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Biomedical subjects

J L Lyon

Publications and source records attributed to J L Lyon.

At least 73 records · Page 4Linked to original sources
PubMed1984

The use of asbestos-cement pipe for public water supply and the incidence of cancer in selected communities in Utah.

We tested the hypothesis that there is an association between the use of asbestos-cement piping for drinking water supplies and the incidence of gastrointestinal and kidney cancer. Cancer incidence in 14 Utah communities that had used predominantly asbestos-cement piping for transporting their drinking water supplies for 20 years or more were compared to 27 Utah communities that had never used asbestos-cement piping. Cancer incidence was tabulated for 11 cancer sites for the years 1967-1976. Increased Standard Incidence Ratios (SIRs) were found for cancer of the kidney in men (SIR 192) and leukemia (a control site) in women (SIR 203). No increased SIRs were found for the opposite sex at these sites or for the other gastrointestinal sites singly or in combination. There was no increase in age-adjusted cancer incidence for the 11 sites in 4 of the 14 study communities that had used asbestos-cement piping for 30 years or more. Limitations of the study were that the water supplies were nonaggressive, and leaching from the pipes was minimal if at all. Furthermore, the latent period for observation was very short, suggesting that these results should be considered preliminary.

Adult↗
PubMed1984

Differences in risk estimations from a hospital and a population-based case-control study.

A hospital-based and population-based case-control study of cervical cancer (in situ and invasive) was conducted in urban Utah to determine if methods of respondent selection affect estimates of risk for variables thought to be associated with the disease. Population cases (N = 409) and cases from two large hospitals (N = 124) were identified through the Utah Cancer Registry. Population-based controls (N = 379) were identified through random-digit dialing; hospital-based controls (N = 150) with gynaecological disorders other than cancers and elective abortions were chosen from the same hospitals as the cases for the hospital study. Both control groups were frequency matched to cases by age. Approximately 79% of the identified cases and 85% of the selected controls completed interviews conducted in their homes. Most risk estimates were lower in the hospital-based study because of the more case-like attributes of this group. Stratified analysis for social class led to adjusted risk estimates which were lower than the unadjusted risk estimates for the population-based study, but not for the hospital-based study. The close social class matching in the hospital-based study seems to have led to concurrent overmatching on other risk factors since many of these are closely related to social class. Findings are discussed in terms of implications for case-control study design.

Adult↗
PubMed1983

Events of reproductive life and the incidence of epithelial ovarian cancer.

Women resident in six counties of Washington and Utah for whom diagnoses of epithelial ovarian cancer were made during 1975-1979 were interviewed concerning their menstrual, reproductive and medical histories. For comparison, interviews were also obtained from a random sample of women living in the same countries. Logistic regression methods were used, and histories of childbearing, miscarriages, lactation, and (in Washington) usage of oral contraceptives were found to be associated with decreased risk of ovarian cancer; the estimated relative risks were, respectively, 0.88 per pregnancy (i.e., 0.88(2) for two pregnancies, etc.) (p = 0.016), 0.82 per miscarriage (p = 0.049), 0.79 per year of lactation (p = 0.034), and 0.89 per year of oral contraception (p = 0.009). In addition, it was observed that the magnitudes of the diminished risks from these exposures substantially exceeded those which would have been expected solely on the basis of their inhibition of ovulation (X2(5) = 21.5, p = 0.0006). On the other hand, the lack of association found between the occurrence of ovarian cancer and either total dose or total time of exposure to noncontraceptive estrogens, or with a history of usage of thyroid medications, suggests that periods of reduced pituitary gonadotrophin secretion fail to reduce risk of ovarian cancer. Thus, although pregnancy, lactation and oral contraception appear to offer some protection against the development of epithelial ovarian cancer, the reasons remain obscure.

Adult↗
PubMed1983

Lymphocyte sister chromatid exchange (SCE) frequencies in coke oven workers.

Lymphocyte sister chromatid exchange (SCE) frequencies were determined for 12 long-term coke oven workers and 12 other age-matched steelworkers with no coke oven work exposure. All study participants were nonsmokers. The exposed group had a mean of 28.9 years' exposure to the coke oven emissions. SCE frequencies for the exposed individuals ranged from 7.97 to 11.20 SCEs per cell while the control individuals ranged from 6.73 to 10.60 SCEs per cell. The mean SCE frequency for the exposed group was 9.54 +/- SD 1.15 SCEs per cell, and was 14% higher than the 8.35 +/- SD 1.09 SCEs per cell of the control group (p = .016). The long-term exposure to coke oven emissions experienced by the coke oven workers may be the explanation for this small difference.

Adult↗
PubMed1983

Smoking and carcinoma in situ of the uterine cervix.

We carried out a case-control study of 217 cases of in situ carcinoma of the uterine cervix and 243 controls chosen from the general population of Utah. We found a relative risk of 3.0 for cigarette smoking after controlling for sexual and socioeconomic risk factors. The smoking association was strongest in the youngest age group (ages 20-29), reaching seventeenfold, and was weaker in the older age groups. These data suggest that cigarette smoking may be an independent risk factor for cancer of the uterine cervix, after considering sexual behavior and other well-established risk factors.

Adult↗
PubMed1983

Coffee drinking and risk of bladder cancer.

The relationship between coffee drinking and risk of bladder cancer was assessed with the use of data from a case-control study of bladder cancer. Incident cases (2,982) and general population controls (5,782) were interviewed. Overall, the relative risk (RR) of bladder cancer for subjects who had ever drunk coffee was estimated as 1.4 (95% confidence interval = 1.1-1.8). There was no consistent relation between the RR estimate and the current consumption level. Among men who drank coffee, those who drank more than 49 cupfuls of coffee per week had an apparent excess in risk, but women who drank that much had an apparent deficit in risk.

Adult↗
PubMed1983

Methodological issues in epidemiological studies of diet and cancer.

We review the goals of epidemiological nutritional studies and evaluate methods of dietary data collection in terms of these goals. Special problems for the cancer epidemiologist studying diet are then reviewed, including methods of data collection, quantification of food intake, and analysis of nutritional data. Food frequency methods are generally best for collection of dietary data in epidemiological studies, and the use of food data banks enables the study of specific dietary components. The major problems in analysis stem from the complex interrelationships among nutrients and their high correlation with each other.

Data Collection↗
PubMed1982

Cancer in Utah Mormon men by lay priesthood level.

Mormons have been shown to have low cancer rates at several common sites, particularly those associated with tobacco and alcohol use. This likely reflects adherence to their Church doctrines advocating abstention from the use of these substances. All Mormons, however, do not adhere to the health practices of their Church, and this study classifies Utah Mormon men by their lay priesthood offices, which reflect degree of adherence to Church doctrines. Follow-up cancer rates for 1966-1970 indicate that the most devout group (Seventies and High Priests) have lung cancer rates 80% lower than those of the least devout group. The same was seen for all smoking- and alcohol-associated cancer sites combined. Cancer of the stomach and the leukemias and lymphomas also had lower rates in the most devout group. Cancers of the colon-rectum, prostate, and pancreas showed little difference in rates when classified by lay priesthood office. These data provide a demonstration of the effects of a healthy lifestyle on cancer occurrence in men.

Adolescent↗
PubMed1982

Cancer in Utah Mormon women by church activity level.

In light of low cancer rates by the Mormon Church, this study classifies female Mormon cancer patients in Utah according to measures of adherence to Church doctrines. The distribution by Church activity level is compared for each site to a group of other cancer sites felt to represent the overall activity level distribution of Utah Mormon women. Mormon women classified as having the strongest adherence to Church doctrines had lung cancer rates during 1966-1970 much lower than did women with the weakest adherence. The relationship was not as strong, however, as that seen in Mormon men when classified by lay priesthood office. Cancer of the uterine cervix also showed lower rates in the more active groups, but this finding was not statistically significant. Cancers of the breast and ovary did not show consistent associations with Church activity level, nor did most of the gastrointestinal cancers. These data suggest that some of the differences in cancer incidence between Mormons and non-Mormons may not be explained by adherence to specific Church doctrines.

Adult↗
PubMed1982

Neonatal mortality in Utah.

A cohort study of neonatal mortality (N = 106) in white singleton births (N = 14,486) in Utah for January-June 1975 was conducted. Using membership and activity in the Church of Jesus Christ of Latter-day Saints (LDS or Mormon) as a proxy for parental health practices, i.e., tobacco and alcohol abstinence, differential neonatal mortality rates were calculated. The influence of potential confounding factors was evaluated. Low activity LDS members were found to have an excess risk of neonatal death five times greater than high activity LDS, with an upper bound of a two-sided 95% confidence interval of 7.9. The data consistently indicate a lower neonatal mortality rate for active LDS members. Non-LDS were found to have a lower rate than either medium or low activity LDS.

Birth Weight↗
PubMed1982

Lung cancer mortality among residents living near the El Paso smelter.

Occupational exposure to arsenic has been associated with cancer of the lung, but epidemiological studies of cancer of the lung and environmental exposure to arsenic have produced conflicting results. Case-control studies about point sources of pollution have been useful in identifying environmental hazards. This technique was used to evaluate the risk for lung cancer near a smelter in El Paso, Texas, that uses an arsenic-containing ore and has been in continuous operation since 1887. A comparison of 575 cases of lung cancer with 1490 breast and prostate controls collected from 1944 to 1973 found no significant associations with distance using 2-km concentric circles out to 20 km from the smelter.

Arsenic↗
PubMed1982

Noncontraceptive estrogen use and the occurrence of ovarian cancer.

Female residents of six counties in Washington and Utah in whom ovarian cancer was diagnosed during 1975-79 were interviewed concerning prior use of noncontraceptive estrogens. Interviews with a random sample of women drawn from these counties were obtained for comparison. Taken as a whole, women with epithelial ovarian tumors reported estrogen use for 1 year or more somewhat more often than did controls [relative risk (RR) = 1.3, 95% confidence interval (CL) = 0.9-1.8]. The proportion of women who had used estrogens varied according to the histology of their tumor; notably, of 17 women with endometrioid tumors, 12 had used estrogens (RR = 3.1, 95% CL = 1.0-9.8). The excess risk of endometrioid carcinoma related to estrogen use was not further increased when these hormones were taken for long durations, in high doses, or proximate to the time of diagnosis. Neither was there any evidence of increased risk from estrogen use in the small group of women with clear cell tumors, a histologic tumor type believed to be closely related to endometrioid carcinoma. Thus the observed association between menopausal estrogen use and the occurrence of ovarian endometrioid tumors should be interpreted cautiously until the results of additional studies are available.

Adenocarcinoma↗
PubMed1981

Relationship between lung cancer and distance of residence from nonferrous smelter stack effluent.

Because of a reported association between residence in counties with nonferrous smelters and increased risk of lung cancer, we studied the relationship between distance of residence from nonferrous smelters and lung cancer. Patients with lung cancer and patients with other cancers not known to be associated with smelter effluent (breast, prostate, and colon) were compared. All patients lived within a 20-kilometer radius around one of 10 nonferrous smelters in five western states during 1970-1977. Data were obtained from cancer registries or death certificates and were examined separately for each area. Addresses at the time of diagnosis or death were plotted on U.S. Geological Survey maps to calculate distance from each smelter. The distribution of lung cancer near the smelters was not significantly different from the distribution of control cancers in any of the areas studied.

Adult↗
PubMed1981

Incidence of ovarian cancer in relation to the use of oral contraceptives.

Female residents of six counties in Washington and Utah in whom a diagnosis of ovarian cancer was made during 1975-79 were interviewed concerning prior use of oral contraceptives. Interviews with a random sample of women drawn from these same counties were obtained for comparison. A smaller proportion of women with epithelial ovarian tumors had taken oral contraceptives than had controls: the estimated risk of ovarian cancer in uses relative to that in non-users was 0.57 (p = 0.04). The magnitude of the decreased risk depended on the duration over which oral contraceptives had been taken, as the negative association was present only after 4 or more years of use. In many ways, the use of oral contraceptives mimics the physiologic effects of pregnancy. The results of the present investigation, when interpreted together with those from other epidemiologic studies and from experiments in animals, suggest that, like pregnancy, the use of oral contraceptives has a protective effect against the development of ovarian cancer.

Adult↗