Isao Oze

DNA methylation in peripheral blood: a potential biomarker for cancer molecular epidemiology.

Aberrant DNA methylation is associated with cancer development and progression. There are several types of specimens from which DNA methylation pattern can be measured and evaluated as an indicator of disease status (from normal biological process to pathologic condition) and even of pharmacologic response to therapy. Blood-based specimens such as cell-free circulating nucleic acid and DNA extracted from leukocytes in peripheral blood may be a potential source of noninvasive cancer biomarkers. In this article, we describe the characteristics of blood-based DNA methylation from different biological sources, detection methods, and the factors affecting DNA methylation. We provide a comprehensive literature review of blood-based DNA methylation as a cancer biomarker and focus on the study of DNA methylation using peripheral blood leukocytes. Although DNA methylation patterns measured in peripheral blood have great potential to be useful and informative biomarkers of cancer risk and prognosis, large systematic and unbiased prospective studies that consider biological plausibility and data analysis issues will be needed in order to develop a clinically feasible blood-based assay.

Twenty-Seven Years of Phase III Trials for Patients with Extensive Disease Small-Cell Lung Cancer: Disappointing Results

Background Few studies have formally assessed whether treatment outcomes have improved substantially over the years for patients with extensive disease small-cell lung cancer (ED-SCLC) enrolled in phase III trials. The objective of the current investigation was to determine the time trends in outcomes for the patients in those trials. Methods and Findings We searched for trials that were reported between January 1981 and August 2008. Phase III randomized controlled trials were eligible if they compared first-line, systemic chemotherapy for ED-SCLC. Data were evaluated by using a linear regression analysis. Results: In total, 52 trials were identified that had been initiated between 1980 and 2006; these studies involved 10,262 patients with 110 chemotherapy arms. The number of randomized patients and the proportion of patients with good performance status (PS) increased over time. Cisplatin-based regimens, especially cisplatin and etoposide (PE) regimen, have increasingly been studied, whereas cyclophosphamide, doxorubicin, and vincristine–based regimens have been less investigated. Multiple regression analysis showed no significant improvement in survival over the years. Additionally, the use of a PE regimen did not affect survival, whereas the proportion of patients with good PS and the trial design of assigning prophylactic cranial irradiation were significantly associated with favorable outcome. Conclusions and Significance The survival of patients with ED-SCLC enrolled in phase III trials did not improve significantly over the years, suggesting the need for further development of novel targets, newer agents, and comprehensive patient care.

Diabetes mellitus and cancer risk: pooled analysis of eight cohort studies in Japan.

Although a growing body of evidence suggests a link between diabetes and cancer, it is not clear whether diabetes independently increases the risk of cancer. We conducted a comprehensive assessment of the association between pre‐existing diabetes and total and site‐specific cancer risk based on a pooled analysis of eight cohort studies in Japan (>330 000 subjects). We estimated a summary hazard ratio by pooling study‐specific hazard ratios for total and site‐specific cancer by using a random‐effects model. A statistically increased risk was observed for cancers at specific sites, such as colon (hazard ratio; HR = 1.40), liver (HR = 1.97), pancreas (HR = 1.85) and bile duct (HR = 1.66; men only). Increased risk was also suggested for other sites, and diabetes mellitus was associated with an overall 20% increased risk in total cancer incidence in the Japanese population. The association between these two diseases has important implications for reiterating the importance of controlling lifestyle factors and may suggest a possible strategy for cancer screening among patients with diabetes. Studies continuously investigating the risk factors for diabetes are also important.

Impact of Multiple Alcohol Dehydrogenase Gene Polymorphisms on Risk of Upper Aerodigestive Tract Cancers in a Japanese Population

Alcohol intake is positively associated with the risk of upper aerodigestive tract (UAT) cancer. The genes that encode alcohol-metabolizing enzymes, primarily alcohol dehydrogenases (ADH) and aldehyde dehydrogenases (ALDH), are polymorphic. In Caucasians, significant associations between polymorphisms in ADH1B (rs1229984) and ADH1C (rs698 and rs1693482), and UAT cancer have been observed, despite strong linkage disequilibrium among them. Moreover, UAT cancer was significantly associated with rs1573496 in ADH7, and not with rs1984362 in ADH4. However, little evidence is available concerning ADH4 or ADH7 polymorphisms in Asian populations. We conducted a matched case-control study to clarify the role of ADH polymorphisms in a Japanese population. Cases and controls were 585 patients with UAT cancer and 1,170 noncancer outpatients. Genotyping for ADHs and ALDH2 was done using TaqMan assays. Associations between polymorphisms and UAT cancer were assessed by odds ratios and 95% confidence intervals using conditional logistic regression models that adjusted for age, sex, smoking, drinking, and ALDH2. Adjusted odds ratios were significant for rs4148887 and rs3805322 in ADH4, rs1229984 in ADH1B, rs698 and rs1693482 in ADH1C, and rs284787, rs1154460, and rs3737482 in ADH7. We also observed that ADH7 rs3737482 and ADH4 rs4148887 had independently and statistically significant effects on UAT cancer. The magnitude of effect of these ADH polymorphisms was greater in subjects who were heavy drinkers, heavy smokers, and had esophageal cancer. These findings show that multiple ADH gene polymorphisms were associated with UAT cancer in this Japanese population. Further studies in various ethnicities are required. (Cancer Epidemiol Biomarkers Prev 2009;18(11):3097–102)

Comparison between self‐reported facial flushing after alcohol consumption and ALDH2 Glu504Lys polymorphism for risk of upper aerodigestive tract cancer in a Japanese population

Some Japanese exhibit facial flushing after drinking alcohol. Facial flushing was considered to be caused by acetaldehydemia. The concentration of blood acetaldehyde was concerned with the catalytic activity of acetaldehyde dehydrogenase (ALDH). Acetaldehyde dehydrogenase (ALDH)‐2 polymorphism (rs671, Glu504Lys) was known to be associated with upper aerodigestive tract (UAT) cancer due to modulation of ALDH2 enzyme activity. It remains controversial whether facial flushing is useful in predicting UAT cancer risk as a surrogate marker of ALDH2 polymorphism. We conducted a case–control study to assess the risk of UAT cancer and facial flushing and ALDH2 polymorphism. Cases and controls were 585 UAT cancer patients and matched 1170 noncancer outpatients of Aichi Cancer Center Hospital. Information on facial flushing and other lifestyle factors was collected via a self‐administered questionnaire. Association between facial flushing, polymorphism, and UAT cancer was assessed by odds ratios and 95% confidence intervals by using conditional logistic regression models. The facial flushing had no significant association with UAT cancer, although ALDH2 Lys allele was significantly associated with UAT cancer. No significant interaction between facial flushing and alcohol consumption was observed in this study, whereas ALDH2 Lys allele had significant association with UAT cancer. The misclassification between facial flushing and ALDH2 genotype was observed in 18% of controls with ALDH2 Glu/Glu genotype and in 16% of controls with ALDH2 Glu/Lys genotype. Facial flushing was less useful to predict UAT cancer risk than genotyping ALDH2 polymorphism. (Cancer Sci 2010)

The aldehyde dehydrogenase 2 (ALDH2) Glu504Lys polymorphism interacts with alcohol drinking in the risk of stomach cancer

The impact of alcohol on the risk of stomach cancer is controversial. Although aldehyde dehydrogenase 2 (ALDH2) Glu504Lys (rs671) polymorphism has a strong effect on acetaldehyde metabolism, little is known about its impact on stomach cancer risk when combined with alcohol drinking. This case-control study included a total of 697 incident stomach cancer case subjects and 1372 non-cancer control subjects who visited Aichi Cancer Center between 2001 and 2005. We estimated odds ratios (OR) and 95% confidence intervals (CI) for ALDH2 genotypes and alcohol consumption using logistic regression models after adjustment for potential confounders, including Helicobacter pylori infection. The ALDH2 504Lys allele was associated with the risk of stomach cancer, with adjusted ORs of 1.40 (95% CI, 1.11-1.76) for Glu/Lys and 1.73 (1.12-2.68) for Lys/Lys compared with Glu/Glu. Heavy drinking was associated with risk (OR 1.72, 1.17-2.52) after adjustment for ALDH2 genotype and other confounders. Moreover, ORs for heavy drinking were 1.28 (0.77-2.12) for those with ALDH2 Glu/Glu and 3.93 (1.99-5.79) for those with the ALDH2 Lys allele relative to non-drinkers with the Glu/Glu genotype (P for interaction = 0.0054). In conclusion, ALDH2 and alcohol drinking showed interaction for risk factors of stomach cancer, indicating that acetaldehyde plays a role in stomach carcinogenesis.

Phase II Trial of Gefitinib in Combination with Bevacizumab as First-Line Therapy for Advanced Non–Small Cell Lung Cancer with Activating EGFR Gene Mutations: The Okayama Lung Cancer Study Group Trial 1001

Purpose: Whether bevacizumab enhances the effect of the epidermal growth factor receptor (EGFR) inhibitor gefitinib on EGFR mutant non–small cell lung cancers (NSCLCs) remains unknown. We conducted a phase II trial to investigate the efficacy and safety of gefitinib when combined with bevacizumab as first-line therapy in patients with advanced NSCLC harboring EGFR gene mutations. Methods: In this trial, 42 patients with a performance status of 0 to 2 received gefitinib (250 mg/d) and bevacizumab (15 mg/kg, every 3 weeks). The primary end point of this study was the 1-year progression-free survival (PFS) rate. We assumed that a 1-year PFS rate of 55% would indicate potential usefulness and that a 1-year PFS rate of 40% would constitute the lower limit of interest. Results: Forty-two patients were enrolled in the study with a median age of 73 (range 42–86) years. Activating EGFR gene mutations included exon 19 deletion (57%) and L858R point mutations in exon 21 (38%). The objective response rate was 73.8% and included two complete responses. The 1-year PFS rate and median PFS time were 56.7% (95% confidence interval [CI] 39.9–70.5) and 14.4 months (95% CI 10.1–19.2), respectively. The median PFS differed significantly between EGFR exon 19 deletion and the L858R point mutation (18.0 versus 9.4 months, respectively; p = 0.006). The median overall survival had not yet been reached. Severe adverse events included grade 3 skin rash (15%), hypertension (17%), aspartate transaminase/alanine aminotransferase elevation (17%), proteinuria (7%), intracranial hemorrhage (2%), and grade 4 perforation of the digestive tract (2%). There were no treatment-related deaths. Conclusion: Gefitinib in combination with bevacizumab as first-line therapy seems to be a favorable and well-tolerated treatment for patients with advanced NSCLC with activating EGFR gene mutations, especially those with EGFR exon 19 deletion mutations, although the primary end point was not met because the lower limit of the CI was less than 40%.

Meta-analysis of neutropenia or leukopenia as a prognostic factor in patients with malignant disease undergoing chemotherapy.

PurposeWe performed a systematic review and meta-analysis to determine the impact of neutropenia or leukopenia experienced during chemotherapy on survival.MethodsEligible studies included prospective or retrospective analyses that evaluated neutropenia or leukopenia as a prognostic factor for overall survival or disease-free survival. Statistical analyses were conducted to calculate a summary hazard ratio and 95% confidence interval (CI) using random-effects or fixed-effects models based on the heterogeneity of the included studies.ResultsThirteen trials were selected for the meta-analysis, with a total of 9,528 patients. The hazard ratio of death was 0.69 (95% CI, 0.64–0.75) for patients with higher-grade neutropenia or leukopenia compared to patients with lower-grade or lack of cytopenia. Our analysis was also stratified by statistical method (any statistical method to decrease lead-time bias; time-varying analysis or landmark analysis), but no differences were observed.ConclusionsOur results indicate that neutropenia or leukopenia experienced during chemotherapy is associated with improved survival in patients with advanced cancer or hematological malignancies undergoing chemotherapy. Future prospective analyses designed to investigate the potential impact of chemotherapy dose adjustment coupled with monitoring of neutropenia or leukopenia on survival are warranted.

Impact of smoking on lung cancer risk is stronger in those with the homozygous aldehyde dehydrogenase 2 null allele in a Japanese population

The main lifestyle contributor to acetaldehyde exposure is the drinking of alcoholic beverages, but tobacco smoke also makes some contribution. Although acetaldehyde is associated with upper aerodigestive tract cancer risk, in accordance with genetically determined acetaldehyde metabolism, it is unclear whether lung cancer, a representative smoking-related cancer, is associated with acetaldehyde or genes impacting its metabolism. We conducted a case-control study to examine possible interaction between smoking and aldehyde dehydrogenase 2 (ALDH2) Glu504Lys polymorphism (rs671) on the risk of lung cancer in Japanese. Subjects were 718 lung cancer cases and 1416 non-cancer controls enrolled in the Hospital-based Epidemiologic Research Program at Aichi Cancer Center. Lifestyle factors, including smoking, were determined by self-administered questionnaire. We applied pack-years (PY; categorized into five levels: never, <15, <30, <45 and > or =45) as a marker of cumulative exposure to smoking. The impact of smoking, ALDH2 genotype, and their interaction on lung cancer risk were assessed by odds ratio (OR) and 95% confidence interval adjusted for potential confounders. Adjusted ORs for PY <15, <30, <45 and > or =45 relative to never smokers among those with Glu/Glu or Glu/Lys were 1.39, 1.80, 3.44 and 6.25, respectively (P-trend = 1.4 x 10(-30)). In contrast, ORs among Lys/Lys were 1.01, 10.2, 11.4 and 23.2, respectively (P-trend = 2.6 x 10(-7)). Interaction between ALDH2 genotype (Glu/Glu + Glu/Lys versus Lys/Lys) and cumulative smoking dose was statistically significant (P = 0.036) and was consistently observed in the analysis among never-drinkers (interaction P = 0.041). These results suggest that ALDH2 Lys/Lys, a null enzyme activity genotype, modifies the impact of smoking on the risk of lung cancer.

Folate, alcohol, and aldehyde dehydrogenase 2 polymorphism and the risk of oral and pharyngeal cancer in Japanese

Folate consumption is inversely associated with the risk of oral and pharyngeal cancer (OPC) and potentially interacts with alcohol drinking in the risk of OPC. Aldehyde dehydrogenase 2 (ALDH2) gene polymorphism is known to interact with alcohol consumption. The aim of this study was to investigate potential interaction between folate, alcohol drinking, and ALDH2 polymorphism in the risk of OPC in a Japanese population. The study group comprised 409 head and neck cancer cases and 1227 age-matched and sex-matched noncancer controls; of these, 251 cases and 759 controls were evaluated for ALDH rs671 polymorphism. Associations were assessed by odds ratios and 95% confidence intervals in multiple logistic regression models. We observed an inverse association between folate consumption and OPC risk. The odds ratio for high folate intake was 0.53 (95% confidence interval: 0.36–0.77) relative to low intake (P trend=0.003). This association was consistent across strata of sex, age, smoking, and ALDH2 genotypes. Interaction between folate consumption, drinking, and ALDH2 genotype was remarkable (three-way interaction, P<0.001). We observed significant interaction among folate, drinking, and ALDH2 genotype in the Japanese population.