Alcohol, methylxanthine-containing beverages, and colorectal cancer in Córdoba, Argentina

The relationship between social class indicators, body mass index (BMI), selected life-style habits (alcohol, coffee, maté and tea drinking) and colorectal cancer was investigated in a case-control study conducted between 1993 and 1997 in Córdoba, Argentina, a relatively high mortality area of colorectal cancer. Cases were 190 patients below age 80 years with incident, histologically confirmed colorectal adenocarcinomas, and controls were 393 patients admitted to hospital for a wide spectrum of acute, non-neoplastic disorders. Higher social class, based on occupation of the head of the household, was significantly associated with colorectal cancer risk: the odds ratios (OR) and 95% confidence intervals (95% CI) were 1.9 (1.2-2.9) for intermediate and 2.0 (1.2-3.4) for the highest as compared to the lowest social class individuals. When compared with subjects whose BMI was < 25 kg/m2, the OR was 1.1 (0.7-1.6) for those with BMI 25 to 29 kg/m2, and 1.3 (0.7-2.3) for those > or = 30. In comparison with alcohol abstainers, the OR was 2.8 (1.6-5.1) for drinkers, and there was a significant trend in risk with dose. The association was observed with wine (the most common alcoholic beverage in Argentina), as well as for beer and spirits. The consumption of coffee, maté and tea was not significantly related to colorectal cancer, but the ORs were below unity (0.9 (0.7-1.3) for coffee, 0.9 (0.6-1.2) for maté and 0.8 (0.6-1.2) for tea drinkers). The relationship between social class, alcohol drinking and colorectal cancer were consistent across strata of sex and age. This study confirms that colorectal cancer has positive social class correlates. The association with alcohol drinking is apparently stronger than previously reported, and may be due to the role of chance and/or peculiar correlates of alcohol drinking in this Argentinean population.

The influence of reproductive and hormonal factors on the risk of colon and rectal cancer in women

A case-control study was conducted between 1992 and 1996 in six Italian areas. It included 537 women with colon cancer, 291 women with rectal cancer and 2081 control women in hospital for acute conditions, unrelated to hormonal or gynaecological diseases. A higher age at menopause was associated with increased colon cancer risk (odds ratio (OR) for > or = 53 years compared with < 50 years = 1.39, 95% confidence interval (CI) 1.04-1.87). Among parous women, a significant trend of decreasing colon cancer risk with increasing number of births was seen for colon (OR for > or = 4 births compared with 1 birth = 0.62, 95% CI 0.42-0.90), but not for rectal cancer. Nulliparous women, however, were at lower risk than women with a single birth, and age at first birth was directly associated with risk. While oral contraceptive use showed no significant influence, ever users of hormone replacement therapy had a reduced risk of rectal cancer (OR = 0.56, 95% CI 0.31-1.01). Thus, the association of colorectal cancer with reproductive and menstrual factors is neither strong nor consistent.

Macronutrient intake and risk of colorectal cancer in Italy

To provide further insight on the relationship between macronutrients and colorectal cancer, overall and by specific subsite(s), we carried out between 1992 and 1996 in 6 Italian areas a case-control study on 1,953 individuals of both sexes with incident colorectal cancer (age range 19-74) and 4,154 controls (age range 19-74) in hospital with acute, non-neoplastic diseases. A validated food-frequency questionnaire was used, including questions on 78 foods or recipes and on individual fat-intake pattern. The risk of cancer of the colon and rectum increased with total energy intake (odds ratio in highest vs. lowest quintile 1.43 and 1.50, respectively). The risk also rose significantly with an increase of starch intake, whereas it moderately decreased with an increase of protein intake. Monounsaturated fat intake appeared uninfluential, while saturated fat intake showed a modest direct association with rectal cancer. Polyunsaturated fat intake was inversely associated with colon cancer risk, particularly with the right colon.

Trends in male:female ratio among newborn infants in 29 countries from five continents

We have analysed trends in male:female ratios among newborns between 1950 and 1990 in 29 countries from five continents. The numbers of liveborn males and females over the period 1950-1994 were derived from the World Health Organization (WHO) database. Countries for which reliable data were available included 20 major European countries (excluding the former Soviet Union, Albania and a few small countries), Canada, the USA, selected countries of Central and South America, Japan, Australia and New Zealand. From the original numbers of males and females, we computed the proportion of males among liveborns for each country and for selected broader areas within Europe. In most countries the proportion of male liveborns was constant during the study period. In particular, the proportion of male newborns in the European Union was 0.515 in 1950-1954, 0.514 in 1970-1974 and 0.514 in 1990-1994. In the USA, corresponding values were 0.513, 0.513 and 0.512. In Japan the ratios were 0.513 in 1950-1954, 0.516 and 1970-1974 and 0.514 in 1990-1994. Decreasing ratios were observed in some northern and eastern European countries plus Greece and Portugal and, particularly, in Mexico. In contrast, the proportion of male liveborns tended to increase in southern Europe and Australia. Overall, among the 29 countries considered, the proportion of males declined in 16, increased in six, and remained stable in seven.

Oral contraceptive use and risk of colorectal cancer

To evaluate the relation between oral contraceptives and colon and rectal cancer, we analyzed combined data from two case-control studies conducted in six Italian regions between 1985 and 1996. The studies included 803 women with incident colon cancer, 429 with rectal cancer, and 2,793 controls with acute, nonneoplastic, nondigestive, non-hormone-related disorders. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) from unconditional multiple logistic regression equations, including terms for age, center/study period, education, family history of colorectal cancer, menopausal status, age at menopause, parity, use of hormone replacement therapy, body mass index [weight (kg) per height squared (m2)], and total energy intake. Ever-use of oral contraceptives was inversely associated with colon cancer (OR = 0.63; 95% CI = 0.45-0.87) and rectal cancer (OR = 0.66; 95% CI = 0.43-1.01). Duration of use of oral contraceptives was inversely related to risk of colon but not rectal cancer. This study suggests that women who have ever used oral contraceptives are at lower risk of colon and rectal cancer.

Time since last use of oral contraceptives and risk of invasive cervical cancer

The time-risk relationship for the association between cervical cancer and oral contraceptives (OC) was examined using data on 592 cases of invasive cervical cancer aged 60 years or less and 616 controls with acute, non-gynaecological, non-hormone-related, non-neoplastic diseases. A total of 125 cases and 114 controls reported ever using OC and the multivariate odds ratio (OR) for ever versus never users was 1.21 (95% confidence interval (CI) 0.82-1.74). The risk of invasive cervical cancer was above unity in current users (OR 1.23) and in women who had stopped OC use less than 10 years before diagnosis, but not in those who had stopped their OC use > or = 10 years before (OR 0.85). Similarly, the OR was less for women who had started OC use 15 years or more previously than for more recent users. These data suggest that OCs may have a late stage (promoter) effect on cervical carcinogenesis and thus have public health implications, since the incidence of invasive cervical cancers is low at young ages, when OC use is more common and increases during middle age. The absence of a persisting risk is therefore of interest both for assessing individual risk and for its public health implications.

Italian study on colorectal cancer with emphasis on influence of cereals

To elucidate the influence of diet on colorectal carcinogenesis, 1225 subjects with cancer of the colon, 728 with cancer of the rectum and 4154 controls, hospitalized with acute non-neoplastic diseases, were interviewed between 1992 and 1996 in six Italian areas. The validated food frequency questionnaire included 79 questions on food items and recipes which were grouped into 16 food groups. After allowing for nondietary confounding factors and total energy intake, a significant trend towards an increasing risk of colorectal cancer with increasing intake was found for bread and cereal dishes (odds ratio for increase of one daily serving 1.11), cakes and desserts (odds ratio 1.02) and refined sugar (odds ratio 1.11). The intake of fish (odds ratio 0.53), raw and cooked vegetables (odds ratios 0.79 and 0.65, respectively) and fruit (odds ratio 0.93) showed an inverse association with risk. Wholemeal bread was consumed by only 12.5% of cases and 13.9% of controls and, at variance with refined bread, did not show a significant direct association with colorectal cancer risk (odds ratio 0.88). In view of these findings, current hypotheses on the carcinogenic effects of refined starchy foods and refined sugar should be revised to take into account the digestive physiology of carbohydrates and the possible relationship between insulin and colon cancer. The beneficial influence of most vegetables is confirmed, and a possible difference between refined and wholemeal bread is suggested.

Fibres, whole-grain foods and breast and other cancers

The possible relationship between fibre intake and breast cancer risk has been considered in several studies, but the issue is still unsettled. Epidemiological data are compatible with moderate protection from fibre-rich foods against the risk of breast cancer, but also with an absence of association. The apparently inconsistent results may be due to chance or bias, to different approaches to data analysis and interpretation, but may also reflect heterogeneity in the dietary sources of fibres (cereals or vegetables and fruit) in various populations, and different correlates of fibre intake.

Role of different types of vegetables and fruit in the prevention of cancer of the colon, rectum, and breast

We compared the effect of 26 types or groups of vegetables and fruit on the risk of cancer using data from two case-control studies that included 1,225 cases of cancer of the colon, 728 cases of cancer of the rectum, 2,569 cases of cancer of the breast, and 5,155 hospital controls interviewed between 1991 and 1996 in six Italian areas. Most vegetables were inversely associated with cancer of the colon and rectum, whereas only carrots and raw vegetables lowered breast cancer risk. High fruit intake was associated only with a reduction of rectal cancer. Different contents of sugar, fiber, carotenoids, and folic acid in fruits vs vegetables plus the concurrent consumption of oil with vegetables may partly explain these findings.

Incidence of invasive cancers following basal cell skin cancer

To obtain quantitative information on the risk of invasive cancers following a diagnosis of basal cell carcinoma (BCC) of the skin, patients with incident BCC cases listed in the cancer registries of the Swiss cantons of Vaud and Neuchâtel between 1974 and 1994 were actively followed up through December 31, 1994, for the occurrence of subsequent invasive neoplasms. Among 11,878 persons with incident BCC who were followed for a total of 76,510 person-years at risk, 1,543 metachronous cancers were observed versus 1,397.9 expected, corresponding to a standardized incidence ratio (SIR) of 1.1 (95% confidence interval (CI) 1.0-1.2). However, after exclusion of skin cancers (mostly squamous cell carcinoma and melanoma), 975 second primary cancers were observed versus 1,059 expected (SIR = 0.9, 95% CI 0.8-1.0). Significant excesses were registered for cancer of the lip (SIR = 2.2), for squamous cell skin cancer (SIR = 4.5) and melanoma of the skin (SIR = 2.5), and for non-Hodgkin's lymphoma (SIR = 1.9). The SIRs were also above unity, though not significantly, for cancers of the salivary glands (SIR = 2.8) and the small intestine (SIR = 2.1) and for soft-tissue sarcomas (SIR = 1.7). The SIR for lung cancer was 0.9. The SIRs for salivary gland and skin cancer were appreciably greater below age 70 years. For most sites, particularly for squamous cell cancer and melanoma of the skin, the SIRs remained elevated 5 or more years after BCC diagnosis. The cumulative incidence of squamous cell skin cancer was 13% at 19 years; this stresses the importance of carefully monitoring skin lesions among persons previously diagnosed with BCC.

Hormone replacement therapy and risk of colon and rectal cancer

The hypothesis that sex hormones may influence colorectal cancer risk was formulated in the early 1980s, but epidemiological studies on a relationship between colorectal cancer risk and hormone replacement therapy (HRT) have only accumulated over the last few years. To investigate the relationship between HRT and colon and rectal cancer and the role of other covariates that might modify it, we analyzed combined data from two case-control studies conducted in Italy between 1985 and 1996, including 994 women with incident colon cancer, 542 with rectal cancer, and 3110 controls with acute, non-neoplastic, nondigestive, non-hormone-related disorders. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived from unconditional multiple logistic regression equations including terms for age, center/study period, education, family history of colorectal cancer, status and age at menopause, parity, use of oral contraceptives, total energy intake, and body mass index. Ever use of HRT was inversely associated with cancer of the colon (OR = 0.64, 95% CI = 0.46-0.88) and of the rectum (OR = 0.46, 95% CI = 0.29-0.72). Increasing duration of use of HRT was related to decreasing risk for colon and rectal cancers (P for trend < 0.01). No interaction emerged, and the inverse association persisted across separate strata of other risk factors. This study, one of the largest case-control investigations on exogenous female hormones and colorectal cancer thus far, provides further evidence that women who have ever used HRT are at lower risk of colon and rectal cancer. Because colorectal cancer is the second most common neoplasm and cause of death among nonsmoking women in developed countries, these results may have a major public health impact.

Schistosomiasis and the risk of bladder cancer in Alexandria, Egypt

The relationship between history of schistosomiasis and bladder cancer risk was investigated using data from a case-control study conducted between January 1994 and July 1996 in Alexandria, Egypt. Cases were 190 subjects with incident, histologically confirmed invasive cancer of the bladder, and controls were 187 subjects admitted to hospital for acute, non-neoplastic, non-urinary tract conditions. Eighty-six cases (45%) vs 69 controls (37%) reported a history of urinary schistosomiasis. The corresponding multivariate odds ratio (OR) of bladder cancer -- after allowance for age, sex, education, smoking, other urinary infections and high-risk occupations -- was 1.72 (95% confidence interval (CI) 1.0-2.9). The ORs were 0.22 (95% CI 0.1-0.4) for intestinal schistosomiasis and 0.32 (95% CI 0.1-1.9) for schistosomiasis of other types. The OR for urinary schistosomiasis was higher in subjects who were younger at first diagnosis (OR of 3.3 for <15 years) and in those with a long time since first diagnosis (OR of 3.0 for > or = 35 years). The ORs were 15.8 for male ever-smokers with a history of urinary schistosomiasis, compared with never-smokers without such a history, and 3.2 for men ever-infected with urinary Schistosoma haematobium and ever-employed in high-risk occupations, compared with those never-infected and with no high-risk occupational history. This study confirms that clinical history of urinary schistosomiasis is significantly, but modestly, associated with increased bladder cancer risk, explaining some 16% of bladder cancer cases in this Egyptian population.

Attributable risk for symptomatic liver cirrhosis in Italy. Collaborative Groups for the Study of Liver Diseases in Italy

BACKGROUNDS/AIMS

Knowledge of the proportion of liver cirrhosis attributable to the main risk factors is largely based on methodologically questionable clinical reports.

METHODS

The proportion of newly diagnosed cases of symptomatic liver cirrhosis attributable to known risk factors was estimated by a case-control study performed during 1989-1996 in 23 medical divisions of several hospitals distributed throughout Italy. Cases were 462 inpatients with cirrhosis admitted for the first time for liver decompensation. Controls were 651 patients admitted during the same period and to the same hospitals as the cases, for acute diseases unrelated to alcohol and virus infection. The proportion of symptomatic liver cirrhosis cases due to alcohol intake and hepatitis B and C viruses and the combination of these was expressed as the population attributable risk.

RESULTS

Attributable risks were 67.9% (95% confidence interval (CI): 53.8-79.4) for alcohol, 40.1% (95% CI: 35.3-45.2) for hepatitis C virus and 4.4% (95% CI: 2.5-7.6) for hepatitis B virus. The three factors together explained 98.1% (95% CI: 81.6-99.6) of cases in men and 67.0% (95% CI: 50.4-85.8) in women.

CONCLUSIONS

Alcohol is the risk factor with the highest impact on symptomatic liver cirrhosis risk in Italy. From a public health viewpoint, with the elimination of the well-known risk factors (particularly alcohol and hepatitis C virus), liver cirrhosis should become a rare disease.

Population attributable risk for breast cancer: diet, nutrition, and physical exercise

BACKGROUND

The percentages of breast cancer cases in a given population attributable to specific risk factors (i.e., the population-attributable risks) can be calculated; determination of such risks associated with potentially modifiable risks factors, such as diet (e.g., levels of consumption of fruits, vegetables, vitamins, etc.), alcohol consumption, exercise, and body weight, are necessary to focus prevention strategies.

METHODS

With the use of data from a case-control study conducted in Italy from June 1991 through April 1994 on 2569 breast cancer case subjects and 2588 control subjects, we calculated multivariate odds ratios and population-attributable risks for breast cancer in relation to dietary beta-carotene and vitamin E intake, alcohol consumption, physical activity, and, for postmenopausal women, body mass index.

RESULTS

Among all subjects, the following attributable risks for the indicated risk factors were observed: 10.7% (95% confidence interval [CI] = 4.4%-17.0%) for high alcohol intake (i.e., >20 g/day), 15.0% (95% CI = 7.4%-22.9%) for low beta-carotene intake (i.e., <3366 microg/day), 8.6% (95% CI = -0.4%-17.5%) for low vitamin E intake (i.e., <8.5 mg/day), and 11.6% (95% CI = -0.1%-23.3%) for low levels of physical activity. The risks associated with alcohol and beta-carotene intake were larger among premenopausal women, and the risk associated with physical activity was larger among postmenopausal women. Being overweight accounted for 10.2 % (95% CI = 0.2%-20.2%) of breast cancer cases in postmenopausal women. Beta-carotene plus alcohol accounted for 28.1% (95% CI = 16.8-39.4) of the cases. Beta-carotene and physical activity accounted for 32% (95% CI = 14.3-49.8), and these three factors together accounted for 33% (95% CI = 19.9-46.1) of the breast cancer cases in the overall dataset.

CONCLUSION

Exposure to a few selected and potentially modifiable risk indicators explained about one third of the cases of breast cancer in this Italian population, indicating the theoretical scope for prevention of the disease.

Vegetable consumption and risk of chronic disease

We used data from the 1993 Italian Household Multipurpose Survey, based on a sample of 46,693 subjects ages 15 years or over, to analyze the relation between frequency of vegetable consumption and prevalence of 12 chronic diseases. We observed little association with diabetes mellitus, hypertension, and allergy. There were inverse relations between vegetable consumption and myocardial infarction [odds ratio (OR) = 0.79 for the highest tertile], angina pectoris (OR = 0.89), chronic bronchitis (OR = 0.69), bronchial asthma (OR = 0.70), peptic ulcer (OR = 0.74), gallstones (OR = 0.92), liver cirrhosis (OR = 0.71), kidney stones (OR = 0.68), and arthritis (OR = 0.84). Adjustment for alcohol and tobacco use made little difference.

Treatment for fertility and risk of ovarian tumors of borderline malignancy

The relationship between fertility drug use and risk of borderline ovarian cancer has been analyzed using data from a case-control study. Cases were 93 women aged 23 to 64 years with histologically confirmed diagnosis of borderline ovarian tumor (according to the World Health Organization criteria) who were admitted to the Obstetrics and Gynecology Clinics of the University of Milan. Control subjects were 273 women (ages 24-64 years) admitted for acute nongynecological, nonhormonal, and nonneoplastic conditions. Four cases (4.3%) and no control reported fertility drugs use: this difference was statistically significant (Fisher's exact test P = 0.004).

Height and breast cancer risk

The relationship between adult height and breast cancer risk was considered, combining data from two case-control studies, one conducted between 1983 and 1991 in northern Italy and the other between 1991 and 1994 in six Italian centres. Cases were 5984 women, below the age of 75 years, with histologically confirmed breast cancer, and controls were 5504 women admitted to hospital for a wide spectrum of acute, non-neoplastic, non-hormone-related diseases. No relationship was observed between height and the risk of breast cancer, with a multivariate odds ratio (OR) of 0.96 (95% confidence intervals (CI) 0.85-1.08) for the tallest women (height > or = 166 cm) compared with the shortest (height < 156 cm). No significant heterogeneity was found across strata of age at diagnosis, education, body mass index, body weight, alcohol intake, age at menarche and menopause, parity, age at first birth, ever use of oral contraceptives and hormone replacement therapy, history of benign breast disease and family history of breast cancer. Thus, this study indicates that adult height is not appreciably related to breast cancer risk in this Italian population.

Determinants of risk of invasive cervical cancer in young women

We analysed determinants of risk of cervical cancer in women aged less than 45 years using data from a case-control study conducted in Italy. Cases were 261 women aged < 45 years with histologically confirmed invasive cervical cancer. Controls were 257 women aged < 45 years, with acute, non-neoplastic conditions, judged to be unrelated to any of the known or suspected risk factors for cervical cancer. In comparison with women reporting one or no sexual partner, the multivariate odds ratio (OR) of cervical cancer was 2.4 (95% confidence interval, CI, 1.3-4.6), for women reporting two or more sexual partners, and, in comparison with women reporting their first intercourse at 17 years of age or before, the multivariate OR was 0.5 (95% CI 0.3-0.9) in women aged > or =23 years at first intercourse. The risk of cervical cancer was higher in parous women and increased with number of births (OR = 8.1 for three or more births). Among parous women the risk tended to increase with later age at last birth; in comparison with parous women reporting their last birth before age 25, the OR was 1.9 in those reporting their last birth at > or =35 years. No clear association emerged between oral contraceptive use, smoking, education, social class and risk of cervical cancer.

[Pancreas carcinoma]

Pancreatic cancer mortality has appreciably increased for both sexes in Italy over the last few decades, although Italian rates are still relatively low or a European scale (7.0/100000 men, 4.1/100000 women, world standard). These rises are likely due, at least in part, to improved diagnosis and certification of the disease, and are related to increased exposure to tobacco smoking-the best recognised risk factor for the disease-in subsequent generations of Italian men and women. Besides cigarette smoking, pancreatitis is a recognised risk factor for pancreatic cancer, although it accounts only for a small proportion of cases, whereas a potential association with diabetes mellitus is restricted-or stronger-to the few years before diagnosis of the disease. A diet rich in fats and poor in fresh fruits and vegetables is apparently related to increased risk, but the dietary correlates of pancreatic cancer are still poorly understood. No consistent association has been reported between coffee and alcohol consumption and pancreatic cancer risk.

[Time trends of digestive system tumor mortality in Italy, 1970-89]

Time trends of mortality from digestive cancers in Italy during the period 1970-1989 were here studied either at the national level and for wide geographical areas (North, Center and South). Cancers of oral cavity and pharynx, of colon and rectum, of gallbladder and of the pancreas presented, during the considered period a generalized increasing trend. Stomach cancer mortality was decreasing in both sexes and in all areas, but a less marked rate of decrease appeared for younger cohorts, particularly for women. Trends almost stable, or contrasting across sexes and age classes, were observed for malignant tumours of the oesophagus and of the liver.

[Biliary tract tumors]

Biliary tract cancers are rare neoplasms including gallbladder cancer (the commonest), extrahepatic biliary tract cancer and cancer of the ampulla of Vater. Descriptive epidemiology of biliary tract cancers as a whole has two peculiarities: incidence and mortality rates are higher for women than men, and in some specific populations. Mortality rates are highest among New Mexico American Indian women, in Chile and Japan, lowest in Great Britain and Greece. Mortality trends vary widely: the largest increases have been observed in Japan, Hong-Kong and Spain and the largest decreases in the Anglo-Saxon populations. Our knowledge of biliary tract cancer etiology is limited. Defined risks include genetic factors (family history of biliary tract cancers, ethnicity), history of gallbladder disease, and cholelithiasis. Risk factors reported in some studies, on which, however, information is not consistent and which need further study, include overweight, some menstrual and reproductive factors (multiparity, young age at first birth, late menopause), low education, cigarette smoking, selected bacterial infections, some intestinal diseases and diabetes.

[Esophageal carcinoma]

After early rises, oesophageal cancer mortality rates have tended to level off in Italy over the last two decades, and are now intermediate on a European scale (4.7/100000 males, 0.8/100000 females, world standard). This reflects the trends in consumption of the major risk factors for the disease, tobacco and alcohol, particularly in men. Within Italy, there is also a substantial variation in oesophageal cancer rates, with high mortality areas in the North-East of the country. On the basis of a case-control study conducted in northern Italy, the relative risk (RR) of the disease was 4.3 in heavy smokers and 3.5 in heavy drinkers. A diet poor in fresh fruit and vegetables was also related to the risk of the disease (RR = 2.5). In terms of population attributable risk, 71% of cases in men and 32% in women were accounted for tobacco smoking, 45% in males and 10% in females by alcohol drinking, 40% in men and 29% in women by a diet poor in fresh fruit and vegetables (and hence in beta-carotene). These three factors together accounted for 90% of cases in Italian men, and 58% in women (83% in both sexes combined).