Claudio Pelucchi

Alcohol consumption and site-specific cancer risk: a comprehensive dose-response meta-analysis

Background:Alcohol is a risk factor for cancer of the oral cavity, pharynx, oesophagus, colorectum, liver, larynx and female breast, whereas its impact on other cancers remains controversial.Methods:We investigated the effect of alcohol on 23 cancer types through a meta-analytic approach. We used dose–response meta-regression models and investigated potential sources of heterogeneity.Results:A total of 572 studies, including 486 538 cancer cases, were identified. Relative risks (RRs) for heavy drinkers compared with nondrinkers and occasional drinkers were 5.13 for oral and pharyngeal cancer, 4.95 for oesophageal squamous cell carcinoma, 1.44 for colorectal, 2.65 for laryngeal and 1.61 for breast cancer; for those neoplasms there was a clear dose–risk relationship. Heavy drinkers also had a significantly higher risk of cancer of the stomach (RR 1.21), liver (2.07), gallbladder (2.64), pancreas (1.19) and lung (1.15). There was indication of a positive association between alcohol consumption and risk of melanoma and prostate cancer. Alcohol consumption and risk of Hodgkin’s and Non-Hodgkin’s lymphomas were inversely associated.Conclusions:Alcohol increases risk of cancer of oral cavity and pharynx, oesophagus, colorectum, liver, larynx and female breast. There is accumulating evidence that alcohol drinking is associated with some other cancers such as pancreas and prostate cancer and melanoma.

Mechanisms of Disease: the epidemiology of bladder cancer

Mortality from bladder cancer has shown downward trends over the last 2 decades in several western European countries (albeit 10–15 years later than similar trends in the US), but is still increasing in some eastern European countries. Tobacco smoking and occupational exposure to aromatic amines are the two major established environmental risk factors for bladder cancer. Controlling exposure to these factors has been an important contributor to the reduction in bladder cancer mortality, particularly among men. Diet could influence bladder carcinogenesis, as many compounds contained in foods—and their metabolites—are excreted through the urinary tract. Fruit and vegetable consumption was inversely related with bladder cancer in many studies, but no consistent association has emerged between intake of related micronutrients and reduced risk of bladder cancer. Other widely investigated lifestyle habits are probably not associated with risk of developing bladder cancer (e.g. coffee consumption, artificial sweetener use, hair dyes) or are difficult to assess (e.g. fluid intake). Infections and stones in the urinary tract might cause chronic irritation of the bladder epithelium, and thus increase bladder cancer risk. First-degree relatives of bladder cancer patients have a 50–100% increased relative risk of developing the disease, a risk that could be even higher when the proband is diagnosed at an early age.

Probiotics supplementation during pregnancy or infancy for the prevention of atopic dermatitis: A meta-analysis

Background: The study of probiotics to prevent allergic conditions has yielded conflicting results in children. We undertook a meta-analysis of randomized controlled trials to investigate whether probiotic use during pregnancy and early life decreases the incidence of atopic dermatitis and immunoglobulin E (IgE)-associated atopic dermatitis in infants and young children. Methods: We performed a systematic literature search in Medline, Embase, and Cochrane Library, updated to October 2011. The intervention was diet supplementation with probiotics versus placebo. Primary outcomes were incidence of atopic dermatitis and IgE-associated atopic dermatitis. We calculated summary relative risks (RRs) and corresponding 95% confidence intervals (CIs), using both fixed- and random-effects models. We computed summary estimates across several strata, including study period, type of patient, dose, and duration of intervention, and we assessed the risk of bias within and across trials. Results: We identified 18 publications based on 14 studies. Meta-analysis demonstrated that probiotic use decreased the incidence of atopic dermatitis (RR = 0.79 [95% CI = 0.71−0.88]). Studies were fairly homogeneous (I2 = 24.0%). The corresponding RR of IgE-associated atopic dermatitis was 0.80 (95% CI = 0.66−0.96). No appreciable difference emerged across strata, nor was there evidence of publication bias. Conclusions: This meta-analysis provided evidence in support of a moderate role of probiotics in the prevention of atopic dermatitis and IgE-associated atopic dermatitis in infants. The favorable effect was similar regardless of the time of probiotic use (pregnancy or early life) or the subject(s) receiving probiotics (mother, child, or both).

Alcohol and tobacco use, and cancer risk for upper aerodigestive tract and liver

This study reviews the association between alcohol, tobacco, and the risk of cancers of the upper digestive and respiratory tract (i.e. oral cavity and pharynx, larynx, and esophagus) and liver. Alcohol drinking and tobacco smoking are the major risk factors for upper aerodigestive tract cancers, accounting for a large proportion (i.e. about three-quarters) of cases in developed countries. Consumption amount is the strongest alcohol-related determinant of risk, whereas the pattern of alcohol-related risk with duration is inconsistent. Both dose and duration of smoking have important effects on the risk of upper aerodigestive tract cancers. The combined exposure to alcohol and tobacco has a multiplicative effect on carcinogenesis of this tract. Alcohol and tobacco consumption are also causally related to liver cancer, although the associations are moderate and a lower fraction of neoplasms is attributable to these factors as compared with cancers of the upper aerodigestive tract. An interaction between alcohol drinking and tobacco smoking has been reported, but the issue is not adequately assessed.

A meta-analysis on alcohol drinking and gastric cancer risk

BACKGROUND Whether an association between alcohol drinking and gastric cancer risk exists is an open question. In order to provide a definite quantification of the association between alcohol drinking and gastric cancer risk, we conducted a meta-analysis of available data. PATIENTS AND METHODS We carried out a PubMed search of articles published up to June 2010 and identified 44 case-control and 15 cohort studies, including a total of 34 557 gastric cancer cases. We derived meta-analytic estimates using random-effects models, taking into account correlation between estimates. We carried out a dose-risk analysis using nonlinear random-effects meta-regression models. RESULTS Compared with nondrinkers, the pooled relative risk (RR) was 1.07 [95% confidence interval (CI) 1.01-1.13] for alcohol drinkers and 1.20 (95% CI 1.01-1.44) for heavy alcohol drinkers (≥4 drinks per day). The pooled estimates were apparently higher for gastric noncardia (RR for heavy drinkers = 1.17, 95% CI 0.78-1.75) than for gastric cardia (RR = 0.99, 95% CI 0.67-1.47) adenocarcinoma. The dose-risk model estimated a RR of 0.95 (95% CI 0.91-0.99) for 10 g/day and 1.14 (95% CI 1.08-1.21) for 50 g/day. CONCLUSIONS This meta-analysis provides definite evidence of a lack of association between moderate alcohol drinking and gastric cancer risk. There was, however, a positive association with heavy alcohol drinking.BACKGROUND Whether an association between alcohol drinking and gastric cancer risk exists is an open question. In order to provide a definite quantification of the association between alcohol drinking and gastric cancer risk, we conducted a meta-analysis of available data. PATIENTS AND METHODS We carried out a PubMed search of articles published up to June 2010 and identified 44 case-control and 15 cohort studies, including a total of 34 557 gastric cancer cases. We derived meta-analytic estimates using random-effects models, taking into account correlation between estimates. We carried out a dose-risk analysis using nonlinear random-effects meta-regression models. RESULTS Compared with nondrinkers, the pooled relative risk (RR) was 1.07 [95% confidence interval (CI) 1.01-1.13] for alcohol drinkers and 1.20 (95% CI 1.01-1.44) for heavy alcohol drinkers (≥4 drinks per day). The pooled estimates were apparently higher for gastric noncardia (RR for heavy drinkers=1.17, 95% CI 0.78-1.75) than for gastric cardia (RR=0.99, 95% CI 0.67-1.47) adenocarcinoma. The dose-risk model estimated a RR of 0.95 (95% CI 0.91-0.99) for 10 g/day and 1.14 (95% CI 1.08-1.21) for 50 g/day. CONCLUSIONS This meta-analysis provides definite evidence of a lack of association between moderate alcohol drinking and gastric cancer risk. There was, however, a positive association with heavy alcohol drinking.

Epidemiology and Pathophysiology of Alcohol and Breast Cancer: Update 2012

AIMS To update epidemiological data on alcohol and breast cancer, with special emphasis on light alcohol consumption, and to review mechanisms of alcohol mediated mammary carcinogenesis. METHODS For epidemiological data, in November 2011 we performed a literature search in various bibliographic databases, and we conducted a meta-analysis of data on light alcohol drinking. Relevant mechanistic studies were also reviewed to November 2011. RESULTS A significant increase of the order of 4% in the risk of breast cancer is already present at intakes of up to one alcoholic drink/day. Heavy alcohol consumption, defined as three or more drinks/day, is associated with an increased risk by 40-50%. This translates into up to 5% of breast cancers attributable to alcohol in northern Europe and North America for a total of approximately 50,000 alcohol-attributable cases of breast cancer worldwide. Up to 1-2% of breast cancers in Europe and North America are attributable to light drinking alone, given its larger prevalence in most female populations when compared with heavy drinking. Alcohol increases estrogen levels, and estrogens may exert its carcinogenic effect on breast tissue either via the ER or directly. Other mechanisms may include acetaldehyde, oxidative stress, epigenetic changes due to a disturbed methyl transfer and decreased retinoic acid concentrations associated with an altered cell cycle. CONCLUSIONS Women should not exceed one drink/day, and women at elevated risk for breast cancer should avoid alcohol or consume alcohol occasionally only.

Cancer prevention in Europe: The Mediterranean diet as a protective choice

In the coming years, European death rates because of cancer will further decline, but the overall number of cases will increase, mostly as a consequence of the ageing of the population. The target for cancer prevention in Europe will remain a healthy diet and control of obesity in addition to a decrease in smoking. A healthy diet model in European countries is the traditional Mediterranean diet, which is based on abundant and variable plant foods, high consumption of cereals, olive oil as the main (added) fat, low intake of (red) meat and moderate consumption of wine. The Mediterranean diet is associated with a reduced risk of cardiovascular disease and cancer. The biological mechanisms for cancer prevention associated with the Mediterranean diet have been related to the favourable effect of a balanced ratio of omega 6 and omega 3 essential fatty acids and high amounts of fibre, antioxidants and polyphenols found in fruit, vegetables, olive oil and wine. The Mediterranean diet also involves a ‘Mediterranean way of drinking’, that is, regular, moderate consumption of wine mainly with food. This pattern of drinking increases longevity, reduces the risk of cardiovascular disease and does not appreciably influence the overall risk of cancer. However, heavy alcohol drinking is associated with digestive, upper respiratory tract, liver and breast cancers; therefore, avoidance or restriction of alcohol consumption to two drinks/day in men and one drink/day in women is a global public health priority.

Dietary acrylamide and human cancer

Low levels of acrylamide have been found in several foods cooked at high temperatures. While there is sufficient evidence for the carcinogenicity of acrylamide in experimental animals, the few epidemiologic studies conducted to date on occupational and dietary exposure to acrylamide have found no consistent evidence of association with human cancer risk. Using data from an integrated network of Italian and Swiss hospital‐based case‐control studies, we analyzed the relation between dietary acrylamide intake and cancers of the oral cavity and pharynx (749 cases, 1,772 controls), esophagus (395 cases, 1,066 controls), large bowel (1,394 cases of colon, 886 cases of rectal cancer, 4,765 controls), larynx (527 cases, 1,297 controls), breast (2,900 cases, 3,122 controls), ovary (1,031 cases, 2,411 controls) and prostate (1,294 cases, 1,451 controls). All the studies included incident, histologically confirmed cancer cases and controls admitted to the same network of hospitals for acute nonneoplastic conditions. We calculated odds ratios (ORs) using multivariate logistic regression models, adjusted for energy intake and other major covariates of interest. The ORs for the highest versus the lowest quintile of acrylamide intake were 1.12 (95% CI = 0.76–1.66) for cancer of the oral cavity/pharynx, 1.10 (95% CI = 0.65–1.86) for esophageal, 0.97 (95% CI = 0.80–1.18) for colorectal, 1.23 (95% CI = 0.80–1.90) for laryngeal, 1.06 (95% CI = 0.88–1.28) for breast, 0.97 (95% CI = 0.73–1.31) for ovarian and 0.92 (95% CI = 0.69–1.23) for prostate cancer. None of the trend in risk was significant. This uniquely large and comprehensive data set does not show any consistent association between intake of acrylamide and the risk of breast and several other common cancers.

Dietary folate and colorectal cancer

Folate may be inversely related to colorectal cancer risk, possibly in combination with low methionine and high alcohol consumption. We considered, therefore, the relation between folate and colorectal cancer in a multicentric case‐control study of 1,953 cases and 4,154 controls from Italy, i.e., a population with frequent regular alcohol drinking. In the overall data set, the odds ratio (OR) was 0.72 for the highest quintile of folate, and the continuous OR per 100 μg was 0.86. The inverse relation was similar in men and women and somewhat stronger for the rectum (OR = 0.59 for the highest quintile) compared to the colon (OR = 0.81). It was also somewhat stronger in the highest tertile of alcohol drinking (OR = 0.65), though trends were not heterogeneous across strata of alcohol, whereas no appreciable difference was observed across strata of methionine intake. Compared to subjects reporting low alcohol, high methionine and high folate intake, the OR was 1.83 for those reporting high alcohol, low methionine and low folate intake. The present findings support a favorable role of folate in colorectal carcinogenesis.

Fried potatoes and human cancer

A considerable public concern about cancer risk from acrylamide‐rich foods followed the announcement that high concentrations of acrylamide are found in fried potatoes and potato chips and, more generally, in starch‐containing foods cooked at high temperatures. From a series of hospital‐based case–control studies conducted in Italy and Switzerland between 1991 and 2000, we have analyzed the relation between intake of fried/baked potatoes and cancer risk. The cancer sites considered were oral cavity and pharynx (749 cases, 1,772 controls), esophagus (395 cases, 1,066 controls), larynx (527 cases, 1,297 controls), large bowel (1,225 colon and 728 rectum cases, 4,154 controls), breast (2,569 cases, 2,588 controls) and ovary (1,031 cases, 2,411 controls). All cancer cases were incident and histologically confirmed. Controls were subjects admitted to the same network of hospitals of cases for acute, non‐neoplastic conditions. All the odds ratios (OR) for the highest vs. the lowest tertile of intake ranged between 0.8–1.1. We found no evidence of interaction with age, gender, alcohol and tobacco use. Our data provide reassuring evidence for the lack of an important association between consumption of fried/baked potatoes and cancer risk.