Cancer risk among women exposed to exogenous estrogens during pregnancy.

A cohort of 3,139 obstetric patients, who delivered children between 1946 and 1965, was followed retrospectively to assess the relationship between exposure to diethylstilbestrol [(DES) CAS: 56-53-1; alpha, alpha'-diethyl-4,4'-stilbenediol] or other estrogenic substances during pregnancy and subsequent cancer incidence. Among the 1,531 women exposed to DES, the relative risk (RR) for all cancers was 1.46 [95% confidence interval (CI), 1.07-2.00]. The RR for cancers of the breast, cervix, and ovary were 1.37 (adjusted), 1.40, and 2.83, respectively, but none of these estimates was statistically significant. For breast cancer an RR in excess of 2.28 can be excluded, with 95% CI for doses averaging 2,100 mg. Within the exposed group there was no evidence for a dose-response relationship.

Evaluation of self-collected cervicovaginal cell samples for human papillomavirus testing by polymerase chain reaction.

As human papillomavirus (HPV) becomes accepted as the central cause of cervical cancer, longitudinal studies are shifting focus away from causality to a more detailed investigation of the natural history of HPV infections. These studies commonly require repeated samples for HPV testing over several years, usually collected during a pelvic exam, which is inconvenient to the participants and costly to the study. To alleviate the inconvenience and cost of repeated clinic visits, it has been proposed that women collect cervicovaginal cells themselves, hopefully increasing participation in the natural history studies. We evaluated the technical feasibility of self-collection of cervicovaginal cells using a Dacron swab for HPV DNA detection. We compared the self-collected swab sample and two clinician-administered swab samples (one from the endocervix and another from the ectocervix) from a total of 268 women participating in a case-control study of adenocarcinoma and squamous cell carcinomas of the uterine cervix (111 cases and 157 controls). HPV DNA was detected and genotyped using an L1 consensus PCR assay. The overall agreement between the clinician- and self-collected swabs was excellent [88.1%; kappa = 0.73 (95% confidence interval (CI), 0.61-0.85)]. The correlation was highest between the two clinician-administered swabs [kappa = 0.81 (95% CI, 0.69-0.93)] but was still excellent when comparing either clinician-administered swab to the self-administered sample [kappa = 0.75 (95% CI, 0.63-0.87) and 0.67 (95% CI, 0.55-0.79) for ectocervix and endocervix, respectively]. The type-specific agreement between samples was higher for high-risk, or cancer-associated, HPV genotypes than for low risk, noncancer-associated HPV genotypes when comparing the self-administered swab sample to the clinician-administered swab sample (kappa = 0.78 for high-risk versus 0.66 for low-risk HPV infections, t = -1.45, P = 0.15). The decrease in agreement for low risk types was largely attributable to an increased detection of these types in the self-administered sample (McNemar's chi2 = 6.25, P = 0.01 for clinician- versus self-administered swab comparisons). The agreement did not vary significantly by age, menopausal status, case status, or clinic center. We have demonstrated that a self-collected Dacron swab sample of cervicovaginal cells is a technically feasible alternative to clinician-administered cervical cell collection in natural history studies of HPV and cervical cancer.

Oral contraceptives as risk factors for cervical adenocarcinomas and squamous cell carcinomas.

To assess the hypothesis that oral contraceptives (OCs) increase the risk of cervical adenocarcinomas, we conducted a six-center case-control study of 124 patients with adenocarcinomas, 139 with squamous cell carcinomas, and 307 population controls. Women between the ages of 18 and 69 who were newly diagnosed with cervical adenocarcinomas between 1992 and 1996 were eligible. Healthy female controls and a second case group of incident cervical squamous cell carcinomas were matched to the adenocarcinoma cases. All participants were interviewed regarding OCs, other risk factors for cervical carcinoma, and utilization of cytological screening, and a PCR-based test determined HPV genotype of cervical samples for both case groups and controls. Use of OCs was positively and significantly associated with adenocarcinomas and positively but weakly associated with squamous cell carcinomas. Associations between OCs and invasive adenocarcinomas (n = 91), squamous cell carcinoma in situ (n = 48), and invasive squamous cell carcinomas (n = 91) disappeared after accounting for HPV infection, sexual history, and cytological screening, but a positive association remained between current use of OCs and cervical adenocarcinoma in situ (n = 33). This association persisted after stratification by screening and sexual history and after restriction according to HPV status, but small numbers made it difficult to exclude detection bias, selection bias, or residual confounding by HPV as potential explanations Current OC use was associated with cervical adenocarcinomas in situ, but we saw no other evidence that OCs independently increase the risk of cervical carcinomas.

Evaluation of an occupational respiratory exposure to a zirconium-containing dust.

A group of handfinishers of zirconium metal reactor components questioned whether the dust to which they were exposed would cause chronic lung disease or cancer, or both. To investigate this possibility, the work environment was surveyed, and 32 male employees who had worked as handfinishers from one to seventeen years, were compared to a group of controls in reference to a respiratory questionnaire, chest x-ray findings, and expiratory lung function tests. The controls were matched to the handfinishers for age, sex, payroll status and smoking history. No significant differences were found between the exposed and the control groups. Results of earlier animal respiratory studies vary from no effect to definite pathology. Previous employee exposure studies are short-term and have methodological shortcomings. It would appear that lifetime animal respiratory studies and systematic epidemiological studies of employee populations with long-term inhalation exposure are needed to demonstrate unequivocally whether zirconium and zirconium compounds are harmful.

Abortion before first livebirth and risk of breast cancer.

The present study examined the association between abortion prior to a first livebirth and breast cancer risk among a cohort of 3,315 women who had been delivered of liveborn children between 1946 and 1965 in a group of private gynaecology practices in Connecticut and followed through 1980 for the incidence of cancer. Among women with one livebirth at the time of cohort identification, a spontaneous abortion before this livebirth was associated with a 3.5-fold increase in the risk of breast cancer. The elevation in risk was independent of some of the major risk factors of breast cancer and became more pronounced as the number of years since the abortion increased.

Prevalence and treatment of spasticity reported by multiple sclerosis patients.

The objective of this study was to characterize the population of multiple sclerosis (MS) patients suffering from spasticity and to evaluate treatment patterns, including intrathecal baclofen (ITB) delivery, related to patient quality of life (QOL). We conducted a cross-sectional, two-level study using data from the Patient Registry of the North American Research Committee on MS (NARCOMS). In addition, we surveyed a subgroup of 198 preselected patients who are using ITB (ITBG) and a random sample of 315 oral drug users (ORALG). Among the registrants, 16% reported no spasticity, 31% minimal, 19% mild, 17% moderate (frequently affects activities), 13% severe (daily forced to modify activities) and 4% total (prevents daily activities). Patients experiencing greater severity included by proportion males, and those older and with longer duration of MS. QOL scores decreased inversely with severity. In the focused survey, ITBG reported lower levels of spasticity than ORALG, less stiffness in the legs, less pain and fewer spasms at any time. They scored significantly lower in the SF-36 physical component, yet reported less fatigue on the MFIS scale. Prevalence data reveal that one third of MS patients modify or eliminate daily activities as a result of spasticity. Treatment of spasticity can significantly impact QOL parameters by reducing spasms, pain and fatigue.

The mortality of US nuclear submariners, 1969-1982.

A mortality study of 76,160 men who served on US nuclear submarines is reported. Indirect standardization was used to compare mortality rates to those of the US male population. Multiplicative models were developed to explore patterns of mortality within the cohort. Mortality rates for leukemia, acute myocardial infarction, and for motor vehicle accidents were equivalent to those of US males; rates for other causes were lower, generally consistent with the "healthy worker effect." Motor vehicle accident mortality dropped during the study period, perhaps reflecting efforts to control the problem. Suicide rates were depressed during the period of active duty. There was a suggestion that cancer mortality was associated with submarine type; however, the age distribution casts doubt that the excess was occupationally induced.

Mortality and cancer incidence experience of employees in a nuclear fuels fabrication plant.

The mortality and cancer incidence experience of 4,106 employees in a nuclear fuels fabrication plant was evaluated in this retrospective cohort study. Standardized mortality (SMR) and incidence ratios were calculated for groups of employees holding different jobs in the company associated with various types of industrial exposures and with low levels of radiation. Connecticut population mortality rates and Connecticut Tumor Registry incidence rates, specific for age-sex, calendar year and cause of death or cancer site, were used for the calculation of expected rates. Results showed the SMR for all male employees to be significantly lower than expected for all causes and what would be expected for all cancer deaths. More deaths were observed than expected from diseases of the central and peripheral nervous system and from obstructive pulmonary disease. The overall cancer incidence experience of the male employees was significantly lower than expected; cancer of the brain was found to be significantly higher than expected among the industrial employees. These was no risk associated with any particular job exposure group. Log linear models analysis showed no significant effect from industrial and radiation exposures or from their combined influence.

Use of hormone replacement therapy and adenocarcinomas and squamous cell carcinomas of the uterine cervix.

INTRODUCTION: Exogenous hormones may influence the development of cervical adenocarcinomas. Incidence rates of adenocarcinomas and use of noncontraceptive hormones have increased since the 1970s, but few studies have investigated this potential relationship. METHODS: We conducted a multicenter case-control study of 124 women with adenocarcinomas, 139 women with squamous cell carcinomas matched on age, diagnosis date, clinic, and stage of disease (in situ or invasive) to adenocarcinoma cases, and 307 healthy community controls who were also matched on age, ethnicity, and residence to adenocarcinoma cases. Participants completed in-person interviews regarding exogenous hormone use before diagnosis and other risk factors and volunteered cervical samples for human papillomavirus (HPV) testing via a PCR-based method. Odds ratios (ORs) with 95% confidence intervals (CIs) estimated relative risks. RESULTS: Only 13 adenocarcinoma cases (10.5%), 7 squamous carcinoma cases (5%), and 20 controls (6.5%) had used noncontraceptive hormones for menopausal symptoms, irregular periods, or disease prevention; most use was short-term, former use. Ever-use was associated with adenocarcinomas (OR = 2.1, 95% CI 0.95-4.6) but not squamous carcinomas (OR = 0.85, 95% CI 0.34-2.1). No trends were seen with duration of use or ages at first use, but unopposed estrogens were positively associated with adenocarcinomas (OR = 2.7). Unopposed estrogens remained associated with adenocarcinomas (OR = 2.0) when analyses were restricted to the HPV-positive controls. Menopausal status was not associated with adenocarcinomas or squamous carcinomas and did not modify the other associations. CONCLUSION: Although small numbers warrant tentative conclusions, exogenous estrogens, especially unopposed estrogens, were positively associated with adenocarcinomas. Noncontraceptive hormones were negatively but weakly associated with squamous carcinomas.

Associations between smoking and adenocarcinomas and squamous cell carcinomas of the uterine cervix (United States).

OBJECTIVES: Few studies of smoking and cervical carcinoma have addressed the rare cervical adenocarcinomas or used DNA-based tests to control for human papillomavirus (HPV) infection. METHODS: This multicenter case-control study included 124 adenocarcinoma cases, 307 community controls (matched on age, race, and residence to adenocarcinoma cases), and 139 squamous carcinoma cases (matched on age, diagnosis date, clinic, and disease stage to adenocarcinoma cases). Participants completed risk-factor interviews and volunteered cervical samples for PCR-based HPV testing. Polychotomous logistic regression generated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for both histologic types. RESULTS: Eighteen percent of adenocarcinoma cases, 43% of squamous carcinoma cases, and 22% of controls were current smokers. After control for HPV and other questionnaire data, adenocarcinomas were consistently inversely associated with smoking (e.g. current: OR = 0.6, 95% CI 0.3-1.1; > or = 1 pack per day: OR = 0.7, 95% CI 0.4-1.3), while squamous carcinomas were positively associated with smoking (e.g. current: OR = 1.6, 95% CI 0.9-2.9; > or = 1 pack per day: OR = 1.8, 95% CI 1.0-3.3). Results in analyses restricted to HPV-positive controls were similar. CONCLUSION: Smoking has opposite associations with cervical adenocarcinomas and squamous carcinomas. Although both histologic types are caused by HPV and arise in the cervix, etiologic co-factors for these tumors may differ.