The relation between allergy and cancer has been investigated within an integrated series of case-control studies of digestive tract and laryngeal neoplasms conducted in Italy since the early 1990s. These included 598 patients with incident, histologically confirmed cancer of the oral cavity and pharynx, 304 of the oesophagus, 1225 of the colon, 728 of the rectum, 460 of the larynx and 4999 controls, selected among patients admitted to the same network of hospitals as cases for acute, non-neoplastic diseases. Inverse associations with history of allergy were found for all cancer sites examined (odds ratio=0.44 for oral cavity and pharynx, 0.80 for oesophagus, 0.76 for colon, 0.54 for rectum and 0.33 for larynx). The associations were consistent in strata of age and sex, and when subjects with a first diagnosis of allergy 5 or more years before cancer diagnosis or hospital admission were considered. The present study therefore provides further evidence for a possible protective effect of prior history of allergy on cancer risk.
We analyzed the role of reproductive factors on the risk of endometrial cancer using data from a case-control study conducted in Italy. Cases were 752 women with histologically confirmed endometrial cancer < 75 years of age. Controls were 2,606 patients < 75 years of age admitted for acute, non-gynecological non-hormone-related, non-neoplastic conditions to the same network of hospitals where cases had been identified. In comparison with nulliparae, the risk of endometrial cancer tended to be lower in parous women, and the estimated multivariate odds ratios (ORs) were 0.9, 0.8 and 0.7, respectively, for women reporting 1, 2 and 3 or more births (chi(2)(1) trend and 10.21). In comparison with women reporting no induced abortion, the ORs of endometrial cancer were 0.6 in women reporting 1 and 0.4 in those reporting 2 or more induced abortions. When considering parous women only, in comparison with women reporting their last birth 20 years before or longer, the ORs of endometrial cancer were 0.6 in those reporting their last birth 10-19 years before and 0.3 in those reporting their last birth < 10 years before. Our results confirm and further quantify a protective role of pregnancy on the risk of endometrial cancer and provide insights on the time-risk relationship between pregnancy and cancer of corpus uteri.
Evidence of a protective role of aspirin on the risk of colorectal and other common cancers has been building up since the end of the 1980s. There are now more than 15 epidemiological (case-control and cohort) studies indicating that long-term use of aspirin is associated with a reduced risk of colorectal cancer. The overall relative risk (RR) estimate for regular aspirin users was 0.71 (95% confidence interval (CI) 0.66-0.77) from case-control studies, and 0.84 (95% CI 0.72-0.98) from cohort studies. A recent meta-analysis reported a RR of breast cancer for aspirin use of 0.70 (95% CI 0.61-0.81) in case-control studies, and of 0.79 (95% CI 0.59-1.06) in cohort studies. Furthermore, various epidemiological studies have suggested that aspirin use might have a favourable effect on ovarian cancer as well: the overall RR estimate was 0.82 (95% CI 0.69-0.99), although the evidence is too limited to permit firm conclusions. Data are more scanty, though in the same direction, for other neoplasms, including in particular stomach and oesophageal cancer.
The authors describe the incidence of new primary cancers among 4,639 cases of squamous cell skin cancer (SCC) diagnosed between 1974 and 1994 in the cancer registries of the Swiss cantons of Vaud and Neuchâtel (total person-years at risk = 23,152). Overall, 729 metachronous cancers were observed versus 527.6 expected, corresponding to a standardized incidence ratio (SIR) of 1.4 (95% confidence interval (CI) 1.3-1.5). After exclusion of skin cancers, however, 384 second primary neoplasms were observed versus 397.2 expected (SIR = 1.0). Excesses were observed for cancers of the lip (SIR = 3.1) and lung (SIR = 1.3), for basal cell (SIR = 4.3) and melanomatous skin cancers (SIR = 3.3), and non-Hodgkin's lymphomas (SIR = 1.7). Rates were elevated for cancers of the salivary glands (SIR = 4.3) and for Hodgkin's disease (SIR = 2.7), and, below age 65 years, for cancers of the lung (SIR = 1.6), breast (SIR = 1.5), and prostate (SIR = 1.8), for Hodgkin's disease (SIR = 15.8), as well as for all neoplasms except skin (SIR = 1.2; 95% CI 1.0-1.5). The cumulative risk of basal cell skin cancer reached 17% after 15 years. The authors believe that the excesses for basal cell carcinomas and melanomas of the skin following SCC, and possibly of lymphomas, were likely attributable to common phenotypic characteristics and exposure to UV radiation. The elevated rates of lung cancer are suggestive for a role of tobacco as a cause of squamous cell skin cancer.
The relationship between beer consumption and the risk of colon and rectal cancer was considered in a case-control study conducted in northern Italy. The study was based on 828 histologically confirmed incident cases of colon cancer, 498 of rectal cancer, and 2,024 controls in hospital for a wide spectrum of acute, nonneoplastic, nonalcohol-related diseases. Beer drinking was reported by 6% of colon cancer cases, 7% of rectal cancer cases, and 10% of controls; regular beer drinkers (> or = 1 drinks/day) made up 2.6% of colon cancer cases, 3.2% of rectal cancer cases, and 4.1% of controls. Thus the multivariate relative risks (RR) for irregular drinkers were 0.6 [95% confidence interval (CI) 0.4-1.0] for colon and 0.7 (95% CI 0.4-1.2) for rectum. Corresponding values for regular drinkers were 0.7 (95% CI 0.4-1.2) for colon and 0.9 (95% CI 0.5-1.5) for rectal cancer. Despite the low frequency of beer drinking in this study, and hence its limited statistical power, the originality of the population in terms of colorectal cancer incidence, patterns of risk factor exposure, and the large dataset provide interesting and useful confirmation that moderate beer drinking is not associated with elevated colon or rectal cancer risk.
The fall in cancer mortality observed over the last decade in Italy is attributable to a decline in lung and other tobacco-related neoplasms in males, together with a persistent fall in stomach and uterine (cervical) cancer. In women, there were also recent falls in intestinal and breast cancer rates, and declines in both sexes in rarer neoplasms influenced by therapeutic advancements.