Epidemiological studies on risk factors for CRC have focused mainly on diet. In any case, the results of these studies show several inconsistencies, except for the beneficial role of high intake of vegetables and, to some lesser extent, of fruit. Weight and height have also been studied, partly because they reflect the balance between energy intake and expenditure in different age periods. Energy intake, body size and physical activity will be reviewed in this paper focusing mostly on recent data coming from Italian, English and Scandinavian studies. Overweight has long been recognized as a risk factor for hormone related and other cancers and this is confirmed not simply from case-control studies but from large cohort studies as well. The major findings of recent Italian studies are that excessive weight at various ages predicts colorectal cancer risk in men while in women, abdominal obesity, as indicated by a high WHR, represents a more reliable risk indicator. If all men could reduce their BMI below 25, about 9% of male colorectal cancer might be avoided in Italy. A decrease of WHR below 0.82 might reduce colorectal cancer in women by 19%. In addition, the epidemiological evidence consistently shows that physical activity reduces the risk of colon cancer. On the contrary, evidence on rectal cancer is less impressive. Some uncertainty still exists in relation to the intensity and duration of physical activity. In conclusion, body size control along all life and physical activity represent important factors to prevent colon cancer and a wide range of chronic conditions. Therefore, strategies to favour these goals through counselling from health-care providers, regulatory changes and programs aimed at individuals and communities should be implemented.
EDITOR—Owen et al report that the prevalence of smoking in pregnancy and the rates of stopping did not change in England between 1992 and 1995, remaining at around 25%.1They also reported that the prevalence of smoking in pregnancy is higher in young women, unemployed women, and manual workers. We analysed the characteristics of women who gave up or continued smoking during pregnancy in Italy, using the comparison group of a case-control …
To determine whether lactase persistence might be related to ovarian cancer risk, in 1994-1995 the authors assessed the capacity to digest lactose by measuring breath hydrogen production after oral administration of lactose in 50 women with ovarian cancer and 100 healthy controls. All of the women came from Sassari (Sardinia), Italy, an area where the population has a high frequency of lactose malabsorption. Thirty percent of cases were lactose absorbers, as compared with 15% of controls. The odds ratio for ovarian cancer among lactose absorbers was 2.51 (95% confidence interval 1.10-5.68). These results provide some support for a role of lactose ingestion and galactose cytotoxicity in the pathogenesis of ovarian cancer.
The relation between hormonal and lifestyle factors and breast cancer risk in nulliparae was investigated using data from two case-control studies conducted in Italy between 1983 and 1994. The study included 1041 nulliparae with histologically confirmed incident breast cancer and 1002 nulliparous controls admitted to hospital for a wide range of acute, non-neoplastic, nonhormone-related diseases. In premenopausal nulliparae, there was an inverse relation with age at menarche [odds ratios (OR) 0.45; 95% confidence intervals (CI) 0.24-0.86 for > or = 15 years vs < 12], while no association emerged in postmenopausal. Breast cancer risk increased with age at menopause, the OR being 1.91 (95% CI 1.26-2.90) for nulliparae reporting age at menopause > or = 53 years compared with < 45. Abortion was not related to breast cancer risk, the OR being 0.92 for any spontaneous, 0.97 for any induced and 0.77 for > or = 2 total abortions compared to none. The OR was 1.75 (95% CI 1.03-2.97) for women reporting their first abortion at age > or = 30 years compared with < 30. Oral contraceptives and hormone replacement therapy in menopause were moderately related to risk. The OR was 2.71 (95% CI 1.85-3.95) in nulliparae with a family history of breast cancer and 1.60 (95% CI 1.20-2.14) in those with a history of benign breast disease. Compared with nulliparae reporting a low physical activity, the OR was 0.79 (95% CI 0.54-1.16) for those reporting intermediate/high activity. Breast cancer risk increased with total energy intake, the OR being 1.65 (95% CI 0.99-2.75) in the highest tertile; beta-carotene was inversely related to risk (OR 0.60, 95% CI 0.38-0.95) for the highest tertile. Thus, most risk factors for breast cancer in nulliparae were similar to those in women generally.
During 1985-93, paediatric AIDS incidence rates increased in most European countries and levelled off thereafter. No paediatric AIDS epidemic occurred; in a few countries, incidence rates persisted at around one case per million.
Read moreTo elucidate the role of dietary habits, a study was carried out in 1992-1997 in the province of Pordenone in Northeastern Italy, and those of Rome and Latina in central Italy. Cases were 512 men and 86 women with cancer of the oral cavity and pharynx (lip, salivary glands and nasopharynx excluded) and controls were 1008 men and 483 women who had been admitted to local hospitals for a broad range of acute non-neoplastic conditions. The validated dietary section of the questionnaire included 78 foods or recipes and ten questions on fat intake patterns. After allowance for education, smoking, alcohol and total energy intake, significant trends of increasing risk with increasing intake emerged for soups, eggs, processed meats, cakes and desserts, and butter. Risk was approximately halved in the highest compared to the lowest intake quintile for coffee and tea, white bread, poultry, fish, raw and cooked vegetables, citrus fruit, and olive oil. The inverse association with oils, especially olive oil, was only slightly attenuated by allowance for vegetable intake. Thus, frequent consumption of vegetables, citrus fruit, fish and vegetable oils were the major features of a low-risk diet for cancer of the oral cavity and pharynx.
Read moreWe considered the association between diabetes and risk of endometrial cancer using data from a large case-control study conducted in Italy. Cases were 752 women with incident, histologically confirmed endometrial cancer < 75 years of age (median age 60 years, range 28-74) admitted to a network of hospitals in Milan. Controls were 2,606 patients (median age 54 years, range 25-74) aged < 75 years, admitted for acute non-neoplastic, non-gynecological, non-hormone-related conditions to the same network of hospitals where cases had been identified. A total of 132 (17.6%) cases and 116 controls (4.5%) reported a history of diabetes. The corresponding multivariate odds ratio (OR) was 2.9 [95% confidence interval (CI) 2.2-3.9]. No association emerged with diabetes diagnosed under age 40 (likely to be insulin-dependent diabetes), whereas the OR of endometrial cancer was 3.1 (95% CI 2.3-4.2) for diabetes diagnosed at age > or = 40 years. The OR of endometrial cancer in women with history of diabetes was 3.0 for women with a body mass index (BMI) (QI) kg/m2 < 25, 3.6 for those with a BMI of 25-29, and 3.3 for those with a BMI > or = 30. No consistent interaction or modifying effect was observed for any other covariate. Our results confirm that non-insulin-dependent diabetes is associated with the risk of endometrial cancer. The association may be mediated through elevated oestrogen levels in diabetic women, hyperinsulinemia or insulin-like growth factor-I (IGF-I).
Read moreBackground Since the early 1990s, various European electricity companies have set up a research program, named EURELEX, devoted to the development of a comprehensive and validated title-occupation - job-exposure matrix (i.e., an instrument to assess exposures from occupations and jobs), in order to estimate and quantify past exposure to a number of potentially carcinogenic agents plus a few selected other toxic substances. The EURELEX program was first applied in Italy to a cohort of geothermal workers in Larderello, Tuscany. Methods The cohort mortality study comprised 4,237 men who had worked at the geothermal power plant between 1950 and 1990. Vital status and death certificates were obtained from registration offices in the municipality of birth or death. Particular attention was paid to neoplastic effects of exposure to asbestos, largely used in the past for pipeline insulating purposes. The matrix allowed the workers to be subdivided into several categories according to estimated asbestos exposure. Smoking information was not available. Results No excess mortality was found for all causes and total cancer mortality. A small excess of pleural cancer (2 obs. vs 1.4 exp.) was not statistically significant. The effect of other agents included in the matrix was also examined: the small excess of leukemia among those exposed to solvents prior to 1963 (year of benzene ban in Italy) did not reach the level of statistical significance. No cases of leukemia were found among the workers presumed to have been exposed to important ELF electromagnetic fields. Conclusion The study provides reassuring information on a large cohort of a unique geothermal power plant since no significant excess mortality for asbestos related cancers was observed. Furthermore, it represents a useful application and validation of a comprehensive job-exposure matrix for the electric industry in Europe. Am. J. Ind. Med. 35:536–539, 1999. © 1999 Wiley-Liss, Inc.
Read moreA hospital-based case-control study was conducted in the Heilongjiang Province of northeast China between May 1993 and May 1995. A total of 129 histologically confirmed brain cancer cases (73 gliomas and 56 meningiomas) and 258 matched controls were interviewed in 6 major hospitals to examine the influence of dietary factors in developing brain cancer. Information was obtained about frequency of consumption of 57 food items. Odds ratios (ORs) were obtained from conditional logistic regression, including allowance for socio-demographic factors, alcohol, tobacco and total energy intake. Consumption of fresh vegetables (OR = 0.29 for the highest quartile compared with the lowest one), and specifically of Chinese cabbage and onion, fruit (OR = 0.15), fresh fish (OR = 0.38) and poultry (OR = 0.16) was inversely related to the risk of developing brain cancer. A protective effect was also seen for vitamin E intake, calcium and, although non-significantly, beta-carotene and vitamin C. Risk of brain cancer increased with consumption of salted vegetables (OR = 2.54) and salted fish.
Read more