Dietary glycemic load,glycemic index,and carbohydrates on the risk of primary liver cancer among Chinese women and men

BackgroundDietary glycemic index (GI) and glycemic load (GL) typically have a positive relationship with obesity and diabetes, which are risk factors for liver cancer. However, studies on their association with liver cancer have yielded inconsistent results. Therefore, we assessed the association of GI, GL, and carbohydrates with liver cancer risk.Patients and methodsA total of 72 966 women and 60 207 men from the Shanghai Women's Health Study (SWHS) and the Shanghai Men's Health Study (SMHS) were included for analysis. Food frequency questionnaire (FFQ) data were used to calculate daily dietary GI, GL, and carbohydrate intake. These values were energy adjusted and categorized into quintiles. The hazard ratios (HRs) and 95% confidence intervals (CI) were calculated with adjustment for potential confounders.ResultsAfter a median follow-up time of 11.2 years for the SWHS and 5.3 years for the SMHS, 139 and 208 incident liver cancer cases were identified in the SWHS and SMHS, respectively. In multivariable Cox regression models, no statistically significant trends by quintile of GI, GL, or carbohydrate intake were observed. Stratification by chronic liver disease/hepatitis, diabetes, or body mass index (BMI) did not alter the findings.ConclusionsThere is little evidence that dietary GI, GL, or carbohydrates affect the incidence of liver cancer in this Asian population.     

Periodontal disease,tooth loss and colorectal cancer risk: Results from the Nurses' Health Study

Periodontal diseases including tooth loss might increase systemic inflammation, lead to immune dysregulation and alter gut microbiota, thereby possibly influencing colorectal carcinogenesis. Few epidemiological studies have examined the association between periodontal diseases and colorectal cancer (CRC) risk. We collected information on the periodontal disease (defined as history of periodontal bone loss) and number of natural teeth in the Nurses' Health Study. A total of 77,443 women were followed since 1992. We used Cox proportional hazard models to calculate multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) after adjustment for smoking and other known risk factors for CRC. We documented 1,165 incident CRC through 2010. Compared to women with 25–32 teeth, the multivariable HR (95% CI) for CRC for women with <17 teeth was 1.20 (1.04–1.39). With regard to tumor site, the HRs (95% CIs) for the same comparison were 1.23 (1.01–1.51) for proximal colon cancer, 1.03 (0.76–1.38) for distal colon cancer and 1.48 (1.07–2.05) for rectal cancer. In addition, compared to those without periodontal disease, HRs for CRC were 0.91 (95% CI 0.74–1.12) for periodontal disease, and 1.22 (95% CI 0.91–1.63) when limited to moderate to severe periodontal disease. The results were not modified by smoking status, body mass index or alcohol consumption. Women with fewer teeth, possibly moderate or severe periodontal disease, might be at a modest increased risk of developing CRC, suggesting a potential role of oral health in colorectal carcinogenesis.     

Vegetable‐based dietary pattern and liver cancer risk: Results from the Shanghai Women's and Men's Health Studies

Although dietary patterns, specific foods, and their constituents have been linked to cancer risk, the role of dietary patterns and specific food groups in liver cancer risk has not been investigated. In the Shanghai Women's Health Study (SWHS) and Shanghai Men's Health Study (SMHS), two cohort studies of 132 837 Chinese women and men, we evaluated the relationship between dietary patterns, food groups, and liver cancer risk. Through in‐person interviews, dietary information intake over the preceding year was collected by using a validated food‐frequency questionnaire. Cox regression model was used to estimate hazard ratios and 95% confidence intervals with adjustment for potential confounders. During an average follow‐up of 10.9 (SWHS) or 5.5 (SMHS) years, 267 incident liver cancer cases were identified after the first 2 years of study enrolment. Three dietary patterns were derived by factor analysis. A vegetable‐based dietary pattern was inversely associated with liver cancer; hazard ratios (95% confidence intervals) for the lowest to highest quartiles were: 1.00; 0.98 (0.71–1.35); 0.93 (0.67–1.29); and 0.58 (0.40–0.84); P_trend = 0.01. The association was stronger among participants with a history of chronic liver disease. Further analyses showed high intakes of celery, mushrooms, allium vegetables, composite vegetables (including asparagus lettuce and garland chrysanthemum), legumes and legume products were associated with reduced liver cancer risk (all P_trend < 0.05). Fruit‐ and meat‐based dietary patterns were not associated with liver cancer risk. Our study suggests that a vegetable‐based dietary pattern is associated with reduced liver cancer risk.     

Prospective evaluation of type 2 diabetes mellitus on the risk of primary liver cancer in Chinese men and women

BackgroundNo prospective study has investigated the relationship between type 2 diabetes mellitus (T2DM) and the risk of primary liver cancer (PLC) in mainland China, and little is known about the effect of diabetes duration on PLC risk.DesignData from two population-based cohorts (the Shanghai Men's Health Study, SMHS, 2002–2006 and the Shanghai Women's Health Study, SWHS, 1996–2000) were thus used to assess the associations among T2DM, diabetes duration and PLC risk in Chinese population.ResultsDuring follow-up through 2009, 344 incident PLC cases were identified among 60 183 men and 73 105 women. T2DM is significantly associated with the increased risk of PLC in both men [hazard ratio (HR) = 1.63, 95% confidence interval (CI) 1.06–2.51] and women (HR = 1.64, 95% CI 1.03–2.61). The highest risk of incident liver cancer was observed in the first 5 years after diabetes diagnosis, and decreased substantially with the prolonged diabetes duration (P_trend < 0.001). No synergistic interaction in the development of PLC was found between diabetes and other known risk factors.ConclusionsT2DM is associated with the increased risk of subsequent liver cancer within 5 years after diagnosis in Chinese population, suggesting that hyperinsulinaemia rather than hyperglycaemia is more likely to be a primary mediator for this association.     

The role of oral hygiene in head and neck cancer: results from International Head and Neck Cancer Epidemiology (INHANCE) consortium

BackgroundPoor oral hygiene has been proposed to contribute to head and neck cancer (HNC) risk, although causality and independency of some indicators are uncertain. This study investigates the relationship of five oral hygiene indicators with incident HNCs.MethodsIn a pooled analysis of 8925 HNC cases and 12 527 controls from 13 studies participating in the International Head and Neck Cancer Epidemiology Consortium, comparable data on good oral hygiene indicators were harmonized. These included: no denture wear, no gum disease (or bleeding), <5 missing teeth, tooth brushing at least daily, and visiting a dentist ≥once a year. Logistic regression was used to estimate the effects of each oral hygiene indicator and cumulative score on HNC risk, adjusting for tobacco smoking and alcohol consumption.ResultsInverse associations with any HNC, in the hypothesized direction, were observed for <5 missing teeth [odds ratio (OR) = 0.78; 95% confidence interval (CI) 0.74, 0.82], annual dentist visit (OR = 0.82; 95% CI 0.78, 0.87), daily tooth brushing (OR = 0.83, 95% CI 0.79, 0.88), and no gum disease (OR = 0.94; 95% CI 0.89, 0.99), and no association was observed for wearing dentures. These associations were relatively consistent across specific cancer sites, especially for tooth brushing and dentist visits. The population attributable fraction for ≤ 2 out of 5 good oral hygiene indicators was 8.9% (95% CI 3.3%, 14%) for oral cavity cancer.ConclusionGood oral hygiene, as characterized by few missing teeth, annual dentist visits, and daily tooth brushing, may modestly reduce the risk of HNC.     

Prospective study of urinary prostaglandin E2 metabolite and pancreatic cancer risk

The cyclooxygenase 2 (COX‐2) pathway is upregulated in many pancreatic cancer cells, and it is believed that carcinogenetic effects of COX‐2 upregulation are largely through prostaglandin E2 (PGE2) overproduction. We tested this hypothesis by evaluating the association between urinary PGE2 metabolites (PGE‐M), a biomarker of in vivo PGE2 overproduction, and pancreatic cancer risk. We conducted a case–control study with 722 subjects (239 cases and 483 controls) nested within two prospective cohort studies, the Shanghai Women's Health Study (SWHS) and Shanghai Men's Health Study (SMHS). Pre‐diagnosis urine samples were measured for PGE‐M using a liquid chromatography/tandem mass spectrometric method. Conditional logistic regression was used to estimate odds ratio (OR) and 95% confidence intervals (95%CI), with adjustment for potential confounders. Compared to those with the lowest urine level of PGE‐M (the first quartile), individuals with higher urine levels of PGE‐M had an increased risk of developing pancreatic cancer, with adjusted ORs (95%CI) of 1.63 (0.98–2.73), 1.55 (0.90–2.69) and 1.94 (1.07–3.51), for the second to the fourth quartile groups, respectively (p for trend = 0.054). This dose–response positive association was more evident among those who had BMI <25 kg/m² than overweight individuals (p for interaction = 0.058). After excluding cases diagnosed in the first year of follow‐up and their matched controls, this positive association persisted (p for trend = 0.037) and the interaction became statistically significant (p for interaction = 0.017). Our study adds additional evidence that the COX‐2 pathway is involved in pancreatic carcinogenesis and suggests that urinary PGE‐M may serve as a biomarker for predicting pancreatic cancer risk.     

Dietary fatty acids and colorectal cancer risk in men: A report from the Shanghai Men's Health Study and a meta‐analysis

Evidence from animal models suggests that dietary fatty acids have both anticancer and tumor‐promoting effects. Whether dietary fatty acids are associated with colorectal cancer (CRC) in humans remains inconclusive. We investigated associations between dietary fatty acids and risk of CRC among 59 986 men who participated in the Shanghai Men's Health Study (SMHS), an ongoing population‐based prospective cohort study. We identified 876 incident CRC cases in the SMHS during a mean follow‐up of 9.8 years. Associations between dietary fatty acid intake and CRC risk were evaluated by Cox proportional hazard regression analyses. Consumption of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) was not significantly associated with CRC risk. Multivariate hazard ratios (HRs) and respective 95% confidence intervals (CIs) for Quartile 4 vs Quartile 1 were 0.92 (0.74‐1.14; P_trend = 0.47) for SFA, 0.95 (0.79‐1.16; P_trend = 0.74) for MUFA and 1.18 (0.95‐1.46; P_trend = 0.21) for PUFA. No significant associations were found for total n‐6 PUFA or total n‐3 PUFA. Additionally, we performed a meta‐analysis to summarize results from the present study and 28 reports from 26 additional cohorts, which supported the overall null association between dietary fatty acid intake and CRC risk among men. Docosahexanoic acid and eicosapentaenoic acid were associated with 11% to 12% reduced risk, and linoleic acid a 19% increased risk, of CRC in the meta‐analysis of combined sexes. In conclusion, this population‐based prospective study and meta‐analysis of cohort studies found little evidence that dietary fatty acid intake was associated with risk of CRC in men.     

Cruciferous vegetables consumption and the risk of female lung cancer: a prospective study and a meta-analysis

BackgroundEpidemiological studies evaluating the association between cruciferous vegetables (CVs) intake and female lung cancer risk have produced inconsistent results.Patients and methodsThis study followed 74 914 Chinese women aged 40–70 years who participated in the Shanghai Women's Health Study. CV intake was assessed through a validated food-frequency questionnaire (FFQ) at baseline and reassessed during follow-up. Hazard ratios (HRs) and 95% confidence interval (CIs) were estimated by using Cox proportional hazards models. Furthermore, we carried out a meta-analysis of all observational studies until December 2011.ResultsAfter excluding the first 2 years of follow-up, 417 women developed lung cancer over a mean of 11.1 years of follow-up. An inverse association of borderline statistical significance was observed between CV consumption and female lung cancer risk, with HR for the highest compared with the lowest quartiles of 0.73 (95% CI 0.54–1.00, P trend = 0.1607). The association was strengthened in analyses restricting to never smokers, with the corresponding HR of 0.59 (95% CI 0.40–0.87, P trend = 0.0510). The finding of an inverse association between CV intake and lung cancer risk in women was supported by our meta-analysis of 10 included studies.ConclusionsOur study suggests that CV consumption may reduce the risk of lung cancer in women, particularly among never smokers.     

Impact of prediagnostic smoking and smoking cessation on colorectal cancer prognosis: a meta-analysis of individual patient data from cohorts within the CHANCES consortium

BackgroundSmoking has been associated with colorectal cancer (CRC) incidence and mortality in previous studies and might also be associated with prognosis after CRC diagnosis. However, current evidence on smoking in association with CRC prognosis is limited.Patients and methodsFor this individual patient data meta-analysis, sociodemographic and smoking behavior information of 12 414 incident CRC patients (median age at diagnosis: 64.3 years), recruited within 14 prospective cohort studies among previously cancer-free adults, was collected at baseline and harmonized across studies. Vital status and causes of death were collected for a mean follow-up time of 5.1 years following cancer diagnosis. Associations of smoking behavior with overall and CRC-specific survival were evaluated using Cox regression and standard meta-analysis methodology.ResultsA total of 5229 participants died, 3194 from CRC. Cox regression revealed significant associations between former [hazard ratio (HR) = 1.12; 95 % confidence interval (CI) = 1.04–1.20] and current smoking (HR = 1.29; 95% CI = 1.04–1.60) and poorer overall survival compared with never smoking. Compared with current smoking, smoking cessation was associated with improved overall (HR_{<10 years} = 0.78; 95% CI = 0.69–0.88; HR_{≥10 years} = 0.78; 95% CI = 0.63–0.97) and CRC-specific survival (HR_{≥10 years} = 0.76; 95% CI = 0.67–0.85).ConclusionIn this large meta-analysis including primary data of incident CRC patients from 14 prospective cohort studies on the association between smoking and CRC prognosis, former and current smoking were associated with poorer CRC prognosis compared with never smoking. Smoking cessation was associated with improved survival when compared with current smokers. Future studies should further quantify the benefits of nonsmoking, both for cancer prevention and for improving survival among CRC patients, in particular also in terms of treatment response.     

Body image,physical activity and psychological health in older female cancer survivors

ObjectivesTo determine the association of physical activity and body image with psychological health outcomes and whether body image mediates the association of physical activity with psychological health among older female cancer survivors.Materials and MethodsData from the Women's Health Initiative (WHI) Life and Longevity after Cancer (LILAC) Study were used. Surveys assessed body image (appearance, attractiveness, scars), moderate-strenuous physical activity (min/week), and psychological health (depression, anxiety, distress). A mediation analysis was conducted to estimate the percentage of the total effect of physical activity on psychological health mediated by body image concerns.ResultsAmong 4567 female cancer survivors aged 66–98 years, the average time since cancer diagnosis was 9.2 years. Approximately 50% reported no moderate-strenuous physical activity; 15% reported depressive symptoms, 6% reported anxiety, and 5% reported psychological distress; 3% had concerns with appearance, 20% had concerns with attractiveness, and 21% had concerns with scars. When unadjusted for body image concerns, every 30 min/week increase in physical activity was associated with lower risk of depressive symptoms (RR = 0.93, 95%CI: 0.90–0.96), anxiety (RR = 0.92, 95%CI: 0.87–0.97), and distress (RR = 0.92, 95%CI: 0.87–0.98). Body image concerns with appearance mediated 7%, 8.8%, and 14.5% of the association between physical activity and depressive symptoms, anxiety, and distress, respectively.ConclusionOlder female cancer survivors reported body image concerns, which were associated with both physical activity and psychological health. Our findings suggest that interventions designed to address body image concerns in older female cancer survivors could serve to improve the benefit of physical activity on psychological health.     

A meta-analysis on alcohol drinking and esophageal and gastric cardia adenocarcinoma risk

BackgroundIn order to provide a precise quantification of the association between alcohol drinking and esophageal and gastric cardia adenocarcinoma risk, we conducted a meta-analysis of available data.Patients and methodsWe identified 20 case–control and 4 cohort studies, including a total of 5500 cases. We derived meta-analytic estimates using random-effects models, taking into account correlation between estimates, and we carried out a dose–risk analysis using nonlinear random-effects meta-regression models.ResultsThe relative risk (RR) for drinkers versus nondrinkers was 0.96 [95% confidence interval (CI) 0.85–1.09] overall, 0.87 (95% CI 0.74–1.01) for esophageal adenocarcinoma and 0.89 (95% CI 0.76–1.03) for gastric cardia adenocarcinoma. Compared with nondrinkers, the pooled RRs were 0.86 for light (≤1 drink per day), 0.90 for moderate (1 to <4 drinks per day), and 1.16 for heavy (≥4 drinks per day) alcohol drinking. The dose–risk model found a minimum at 25 g/day, and the curve was <1 up to 70 g/day.ConclusionsThis meta-analysis provides definite evidence of an absence of association between alcohol drinking and esophageal and gastric cardia adenocarcinoma risk, even at higher doses of consumption.     

Dental fluorosis and oral health in the African Esophageal Cancer Corridor: Findings from the Kenya ESCCAPE case–control study and a pan-African perspective

There are no studies of oral health in relation to esophageal cancer in Africa, or of Eastern Africa's endemic dental fluorosis, an irreversible enamel hypo-mineralization due to early-life excessive fluoride intake. During 2014–18, we conducted a case–control study of squamous cell esophageal cancer in Eldoret, western Kenya. Odds ratios (AORs (95% confidence intervals)) were adjusted for design factors, tobacco, alcohol, ethnicity, education, oral hygiene and missing/decayed teeth. Esophageal cancer cases (N = 430) had poorer oral health and hygiene than controls (N = 440). Compared to no dental fluorosis, moderate/severe fluorosis, which affected 44% of cases, had a crude OR of 20.8 (11.6, 37.4) and on full adjustment was associated with 9.4-fold (4.6, 19.1) increased risk, whilst mild fluorosis (43% of cases) had an AOR of 2.3 (1.3, 4.0). The prevalence of oral leukoplakia and tooth loss/decay increased with fluorosis severity, and increased cancer risks associated with moderate/severe fluorosis were particularly strong in individuals with more tooth loss/decay. Using a mswaki stick (AOR = 1.7 (1.0, 2.9)) rather than a commercial tooth brush and infrequent tooth brushing also independently increased risk. Geographic variations showed that areas of high esophageal cancer incidence and those of high groundwater fluoride levels have remarkably similar locations across Eastern Africa. In conclusion, poor oral health in combination with, or as a result of, high-altitude susceptibility to hydro-geologically influenced dental fluorosis may underlie the striking co-location of Africa's esophageal cancer corridor with the Rift Valley. The findings call for heightened research into primary prevention opportunities of this highly fatal but common cancer.     

Aspirin use and risk for lung cancer: a meta-analysis

BackgroundAspirin has received increasing attention owing to its potential as a chemopreventive agent against lung cancer. Previous observational studies have reported inconsistent findings on this issue. We investigated the association between aspirin use and risk for lung cancer by conducting a meta-analysis.Patients and methodsRelevant studies were identified by searching Medline, EMBASE, and Cochrane Library to December 2009. We also reviewed relevant bibliographies from the retrieved articles. Two authors independently extracted data and assessed study quality. Disagreements were resolved by consensus.ResultsFifteen studies (six case–control studies and nine prospective cohort studies) were included in the final meta-analysis. When all studies were pooled, the odds ratio (OR) of aspirin use for lung cancer risk was 0.86 [95% confidence interval (CI) 0.76–0.98]. In subgroup meta-analyses, there was no association between aspirin use and lung cancer risk among cohort studies (relative risk, 0.97; 95% CI 0.87–1.08), while there was a significant association among case–control studies (OR, 0.74; 95% CI 0.57–0.99). In a subgroup meta-analysis by quality of study methodology, a significant protective effect of aspirin use on lung cancer was observed only among eight low-quality studies (OR, 0.82; 95% CI 0.68–0.99), but not among seven high-quality studies (OR, 0.90; 95% CI 0.76–1.07).ConclusionsOverall, the findings of this meta-analysis support that there was no association between aspirin use and lung cancer risk. Our findings should be confirmed in future prospective cohort studies or randomized, controlled trials.     

Red blood cell folate and plasma folate are not associated with risk of incident colorectal cancer in the Women's Health Initiative observational study

The relationship between folate and colorectal cancer (CRC) risk is unclear. We investigated the association of two biomarkers of folate status, plasma folate and red blood cell (RBC) folate, with CRC risk using a nested case–control design in the Women's Health Initiative Observational Study. Postmenopausal women (n = 93,676) aged 50–79 years were enrolled in the Women's Health Initiative Observational Study (1993–1998). A fasting blood draw and extensive health, dietary and lifestyle data were collected upon enrollment. Through 2008, 988 incident CRC cases were reported and confirmed with medical records adjudication. Cases and controls were matched on age (±3 years), enrollment date (±1 year), race/ethnicity, blood draw date (±6 months) and hysterectomy status. Plasma and RBC folate were determined by radio assay. Folate biomarker values were divided into quartiles, and conditional logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CI) for the associations of folate with total CRC, by tumor site and by stage at diagnosis. Additional analyses examined whether risks varied across time periods corresponding to the United States folic acid fortification policy: prefortification (1994–1995), perifortification (1996–1997) and postfortification (1998). ORs for overall CRC risk comparing Q4 vs. Q1 were 0.91 (95% CI 0.67–1.24) and 0.91 (95% CI 0.67–1.23) for RBC and plasma folate, respectively. There were no changes in risk attributable to food supply fortification. These results do not support an overall association of folate with CRC risk and suggest that folic acid fortification of the US food supply did not alter the associations in these postmenopausal women.     

Association between genetic risk score for telomere length and risk of breast cancer

Purpose

While leukocyte telomere length (TL) has been associated with breast cancer risk, limited information is available regarding the role of genetically-determined TL on breast cancer risk. We investigated whether aggregated TL-associated variants are associated with the risk of breast cancer in 2,865 breast cancer cases and 2,285 controls from the Shanghai Breast Cancer Genetics Study.

Methods

Six genetic variants, identified through a genome-wide association study (GWAS) of TL in European-ancestry participants, were included in the study. A separate sample [n = 1,536, from the Shanghai Women’s Health Study (SWHS), for whom information on both phenotypical leukocyte TL and genetic information was collected] was used to evaluate the association of six variants with TL in Asians. Three genetic risk scores (GRSs), based on the number of alleles associated with shorter TL that each individual carries for the six variants, were derived for the study: un-weighted, internally weighted (from the SWHS), and externally weighted (from the European-ancestry GWAS study), and evaluated for their association with breast cancer risk by applying logistic regression analysis.

Results

Both internally and externally weighted GRSs were significantly associated with a decreased risk of breast cancer (OR 0.83, 95 % CI 0.72–0.95 and OR 0.84, 95 % CI 0.74–0.96, respectively, for tertile 3 vs. tertile 1). Non-genetic risk factors for breast cancer (i.e., age, years of menstruation/reproduction, oral contraceptive usage, and BMI) did not modify the association between GRSs and the risk of breast cancer.

Conclusion

Our results suggest that short TL, determined by genetic factors, may be associated with a reduced susceptibility to breast cancer.

     

Calcium intake and colorectal cancer risk: Results from the nurses' health study and health professionals follow‐up study

The relationship between calcium intake and colorectal cancer (CRC) risk remains inconclusive. We conducted this study to evaluate whether the association between calcium intake and CRC risk differs by anatomic subsite and determine the dose–response relationship for this association, as well as assess when in carcinogenesis calcium may play a role. We assessed calcium intake every 4 years and followed 88,509 women (1980–2012) in the Nurses' Health Study and 47,740 men (1986–2012) in the Health Professionals Follow‐Up Study. We documented 3,078 incident CRC cases. Total calcium intake (≥1,400 vs. <600 mg/d) was associated with a statistically significant lower risk of colon cancer (multivariable relative risk: 0.78, 95%CI: 0.65–0.95). Similar results were observed by different sources of calcium (from all foods or dairy products only). The inverse association was linear and suggestively stronger for distal colon cancer (0.65, 0.43–0.99) than for proximal colon cancer (0.94, 0.72–1.22, p‐_{common effects} = 0.14). Additionally, when comparing different latencies, the overall pattern suggested that the inverse association appeared to be stronger with increasing latency and was strongest for intakes 12–16 years before diagnosis. Comparing total calcium intakes of ≥1,400 vs. <600 mg/d for intake 12–16 y before diagnosis, the pooled RR (95% CIs) of CRC was 0.76 (0.64–0.91). Higher calcium intake was associated with a lower risk of developing colon cancer, especially for distal colon cancer. Overall inverse association was linear and did not differ by intake source. Additionally, calcium intake approximately 10 years before diagnosis appeared to be associated with a lower risk of CRC.     

Prospective study of oral microbiome and colorectal cancer risk in low-income and African American populations

Oral microbiome may play an important role in cancer pathogenesis. However, no study has prospectively investigated the association of the oral microbiome with subsequent risk of developing colorectal cancer (CRC). We conducted a nested case–control study including 231 incident CRC cases and 462 controls within the Southern Community Cohort Study with 75% of the subjects being African-Americans. The controls were individually matched to cases based on age, ethnic group, smoking, season-of-study enrollment and recruitment method. Oral microbiota were assessed using 16S rRNA gene sequencing in pre-diagnostic mouth rinse samples. Multiple bacterial taxa showed an association with CRC risk at p <0.05. Oral pathogens Treponema denticola and Prevotella intermedia were associated with an increased risk of CRC, with odds ratios (ORs) and 95% confidence intervals (CIs) of 1.76(1.19–2.60) and 1.55(1.08–2.22), respectively, for the individuals carrying these bacteria compared to non-carriers. In the phylum Actinobacteria, Bifidobacteriaceae was more abundant among CRC patients than among controls. In the phylum Bacteroidetes, Prevotella denticola and Prevotella sp. oral taxon 300 were associated with an increased CRC risk, while Prevotella melaninogenica was associated with a decreased risk of CRC. In the phylum Firmicutes, Carnobacteriaceae, Streptococcaceae, Erysipelotrichaceae, Streptococcus, Solobacterium, Streptococcus sp. oral taxon 058 and Solobacterium moorei showed associations with a decreased risk of CRC. Most of these associations were observed among both African- and European-Americans. Most of the associations were not significant after Bonferroni correction for multiple testing, which may be conservative. Our study suggests that the oral microbiome may play a significant role in CRC etiology.     

Meta-analysis of 16 studies of the association of alcohol with colorectal cancer

Alcohol consumption is an established risk factor for colorectal cancer (CRC). However, while studies have consistently reported elevated risk of CRC among heavy drinkers, associations at moderate levels of alcohol consumption are less clear. We conducted a combined analysis of 16 studies of CRC to examine the shape of the alcohol–CRC association, investigate potential effect modifiers of the association, and examine differential effects of alcohol consumption by cancer anatomic site and stage. We collected information on alcohol consumption for 14,276 CRC cases and 15,802 controls from 5 case-control and 11 nested case-control studies of CRC. We compared adjusted logistic regression models with linear and restricted cubic splines to select a model that best fit the association between alcohol consumption and CRC. Study-specific results were pooled using fixed-effects meta-analysis. Compared to non-/occasional drinking (≤1 g/day), light/moderate drinking (up to 2 drinks/day) was associated with a decreased risk of CRC (odds ratio [OR]: 0.92, 95% confidence interval [CI]: 0.88–0.98, p = 0.005), heavy drinking (2–3 drinks/day) was not significantly associated with CRC risk (OR: 1.11, 95% CI: 0.99–1.24, p = 0.08) and very heavy drinking (more than 3 drinks/day) was associated with a significant increased risk (OR: 1.25, 95% CI: 1.11–1.40, p < 0.001). We observed no evidence of interactions with lifestyle risk factors or of differences by cancer site or stage. These results provide further evidence that there is a J-shaped association between alcohol consumption and CRC risk. This overall pattern was not significantly modified by other CRC risk factors and there was no effect heterogeneity by tumor site or stage.     

Cruciferous vegetables intake and the risk of colorectal cancer: a meta-analysis of observational studies

BackgroundEpidemiological studies have reported inconsistent associations between cruciferous vegetable (CV) intake and colorectal cancer (CRC) risk. To our knowledge, a comprehensive and quantitative assessment of the association between CV intake and CRC has not been reported.MethodsRelevant articles were identified by searching MEDLINE. We pooled the relative risks (RR) from individual studies using a random-effect model and carried out heterogeneity and publication bias analyses.ResultsTwenty-four case–control and 11 prospective studies were included in our analysis. When all studies were pooled, we yielded a significantly inverse association between CV (RR: 0.82; 95% confidence interval 0.75–0.90) intake and CRC risk. Specific analysis for cabbage and broccoli yielded similar result. When separately analyzed, case–control studies of CV intake yield similar results, and the results from the prospective studies showed borderline statistical significance. Moreover, significant inverse associations were also observed in colon cancer and its distal subsite both among prospective and case–control studies.ConclusionsFindings from this meta-analysis provide evidence that high intake of CV was inversely associated with the risk of CRC and colon cancer in humans. Further analysis on other specific CV, food preparation methods, stratified results by anatomic cancer site, and subsite of colon cancer should be extended in future study.     

Association between the frequency of tooth brushing and esophageal carcinoma risk: an update systematic review and meta-analysis

BackgroundLower frequency of tooth brushing was thought to be associated with esophageal carcinoma (EC). However, some researchers suggested that this association did not exist or had not yet reached statistical significance. The purpose of this study was to calculate a more precise estimation of the relationship between the frequency of tooth brushing and the risk of EC by combining the results between different studies using the meta-analysis.MethodsWe searched the PubMed, Embase, Web of Science, and Scopus electronic databases up to July 2021. According to PECO approach (Population, Exposure, Comparator and Outcomes), we assessed the association between tooth brushing frequency and EC risk which reported the adjusted risk ratios (adjRR), hazard ratios (adjHR), or odds ratios (adjOR) with 95% confidence interval (CI). The random effects model was used to quantitatively evaluate the combined results. Two researchers independently evaluated the risk bias of the included studies using the Newcastle-Ottawa Scale (NOS). The robustness of results was evaluated by subgroup analysis, sensitivity analysis, and publication bias.ResultsIn total, we identified 13 articles with 14 case-control studies which included 16,773 participants and 5,673 patients. Pooled results showed the lowest frequency of brushing was significantly associated with an increased risk of EC in comparison to the highest (adjOR: 2.00, 95% CI: 1.61–2.48). There was moderate heterogeneity among included studies (P=0.001, I²=61.4%). The original studies included in this meta-analysis were all case-control studies. Study quality was all moderate or above based on NOS score ranges of 6 stars or more.ConclusionsAvailable evidence suggests a low frequency of tooth brushing may be an important risk factor for EC. However, higher quality studies should continue to be conducted to investigate the optimal threshold of brushing frequency for the prevention of EC.