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Biomedical subjects

N S Weiss

Publications and source records attributed to N S Weiss.

At least 19 recordsLinked to original sources

Cancer identification using a tumor registry versus death certificates in occupational cohort studies in the United States.

Studies of cancer incidences among occupational cohorts are rarely performed in the United States because of incomplete registration and a limited time period available for follow-up. This study used data from concurrent studies of cancer mortality and incidence among a cohort of 4,528 fire fighters and police officers employed by the cities of Seattle and Tacoma, Washington, between 1944 and 1979 to examine the relative advantages of tumor registry and death certificate information. As expected, an increased ability to study relatively common cancers with low fatality rates was demonstrated using incidence data. The most dramatic example was seen for bladder cancer. Twenty-four bladder cancers had been diagnosed among the study cohort between 1974 and 1989, whereas only two deaths were attributed to this malignancy. The standardized incidence ratio for bladder cancer was 1.05 (95% confidence interval 0.67-1.55), whereas the corresponding standardized mortality ratio was 0.46 (95% confidence interval 0.05-1.65). The observed relative risk estimates for rapidly fatal cancers were similar using the two sources of information, and no increase in precision was observed. Of 142 persons in the registry area who died of cancer during the study period, 20 (14%) had a different site listed on the death certificate than was identified by the registry. Approximately 7% of the potential person-years of follow-up were lost due to migration out of the registry area; loss to follow-up was greater among older and short-term workers, but did not exceed 13% of the person-years. Population-based tumor registries can be a useful resource in the investigation of occupational cancer in the United States, especially for the study of cancers with high survival rates.

Adult

Association of prior infection with Chlamydia pneumoniae and angiographically demonstrated coronary artery disease.

OBJECTIVE: To evaluate the association between prior infection with Chlamydia pneumoniae, as measured by IgG antibody, and coronary artery disease. DESIGN: A population-based, case-control study. SETTING: Group Health Cooperative of Puget Sound, a Seattle-based health maintenance organization. PARTICIPANTS: Men 55 years of age and younger and women 65 years of age and younger. Cases (n = 171) were members of Group Health Cooperative undergoing diagnostic coronary angiography who had at least one coronary artery lesion occupying 50% or more of the luminal diameter. The population controls (n = 120) were Group Health Cooperative members without known coronary heart disease. MAIN OUTCOME MEASURE: The adjusted odds ratio (OR) for coronary artery disease associated with prior C pneumoniae infection as measured by the presence of IgG antibody. RESULTS: After adjusting for age, gender, and calendar quarter of blood drawing, the OR for coronary artery disease associated with the presence of antibody was 2.6 (95% confidence interval, 1.4 to 4.8). The association was limited to cigarette smokers, in whom the OR was 3.5 (95% confidence interval, 1.7 to 7.0). Among never-smokers, the OR was 0.8 (95% confidence interval, 0.3 to 1.9). When cases and controls were restricted to those assayed concurrently, the adjusted OR (smokers and nonsmokers combined) was 4.2 (95% confidence interval, 1.8 to 10.0). Adjustment for serum cholesterol, hypertension, alcohol use, diabetes, and socioeconomic status did not change these results. Only a week association was found when cases were compared with 63 subjects whose angiographic results were normal (OR, 1.2; 95% confidence interval, 0.6 to 2.2). CONCLUSIONS: These results generally support the previously reported association between C pneumoniae infection and coronary heart disease. However, caution should be used in interpreting the basis for this association.

Adult

Approaches to the analysis of case-control studies of the efficacy of screening for cancer.

To an increasing extent, case-control studies are being undertaken to determine if use of early detection procedures is associated with reduced mortality from cancer. The authors recommend that in such studies the analysis focus on screening activity in cases that occurs during an interval prior to diagnosis in which the cancer is believed to be detectable and still curable and to a corresponding time period in controls. This approach places a heavy burden on the investigator to estimate accurately the period during which the tumor ought to be detectable using the test in question and to sort out reliably tests done in response to signs or symptoms of the cancer from screening tests per se. Nonetheless, the authors feel that it offers the greatest ability to discern a true benefit of screening, while minimizing the numerous potential biases that can be present in this type of study.

Case-Control Studies

Glutathione S-transferase and epoxide hydrolase activity in human leukocytes in relation to risk of lung cancer and other smoking-related cancers.

BACKGROUND: There is considerable interindividual variation in the activity of enzymes which metabolize polycyclic aromatic hydrocarbon constituents of tobacco smoke. Low activity of enzymes which detoxify carcinogenic polycyclic aromatic hydrocarbon metabolites may be associated with increased susceptibility to cancers etiologically related to cigarette smoking. PURPOSE: We conducted a population-based, case-control study to determine whether patients with cancers related to smoking had lower activity of detoxifying isoenzymes of glutathione S-transferase (GST) and epoxide hydrolase (EH) than control subjects. METHODS: Enzyme activities were measured in leukocytes from 113 King County (Washington) residents diagnosed during 1987 with one of three smoking-related cancers (lung, oropharynx/oral cavity, or bladder), 50 King County residents with cancers believed unrelated to smoking (prostate cancer or non-Hodgkin's lymphoma), and 120 persons selected at random from the King County population. Enzyme activity measurements were made for leukocyte cytosolic GST toward transstilbene oxide (TSO), 1-chloro-2,4-dinitrobenzene, and benzo[a]pyrene-4,5-oxide (BaPO), and for microsomal EH toward BaPO. RESULTS: Overall, the distribution of activity levels of GST toward TSO and BaPO did not differ in case patients with smoking-related cancer compared with control subjects. The activities of GST toward 1-chloro-2,4-dinitrobenzene and of EH toward BaPO were somewhat lower on average in case patients with smoking-related cancers than in control subjects, but these differences were well within the limits of chance. Among the heaviest smokers, there were proportionately fewer patients with smoking-related cancers than control subjects with intermediate or high GST activity toward TSO (odds ratio = 0.6), but this difference was also plausibly due to chance (95% confidence interval = 0.3-1.1). CONCLUSIONS: While the findings of this study are compatible with a moderate protective effect of high or intermediate enzyme activity among persons heavily exposed to tobacco, as suggested by an earlier report, the data are by no means conclusive.

Adult

A case-control study of screening sigmoidoscopy and mortality from colorectal cancer.

BACKGROUND: The efficacy of sigmoidoscopic screening in reducing mortality from colorectal cancer remains uncertain. A randomized trial would be ideal for clarifying this issue but is very difficult to conduct. Case-control studies provide an alternative method of estimating the efficacy of screening sigmoidoscopy. METHODS: Using data on the 261 members of the Kaiser Permanente Medical Care Program who died of cancer of the rectum or distal colon from 1971 to 1988, we examined the use of screening by rigid sigmoidoscopy during the 10 years before the diagnosis and compared it with the use of screening in 868 control subjects matched with the case subjects for age and sex. RESULTS: Only 8.8 percent of the case subjects had undergone screening by sigmoidoscopy, as compared with 24.2 percent of the controls (matched odds ratio, 0.30; 95 percent confidence interval, 0.19 to 0.48). Adjustment for potential confounding factors increased the odds ratio to 0.41 (95 percent confidence interval, 0.25 to 0.69). The negative association was as strong when the most recent sigmoidoscopy was 9 to 10 years before diagnosis as it was when examinations were more recent. By contrast, for 268 subjects with fatal colon cancer above the reach of the sigmoidoscope and for 268 controls, the adjusted odds ratio was 0.96 (95 percent confidence interval, 0.61 to 1.50). The specificity of the negative association for cancer within the reach of the sigmoidoscope is consistent with a true efficacy of screening rather than a confounding by unmeasured selection factors. CONCLUSIONS: Screening by sigmoidoscopy can reduce mortality from cancer of the rectum and distal colon. A screening once every 10 years may be nearly as efficacious as more frequent screening.

Aged

Cigarette smoking and the risk of anogenital cancer.

The association between cigarette smoking and cervical cancer has been demonstrated in numerous prior studies. As part of population-based case-control studies of cancers of the vulva, vagina, cervix, anus, and penis in relation to infection with human papillomavirus, conducted in western Washington State and the province of British Columbia from the mid 1980s until the present time, the authors have collected detailed information on smoking history. The proportion of subjects who were current smokers of cigarettes ranged from slightly over 40% among incident cases of vaginal and cervical cancer to 60% among cases of vulvar and anal cancer. In contrast, only about 25% of controls were current smokers. The adjusted odds ratios (OR) associated with current smoking were substantially elevated (OR = 1.9-14.6) for all cancer sites except cancer of the vagina (OR = 1.3). The risks tended to increase in proportion to the number of cigarettes smoked. For most cancer sites, the odds ratios associated with former smoking were substantially less than those associated with current smoking and diminished with increasing time since cessation of smoking. The authors' data and those of other investigators suggest that cigarette smoking plays a role in the etiology of anogenital cancers and that smoking has a late-stage or promotional effect.

Adolescent

Noncontraceptive hormone use and risk of breast cancer.

All British Columbia (Canada) women under 75 years of age who were diagnosed with breast cancer during 1988-89 were asked to complete a postal questionnaire which included detailed information on menopausal estrogen use. Controls were drawn from the Provincial Voters List, matched by five-year age category to the cases. The present analysis consists of 699 cases and 685 controls who were postmenopausal due to natural causes or to a hysterectomy. There was no overall increase in risk of breast cancer associated with ever-use of unopposed estrogen (odds ratio [OR] = 1.0, 95 percent confidence interval [CI] = 0.8-1.3). For estrogen use of 10 years or longer, the relative risk [RR] was 1.6 (CI = 1.1-2.5). The risk estimate for current users was somewhat elevated (OR = 1.4, CI = 1.0-2.0). Compared with women who never used hormone preparations, women who had used estrogen plus progestogen had an RR of 1.2 (CI = 0.6-2.2). Our results suggest that ever-use of estrogen, with or without progestogen, does not appreciably increase the risk of breast cancer. However, long-term and recent use of unopposed estrogen may be associated with a moderately increased risk.

Aged

Incidence of male genital skin tumors: lack of increase in the United States.

In men, genital exposure to ultraviolet radiation (UVR) has been hypothesized to increase the risk of non-melanotic skin tumors at that site. However, during the period 1973-86, no change in the incidence of penile or scrotal skin tumors occurred in the United States, despite a likely increase in the population's level of genital exposure to UVR through the use of sunlamps and sunbeds. While UVR in conjunction with use of 8-methoxypsoralen by men with psoriasis is clearly related to an increase in the incidence of male genital skin tumors, our data provide no support for the hypothesis that, among men in general, UVR alone has this same effect.

Carcinoma, Squamous Cell

Colorectal cancer and solar radiation.

It has been suggested that sunlight might have a role in the prevention of colorectal cancer via a mechanism involving vitamin D. We used data from nine population-based cancer registries in the United States to analyze incidence rates for colon and rectal cancer during 1973-84 as a function of regional variation in the levels of available solar radiation. Data were restricted to include only those persons born and diagnosed in the same state. Incidence rates of colon and rectal cancer among men tended to increase with decreasing levels of solar radiation. Compared to rates in New Mexico and Utah, for example, rates in the Detroit area (MI), Connecticut, and western Washington were 50 percent to 80 percent higher. Among women, colon cancer rates showed a similar trend, though of smaller magnitudes; rates of rectal cancer among women did not vary in relation to levels of available solar radiation.

Colonic Neoplasms

Prevalence of diabetes and impaired glucose tolerance among Navajo Indians.

OBJECTIVE: To estimate the prevalence of diabetes mellitus and impaired glucose tolerance and the incidence of clinically diagnosed diabetes in a community of Navajo Indians. RESEARCH DESIGN AND METHODS: We conducted a survey of a representative Navajo community screened for diabetes 3 yr previously. We used 75-g oral glucose tolerance tests to determine the prevalence of diabetes mellitus and impaired glucose tolerance and conducted medical record reviews to identify cases of diabetes that were diagnosed during routine medical care after the earlier study. RESULTS: By World Health Organization diagnostic criteria, the age-adjusted diabetes prevalence among 419 Navajo Indians 20-74 yr of age was 13.9% (95% confidence interval [CI] 9.2-18.5) for men and 18.4% (95% CI 14-22.8) for women. The ratio of the prevalence of diabetes among the Navajo population studied to that in the general United States population was 2.5. The prevalence of impaired glucose tolerance was 8% (95% CI 3.3-12.7) among men and 12.9% (95% CI 7.9-17.9) among women. Based on clinical diagnoses of diabetes made during routine medical care, mean +/- SE age-adjusted incidence of diagnosed diabetes among men was 8.6 +/- 4.3/1000 person-yr and 11.1 +/- 4.4/1000 person-yr among women. CONCLUSIONS: Although lower than that of some other tribes, the prevalence of diabetes among Navajo Indians is substantially higher than that in the general U.S. population. The high rate of clinical diagnoses suggests that the prevalence of the disease may continue to rise.

Adult

Clinical evaluation of the NBD-PC fluorescence polarization assay for prediction of fetal lung maturity.

OBJECTIVES: 1) To examine a fluorescence polarization (FP) assay with an independent set of data that contained more cases of respiratory distress syndrome (RDS) than a previous study, 2) to determine whether the same reference ranges are applicable to infants born to diabetic women, and 3) to evaluate whether adding the lecithin-sphingomyelin ratio (L/S) would substantially improve the prediction of RDS among women with an intermediate FP value (between 0.26-0.289). METHODS: We identified 389 women who had FP analysis performed at the University of Washington Medical Center from February 1986 to October 1988 and who delivered within 3 days of amniocentesis. We reviewed the medical records of these women and their infants to extract information for our study. RESULTS: For FP values of 0.26 or greater, the sensitivity and specificity for prediction of RDS were 90.2 and 84.6%, respectively, compared with 100 and 82.0% in the previous study. For FP values of 0.29 or greater, the sensitivity and specificity were 62.8 and 94.2%, respectively (80.8 and 96.2% in the previous study). Among diabetics, an FP result below 0.26 was associated with the same low risk of RDS as among non-diabetics. Among the patients with FP between 0.26-0.289, the addition of L/S did not provide a clinically useful improvement in the prediction of fetal lung maturity. CONCLUSION: The NBD-PC FP assay can be used as the sole test of fetal lung maturity in most clinical circumstances.

Amniotic Fluid

Functional ovarian cysts in relation to the use of monophasic and triphasic oral contraceptives.

This population-based case-control study assessed the effect of current use of monophasic or triphasic oral contraceptives (OCs) on the risk of functional ovarian cyst development. The cases were all 15-39-year-old enrollees in the Group Health Cooperative of Puget Sound who had either an inpatient primary diagnosis of functional ovarian cyst in 1988 or 1989 (N = 67) or an outpatient primary diagnosis of functional ovarian cyst from March 1988 through August 1989 at one of five Group Health Cooperative primary care clinics (N = 39). Controls were randomly selected enrollees matched to the cases for age, primary care clinic, and enrollment date (N = 255). Subjects with previous hysterectomy or oophorectomy were excluded from this analysis. Pharmacy and medical record review showed that 16% of cases and 19% of controls were currently using monophasic OCs, whereas 11% of cases and 9% of controls were using triphasic OCs. Compared with women not using hormonal contraception, the relative risks of a diagnosed functional ovarian cyst among women currently using OCs were 0.8 (95% confidence interval [CI] 0.4-1.8) for users of monophasic OCs and 1.3 (95% CI 0.5-3.3) for users of triphasic OCs. In contrast to previous studies of monophasic OCs containing higher steroid dosages, the results of this study suggest that current use of low-dose monophasic OCs does not substantially decrease a woman's risk of functional ovarian cyst formation. In addition, our results do not support recent speculation that current use of triphasic OCs appreciably increases the risk of functional ovarian cysts.

Adult