patients given etoposide-cisplatin (40.6% v 21.9%; P = .02). This superior response rate was associated with a significant delay in time to disease progression (6.9 months v 4.3 months; P = .01) without an impairment in quality of life (QOL). There was no statistically significant difference in survival time between both arms (8.7 months for gemcitabine-cisplatin v 7.2 months for etoposide-cisplatin; P = .18). The overall toxicity profile for both combinations of drugs was similar. Nausea and vomiting were reported more frequently in the gemcitabine arm than in the etoposide arm. However, the difference was not significant. Gemcitabine-cisplatin produced less grade 3 alopecia (13% v 51%) and less grade 4 neutropenia (28% v 56% ) but more grade 3 and 4 thrombocytopenia (56% v 13%) than did etoposide-cisplatin. However, there were no thrombocytopenia-related complications in the gemcitabine arm. CONCLUSION Compared with etoposide-cisplatin, gemcitabine-cisplatin provides a significantly higher response rate and a delay in disease progression without impairing QOL in patients with advanced NSCLC.

Prospective Study of FGFR3 Mutations As a Prognostic Factor in Nonmuscle Invasive Urothelial Bladder Carcinomas

PURPOSE To determine the frequency and the prognostic value of fibroblast growth factor receptor 3 (FGFR3) mutations in patients with nonmuscle invasive bladder tumors according to tumor stage and grade. PATIENTS AND METHODS Seven hundred seventy-two patients with newly diagnosed bladder tumors were recruited. Tumors were reviewed by expert pathologists. Patients were prospectively followed-up (median, 62.6 months for disease-free patients) through review of hospital records and telephone interviews. The sequence of exons 7 and 10 of FGFR3 was analyzed by polymerase chain reaction and direct sequencing. We assessed the association of mutations with stage and grade. The predictive value of mutations for recurrence, progression, and mortality were assessed using Kaplan-Meier and Cox multivariable models. RESULTS Mutations were more common among low malignant potential neoplasms (LMPN; 77%) and TaG1/TaG2 tumors (61%/58%) than among TaG3 tumors (34%) and T1G3 tumors (17%). The S249C, Y375C, S248C, and G372C mutations accounted for 91.5% of all sequence changes. The A393E substitution was associated with LMPN (P < .001). The F386L polymorphism was more frequent among patients with low-grade tumors (odds ratio, 6.97; 95%CI, 1.40 to 47.06; P = .009). In the multivariable analysis of all superficial tumors, mutations were associated with increased risk of recurrence. However, in the stratified analyses only patients with TaG1 tumors had a significantly higher risk of recurrence (hazard ratio, 2.12; 95%CI, 1.28 to 3.53; P = .004). CONCLUSION The findings of this large study strongly support the notion that FGFR3 mutations characterize a subgroup of bladder cancers with good prognosis; patients with mutant TaG1 tumors have a higher risk of recurrence; and the F386L variant is selectively associated with low-grade tumors.

Phase III Study of Capecitabine Plus Oxaliplatin Compared With Continuous-Infusion Fluorouracil Plus Oxaliplatin As First-Line Therapy in Metastatic Colorectal Cancer: Final Report of the Spanish Cooperative Group for the Treatment of Digestive Tumors Trial

PURPOSE The aim of this phase III trial was to compare the efficacy and safety of capecitabine plus oxaliplatin (XELOX) versus Spanish-based continuous-infusion high-dose fluorouracil (FU) plus oxaliplatin (FUOX) regimens as first-line therapy for metastatic colorectal cancer (MCRC). PATIENTS AND METHODS A total of 348 patients were randomly assigned to receive XELOX (oral capecitabine 1,000 mg/m2 bid for 14 days plus oxaliplatin 130 mg/m2 on day 1 every 3 weeks) or FUOX (continuous-infusion FU 2,250 mg/m2 during 48 hours on days 1, 8, 15, 22, 29, and 36 plus oxaliplatin 85 mg/m2 on days 1, 15, and 29 every 6 weeks). RESULTS There were no significant differences in efficacy between XELOX and FUOX arms, which showed, respectively, median time to tumor progression (TTP; 8.9 v 9.5 months; P = .153); median overall survival (18.1 v 20.8 months; P = .145); and confirmed response rate (RR; 37% v 46%; P = .539). The safety profile of the two regimens was similar, although there were lower rates of grade 3/4 diarrhea (14% v 24%) and grade 1/2 stomatitis (28% v 43%), and higher rates of grade 1/2 hyperbilirubinemia (37% v 21%) and grade 1/2 hand-foot syndrome (14% v 5%) with XELOX versus FUOX, respectively. CONCLUSION This randomized study shows a similar TTP of XELOX compared with FUOX in the first-line treatment of MCRC, although there was a trend for slightly lower RR and survival. XELOX can be considered as an alternative to FUOX.

Genomic DNA hypomethylation as a biomarker for bladder cancer susceptibility in the Spanish Bladder Cancer Study: a case-control study.

BACKGROUND DNA hypomethylation has been suggested to cause genomic instability and increase cancer risk. We aimed to test the hypothesis that DNA hypomethylation is associated with increased risk of bladder cancer. METHODS We measured cytosine methylation (5-mC) content in genomic DNA from blood cells from patients with bladder cancer enrolled in a large case-control study in Spain between Jan 1, 1998, and Dec 31, 2001. Cases were men and women with newly diagnosed and histologically confirmed urothelial carcinoma of the bladder. Controls were selected from patients admitted to the same hospital for diseases or conditions unrelated to smoking or other known risk factors for bladder cancer. Controls were individually matched to cases on age (within 5 years), sex, race, and area of hospital referral. 5-mC content was measured in leucocyte DNA by use of a combination of high-performance capillary electrophoresis, Hpa II digestion, and densitometry. Data on demographics, 34 polymorphisms in nine folate metabolism genes, and nutritional intake of six B vitamins (including folate), alcohol, and smoking were assessed as potential confounders. Relative 5-mC content was expressed as a percentage (%5-mC) with respect to the total cytosine content (the sum of methylated and non-methylated cytosines). The primary endpoint was median %5-mC DNA content. FINDINGS %5-mC was measured in leucocyte DNA from 775 cases and 397 controls. Median %5-mC DNA was significantly lower in cases (3.03% [IQR 2.17-3.56]) than in controls (3.19% [2.46-3.68], p=0.0002). All participants were subsequently categorised into quartiles by %5-mC content in controls. When the highest quartile of %5-mC content was used as the reference category (Q4), the following adjusted odds ratios (OR) and 95% CI were recorded for decreasing methylation quartiles: OR(Q3) 2.05 (95% CI 1.37-3.06); OR(Q2) 1.62 (1.07-2.44); and OR(Q1) 2.67 (1.77-4.03), p for trend <0.0001. The lowest cancer risk was noted in never smokers in the highest methylation quartile (never smokers in Q4). By comparison with never smokers in the highest quartile, current smokers in the lowest methylation quartile had the highest risk of bladder cancer (Q1: OR 25.51 [9.61-67.76], p for interaction 0.06). In analyses stratified by smoking, hypomethylation was a strong risk factor in never smokers (OR 6.39 [2.37-17.22]). Amount of methylation in controls were not associated with baseline characteristics, micronutrients, or selected genotypes in folate metabolism pathways. INTERPRETATION For the first time, to our knowledge, we have shown in a large case-control study that leucocyte DNA hypomethylation is associated with increased risk of developing bladder cancer, and this association is independent of smoking and the other assessed risk factors. Amount of global methylation in genomic DNA could provide a useful biomarker of susceptibility to certain cancer types and further research is warranted.

PIK3CA Mutations Are an Early Genetic Alteration Associated with FGFR3 Mutations in Superficial Papillary Bladder Tumors

Bladder tumors constitute a very heterogeneous disease. Superficial tumors are characterized by a high prevalence of FGFR3 mutations and chromosome 9 alterations. High-grade and muscle-invasive tumors are characterized by Tp53 mutations and aneuploidy. We have analyzed the sequence of exons 9 and 20 of PIK3CA in a panel of bladder tumors covering the whole spectrum of the disease. DNA from formalin-fixed, paraffin-embedded tumor sections was amplified by PCR and products were sequenced. In an unselected panel of tumors representative of the disease, the PIK3CA mutation prevalence was 13% (11 of 87). Mutations occurred mainly at the previously identified hotspots (codons 542, 545, 1007, and 1047). The distribution according to stage was as follows: papillary urothelial neoplasms of uncertain malignant potential (PUNLMP; 11 of 43, 25.6%), T(a) (9 of 57, 16%), T(1) (2 of 10, 20%), and muscle-invasive tumors (0 of 20, 0%; P = 0.019). Mutations were associated with low-grade tumors: grade 1 (6 of 27, 22.2%), grade 2 (3 of 23, 13%), and grade 3 (2 of 37, 5.4%; P = 0.047). Overall, PIK3CA mutations were strongly associated with FGFR3 mutations: 18 of 69 (26%) FGFR3(mut) tumors were PIK3CA(mut), versus 4 of 58 (6.9%) FGFR3(wt) tumors (P = 0.005). Our findings indicate that PIK3CA mutations are a common event that can occur early in bladder carcinogenesis and support the notion that papillary and muscle-invasive tumors arise through different molecular pathways. PIK3CA may constitute a novel diagnostic and prognostic tool, as well as a therapeutic target, in bladder cancer.

Gene Expression Signatures Predict Outcome in Non–Muscle-Invasive Bladder Carcinoma: A Multicenter Validation Study

Purpose: Clinically useful molecular markers predicting the clinical course of patients diagnosed with non–muscle-invasive bladder cancer are needed to improve treatment outcome. Here, we validated four previously reported gene expression signatures for molecular diagnosis of disease stage and carcinoma in situ (CIS) and for predicting disease recurrence and progression. Experimental Design: We analyzed tumors from 404 patients diagnosed with bladder cancer in hospitals in Denmark, Sweden, England, Spain, and France using custom microarrays. Molecular classifications were compared with pathologic diagnosis and clinical outcome. Results: Classification of disease stage using a 52-gene classifier was found to be highly significantly correlated with pathologic stage (P < 0.001). Furthermore, the classifier added information regarding disease progression of Ta or T1 tumors (P < 0.001). The molecular 88-gene progression classifier was highly significantly correlated with progression-free survival (P < 0.001) and cancer-specific survival (P = 0.001). Multivariate Cox regression analysis showed the progression classifier to be an independently significant variable associated with disease progression after adjustment for age, sex, stage, grade, and treatment (hazard ratio, 2.3; P = 0.007). The diagnosis of CIS using a 68-gene classifier showed a highly significant correlation with histopathologic CIS diagnosis (odds ratio, 5.8; P < 0.001) in multivariate logistic regression analysis. Conclusion: This multicenter validation study confirms in an independent series the clinical utility of molecular classifiers to predict the outcome of patients initially diagnosed with non–muscle-invasive bladder cancer. This information may be useful to better guide patient treatment.

Smoking and Bladder Cancer in Spain: Effects of Tobacco Type, Timing, Environmental Tobacco Smoke, and Gender

We examined the effects of dose, type of tobacco, cessation, inhalation, and environmental tobacco smoke exposure on bladder cancer risk among 1,219 patients with newly diagnosed bladder cancer and 1,271 controls recruited from 18 hospitals in Spain. We used unconditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for the association between bladder cancer risk and various characteristics of cigarette smoking. Current smokers (men: OR, 7.4; 95% CI, 5.3-10.4; women: OR, 5.1; 95% CI, 1.6-16.4) and former smokers (men: OR, 3.8; 95% CI, 2.8-5.3; women: OR, 1.8; 95% CI, 0.5-7.2) had significantly increased risks of bladder cancer compared with nonsmokers. We observed a significant positive trend in risk with increasing duration and amount smoked. After adjustment for duration, risk was only 40% higher in smokers of black tobacco than that in smokers of blond tobacco (OR, 1.4; 95% CI, 0.98-2.0). Compared with risk in current smokers, a significant inverse trend in risk with increasing time since quitting smoking blond tobacco was observed (≥20 years cessation: OR, 0.2; 95% CI, 0.1-0.9). No trend in risk with cessation of smoking black tobacco was apparent. Compared with men who inhaled into the mouth, risk increased for men who inhaled into the throat (OR, 1.7; 95% CI, 1.1-2.6) and chest (OR, 1.5; 95% CI, 1.1-2.1). Cumulative occupational exposure to environmental tobacco smoke seemed to confer increased risk among female nonsmokers but not among male nonsmokers. After eliminating the effect of cigarette smoking on bladder cancer risk in our study population, the male-to-female incidence ratio decreased from 8.2 to 1.7, suggesting that nearly the entire male excess of bladder cancer observed in Spain is explained by cigarette smoking rather than occupational/environmental exposures to other bladder carcinogens. (Cancer Epidemiol Biomarkers Prev 2006;15(7):1348–54)

Genetic Variation in the Nucleotide Excision Repair Pathway and Bladder Cancer Risk

Nucleotide excision repair (NER) is critical for protecting against damage from carcinogens in tobacco smoke. We evaluated the influence of common genetic variation in the NER pathway on bladder cancer risk by analyzing 22 single nucleotide polymorphisms (SNP) in seven NER genes (XPC, RAD23B, ERCC1, ERCC2, ERCC4, ERCC5, and ERCC6). Our study population included 1,150 patients with transitional cell carcinoma of the urinary bladder and 1,149 control subjects from Spain. Odds ratios (OR) and 95% confidence intervals (95% CI) were adjusted for age, gender, region, and smoking status. Subjects with the variant genotypes for SNPs in four of the seven genes evaluated had small increases in bladder cancer risk compared to subjects with the homozygous wild-type genotypes: RAD23B IVS5-15A>G (OR, 1.3; 95% CI, 1.1-1.5; P = 0.01), ERCC2 R156R (OR, 1.3; 95% CI, 1.1-1.6; P = 0.006), ERCC1 IVS5+33A>C (OR, 1.2; 95% CI, 1.0-1.5; P = 0.06; Ptrend = 0.04), and ERCC5 M254V (OR, 1.4; 95% CI, 1.0-2.0; P = 0.04). A global test for pathway effects indicated that genetic variation in NER characterized by the 22 SNPs analyzed in this study significantly predicts bladder cancer risk (P = 0.04). Pairwise comparisons suggested that carrying variants in two genes could result in substantial increases in risk. Classification tree analyses suggested the presence of subgroups of individuals defined by smoking and NER genotypes that could have substantial increases in risk. In conclusion, these findings provide support for the influence of genetic variation in NER on bladder cancer risk. A detailed characterization of genetic variation in key NER genes is warranted and might ultimately help identify multiple susceptibility variants that could be responsible for substantial joint increases in risk. (Cancer Epidemiol Biomarkers Prev 2006;15(3):536–42)

Recurrent inactivation of STAG2 in bladder cancer is not associated with aneuploidy

Urothelial bladder cancer (UBC) is heterogeneous at the clinical, pathological and genetic levels. Tumor invasiveness (T) and grade (G) are the main factors associated with outcome and determine patient management. A discovery exome sequencing screen (n = 17), followed by a prevalence screen (n = 60), identified new genes mutated in this tumor coding for proteins involved in chromatin modification (MLL2, ASXL2 and BPTF), cell division (STAG2, SMC1A and SMC1B) and DNA repair (ATM, ERCC2 and FANCA). STAG2, a subunit of cohesin, was significantly and commonly mutated or lost in UBC, mainly in tumors of low stage or grade, and its loss was associated with improved outcome. Loss of expression was often observed in chromosomally stable tumors, and STAG2 knockdown in bladder cancer cells did not increase aneuploidy. STAG2 reintroduction in non-expressing cells led to reduced colony formation. Our findings indicate that STAG2 is a new UBC tumor suppressor acting through mechanisms that are different from its role in preventing aneuploidy.