Risk factors for multiple myeloma: A hospital-based case-control study in Northwest China

BackgroundThe distinctive racial/ethnic and geographic distribution of multiple myeloma (MM) suggests that both family history and environmental factors may contribute to its development.MethodsA hospital-based case–control study consisting of 220 confirmed MM cases and 220 individually matched patient controls, by sex, age and hospital was carried out at 5 major hospitals in Northwest China. A questionnaire was used to obtain information on demographics, family history, and the frequency of food items consumed.ResultsBased on multivariate analysis, a significant association between the risk of MM and family history of cancers in first degree relatives was observed (OR = 4.03, 95% CI: 2.50–6.52). Fried food, cured/smoked food, black tea, and fish were not significantly associated with the risk of MM. Intake of shallot and garlic (OR = 0.60, 95% CI: 0.43–0.85), soy food (OR = 0.52, 95% CI: 0.36–0.75) and green tea (OR = 0.38, 95% CI: 0.27–0.53) was significantly associated with a reduced risk of MM. In contrast, intake of brined vegetables and pickle was significantly associated with an increased risk (OR = 2.03, 95% CI: 1.41–2.93). A more than multiplicative interaction on the decreased risk of MM was found between shallot/garlic and soy food.ConclusionOur study in Northwest China found an increased risk of MM with a family history of cancer, a diet characterized by low consumption of garlic, green tea and soy foods, and high consumption of pickled vegetables. The effect of green tea in reducing the risk of MM is an interesting new finding which should be further confirmed.     

Genetic polymorphisms in AURKA,BRCA1, CCNE1 and CDK2 are associated with ovarian cancer susceptibility among Chinese Han women

IntroductionCentrosome aberrations and cell-cycle deregulation have important implications for ovarian cancer development. The AURKA, BRCA1, CCNE1 and CDK2 genes play pivotal roles in centrosome duplication and cell-cycle regulation.MethodsUsing a haplotype-based analysis, this study aimed to investigate whether genetic polymorphisms in these four genes may contribute to ovarian cancer susceptibility. A total of 22 single nucleotide polymorphisms (SNPs) in these four genes were genotyped in 287 cases of ovarian serous cystadenocarcinomas and 618 age-matched cancer-free controls from the Chinese Han population, and then haplotype blocks were reconstructed according to our genotyping data and linkage disequilibrium (LD) status of these SNPs.ResultsFor AURKA, we found that haplotype GA [rs6064391 (T→G) + rs911162 (G→A)] was strongly associated with decreased ovarian cancer risk (adjusted OR = 0.31, 95% CI = 0.15–0.63, P = 0.0012). For BRCA1, we found that haplotype CGTAG was associated with decreased ovarian cancer risk (adjusted OR = 0.64, 95% CI = 0.41–0.98, P = 0.0417). Moreover, women harboring homozygous GA/CGTAG haplotypes showed the lowest risk (OR = 0.12, 95% CI = 0.02–0.94, P = 0.0438). In CCNE1, the SNPs rs3218035 and rs3218042 were significantly associated with increased ovarian cancer risk (rs3218035: adjusted OR = 5.20, 95% CI = 1.85–14.52, P = 0.0017; rs3218042: adjusted OR = 4.98, 95% CI = 1.75–14.19, P = 0.0027). For CDK2, no significant association was found.ConclusionsThis study indicates that genetic polymorphisms of AURKA, BRCA1 and CCNE1 may affect ovarian cancer susceptibility in Chinese Han women.     

Smoking and other risk factors for pancreatic cancer: A cohort study in men in Lithuania

Background: Cancer of the pancreas is a relatively rare, but highly fatal cancer worldwide. Cigarette smoking has been recognized as an important risk factor, but the relation to other potential determinants is still inconsistent. We investigated the association between different lifestyle, biological and anthropometric factors and the risk of pancreatic cancer in a prospective population-based cohort study from Kaunas, Lithuania. Methods: Our study included 7132 urban men initially free from any diagnosed cancer, followed for up to 30 years. 77 incident cases of pancreatic cancer were identified. Cox proportional hazards regression models were used to estimate hazard ratios (HR) and corresponding 95% confidence intervals (95% CI). Results: Compared to never smokers, current smokers had a significantly increased risk of pancreatic cancer, HR was 1.79 (95% CI 1.03–3.09) after adjustment for age, body mass index, education and alcohol consumption. Among smokers, a significant association with higher smoking intensity was shown (≥20 cigarettes/day: HR = 2.60; 95% CI 1.42–4.76, P_trend = 0.046). We also observed a significantly increased risk for ≥30 pack-years of smoking (HR = 2.24; 95% CI 1.12–4.49, P_trend = 0.16) and for age at starting smoking <18 years (HR = 2.29; 95% CI 1.11–4.70, P_trend = 0.43) as compared to never smokers. Alcohol consumption, body mass index and total cholesterol level were not significantly associated with pancreatic cancer. Conclusions: Smoking significantly increases pancreatic cancer incidence and its high prevalence in Lithuania may partly explain high incidence of the disease. No convincing evidence was found that alcohol consumption, body mass index or serum cholesterol level were associated with pancreatic cancer risk, although the assessment was limited by the lack of statistical power.     

Risk factor for clear cell renal cell carcinoma in Chinese population: a case-control study

Background: Risk factors for clear cell renal cell carcinoma (ccRCC) differ among populations and remain controversial. We carried out a hospital-based case–control study to examine the effects of health status, lifestyle, and some genetic polymorphisms on ccRCC risk in Chinese subjects. Methods: Between 2007 and 2009, 250 newly diagnosed, histologically confirmed ccRCC cases and 299 sex-, age-matched healthy controls provided complete information including consumption of tea and alcohol, smoking, occupational exposure, body mass index (BMI), hypertension, diabetes, and urolithiasis by face-to-face interview in Shanghai. Genetic polymorphisms of cytochrome P450 mono-oxygenase (CYP1A1: 6235T>C, 4889A>G, and 4887C>A), glutathione S-transferase (GSTP1: 342A>G), and N-acetyltransferase (NAT2: 481C>T, 590G>A, and 857G>A) were identified by PCR-RFLP and DNA sequencing. Adjusted odds ratio (AOR) and 95% confidence interval (CI) were derived through multivariate logistic regression. Results: Green tea intake (≥500 ml/d) was inversely associated with ccRCC risk, with an AOR of 0.34 (95% CI 0.21–0.55). BMI (≥25 kg/m²), hypertension, and urolithiasis were independently associated with an increased risk of ccRCC, with AOR (95% CI) of 2.10 (1.32–3.34), 2.49 (1.57–3.93), and 3.33 (1.12–9.89), respectively. No association was observed between smoking, alcohol consumption, or occupational exposure with ccRCC risk. The polymorphisms and their interactions with the environmental exposures were mostly not associated with ccRCC risk. Conclusion: BMI (≥25 kg/m²), hypertension, and urolithiasis are independently associated with an increased risk, whereas green tea intake (≥500 ml/d) is independently associated with a decreased risk of ccRCC. The polymorphisms of the xenobiotic-metabolizing enzymes are weakly associated with ccRCC risk in Chinese subjects.     

Consumption of fruits,vegetables, and seaweeds (sea vegetables) and pancreatic cancer risk: The Ohsaki Cohort Study

Studies on the effects of consumption of fruits, vegetables, and seaweeds on the incidence of pancreatic cancer are not conclusive. We examined the association (if any) between the consumption of fruits, vegetables, and seaweeds and the risk of pancreatic cancer in Japan. Data from 32,859 participants registered in the Ohsaki National Health Insurance Cohort Study who were 40–79 years old and free of cancer at baseline were analyzed. Consumption of fruits, vegetables, and seaweeds was assessed at baseline using a self-administered food frequency questionnaire (containing 40 items). Incidences of pancreatic cancer were identified by computer linkage with the Miyagi Prefectural Cancer Registry. During 11 years of follow-up, 137 pancreatic cancers (67 men and 70 women) were identified. The hazard ratios (95% confidence interval) of pancreatic cancer risk for the highest versus the lowest tertile were 0.82 (0.40–1.68, trend P = 0.57) in men and 0.64 (0.35–1.20, trend P = 0.22) in women for total consumption of fruits, 0.89 (0.46–1.73, trend P = 0.76) in men and 0.67 (0.33–1.35, trend P = 0.23) in women for total consumption of vegetables, and 0.92 (0.46–1.84, trend P = 0.81) in men for consumption of seaweeds (results for the consumption of seaweeds in women were not analyzed because of poor reliability), respectively. Total consumption of fruits, vegetables, and seaweeds was not associated with a reduced risk of pancreatic cancer.     

Green tea drinking and risk of pancreatic cancer: A large-scale,population-based case–control study in urban Shanghai

Background: Little is known about the etiology of pancreatic cancer. Epidemiological studies on tea consumption and pancreatic cancer risk have been inconclusive. The purpose of the present study was to investigate the association between green tea drinking and the risk of pancreatic cancer in urban Shanghai, China. Methods: In this population-based case–control study conducted in urban Shanghai, 908 cases of pancreatic cancer and 1067 healthy controls were recruited. Information on tea drinking, including type of tea, amount of tea consumption, temperature of tea, and the duration of regular tea drinking, were collected via interview questionnaire. Results: We examined the association of multiple tea drinking habits with the risk of pancreatic cancer. In women, regular green tea drinking was associated with 32% reduction of pancreatic cancer risk (OR 0.68, 95% CI 0.48–0.96), compared to those who did not drink tea regularly. Increased consumption and longer duration of tea drinking were both associated with reduced pancreatic cancer risk in women. Among regular tea drinkers, lower temperature of tea was associated with reduced risk of pancreatic cancer in both men and women, independent of amount or duration of tea drinking. Conclusions: Habits of green tea drinking, including regular drinking, amount of consumption, persistence of the habit, and tea temperature, may lower pancreatic cancer risk.     

Smoking and alcohol consumption in relation to risk of thyroid cancer in postmenopausal women

Background: Few cohort studies have examined smoking and alcohol consumption in relation to risk of thyroid cancer, and their findings are conflicting. Methods: We therefore assessed the association of smoking and alcohol intake with risk of thyroid cancer in a cohort of 159,340 women enrolled in the Women's Health Initiative. Over 12.7 years of follow-up 331 cases of thyroid cancer, of which 276 were papillary thyroid cancer, were identified. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Results: Compared to never smokers, ever smokers did not have altered risk. Current smokers had reduced risk for all thyroid cancer (HR 0.54, 95% CI 0.29–1.00) and for papillary thyroid cancer (HR 0.34, 95% CI 0.15–0.78); however, the number of current smokers among cases was small. No associations or trends were seen for amount smoked, age of starting smoking, or age at quitting. Smokers of ≥40 pack-years had a significantly reduced risk of papillary thyroid cancer (HR 0.44, 95% CI 0.21–0.89). In contrast, women who had smoked for < 20 years had increased risk of thyroid cancer (HR 1.35, 95% CI 1.05–1.74) and papillary cancer (HR 1.43, 95% CI 1.09–1.89). Alcohol intake was not associated with risk. Conclusion: Our findings suggest that current smoking and having higher pack-years of exposure are associated with a modestly reduced risk of thyroid cancer, whereas alcohol consumption does not appear to affect risk.     

Alcohol consumption and risk of upper-tract urothelial cancer

BackgroundUpper-tract urothelial cancer (UTUC), which includes renal pelvic cancer and ureter cancer, is a rare cancer and its prognosis is poor. Smoking and high-risk occupations (e.g., printing and dyestuff working which involves exposure to aniline dyes) are well-known risk factors for UTUC. However, the risk of alcohol consumption in UTUC remains unclear. This study aimed to determine whether alcohol consumption is an independent risk factor for UTUC.MethodsThe study was a case–control study which used the nationwide clinical inpatient database of the Rosai Hospital group in Japan. We identified 1569 cases and 506,797 controls between 1984 and 2014. We estimated the odds ratio (OR) and 95% confidence interval (95%CI) of alcohol consumption for UTUC – never, up to 15 g/day, >15–30 g/day, or >30 g/day – using unconditional logistic regression. We adjusted for the following covariates: age, sex, study period, hospital, history of smoking, and high-risk occupation.ResultsThe risk of UTUC was significantly higher in ever-drinkers compared with never-drinkers (OR = 1.23, 95%CI, 1.08–1.40; P = 0.001). Compared with never-drinkers, the risk threshold for UTUC was >15 g of alcohol consumption per day (equivalent to 6 ounces of Japanese sake containing 23 g of alcohol). A dose-response was observed (P < 0.001).ConclusionAlcohol consumption may be an independent risk factor for UTUC, with a low-risk threshold of 15 g of alcohol per day.     

IκBα polymorphisms were associated with increased risk of gastric cancer in a southern Chinese population: a case-control study

AimNuclear factor-kappa B inhibitor alpha (IκBα) polymorphisms were found to be associated with inflammatory diseases. However, the association between IκBα polymorphisms with gastric cancer is still unknown. We aim to investigate the association between IκBα polymorphisms and gastric cancer risk in a large population-based case–control study among southern Chinese.Main methodsA population-based case–control study was conducted between 1999 and 2006 in Guangdong Province, China. A total of 1010 gastric cancer patients and 1500 healthy controls were enrolled in this study. IκBα polymorphisms were identified by sequencing of IκBα gene ranging from the 2 kb promoter region to the 3.5 kb genomic region. Polymorphisms in IκBα were analyzed by TaqMan SNP genotyping assay.Key findingsrs17103265 deletion homozygote (?/?) had significantly increased gastric cancer risk (OR = 2.11, 95% CI = 1.17–3.83, P = 0.01), compared with rs17103265 T homozygote (TT). rs17103265 (?/?) genotype was significantly associated with increased risk of intestinal-type gastric cancer with (OR = 2.21, 95% CI = 1.19–4.08, P = 0.01), but not with the diffuse or mix type of gastric cancer. rs17103265 (?/?) was associated with poorly differentiated gastric cancer (OR = 2.05, 95% CI = 1.07–3.94, P = 0.03), but not with moderately or well differentiated gastric cancer. A significant decrease in luciferase activity was observed in rs17103265 deletion allele as compared with the vector containing the rs17103265 T allele (P < 0.0001). rs17103265 polymorphism was not associated with the prognosis of gastric cancer patients.SignificanceIκBα rs17103265 deletion homozygote is a novel genetic risk factor for gastric carcinogenesis, especially for the development of certain subtypes of gastric cancer in southern Chinese population.     

Dietary fat intake and risk of epithelial ovarian cancer in the European Prospective Investigation into Cancer and Nutrition

There are inconsistent and limited data available to assess the relationship between fat intake and risk of epithelial ovarian cancer (EOC). We examined the consumption of total fat, fat sources and fat subtypes in relation to risk of EOC and its major histologic subtypes in the European Prospective Investigation into Cancer and Nutrition which includes incident invasive (n = 1095) and borderline (n = 96) EOC. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). In multivariate models, we observed no association with consumption of total fat, animal or plant fat, saturated fat, cholesterol, monounsaturated fat, or fatty fish and risk of invasive EOC. There was, however, an increased risk of invasive EOC in the highest category of intake (Quartile 4 vs. Quartile 1) of polyunsaturated fat (HR = 1.22, 95% CI = 1.02–1.48, P_trend = 0.02). We did not observe heterogeneity in the risk associations in comparisons of serous and endometrioid histologic subtypes. This study does not support an etiological role for total fat intake in relation to EOC risk; however, based on observations of a positive association between intake of polyunsaturated fat and invasive EOC risk in the current and previous studies, this fat subtype warrants further investigation to determine its potential role in EOC development.     

Polymorphisms in MSH2 gene and risk of gastric cancer, and interactions with lifestyle factors in a Chinese population

Background: Although polymorphisms in DNA mismatch repair (MMR) gene MSH2 have been associated with risks of many cancers, little is known about their etiology role in gastric cancer (GC) and the potential interacting role with lifestyle factors known to damage DNA. Methods: A population-based study was conducted in 3 counties (Jintan, Taixing and Huaian) of Jiangsu Province, the high-risk areas of GC in China. We investigated the association of polymorphisms IVS12?6T>C and IVS10+12G>A in MSH2 gene with the risk of GC and the potential gene–lifestyle interaction. Results: The risk of GC was found to be associated with the IVS12?6C allele (CC vs TT, OR = 2.34, 95% CI: 1.17–4.71) and IVS10+12A allele (GA or AA vs GG, OR = 1.55, 95% CI: 1.14–2.21; and GA vs GG, OR = 1.51, 95% CI: 1.04–2.17). Stratified analysis indicated that an increased risk of GC also was observed in: suspected familial subjects carrying the IVS12?6T>C (OR = 1.68, 95% CI: 1.27–2.66) or IVS10+12G>A (OR = 2.57, 95% CI: 1.53–4.10); or younger subjects carrying the IVS12?6T>C (OR = 2.15, 95% CI: 1.24–3.91) or IVS10+12G>A (OR = 2.23, 95% CI: 1.20–4.33); or male subjects carrying the IVS10+12G>A (OR = 1.64; 95% CI: 1.10–2.54). Furthermore, the combined IVS12?6CC and IVS10+12AA genotypes also significantly increased the risk of GC (OR = 2.12, 95% CI: 1.22–3.66). Statistically significant interactions were observed between: IVS10+12G>A and drinking, high pickled food or fried food intake (OR = 2.32; 95% CI: 1.43–3.78, OR = 2.55; 95% CI: 1.48–4.21 and OR = 2.88; 95% CI: 1.70–4.94, respectively); and IVS12?6T>C and high pickled food intake or fried food intake (OR = 2.65; 95% CI: 1.62–4.47 and OR = 2.48; 95% CI: 1.42–4.13, respectively). Conclusion: The IVS10+12G>A and IVS12?6T>C polymorphisms in MSH2 gene appear to be associated with risk of GC in this Chinese population. Risk for GC, stratified by related genotypes, was further modified by drinking, high pickled food or fried food intake. Larger prospective studies are needed to confirm these findings.     

Breast cancer detection risk in screening mammography after a false-positive result

Background: False-positives are a major concern in breast cancer screening. However, false-positives have been little evaluated as a prognostic factor for cancer detection. Our aim was to evaluate the association of false-positive results with the cancer detection risk in subsequent screening participations over a 17-year period. Methods: This is a retrospective cohort study of 762,506 women aged 45–69 years, with at least two screening participations, who underwent 2,594,146 screening mammograms from 1990 to 2006. Multilevel discrete-time hazard models were used to estimate the adjusted odds ratios (OR) of breast cancer detection in subsequent screening participations in women with false-positive results. Results: False-positives involving a fine-needle aspiration cytology or a biopsy had a higher cancer detection risk than those involving additional imaging procedures alone (OR = 2.69; 95%CI: 2.28–3.16 and OR = 1.81; 95%CI: 1.70–1.94, respectively). The risk of cancer detection increased substantially if women with cytology or biopsy had a familial history of breast cancer (OR = 4.64; 95%CI: 3.23–6.66). Other factors associated with an increased cancer detection risk were age 65–69 years (OR = 1.84; 95%CI: 1.67–2.03), non-attendance at the previous screening invitation (OR = 1.26; 95%CI: 1.11–1.43), and having undergone a previous benign biopsy outside the screening program (OR = 1.24; 95%CI: 1.13–1.35). Conclusion: Women with a false-positive test have an increased risk of cancer detection in subsequent screening participations, especially those with a false-positive result involving cytology or biopsy. Understanding the factors behind this association could provide valuable information to increase the effectiveness of breast cancer screening.     

Dietary fibre intake associated with reduced risk of oesophageal cancer in Xinjiang,China

Objective: To ascertain the relationship between dietary fibre intake and risk of oesophageal cancer in remote northwest China, where the cancer incidence is known to be high. Methods: A case–control study was conducted during 2008–2009 in the Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region of China. Participants were 359 incident oesophageal cancer patients and 380 hospital-based controls. Information on habitual foods consumption was obtained by face-to-face interview, from which dietary fibre intakes were estimated using the Chinese food composition tables. Results: The oesophageal cancer patients reported lower intake levels of total dietary fibre and fibre derived from vegetables and fruits than those of controls. Overall, regular intake of fibre was inversely associated with the oesophageal cancer risk, the adjusted odds ratio being 0.47 (95% confidence interval 0.32–0.69) for the highest (>27 g) versus the lowest (<16 g) tertile of daily intake, with a significant dose-response relationship (p = 0.004). Similar reductions in risk were also apparent for high intake levels of vegetable fibre and fruit fibre, but to a lesser extent for cereal fibre. Conclusion: Habitual intake of dietary fibre was associated with a reduced risk of oesophageal cancer for adults in northwest China.     

Main dietary compounds and pancreatic cancer risk. The quantitative analysis of case-control and cohort studies

Objective: Estimation of the role of main dietary compounds in the risk of developing pancreatic cancer. Research methods and procedures: Literature published till 2010 was reviewed and selected for further analysis. The used terms were: red meat, minced meat, ham, bacon, sausages, white meat, poultry, vegetables, fish, eggs, fruits, lifestyle, diet, pancreatic cancer and pancreatic neoplasm. The collected data were meta-analysed with calculation of combined relative risk and 95% confidence interval as well as studies heterogeneity. Results: A meta-analysis of 11 case–control studies indicates that red meat ingestion elevates pancreatic cancer risk by 48% (95% CI = 1.25–1.76). The vegetables and fruit reduce the risk by 38% (95% CI = 0.54–0.73) and 29% (95% CI = 0.59–0.84), respectively. The pooled analyses of 10 cohort studies do not show significant relations between main dietary compound ingestion and pancreatic cancer risk. Conclusion: The red meat intake is associated with elevated risk of pancreatic cancer in contrast to vegetables and fruit ingestion. The ingestion of red meat, vegetables and fruit in cohort studies was not influenced on pancreatic cancer risk. The role of fish, poultry and eggs was not significant in both case–control and cohort studies, thus further studies were needed.     

Genetic polymorphism of glutathione S-transferase T1 and the risk of colorectal cancer: A meta-analysis

Background: Studies investigating the association between genetic polymorphism of glutathione S-transferase T1 (GSTT1) and risk of colorectal cancer have reported conflicting results. In order to clarify the effect of GSTT1 polymorphism on the risk of developing colorectal cancer, we carried out a meta-analysis using published data to obtain more precise estimates of risk. Methods: Electronic searches of PubMed and EMBASE were conducted to select studies for this meta-analysis. Papers were included if they were observational studies investigating the association between GSTT1 polymorphism and colorectal cancer risk. The principal outcome measure was the odds ratio (OR) with 95% confidence interval (CI) for the risk of colorectal cancer associated with GSTT1 null genotype. Results: We identified 30 eligible studies, which included 7635 cases and 12,911 controls. The combined results based on all studies showed that there was a statistically significant link between GSTT1 null genotype and colorectal cancer risk (OR = 1.20, 95% CI = 1.03–1.40). In the analysis of ethnic groups, we observed distinct differences associated with GSTT1 null genotype, the pooled odds ratios for the GSTT1 polymorphism were 1.32 in Caucasians (95% CI = 1.09–1.58) and 1.03 in Asians (95% CI = 0.81–1.32). As far as concerned the interaction between GSTT1 genotype and colorectal cancer risk in relation to smoking history, there was no increase in risk for smokers or nonsmokers with the GSTT1 null genotype (smokers: OR = 1.13, 95% CI = 0.80–1.60, nonsmokers: OR = 0.99, 95% CI = 0.71–1.38). When stratifying by the location of colorectal cancer, we found that there was a statistically significant link in rectal cancer (OR = 1.50, 95% CI = 1.09–2.07), but not in colon cancer (OR = 1.33, 95% CI = 0.94–1.88). No associations could be detected between null GSTT1 polymorphism and age, sex, tumor stage and differentiation. Conclusion: Our current study demonstrates that GSTT1 null genotype is associated with an increased risk of colorectal cancer, specifically, among Caucasians.     

An updated meta-analysis on the association of TGF-β1 gene promoter -509C/T polymorphism with colorectal cancer risk

AimPublished data on the association between transforming growth factor-β1 (TGF-β1) gene promoter-509C/T polymorphism and colorectal cancer (CRC) risk are inconsistent and inconclusive. To derive a more precise estimation of this association, a meta-analysis was carried out.MethodsMeta-analysis was performed to evaluate reported studies of the relationship between TGF-β1 gene promoter-509C/T polymorphism and colorectal cancer risk using fixed-effects model and random-effects model.ResultsWe observed an increased colorectal cancer risk among subjects carrying TGF-β1 gene promoter-509CC + CT genotype (odds ratio (OR) = 1.18%, 95% confidence interval (95% CI): 1.06–1.32) using 4440/6785 cases/controls in total population. We observed an increased risk of the TGF-β1 gene promoter -509CC, CT and CC + CT polymorphisms for colorectal cancer in population-based study (OR = 1.36, 95% CI: 1.19–1.56, OR = 1.18, 95% CI: 1.03–1.34 and OR = 1.26, 95% CI: 1.12–1.43, respectively) in stratified analysis. We observed an increased colorectal risk among CC and CC + CT carriers in European and American population (OR = 1.22, 95% CI: 1.04–1.43 and OR = 1.18, 95% CI: 1.02–1.38, respectively). We also observed an increased risk of colon cancer among subjects carrying CC + CT genotype (OR = 1.31, 95% CI: 1.05–1.63).ConclusionsThe present meta-analysis results suggest that TGF-β1 gene promoter -509C allele variant is a possible risk factor for developing colorectal cancer. Recommendations for further studies include pooling of individual data to verify results from the study and to facilitate evaluation of multigenic effects and detailed analysis of effect modification by environmental and lifestyle factors.     

10-Year risk of colorectal cancer: Development and validation of a prediction model in middle-aged Japanese men

Background: To estimate an individual's probability of developing colorectal cancer (CRC) may aid health professionals and individuals in improving lifestyle behaviors or deciding the screening regimens. As fewer studies on cancer risk prediction were seen so far, we initially developed an assessment tool with synthesizing key information from a variety of CRC risk factors through a large population-based cohort study. Method: The prediction model was derived from 28,115 men in the Japan Public Health Center-based (JPHC) Prospective Study Cohort II (follow-up: 1993–2005), with risk factors selected by Cox proportion hazard regression. 18,256 men in the JPHC Study Cohort I (follow-up: 1995–2005) were used to evaluate the model's performance. Results: 543 and 398 CRCs were diagnosed during the follow-up period in Cohorts II and I, respectively. The prediction model, including age, BMI, alcohol consumption, smoking status, and the daily physical activity level, showed modest discrimination ability for CRC (C = 0.70; 95% confidential interval, 0.68–0.72) in Cohort II and well calibrated in Cohort I (Hosmer–Lemeshow χ² = 14.2, P = 0.08). Conclusion: The 10-year CRC risk prediction model may be used to estimate CRC risk in Japanese men. It may also play a role in the promotion of CRC prevention strategies.     

Effects of polymorphisms in translesion DNA synthesis genes on lung cancer risk and prognosis in Chinese men

PurposeTranslesion DNA synthesis (TLS) plays an important role in promoting replication through DNA lesions. Genetic polymorphisms in TLS genes may have potential roles in lung cancer development in humans.MethodsWe evaluated the association between genetic variants in six TLS genes and the risk and survival of lung cancer in a case–control study in China. Included in the study are 224 lung cancer patients and 448 healthy controls.ResultsCarriers of the G allele of POLκ rs5744724 had significantly reduced risk of lung cancer (odds ratio (OR) = 0.62, 95% confidence interval (CI): 0.44–0.89), comparing with those carrying the C allele, and the AA genotype of PCNA rs25406 was also associated with significantly decreased cancer risk compared with the major homozygote alleles (OR = 0.47, 95% CI: 0.25–0.86). Haplotype analysis showed that subjects with the POLκ C-G (rs5744533–rs5744724) haplotype had decreased risk of lung cancer (OR = 0.69, 95% CI: 0.49–0.98), comparing with those carrying the C-C haplotype. Besides, the heterozygote of REV1 rs3087386 and rs3792136 were independent prognostic factors for lung cancer survival with hazard radio (HR) 1.54 (95% CI: 1.12–2.12) and 1.44 (95% CI: 1.06–1.97) respectively.ConclusionsOur findings suggested that genetic variants in POLκ and PCNA genes may play roles in the susceptibility of lung cancer, and REV1 gene may have roles in lung cancer survival in Chinese men.     

Prolonged breastfeeding reduces risk of breast cancer in Sri Lankan women: A case–control study

Goal: To assess the association between duration of breastfeeding and the risk of breast cancer in Sri Lankan women. Methods: We conducted a case–control study in women aged 30–64 years in selected health care facilities in the Western province. A total of 100 recent cases of breast cancer (histologically confirmed) and 203 controls (age and parity matched) were included. Detailed information regarding breastfeeding, menstruation, reproductive factors, passive smoking and other confounders was collected using a structured questionnaire. Adjusted odds ratios and 95% confidence intervals were calculated using multiple logistic regressions. Principle results: Multivariate analysis found that those women who breastfed for ≥24 months during lifetime had significantly lower risk of breast cancer than those who breastfed for less than 24 months (OR = 0.40; 95%CI = 0.22, 0.73). Compared to 0–11 months of lifetime breastfeeding, there was a 66.3% reduction in breast cancer risk in women who breastfed for 12–23 months, 87.4% reduction in 24–35 months and 94% reduction in 36–47 months categories. The mean duration of breastfeeding per child for ≥12 months was also associated with reduced risk of breast cancer (OR = 0.52; 95%CI = 0.28, 0.94). The significant factors associated with increased risk of breast cancer were: post-menopausal women (OR = 1.74; 95%CI = 1.01, 3.01); having an abortion in the past (OR = 3.42; 95%CI = 1.75, 6.66) and exposure to passive smoking (OR = 2.96, 95%CI = 1.53, 5.75). Major conclusions: Prolonged breastfeeding significantly reduces the risk of breast cancer and this protective effect was supported by a dose–response relationship. Risk due to passive smoking should be emphasized in anti-smoking programmes.     

Cytotoxic effects of stem bark extracts and pure compounds from Margaritaria discoidea on human ovarian cancer cell lines

Margaritaria discoidea (Baill.) G. L. Webster (Euphorbiaceae) is a well-known medicinal plant in Africa used for the treatment of various diseases. So far, no cytotoxic effects of plant extracts on cancer cell lines have been reported.Aim of the studyTo evaluate the cytotoxicity against human ovarian cancer cells of extracts of M. discoidea and characterize the major bioactive compounds.MethodsBoth organic and aqueous extracts of this plant were obtained by maceration. The sulforhodamine B cell proliferation assay was used for evaluation of their cytotoxic activities and the potential bioactive compounds were characterized by gas chromatography–mass spectrometry.ResultsThe organic extract of M. discoidea showed stronger cytotoxicity than the aqueous extract with IC₅₀ values of 14.4 ± 3.0, 14.2 ± 1.2 and 34.7 ± 0.5 µg/ml on OVCAR-8, A2780 and cisplatin-resistant A2780cis ovarian cancer cells, respectively. The organic extract was further subjected to bioassay-guided fractionation by partitioning with n-hexane, ethyl acetate, and n-butanol in water. The ethyl acetate fraction was the most potent on the three ovarian cancer cell lines. A GC–MS analysis of trimethylsilyl derivatives of this fraction indicated the presence of phenolic compounds such as gallic acid and the alkaloid securinine. The IC₅₀ values of these two compounds were determined to be in the range of 3–16 µM, which indicated that they could contribute to the cytotoxic activity of the extract of M. discoidea.ConclusionsThis study has evaluated the cytotoxicity of stem bark extracts of M. discoidea against ovarian cancer cells and provided a basis of further development of this plant for the treatment of ovarian cancer.