Urinary phytoestrogen excretion and prostate cancer risk: a nested case-control study in the Multiethnic Cohort.

BACKGROUND: Phytoestrogens are of special interest in prostate cancer research because populations in Asia with a high consumption of phytoestrogens have a lower incidence of the disease than comparable populations in Western countries. METHODS: This case-control study is nested within a large multiethnic cohort in Hawaii and California. Urine samples were analysed for daidzein, genistein, equol, and enterolactone among 249 incident prostate cancer cases and 404 controls matched on age, race/ethnicity, date/time of specimen collection, and fasting status. RESULTS: The median excretion of daidzein was 0.173 nmol mg(-1) creatinine in cases and 0.291 in controls (P=0.01), and the median excretion of genistein was 0.048 in cases and 0.078 in controls (P=0.05). An inverse association was seen for daidzein overall (odds ratio for the highest vs lowest quintile=0.55, 95% confidence interval=0.31-0.98, P(trend)=0.03) and seemed to apply to localized (P(trend)=0.08) as well as advanced or high-grade cancer (P(trend)=0.09). This association was consistent across the four ethnic groups examined. Although the relationship was weaker for genistein, the odds ratios and trends were similarly inverse. Urinary excretion of equol and enterolactone was not significantly related to prostate cancer risk. CONCLUSION: Our findings suggest that high intake of isoflavones, as reflected by urinary excretion of daidzein and genistein, may be protective against prostate cancer.

A prospective study of pancreatic cancer in the elderly.

Risk factors for pancreatic cancer were examined in a cohort study of 13,979 residents of a retirement community. After 9 years of follow-up, 65 incident cases of pancreatic cancer were identified. An increased risk of pancreatic cancer was associated with a history of diabetes and cholecystectomy. Higher intake of vegetables, fruits, dietary beta-carotene, and vitamin C were each associated with a reduced risk of pancreatic cancer, although none of these associations was statistically significant. Risk of pancreatic cancer decreased with increasing tea consumption but was unrelated to coffee consumption. No strong or consistent association was seen between either smoking or alcohol consumption and risk of pancreatic cancer, but a consistent and significant increase in risk followed cholecystectomy.

Intake of vegetables, fruits, beta-carotene, vitamin C and vitamin supplements and cancer incidence among the elderly: a prospective study.

A cohort of 11,580 residents of a retirement community initially free from cancer were followed from 1981 to 1989. A total of 1,335 incident cancer cases were diagnosed during the period. Relative risks of cancer were calculated for baseline consumption of vegetables, fruits, beta-carotene, dietary vitamin C, and vitamin supplements. After adjustment for age and smoking, no evidence of a protective effect was found for any of the dietary variables in men. However, an inverse association was observed between vitamin C supplement use and bladder cancer risk. In women, reduced cancer risks of all sites combined and of the colon were noted for combined intake of all vegetables and fruits, fruit intake alone, and dietary vitamin C. Supplemental use of vitamins A and C showed a protective effect on colon cancer risk in women. There was some suggestion that beta-carotene intake and supplemental use of vitamin A, C, and E were associated with reduced risk of lung cancer in women, but none of these results were statistically significant. These inverse associations observed in women seem to warrant further investigation, although there was inconsistency in results between the sexes.

Aspirin use and chronic diseases: a cohort study of the elderly.

OBJECTIVE: To evaluate the associations between the use of aspirin and the incidences of cardiovascular diseases, cancers, and other chronic diseases. DESIGN: Postal questionnaire survey to elicit details of aspirin use. SETTING: Californian retirement community. SUBJECTS: All 22,781 residents of the community (white, affluent, and well educated) were sent a questionnaire that included questions on medical history and the use of drugs such as analgesics, laxatives, and vitamin supplements. In all 61% responded (13,987, 8881 women and 5106 men; median age 73). They formed the cohort that was followed up for 6 1/2 years using discharge summaries from three hospitals serving the area and death certificates from the health department. Only 13 respondents were lost to follow up but seemed not to have died. MAIN OUTCOME MEASURES: Incidences of cardiovascular diseases, cancers, gastrointestinal bleeding, ulcers, and cataracts were compared in participants who did and did not take aspirin daily. RESULTS: Age adjusted incidences were computed with an internal standard and five age groups. By 1 January 1988 there had been 25 incident cases of kidney cancer among all participants; 341 incident cases of stroke, 253 of acute myocardial infarction, 220 of ischaemic heart disease, and 317 of other heart disease were reported among respondents without a reported history of angina, myocardial infarction, or stroke. The incidence of kidney cancer was raised among those who took aspirin daily compared with those who did not take it, although the increase was significant only in men (relative risks = 6.3, 95% confidence interval 2.2 to 17, for men and 2.1, 0.53 to 8.5, for women). Those who took aspirin daily showed no increased risk of any other cancer, except colon cancer for both sexes combined (relative risk = 1.5, 1.1 to 2.2). The risk of acute myocardial infarction was reduced slightly among regular users of aspirin in men but not women. The risk of ischaemic heart disease was almost doubled in those who took aspirin daily compared with non-users (relative risks = 1.9, 1.1 to 3.1, for men and 1.7, 1.1 to 2.7, for women). Small, non-significant increased risks of stroke were observed in both sexes. CONCLUSION: The daily use of aspirin increased the risk of kidney cancer and ischaemic heart disease.

Risk factors for gliomas and meningiomas in males in Los Angeles County.

Detailed job histories and information about other suspected risk factors were obtained during interviews with 272 men aged 25-69 with a primary brain tumor first diagnosed during 1980-1984 and with 272 individually matched neighbor controls. Separate analyses were conducted for the 202 glioma pairs and the 70 meningioma pairs. Meningioma, but not glioma, was related to having a serious head injury 20 or more years before diagnosis [odds ratio (OR) = 2.3; 95% confidence interval (CI) = 1.1-5.4], and a clear dose-response effect was observed relating meningioma risk to number of serious head injuries (P for trend = 0.01; OR for greater than or equal to 3 injuries = 6.2; CI = 1.2-31.7). Frequency of full-mouth dental X-ray examinations after age 25 related to both glioma (P for trend = 0.04) and meningioma risk (P for trend = 0.06). Glioma, but not meningioma risk, related to duration of prior employment in jobs likely to involve high exposure to electric and magnetic fields (P for trend = 0.05). This risk was greatest for astrocytoma (OR for employment in such jobs for greater than 5 years = 4.3; CI = 1.2-15.6). More glioma cases had worked in the rubber industry (discordant pairs 6/1) and more worked in hot processes using plastics (9/1). More meningioma cases had jobs that involved exposure to metal dusts and fumes (discordant pairs 13/5), and six of these cases and two controls worked as machinists. Finally, there was a protective effect among glioma pairs relating to frequency of use of vitamin C and other vitamin supplements (P for trend = 0.004); the OR for use at least twice a day was 0.4 (CI = 0.2-0.8).

Analgesics, cigarette smoking, and other risk factors for cancer of the renal pelvis and ureter.

Results from a population-based case-control study of cancer of the renal pelvis and ureter are reported. Telephone interviews were conducted with 187 residents of Los Angeles County diagnosed with cancer of the renal pelvis and ureter over a 4-year period ending December 31, 1982, and with individually sex-, age- and race-matched neighborhood controls. The major risk factor identified for cancer of the renal pelvis and ureter was cigarette smoking. Subjects who smoked more than 25 years had a relative risk of 4.5 of developing these tumors, compared to nonsmokers (P less than 0.0001). Heavy use of over-the-counter analgesics was also associated with a significant increase in risk; it appears that an elevated risk was conveyed by all the major active constituents of those compounds currently marketed in the United States, aspirin, caffeine, and acetaminophen. Persons who had used these drugs for 30 consecutive days at any time in their life preceding diagnosis had twice the risk of developing cancer of the renal pelvis or ureter compared to persons not reporting such use (P less than 0.01). Heavy coffee drinkers (greater than or equal to 7 cups/day) had a 1.8-fold increase in risk compared to nondrinkers. Although risk tended to increase with increasing consumption, this result was not statistically significant. The risk associated with heavy coffee consumption was reduced to 1.3 after adjusting for smoking. Nine cases compared to no controls reported a first degree relative with kidney cancer. A history of kidney stones was associated with an increased risk of cancer of the ureter (relative risk = 2.5) that was not, however, statistically significant.

Vitamin A, beta-carotene, and the risk of cancer: a prospective study.

A cohort of 10,473 residents of Leisure World, Laguna Hills, CA, who were initially free of cancer were followed from 1981 to 1986. A health survey questionnaire completed by all cohort members included usual frequencies of consumption of certain food items, including vegetables, fruits, dairy products, liver, and cereal, as well as specific information on brand and formulation of vitamin supplements containing vitamins A, C, or E. Pathologic diagnosis of incident cancer was confirmed in 643 persons (56 lung, 110 colon, 59 bladder, 93 prostate, 123 female breast, and 202 cancers of other sites). Our study found little indication that increased intake of vitamin A or beta-carotene from the diet or supplements protects against the development of cancer overall. Dietary vitamin A intake was highly associated with smoking status; 25% of current smokers were in the highest third of dietary vitamin A consumption versus 32% of past smokers and 36% of never-smokers. In males who never smoked there was some indication that cancer rates decreased with increasing vitamin A intake, but the results were not statistically significant.

Alcohol, physical activity and other risk factors for colorectal cancer: a prospective study.

The aetiology of colorectal cancer was studied in a cohort of 11,888 residents of a retirement community. After four and one-half years of follow-up, 58 male and 68 female incident colorectal cancers were identified. Daily alcohol drinkers experienced nearly a two-fold increase in risk (2 sided P = 0.002). Colorectal cancer was also positively associated with Quetelet's index and inversely associated with avocational physical activity. The results were consistent for both sexes but were statistically significant only for males. With the exception of dietary vitamin C, none of the nutrients under study (i.e., vitamins A and E, dietary fibre, calcium, and beta carotene) showed a significant association with colorectal cancer. An inverse relationship between colorectal cancer and dietary vitamin C was observed in females, but there was no association with either vitamin C from supplements or with total vitamin C intake. Males and females who had 3 or more children showed a significantly reduced risk of colorectal cancer (RR = 0.45, 95% CI = 0.2, 0.9), but those with no children did not show the highest risk.

Cigarette smoking, obesity, diuretic use, and coffee consumption as risk factors for renal cell carcinoma.

One hundred sixty incident cases of renal cell carcinoma under the age of 55 years and an equal number of age-(within 5 yr), race-, and sex-matched neighborhood controls were interviewed. Cigarette smoking was a risk factor for renal cell carcinoma in males [relative risk (RR) = 2.1, one-sided P = .02] but not in females (RR = 1.1, P = .50). Obesity was a significant risk factor in both males and females: The RR for a 4th quartile compared to a 1st quartile Quetelet's Index 10 years ago was 2.5 for males and 3.3 for females. Additional risk factors in females were diuretic use (RR = 4.5, P = .002) and daily coffee consumption (RR = 2.3, P = .06).

Vitamin supplement use in a Southern California retirement community.

Vitamin supplement were taken regularly by 62% of men and 69% of women surveyed in a Southern California retirement community. Supplement use was associated with more frequent use of health screening procedures and with several other health-related habits. A substantial proportion of residents consumed high levels of vitamins C and E, and 3.2% consumed potentially toxic doses of vitamin A.

Pancreas cancer and smoking, beverage consumption, and past medical history.

Four hundred and ninety pancreas cancer patients representative of confirmed cases in Los Angeles County residents of working age were compared to healthy controls individually matched by age, sex, race, and neighborhood. Home interviews were conducted on occupation, smoking, food and beverage consumption, and medical history. Cigarette smoking was a strong and consistent predictor of pancreas cancer occurrence; the effect disappeared after a decade of nonsmoking, and there was no increase in risk among current smokers as daily dose increased. There was no link between pancreas cancer and past consumption of tea, carbonated beverages, beer, or spirits; and an association with coffee consumption was inconsistent. A strong association between pancreas cancer and history of subtotal gastrectomy at any past time could not be explained by chance or any other factor. Pancreas cancer patients had experienced fewer allergies of any kind.

Vitamin A and cancer incidence in a retirement community.

The use of vitamin A supplements and the risk of cancer was examined in a cohort of 11,888 residents of a retirement community near Los Angeles, California. After 2 1/2 years of follow-up, 445 incident cancers occurred in 435 of the study participants. Overall, the relative risk of cancer for supplement users versus nonusers was 1.0. In a subset of 32 randomly selected individuals, the 14 supplement users had a significantly higher mean serum retinol level (86 micrograms/dl) than did the 18 nonusers (74 micrograms/dl).

Smoking and other risk factors for lung cancer in women.

A case-control study among white women in Los Angeles County was conducted to investigate the role of smoking and other factors in the etiology of lung cancer in women. A total of 149 patients with adenocarcinoma (ADC) and 71 patients with squamous cell carcinoma (SCC) of the lung and their age- and sex-matched controls were interviewed. Personal cigarette smoking accounted for almost all of SCC and about half of ADC in this study population. Among nonsmokers, slightly elevated relative risk(s) (RR) for ADC were observed for passive smoke exposure from spouse(s) [RR = 1.2; 95% confidence interval (Cl) = 0.5, 3.3] and at work (RR = 1.3; 95% Cl = 0.5, 3.3). Childhood pneumonia (RR = 2.7; 95% Cl = 1.1, 6.7) and childhood exposure to coal burning (RR = 2.3; 95% Cl = 1.0, 5.5) were additional risk factors for ADC. For both ADC and SCC, increased risks were associated with decreased intake of beta-carotene foods but not for total preformed vitamin A foods and vitamin supplements.

Assessment of three brief methods of estimation of vitamin A and C intakes for a prospective study of cancer: comparison with dietary history.

Three methods of estimating vitamin A and C intakes from food frequency data obtained in June 1981 were compared with estimates obtained from dietary histories taken in September 1982, in 50 elderly residents of a Southern California retirement community. The first method of estimating vitamin A and C intakes (Af and Cf) was to add the products of the frequency of use of foods and the vitamin content of an average serving. The second method of estimating the intakes of these vitamins (Ai and Ci) was to develop an index based on the sum of frequencies of consumption of foods rich in these vitamins. This was then converted to absolute amounts using a regression equation. The third method (Ar and Cr) was to use stepwise multiple regression with the estimated intakes from the history (Ah and Ch) as dependent variables and to develop an equation with a small number of foods as the independent variables. When intakes from food alone were examined, the Spearman correlations between Ah and Af, Ai, and Ar, respectively, were 0.03, 0.16, and 0.43; the correlations between Ch and Cf, Ci, and Cr were 0.29, 0.36, and 0.38. When supplemental vitamin intakes were included, the correlations were between 0.35 and 0.44 for vitamin A and between 0.62 and 0.64 for vitamin C. The results demonstrated the importance of including the contribution of supplemental vitamins in estimating total vitamin A and C intake and suggested that the index and regression approaches may be superior to Af and Cf for estimating dietary vitamin intakes from food frequency questionnaires.

Bladder cancer etiology. A different perspective.

The descriptive epidemiologic features of bladder cancer and lung cancer in Los Angeles County were studied for the period 1972-1976, using data from the Los Angeles County/University of Southern California Cancer Surveillance Program. The incidence pattern for bladder cancer was found to differ markedly from the pattern observed for lung cancer. As expected, the descriptive pattern for lung cancer closely paralleled the known epidemiology of cigarette smoking; in addition, it was consistent with the expected pattern of an occupationally linked disease. In contrast, the pattern observed for bladder cancer indicated that factors other than cigarette smoking and occupational exposures may be etiologically important. The available descriptive epidemiology of coffee consumption, unlike that of cigarette smoking, is consistent with the pattern of bladder cancer occurrence in Los Angeles. Available analytic studies on the association of bladder cancer and coffee consumption are consistent with a causal relationship.

Cancer in Papua New Guinea.

Among the Melanesian population of Papua New Guinea, cancer of the oral cavity associated with betel nut chewing is the most commonly reported. Liver cancer is also common and is closely associated with chronic hepatitis-B infection. Burkitt's lymphoma occurs along coastal areas with a high rainfall and intense malaria transmission. The descriptive epidemiology of other cancers in Papua New Guinea is also discussed.