Effects of supplemental alpha-tocopherol and beta-carotene on urinary tract cancer: incidence and mortality in a controlled trial (Finland)

Objectives: Epidemiological studies have suggested a protective effect of vegetables and fruits on urinary tract cancer but the possible protective nutrients are unknown. We studied the effect of alpha-tocopherol (a form of vitamin E) and beta-carotene supplementation on urinary tract cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. Methods: A total of 29,133 male smokers aged 50–69 years from southwestern Finland were randomly assigned to receive alpha-tocopherol (50 mg), beta-carotene (20 mg), both agents, or a placebo daily for 5–8 years (median 6.1 years). Incident urothelial cancers (bladder, ureter, and renal pelvis; n = 169) and renal cell cancers (n = 102) were identified through the nationwide cancer registry. The diagnoses were centrally confirmed by review of medical records and pathology specimens. The supplementation effects were estimated using a proportional hazards model. Results: Neither alpha-tocopherol nor beta-carotene affected the incidence of urothelial cancer, relative risk 1.1 (95% confidence interval (CI) 0.8–1.5) and 1.0 (95% CI 0.7–1.3), respectively, or the incidence of renal cell cancer, relative risk 1.1 (95% CI 0.7–1.6) and 0.8 (95% CI 0.6–1.3), respectively. Conclusion: Long-term supplementation with alpha-tocopherol and beta-carotene has no preventive effect on urinary tract cancers in middle-aged male smokers.     

Effects of beta-carotene supplementation on cancer incidence by baseline characteristics in the Physicians' Health Study (United States)

Objectives: The Physicians' Health Study (PHS) was a randomized trial of beta-carotene (50 mg, alternate days) and aspirin in primary prevention of cancer and cardiovascular disease among 22,071 US male physicians. This report updates results for beta-carotene and examines effect modification by baseline characteristics. Methods: Beta-carotene's effect on cancer over nearly 13 years was examined overall and within subgroups defined by baseline characteristics using proportional-hazards models. Results: 2667 incident cancers were confirmed, with 1117 prostate, 267 colon, and 178 lung cancers. There were no significant differences with supplementation in total (relative risk (RR) = 1.0, 95% confidence interval (CI) = 0.9–1.0); prostate (RR = 1.0, 95% CI = 0.9–1.1); colon (RR = 0.9, 95% CI = 0.7–1.2); or lung (RR = 0.9, 95% CI = 0.7–1.2) cancer, and no differences over time. In subgroup analyses, total cancer was modestly reduced with supplementation among those aged 70+ years (RR = 0.8, 95% CI = 0.7–1.0), daily drinkers of alcohol (RR = 0.9, 95% CI = 0.8–1.0), and those in the highest BMI quartile (RR = 0.9, 95% CI = 0.7–1.0). Prostate cancer was reduced with supplementation among those in the highest BMI quartile (RR = 0.8, 95% CI = 0.6–1.0), and colon cancer was reduced among daily drinkers of alcohol (RR = 0.5, 95% CI = 0.3–0.8). Conclusions: The PHS found no overall effect of beta-carotene on total cancer, or the three most common site-specific cancers. The possibility of risk reduction within specific subgroups remains.     

A prospective study on active and environmental tobacco smoking and bladder cancer risk (The Netherlands)

Objective: In a prospective cohort study among 120,852 adult subjects the authors investigated the associations between cigarette, cigar, pipe, environmental tobacco smoking (ETS), and bladder cancer. Methods: In 1986 all subjects completed a questionnaire on cancer risk factors. Follow-up for incident bladder cancer was established by linkage to cancer registries until 1992. The case–cohort analysis was based on 619 cases and 3346 subcohort members. Results: Compared with lifelong non-smokers the age- and sex-adjusted incidence rate ratios (RR) for ex- and current cigarette smokers were 2.1 (95% CI 1.5–3.0) and 3.3 (95% CI 2.4–4.6), respectively. The RR for smoking duration was 1.03 (95% CI: 1.02–1.04) per 1-year increment. The RR per 10 cigarettes/day was 1.3 (95% CI 1.2–1.4). Tar and nicotine exposure increased bladder cancer risk only weakly. It appeared that associations of cigarette smoking characteristics with bladder cancer risk were largely attributable to cigarette smoking duration only. Smoking cessation, age at first exposure, filter-tip usage, cigar and pipe smoking, and ETS were no longer associated with bladder cancer risk after adjustment for frequency and duration of smoking. Conclusions: The authors conclude that current cigarette smokers have a three-fold higher bladder cancer risk than non-smokers. Ex-smokers experience a two-fold increased risk. About half of male bladder cancer and one-fifth of female bladder cancer was attributable to cigarette smoking. Other smoking types (cigar, pipe, or ETS) were not associated with increased risks.     

A prospective study of lifestyle factors and the risk of pancreatic cancer in Nord-Trøndelag, Norway

Objectives: Cancer of the pancreas is highly fatal and, despite extensive scrutiny, only cigarette smoking stands out as a likely causal agent in epidemiological studies. To explore to what extent different lifestyle factors are associated with the risk of pancreatic cancer, data from a large health screening survey in a county in Norway were analyzed. Methods: Our study included 31,000 men and 32,374 women initially free from any diagnosed cancer, and during 12 years of follow-up, 166 incident cases of pancreatic cancer were diagnosed at the Cancer Registry. Results: Compared with never smokers, we found a two-fold increased risk among current smokers, and a dose–response association with number of cigarettes (p for trend = 0.02 for both men and women) and with number of pack-years (p for trend = 0.02 for men and 0.01 for women). The risk among former smokers quitting more than 5 years before study entry was close to the risk of never smokers. Compared with persons who reported never or infrequently to be physically worn out after a day's work, the relative risk (RR) among those who nearly always became worn out was 2.9 (95% confidence interval (CI) = 1.4–5.8) for men and 3.8 (95% CI = 1.6–9.2) for women. Divorced or separated men had a risk of 3.1 (95% CI = 1.3–7.2) compared with married men. We observed a higher risk among women in occupations of high socioeconomic status (RR = 2.5; 95% CI = 1.2–5.2), and among men occupied in farming, agriculture or forestry (RR = 2.1; 95% CI = 1.1–4.0), compared with persons in occupations of low socioeconomic status. Conclusions: Our results confirm the findings of previous studies that indicate a causal role of cigarette smoking in pancreatic cancer. Moreover, we found that the risk of former smokers may approach the risk of never smokers within a few years subsequent to quitting.     

Diet and prostate cancer risk in a cohort of smokers, with a specific focus on calcium and phosphorus (Finland)

Background:Calcium, phosphorus, fructose, and animal protein are hypothesized to be associated with prostate cancer risk, potentially via their influence on 1,25-dihydroxyvitamin D₃. We examined these nutrients and overall diet and prostate cancer risk in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (ATBC Study). Materials and methods:The ATBC Study was a randomized 2 × 2 trial of alpha-tocopherol and beta-carotene on lung cancer incidence conducted among Finnish male smokers; 27,062 of the men completed a food-use questionnaire at baseline, and comprise the current study population. There were 184 incident clinical (stage 2–4) prostate cancer cases diagnosed between 1985 and 1993. We used Cox proportional hazards models to examine associations between dietary intakes and prostate cancer. Results:We did not observe significant independent associations for calcium and phosphorus and prostate cancer risk. However, men with lower calcium and higher phosphorus intake had a multivariate relative risk of 0.6 (95% CI 0.3–1.0) compared to men with lower intakes of both nutrients, adjusting for age, smoking, body mass index, total energy, education, and supplementation group. Of the other foods and nutrients examined, none was significantly associated with risk. Discussion:This study provides, at best, only weak evidence for the hypothesis that calcium and phosphorus are independently associated with prostate cancer risk, but suggests that there may be an interaction between these nutrients.     

Hormonal risk factors for endometrial cancer: modification by cigarette smoking (United States)

Objectives: To evaluate whether smoking modifies the risk of endometrial cancer associated with body mass index (BMI), postmenopausal hormone use, and other hormonal factors. Methods: Using multivariate adjusted models we examined interview data from a population-based case–control study of Wisconsin women (n = 740 cases, n = 2372 controls). Results: The relative risk for endometrial cancer associated with current smoking was 0.8 (95% CI: 0.6–1.0) compared to never smokers. No clear dose–response relationship was evident for pack-years smoked. When examined according to smoking status the risk associated with the highest quartile of BMI seemed to be greater among non-smokers (OR = 3.6, 95% CI: 2.4–5.3) than among current smokers (OR = 2.8, 95% CI: 1.4–5.6). Among postmenopausal women the risk associated with current use of postmenopausal hormones appeared to be greater among non-smokers (OR = 3.3, 95% CI: 2.3–4.9) than among current smokers (OR = 2.7, 95% CI: 1.3–5.5). Risk for long-term use (10 or more years) compared with never users was 8.3 (95% CI: 4.6–15.1) among never smokers and 2.5 (95% CI: 0.8–7.9) among current smokers. The risk associated with non-insulin-dependent diabetes was greater among non-smokers (OR = 2.5, 95% CI: 1.7–3.6) than current smokers (OR = 1.1, 95% CI: 0.4–3.1). There was no modifying effect of smoking on the risk associated with parity. Conclusion: These results suggest that smoking moderates the risk associated with endometrial cancer among women at greatest risk, specifically women who are obese or who use postmenopausal hormones.     

Serum and dietary vitamin E in relation to prostate cancer risk.

Alpha-tocopherol supplementation (50 mg daily for 5-8 years) reduced prostate cancer incidence by 32% in the alpha-Tocopherol, beta-Carotene Cancer Prevention Study. We investigated whether serum alpha-tocopherol or intake of vitamin E (eight tocopherols and tocotrienols) was associated with prostate cancer risk with up to 19 years of follow-up in the alpha-Tocopherol, beta-Carotene Cancer Prevention Study cohort. Of the 29,133 Finnish male smokers, ages 50 to 69 years recruited into the study, 1,732 were diagnosed with incident prostate cancer between 1985 and 2004. Baseline serum alpha-tocopherol was measured by high-performance liquid chromatography and the components of vitamin E intake were estimated based on a 276-item food frequency questionnaire and food chemistry analyses. Proportional hazard models were used to determine multivariate-adjusted relative risks (RR) and 95% confidence intervals (95% CI). Higher serum alpha-tocopherol was associated with reduced risk of prostate cancer (RR, 0.80; 95% CI, 0.66-0.96 for highest versus lowest quintile; Ptrend = 0.03) and was strongly and inversely related to the risk of developing advanced disease (RR, 0.56; 95% CI, 0.36-0.85; Ptrend = 0.002). The inverse serum alpha-tocopherol-prostate cancer association was greater among those who were supplemented with either alpha-tocopherol or beta-carotene during the trial. There were no associations between prostate cancer and the individual dietary tocopherols and tocotrienols. In summary, higher prediagnostic serum concentrations of alpha-tocopherol, but not dietary vitamin E, was associated with lower risk of developing prostate cancer, particularly advanced prostate cancer.     

Cigarette Smoking, Alcohol Consumption, and Endometrial Cancer Risk: A Population-based Study in Sweden

Objective: To assess effects of cigarette smoking and alcohol consumption on the risk of endometrial cancer among postmenopausal women. Methods: We performed a nationwide population-based case–control study among postmenopausal women aged 50–74 years in Sweden, including 709 incident endometrial cancer cases and 3368 controls. Results: Compared to never smokers, recent/current smokers had a decreased risk of endometrial cancer (multivariate OR 0.61, 95% CI 0.47–0.80), but former smokers presented no substantial difference in risk (multivariate OR 0.90, 95% CI 0.72–1.14). We observed a decreased risk of endometrial cancer for postmenopausal smoking, but there was no clear impact on risk for premenopausal smoking. The inverse association of smoking with risk was not explained by differences in body mass index between smokers and nonsmokers. Alcohol consumption was not clearly associated with risk of endometrial cancer. The multivariate OR for women consuming up to 1.6 g of alcohol per day was 1.12 (95% CI 0.88–1.44), and 0.92 (95% CI 0.70–1.20) for women consuming more than 4 g per day (p for trend over categories=0.44). Conclusions: Current cigarette smoking reduces the risk of postmenopausal endometrial cancer, but the inverse association dissipates after smoking cessation. Premenopausal smoking might not affect risk of postmenopausal endometrial cancer. Alcohol consumption is not materially associated with risk.     

Height and Body Mass Index in Relation to Colorectal and Gallbladder Cancer in Two Million Norwegian Men and Women

Objectives: The present study aimed at exploring the relations between BMI and stature and colorectal and gallbladder cancer in a huge Norwegian cohort with measured height and weight.Material and methods: Height and weight were measured in two million Norwegian men and women aged 20–74 during 1963–2001. During follow-up, 47,117 colorectal and 1715 gallbladder cancer cases were registered. Relative risks (RRs) of colorectal and gallbladder cancer were estimated using Cox proportional hazards regression.Results: The risk of colon cancer increased with increasing BMI in men; the RR of colon cancer per unit increase in BMI was 1.04 (95% CI: 1.04–1.05). For mucinous colorectal adenocarcinomas, the risk increased to a larger extent with increasing BMI in both sexes. The RR of colorectal cancer associated with 10 cm increase in height was 1.14 (95% CI: 1.11–1.16) in men and 1.17 (95% CI: 1.14–1.20) in women. The risk of gallbladder cancer increased with increasing BMI in women; the overall RR associated with one unit increase in BMI was 1.06 (95% CI: 1.04–1.07). There was no association between height and gallbladder cancer in either sex.Conclusion: The risk of colon cancer increased with increasing BMI in men, and the risk of gallbladder cancer increased with increasing BMI in women. In both sexes, the risk of colon cancer increased with increasing height.     

Beta‐carotene supplementation and cancer risk: a systematic review and metaanalysis of randomized controlled trials

The effect of beta‐carotene supplementation on cancer incidence has been investigated in several randomized controlled trials. The objective was to review the effect of beta‐carotene supplementation on cancer incidence in randomized trials by cancer site, beta‐carotene supplementation characteristics and study population. Relevant trials were retrieved by searching PubMed (up to April 2009). Authors involved in selected studies were contacted for additional information. Thirteen publications reporting results from 9 randomized controlled trials were included. Overall, no effect of beta‐carotene supplementation was observed on the incidence of all cancers combined (RR, 1.01; 95% CI, 0.98–1.04), pancreatic cancer (RR, 0.99; 95% CI, 0.73–1.36), colorectal cancer (RR, 0.96; 95% CI, 0.85–1.09), prostate cancer (RR, 0.99; 95% CI, 0.91–1.07), breast cancer (RR, 0.96; 95% CI, 0.85–1.10), melanoma (RR, 0.98; 95% CI, 0.65–1.46) and non melanoma skin cancer (RR, 0.99; 95% CI, 0.93–1.05). The incidence of lung and stomach cancers were significantly increased in individuals supplemented with beta‐carotene at 20–30 mg day⁻¹ (RR, 1.16; 95% CI, 1.06–1.27 and RR, 1.34; 95% CI, 1.06–1.70), in smokers and asbestos workers (RR, 1.20; 95% CI, 1.07–1.34 and RR, 1.54; 95% CI, 1.08–2.19) compared to the placebo group. Beta‐carotene supplementation has not been shown to have any beneficial effect on cancer prevention. Conversely, it was associated with increased risk not only of lung cancer but also of gastric cancer at doses of 20–30 mg day⁻¹, in smokers and asbestos workers. This study adds to the evidence that nutritional prevention of cancer through beta‐carotene supplementation should not be recommended.     

Tubal sterilization and risk of breast cancer mortality in US women

Objective: To investigate the hypothesis that tubal sterilization is associated with a reduced risk of breast cancer. Methods: We examined this hypothesis in a large prospective study of US adults. After 14 years of mortality follow-up, 3837 deaths from breast cancer were observed in a cohort of 619,199 women who were cancer-free at study entry in 1982. Results: Cox proportional hazards models (adjusted for multiple breast cancer risk factors) showed a significant inverse association between tubal sterilization and breast cancer mortality (adjusted rate ratio (RR) = 0.82, 95% confidence interval (CI) 0.70–0.96). Women who were sterilized before age 35 had a lower risk (adjusted RR = 0.69, 95% CI 0.53–0.88) than women who were sterilized at 35 years of age or older (adjusted RR = 0.92, 95% CI 0.75–1.13). Also, sterilizations performed before 1975 resulted in a lower risk (RR = 0.75, 95% CI 0.62–0.91) than those performed during or after 1975 (RR = 0.98, 95% CI 0.74–1.29), possibly reflecting the likelihood of greater tissue damage with earlier procedures. Conclusions: These results suggest that tubal sterilization may lower subsequent risk of breast cancer, especially among women who are sterilized at a relatively young age. Additional studies are needed to confirm or refute these findings.     

Rapid N-acetyltransferase 2 imputed phenotype and smoking may increase risk of colorectal cancer in women (Netherlands)

Objective: The relationship between smoking and colorectal cancer risk and whether such effect is modified by variations in the NAT2 genotype is investigated. Methods: In the prospective DOM (Diagnostisch Onderzoek Mammacarcinoom; 27,722 women) cohort follow-up from 1976 until 1987 revealed 54 deaths due to colon or rectal cancer, and follow-up from 1987 to 01-01-1996 revealed 204 incident colorectal cancer cases. A random sample (n = 857) from the baseline cohort was used as controls. Four NAT2 restriction fragment length polymorphisms (RFLPs) were analysed using DNA extracted from urine samples. Rapid or slow acetylator phenotype status was attributed to individuals. Results: Smoking may increase the risk for colon cancer (RR = 1.36, 95% CI 0.97–1.92) as well as for rectal cancer (RR = 1.31, 95% CI 0.76–2.25), although not statistically significant. Rapid NAT2 acetylation did not increase colorectal cancer risk, but in combination with smoking the risk was statistically significant increased, compared to women who had a slow NAT2 imputed phenotype and never smoked (RR = 1.56, 95% CI 1.03–2.37). For colon cancer, but not for rectal cancer the increased risk was statistically significant (RR = 1.67, 95% CI, 1.05–2.67 versus RR = 1.30 95% CI 0.63–2.68). Conclusions: Our study points to smoking as a risk factor for colon and rectal cancer and, in addition, especially in women with rapid NAT2 imputed phenotype.     

Are Coffee, Tea, and Total Fluid Consumption associated with Bladder Cancer Risk? Results from the Netherlands Cohort Study

Objectives: Coffee, tea, and fluid consumption have been thought to influence bladder cancer incidence. In a large prospective study, these associations were investigated. Methods: In 1986, cohort members (55–69 years) completed a questionnaire on cancer risk factors. Follow-up was established by linkage to cancer registries until 1992. The multivariable case–cohort analysis was based on 569 bladder cancer cases and 3123 subcohort members. Results: The incidence rate ratios (RR) for men consuming <2 cups of coffee/day was 0.89 (95% CI 0.51–1.5) using the median consumption category (4–<5 cups/day) as reference. This RR increased to 1.3 (95% CI 0.94–1.9) for men consuming 7 cups/day, although no clear dose–response association was found. The RRs decreased from 1.2 (95% CI 0.56–2.7) for women consuming <2 cups of coffee/day to 0.36 (95% CI 0.18–0.72) for women consuming 5 cups/day compared to the median consumption category (3–<4 cups/day). Men and women who abstained from drinking tea had a RR of 1.3 (95% CI 0.97–1.8) compared to those consuming 2–<3 cups of tea per day (median consumption category). The RR for men and women comparing highest to lowest quintile of total fluid consumption was 0.87 (95% CI 0.63–1.2). Conclusion: The data suggest a possible positive association between coffee consumption and bladder cancer risk in men and a probable inverse association in women. Tea consumption was inversely associated with bladder cancer. Total fluid consumption did not appear to be associated with bladder cancer.     

Employment as butcher and cancer risk in a record-linkage study from Sweden

Objective: To investigate the risk of cancer among butchers and other meat workers in a large record-linkage study from Sweden. Methods: The Swedish Cancer Environment Register III contains nationwide data on cancer incidence during 1971–1989 for all residents, by occupation and industry of employment as reported at the 1960 and 1970 censuses. We identified 25,049 men classified as butchers or meat workers at either census. We used as a comparison group the remaining part of the active male population, after exclusion of workers with direct contact with animals. Results: Butchers in the meat industry had a slight increase in the risk of cancer (relative risk [RR] 1.1, 95% confidence interval [CI] 1.0–1.3), which was due to an increased risk of cancers of the oral cavity and pharynx (RR 1.6, 95% CI 1.0–2.7), stomach (RR 1.6, 95% CI 1.1–2.7), larynx (RR 1.4, 95% CI 0.6–3.4), and lung (RR 1.4, 95% CI 1.1–1.9). The risk of stomach cancer was highest during the first 5 years of the study, and among butchers from urban areas. No temporal or geographic variations were seen for lung cancer risk, with elevations restricted to squamous cell carcinoma. An increased risk of stomach, laryngeal and lung cancers was present in butchers and meat workers outside the meat industry. There was no clear indication of an increased risk of other neoplasms. Conclusions: The increased risk of oral, laryngeal, lung and stomach cancers among Swedish butchers may be at least partly due to confounding by tobacco smoking, alcohol drinking, and other lifestyle factors. However, exposures in the meat industry (e.g., viruses, nitrosamines, polycyclic aromatic hydrocarbons) may contribute the elevated cancer risks.     

Cigarette smoking and risk of epithelial ovarian cancer (Australia)

Objectives: We studied the association between cigarette smoking and ovarian cancer in a population-based case–control study. Methods: A total of 794 women with histologically confirmed epithelial ovarian cancer who were aged 18–79 years and resident in one of three Australian states were interviewed, together with 855 controls aged 18–79 years selected at random from the electoral roll from the same states. Information was obtained about cigarette smoking and other factors including age, parity, oral contraceptive use, and reproductive factors. We estimated the relative risk of ovarian cancer associated with cigarette smoking, accounting for histologic type, using multivariable logistic regression to adjust for confounding factors. Results: Women who had ever smoked cigarettes were more likely to develop ovarian cancer than women who had never smoked (adjusted odds ratio (OR) = 1.5; 95% confidence interval (CI) = 1.2–1.9). Risk was greater for ovarian cancers of borderline malignancy (OR = 2.4; 95% CI = 1.4–4.1) than for invasive tumors (OR = 1.7; 95% CI = 1.2–2.4) and the histologic subtype most strongly associated overall was the mucinous subtype among both current smokers (OR = 3.2; 95% CI = 1.8–5.7) and past smokers (OR = 2.3; 95% CI = 1.3–3.9). Conclusions: These data extend recent findings and suggest that cigarette smoking is a risk factor for ovarian cancer, especially mucinous and borderline mucinous types. From a public health viewpoint, this is one of the few reports of a potentially avoidable risk factor for ovarian cancer.     

Diet in the epidemiology of endometrial cancer in Western New York (United States)

Objectives: We examined diet and risk of endometrial cancer among women in the Western New York Diet Study (1986–1991). Methods: Self-reported frequency of use of 172 foods and beverages during the 2 years before the interview and other relevant data were collected by detailed interviews from 232 endometrial cancer cases and 639 controls, frequency-matched for age and county of residence. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by unconditional logistic regression, adjusting for age, education, body mass index (BMI), smoking history, hypertension, diabetes, age at menarche, parity, oral contraceptive use, menopausal status, menopausal estrogen use, and energy. Results: Risks were reduced for women in the highest quartiles of intake of protein (OR 0.4, 95% CI: 0.2–0.9), dietary fiber (OR 0.5, 95% CI: 0.3–1.0), phytosterols (OR 0.6, 95% CI: 0.3–1.0), vitamin C (OR 0.5, 95% CI: 0.3–0.8) folate (OR 0.4, 95% CI: 0.2–0.7), alpha-carotene (OR 0.6, 95% CI: 0.4–1.0), beta-carotene (OR 0.4, 95% CI: 0.2–0.6), lycopene (OR 0.6, 95% CI: 0.4–1.0), lutein + zeaxanthin (OR 0.3, 95% CI: 0.2–0.5) and vegetables (OR 0.5, 95% CI: 0.3–0.9), but unrelated to energy (OR 0.9, 95% CI: 0.6–1.5) or fat (OR 1.6, 95% CI: 0.7–3.4). Conclusions: Our results support previous findings of reduced endometrial cancer risks associated with a diet high in plant foods.     

A prospective study of medical conditions,anthropometry, physical activity,and pancreatic cancer in male smokers (Finland)

Objective: To examine the association between several medical conditions, anthropometric measurements, occupational and leisure physical activity, and pancreatic cancer in a cohort of male Finnish smokers. Methods: We performed a cohort analysis of the 172 subjects who developed pancreatic cancer between 1985 and 1997 (median 10.2 years follow-up) among the 29,048 male smokers, 50–69 years old, who had complete baseline data and participated in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. Cox proportional hazards models were used to estimate multivariable adjusted hazard ratios (HR) and 95% confidence intervals (CI). Results: We observed positive associations between pancreatic cancer risk and self-reported history of diabetes mellitus (HR = 2.02, 95% CI 1.17–3.50) and bronchial asthma (HR = 2.16, 95% CI 1.17–3.98). Men having combined occupational and leisure activity greater than at sedentary levels had reduced risk for the cancer; for example those with moderate/heavy activity in both settings showed a HR of 0.42 (95% CI 0.22–0.83). There were no significant associations with other self-reported illnesses, total or HDL (high-density lipoprotein) cholesterol, height, weight, or body mass index. Conclusions: Our data suggest that diabetes mellitus and bronchial asthma predict the subsequent risk of developing pancreatic cancer in male smokers, and that greater physical activity may reduce the risk.     

A prospective cohort study of cigarette smoking and pancreatic cancer in Japan

Objective: To examine the association of cigarette smoking with the risk of death from pancreatic cancer in a prospective cohort study. Methods: A total of 110,792 inhabitants, aged 40–79 years (46,465 men and 64,327 women), were enrolled from 1988 to 1990 and followed up for mortality to the end of 1997. At baseline a self-administered questionnaire was used to obtain information on cigarette smoking and other lifestyle factors. Results: During the follow-up period (mean ± SD: 8.1 ± 1.8 years), 225 deaths due to pancreatic cancer were identified. After adjustment for age, body mass index, history of diabetes mellitus, and gallbladder diseases, the relative risks (RRs) for current smokers were 1.6 (95% CI 0.95–2.6) in males, and 1.7 (95% CI: 0.84–3.3) in females. Men who smoked more than 40 cigarettes per day had a substantially higher risk of pancreatic cancer, with a RR of 3.3 (95% CI: 1.4–8.1). A significantly decreasing trend in risk with increasing years after smoking cessation was observed (trend p = 0.04) among male ex-smokers. The RRs were 0.85 (95% CI 0.36–2.0) and 0.85 (0.36–2.0) for those who had quit smoking for 10–19 and 20 years, respectively. Conclusions: Our cohort study confirmed that cigarette smoking was associated with an increased risk of death from pancreatic cancer.     

Cancer incidence among male Swedish veterinarians and other workers of the veterinary industry: a record-linkage study

Objective: To investigate the risk of cancer among veterinarians in a large record-linkage study from Sweden. Methods: We used the nationwide, Swedish Cancer Environment Registry III, which links the Cancer Register data for 1971–1989 to the national population censuses from 1960 and 1970, to compare the incidence of cancer among male veterinarians to that of the remaining part of the active population using multivariable Poisson regression models and standardized incidence ratios. One thousand one hundred and seventy eight men classified as veterinarians or workers in the veterinary industry at either census were identified. Results: Veterinarians in the veterinary industry experienced increased risk of esophageal (relative risk (RR) 3.78, 95% confidence interval (CI) 1.42–10.09), colon (RR: 2.36, 95% CI: 1.42–3.91), pancreatic (RR: 2.10, 95% CI: 0.94–4.68) and brain (RR: 2.51, 95% CI: 1.04–6.03) cancers as well as melanoma of the skin (RR: 2.77, 95% CI: 1.24–6.17). Similar excess risks were observed when veterinarians were compared with individuals of similar socio-economic status. Conclusion: The increased risks of esophageal, colon, pancreatic and brain cancers as well as melanoma observed among veterinarians did not seem to be explained by the high socio-economic status of this occupational group. Therefore, it is possible that some of these results reflect the carcinogenicity of occupational exposures, including animal viruses, solar or ionizing radiations and anesthetics.