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Biomedical subjects

N S Weiss

Publications and source records attributed to N S Weiss.

At least 127 records · Page 7Linked to original sources
PubMed1996

Exogenous sex hormone use, correlates of endogenous hormone levels, and the incidence of histologic types of sarcoma of the uterus.

BACKGROUND: We analyzed data from a population-based, multi-center, case-control study to determine whether the occurrence of histologic types of uterine sarcoma is related to exogenous hormone use and/or to two correlates of endogenous estrogens: excess weight and cigarette smoking. METHODS: One hundred sixty-seven women with newly-diagnosed uterine sarcoma (56 leiomyosarcoma, 85 mixed mullerian tumors, and 26 endometrial stromal sarcomas) were interviewed by telephone regarding possible risk factors for these neoplasms, For comparison, 208 women identified at random from the general population of the study areas were interviewed as controls. RESULTS: Use of oral contraceptives was positively associated with the risk of leiomyosarcoma (odds ratios [OR] = 1.7, 95% confidence interval [CI] = 0.7, 4.1), primarily among women who last used these medications 15 or more years prior to diagnosis. Use of noncontraceptive estrogens was directly associated with the risk of mixed mullerian tumors, but only among recent and long-term users of these medications. Women in the highest quantile of body mass index (> or = 27.5 kg/m2) one year prior to diagnosis were at increased risk of each type of uterine sarcoma (leiomyosarcoma, OR = 2.5, 95% CI = 1.1, 5.7; mixed mullerian tumors, OR = 2.9, 95% CI = 1.3, 6.7; stromal sarcoma, OR = 3.5, 95% CI = 1.1, 10.9). Women who had ever smoked cigarettes were at reduced risk of leiomyosarcoma (OR = 0.6, 95% CI = 0.3, 1.1) and stromal sarcoma (OR = 0.5, 95% CI = 0.2, 1.2), but the relationship was not more pronounced among heavy smokers; no association with smoking was observed with mixed mullerian tumors. CONCLUSIONS: Several of these findings parallel those from studies of endometrial carcinoma and may indicate a role for unopposed estrogen in the etiology of histologic types of uterine sarcoma.

Adolescent↗
PubMed1996

Cancer incidence among alachlor manufacturing workers.

A historical cohort study was conducted to evaluate cancer incidence among chemical workers with occupational and environmental exposure to alachlor, the active ingredient in a family of pre-emergent acetanilide herbicides. The study followed 943 workers with at least 1 year of cumulative employment at the Monsanto plant in Muscatine, Iowa, from startup of the alachlor manufacturing process in March 1968 through December 1990. Approximately 96% of all workers were successfully traced to determine their last known residence and cancer status. Eighteen workers were diagnosed with cancer during the follow-up period, based on pathology information from the statewide cancer registry maintained by the State Health Registry of Iowa. The standardized incidence ratio for all cancers was 1.5 (95% CI 0.9-2.4) for all workers exposed to alachlor, which was due primarily to elevated rates for colorectal cancer and chronic myeloid leukemia. Workers with 5 or more years in estimated high alachlor exposure jobs had elevated rates of colorectal cancer (3 cases, SIR = 5.2, 95% CI 1.1-15.1). Interpretation of the study results is limited by the small size of the study population, minimal length of follow-up, and current information concerning alachlor metabolism in primates and humans. Nonetheless, the findings suggest the need for continued evaluation of this and other alachlor-exposed cohorts.

Acetamides↗
PubMed1996

Risk of breast cancer in a cohort of infertile women.

The purpose of this study was to assess: (1) the risk of breast cancer associated with use of ovulation-inducing agents (such as clomiphene citrate) as treatment for infertility; and (2) the risk associated with ovulatory abnormalities that result in infertility. We performed a case-cohort study among 3837 women evaluated for infertility at clinics in Seattle, Washington, at some time during 1974-1985. Computer linkage with a population-based tumor registry was used to identify women diagnosed with breast cancer before January 1, 1992. Data regarding infertility testing and treatment were abstracted from the infertility clinic medical records for women who developed breast cancer and a randomly selected subcohort. Twenty-seven women in the cohort developed in situ or invasive breast cancer, in comparison with an expected number of 28.8 cases (standardized incidence ratio, 0.9; 95% confidence interval (CI), ).6-1.4). Infertile women with evidence of an ovulatory abnormality were at a risk of breast cancer similar to that of women whose infertility was believed to be due to other causes. The risk among women who had taken clomiphene was reduced relative to infertile women who had not used this drug (adjusted relative risk, 0.5; 95% CI, 0.2-1.2), but the reduction in risk did not increase with duration of use. The possibility that use of clomiphene as treatment for infertility lowers the risk of breast cancer should be examined in other, larger studies.

Adolescent↗
PubMed1996

The incidence of non-Hodgkin's lymphoma and its histologic subtypes in Asian migrants to the United States and their descendants.

We examined the incidence of non-Hodgkin's lymphoma (NHL) in Chinese, Japanese, and Filipino residents of the United States to obtain further clues about the etiology of the disease. The age, race, and birthplace of residents of Hawaii, San Francisco/Oakland (California), and western Washington who had received a diagnosis of NHL during the period 1973-86 were obtained from population-based cancer registries, and a special tabulation from the 1980 Census was used to estimate the number of person-years at risk for each category of resident. The incidence of NHL in each of the Asian groups examined was 35 to 85 percent that of US-born Whites. However, there was no consistent trend of increasing incidence with increasing generation of residence in any of the groups. In Asian-Americans, the risk of small cell lymphocytic and plasmacytoid lymphoma was 10 to 85 percent that of Whites, although no clear trends of risk with generation of residence in the US were observed. They also were at a reduced risk of follicular lymphoma, and in Chinese and Japanese persons, the risk was lower in first generation than in later generation migrants (Chinese: Asian-born relative risk [RR] = 0.11, US-born, RR = 0.84; Japanese: Asian-born, RR = 0.15, US-born, RR = 0.36). The risk of diffuse lymphoma was similar in Chinese- and Japanese-Americans and US-born Whites. We conclude that, with the exception of follicular lymphoma, the basis for the relatively low incidence of NHL in Asian-Americans does not lie in exposures or characteristics that differ between the migrants themselves and their descendants.

Adolescent↗
PubMed1996

Risk of endometrial cancer following cessation of menopausal hormone use (Washington, United States).

While there are a number of benefits to the health of postmenopausal women from use of unopposed estrogens, the increased risk of endometrial cancer related to these hormones has led many women to use combined estrogen-progestogen therapy instead, or not to use hormones at all. Most women who take hormones do so only in the early portion of their postmenopausal years, so the risk of endometrial cancer following cessation of use might bear heavily on the overall risk/benefit evaluation. We analyzed data from a case-control study of women in western Washington (United States) to assess the magnitude of excess risk of endometrial cancer following discontinuation of estrogen use. Cases (n = 661) consisted of women aged 45 to 74 diagnosed between 1985 and 1991 who resided in one of three countries in Washington State. Controls (n = 865) were identified by random-digit dialing. Subjects were interviewed in-person to ascertain current and prior hormone use. The analysis was restricted to women who had not received combined estrogen-progestin therapy. Among women who had used unopposed estrogens at some time, risk of endometrial cancer declined as time since last use increased. Nonetheless, even among women who used these hormones for just a few years, the risk remained elevated by 30 to 70 percent almost a decade after cessation. These results, combined with those of most (but not all) other studies of this issue, suggest that a women who has discontinued unopposed estrogen therapy may retain a small increased risk of endometrial cancer for a long period of time.

Aged↗
PubMed1996

Incomplete pregnancies and risk of ovarian cancer (Washington, United States).

Because of the reduced risk of ovarian cancer related to prior full-term pregnancies, we sought to determine whether there was any association with a history of one or more incomplete pregnancies. White female residents of three counties in Washington State (United States) diagnosed with ovarian cancer during 1986-88 (n = 322), and a random sample of control women selected from these same counties (n = 426), were interviewed regarding their pregnancy and childbearing histories. Among women who had given birth to at least one child, an additional incomplete pregnancy was not associated with the risk of ovarian cancer (relative risk [RR] = 1.1, 95 percent confidence interval [CI] = 0.8-1.6, adjusting for age, oral contraceptive use, and number of births). For those who had never given birth, a somewhat smaller proportion of cases had a history of incomplete pregnancy than controls (RR = 0.8, CI = 0.4-1.7). In an analysis restricted to ever-pregnant women, a prior induced or spontaneous abortion was not found to be associated with the incidence of ovarian tumors (RR = 1.0, CI = 0.6-1.7, and RR = 1.3, CI = 0.8-1.9, respectively). Other studies of the possible relation between incomplete pregnancies and ovarian cancer generally have observed either a weak negative association or no association at all. It is possible that if incomplete pregnancies do affect the risk of ovarian cancer, their impact might be too small to be identified reliably through epidemiologic studies.

Abortion, Induced↗
PubMed1996

Is diabetes mellitus a risk factor for ovarian cancer? A case-control study in Utah and Washington (United States).

Insulin resistance characterizes non-insulin dependent diabetes (NIDDM). Insulin resistance may coexist in clinical syndromes with hyperestrogenism and hyperandrogenism, suggesting that the ovary may be sensitive to effects of insulin. In addition, insulin-like growth factor-I receptors, which are capable of binding insulin, have been identified in ovarian cancer tissue and are proposed to regulate cell growth. We evaluated the association between a history of diabetes mellitus and ovarian cancer in a case-control study in seven counties in Washington and in Utah (United States) during the years 1975-87. Cases included women newly diagnosed with ovarian cancer over a five-year period who were identified through population-based cancer reporting. Controls similar to cases with regard to age and county of residence were identified via household surveys or random digit dialing. The study included 595 cases and 1,587 controls. Twenty-seven cases (4.5 percent) and 72 controls (4.5 percent) reported a history of diabetes. Logistic regression analysis of the association between diabetes and ovarian cancer controlling for age, body mass index, and race resulted in an odds ratio (OR) of 0.9 (95 percent confidence interval [CI] = 0.6-1.5). The OR was not changed with further controlling for prior oral contraceptive use or prior pregnancy. None of the 20 women with nonepithelial tumors (15 of which were stromal tumors) had a history of diabetes (upper CI = 4.0). These results, together with findings of two earlier cohort studies, do not support the hypothesis that diabetes is a risk factor for epithelial ovarian cancer.

Adult↗
PubMed1996

Liver cancer in Asian migrants to the United States and their descendants.

The incidence of primary liver cancer in Chinese, Japanese, and Filipino migrants to the United States and their descendants is compared with that of United States-born Whites. Incident liver cancer cases were ascertained between 1973 and 1986 from population-based cancer registries serving the San Francisco/Oakland (CA) metropolitan area, 13 counties of western Washington, and Hawaii. The population of these three areas, with regard to age, race, and country of birth, was estimated from a special tabulation of the 1980 US census. Rates of primary liver cancer were higher for men born in Asia than Asian men born in the US, who, in turn, had higher rates than did US Whites (respective annual rates per 100,000: Chinese, 26.5 and 9.8; Japanese, 16.5 and 6.6; Filipinos, 11.4 and 6.5; US Whites, 3.4). Among Asian American women, the trends were not as consistent (respective annual rates per 100,000: Chinese, 2.2 and 3.7; Japanese, 1.9 and 1.4; Filipino, 2.6 and 0; US Whites, 1.1). In general, liver cancer incidence among Asian Americans was lower than among residents of Asia. These findings are compatible with substantial variation among Asians in the prevalence of one or more etiologic factors for liver cancer, such as hepatitis-B infection and aflatoxin consumption, in relation to residence and place of birth.

Adolescent↗
PubMed1996

A population-based study of contralateral breast cancer following a first primary breast cancer (Washington, United States)

To evaluate predictors of contralateral breast cancer risk, we examined data from a nested case-control study of second primary cancers among a cohort of women in western Washington (United States) diagnosed with breast cancer during 1978 through 1990 and identified through a population-based cancer registry. Cases included all women in the cohort who subsequently developed contralateral breast cancer at least six months after the initial diagnosis, but prior to 1992 (n = 234). Controls were sampled randomly from the cohort, matched to cases on age, stage, and year of initial breast cancer diagnosis. Information on potential risk factors for second primary cancer was obtained through medical record abstractions and physician questionnaires. Women who were postmenopausal due to a bilateral oophorectomy (i.e., a surgical menopause) at initial breast cancer diagnosis had a reduction in contralateral breast cancer risk compared with premenopausal women (matched odds ratio [mOR] = 0.25, 95 percent confidence interval [CI] = 0.09-0.68), whereas no reduction in risk was noted among postmenopausal women who had had a natural menopause (mOR = 0.90, CI = 0.39-2.09). Among postmenopausal women, there was a suggestion of a lower risk associated with relatively high parity (2+). A family history of breast cancer was associated with an increased risk (mOR = 1.96, CI = 1.22-5.15) and varied little by menopausal status. Having an initial tumor with a lobular component (c.f. a ductal histology) was not related strongly to risk (mOR = 1.47, CI = 0.79-2.74). The results of the present and earlier studies argue that we have limited ability to predict the occurrence of a contralateral breast tumor. Better predictors will be required before diagnostic and preventive interventions can be targeted to subgroups of patients with unilateral breast cancer.

Adult↗
PubMed1996

Postmenopausal estrogens and progestogens and the incidence of gynecologic cancer.

We reviewed the published medical literature to assess the impact of the use of estrogens, with and without progestogens, on the incidence of gynecologic cancer in postmenopausal women. Long-term use of an estrogen preparation that is not accompanied by a progestogen is associated with a large increase in the risk of endometrial cancer, an association that almost certainly is a causal one. The incidence of endometrial cancer in women who receive combined estrogen-progestogen therapy is not elevated to nearly the same degree. There are suggestions that, depending on the particular combined regimen, the incidence need not be elevated at all beyond that of a women who has never taken hormones. The occurrence of other forms of gynecologic cancer appear not to be associated with the use of unopposed estrogens, though relevant data on cervical cancer are sparse. The relation of ovarian, cervical and vulvar cancer to the prior use of combined estrogen-progestogen therapy has only begun to be evaluated.

Aged↗
PubMed1996

Hypertension and outcomes research. From clinical trials to clinical epidemiology.

Outcomes research seeks to identify effective evidence-based methods of providing the best medical care. While randomized clinical trials (RCT) usually provide the clearest answers, they are often not done or not practicable. More than a decade after the introduction of calcium channel blockers and angiotensin converting enzyme (ACE) inhibitors, clinical trial data about their effect on major disease endpoints in patients with hypertension are still not available. The primary alternatives are the use of randomized trials that include surrogate endpoints, such as level of blood pressure or extent of carotid atherosclerosis, and the use of observational studies that include major disease endpoints. Both approaches, their strengths and limitations, are discussed in detail. The possibility of residual confounding limits the strength of inferences that can be drawn from observational studies. Similarly, the possibility of important drug effects, other than those involving the surrogate endpoint, limits the inferences that can be drawn from randomized trials that rely solely on surrogate outcomes as guides to therapy. In the absence of evidence from large clinical trials that include major disease endpoints, treatment decisions and guidelines need to synthesize the best available information from a variety of sources. Consistency of findings across various study designs, outcomes, and populations is critical to the practice of evidence-based medicine and the effort to maximize the health benefits of antihypertensive therapies.

Clinical Trials as Topic↗
PubMed1996

Risk factors for invasive Haemophilus influenzae disease among children 2-16 years of age in the vaccine era, Switzerland 1991-1993. The Swiss H. Influenzae Study Group.

BACKGROUND: Continued surveillance, and detailed investigation of direct and indirect effects of conjugated vaccines and risk factors for invasive H.influenzae serotype B (Hib) disease in the vaccine era are important. METHODS: 143 cases with invasive disease between 1991 and 1993 aged 2-16 years were selected retrospectively from a large incidence trend study. Controls (n = 336) were recruited from local vital registries and matched to cases for age, gender, and residence. Hib vaccination histories among study subjects and their siblings and other sociodemographic variables were obtained by questionnaires completed by the parents of these children. Adjusted odds ratio (OR) estimates were calculated by conditional logistic regression analysis. RESULTS: Most vaccinated subjects had received the Polysaccharide-Diphtheria Toxoid vaccine and estimated vaccine efficacy was high (95%; 95% confidence interval [CI] 60-99%). Also, the results suggested that protection afforded by vaccination against Hib extended to the family members of vaccinated children. School attendance was found to be protective against invasive Hib disease (OR:0.33; CI:1.2-14.4). Cases more often than controls reported suffering from asthma and allergies (OR:4.8; CI:1.2-19.4). CONCLUSIONS: Post-licensure vaccine efficacy is high among children > or = 2 years of age. The observed association between asthma and epiglottitis is novel and deserves further investigation.

Adolescent↗
PubMed1996

Socioeconomic status and the incidence of multiple myeloma.

This population-based case-control study examined the risk of multiple myeloma in relation to socioeconomic status. Subjects included 689 cases with newly diagnosed multiple myeloma during 1977-1981 from four U.S. populations and 1,680 controls selected from residents of these same populations. We collected lifetime occupational histories and coded them according to the 1970 Duncan Socioeconomic Index and Nam-Powers Socioeconomic Status scores. We classified scores for the occupations held the longest, highest ever held, and held most recently into quartiles based on the distribution among controls. After adjusting for age group, race, and study site, risk of multiple myeloma was inversely associated with socioeconomic status scores in both men and women. Risk among persons in the lowest quartile of scores was 63% higher (95% confidence interval 21%-119%) than that among those in the highest quartile when the highest Nam-Powers score was used. Similar trends were evident for all three methods of classifying occupational history and for both Duncan and Nam-Power scores. These results changed little after removing from analyses occupations previously associated with increased risk. The occupation-based scores were stronger predictors of risk than years of education. As a proxy measure of occupational, environmental, or life-style factors, socioeconomic status may be a clue to etiologic factors for multiple myeloma.

Case-Control Studies↗
PubMed1996

Indices of exposure to fetal and sperm antigens in relation to the occurrence of breast cancer.

We used data from a population-based case-control study to evaluate Janerich's hypothesis that reduced risk of breast cancer in women with multiple marriages may be attributable to an immune response to fetal or sperm antigens. Risk of breast cancer in women with multiple marriages was reduced relative to that in women who had been married only once; however, there was no indication that such risk was reduced among women whose full-term pregnancies were fathered by different men, relative to women whose pregnancies were each fathered by the same man. Increasing lifetime number of male sexual partners was associated with a trend of decreasing risk of breast cancer. Our results indicate that, if there are effects of exposure to fetal or male antigens on risk of female breast cancer, their impact may be heterogeneous.

Antigens↗
PubMed1996

Occurrence of breast cancer in relation to recreational exercise in women age 50-64 years.

To investigate the relation between recreational physical activity and breast cancer, we conducted an analysis of a population-based case-control study of women age 50-64 years in western Washington State. The study included 537 patients with breast cancer diagnosed during 1988-1990 and 492 randomly selected population control women. Detailed information on recreational exercise habits and other risk factors for breast cancer was ascertained by structured in-person interviews. A similar proportion of cases and controls reported exercise in the 2 years before the referent date (about 50%), or during ages 12-21 years (about 40%). Compared with women who reported no exercise, there was a slightly decreased risk of breast cancer in women who exercised more than 1.5 hours per week in the 2 years before diagnosis (cases) or referent date (controls) [odds ratio (OR) = 0.7; 95% confidence interval (CI) = 0.4-1.1], or who engaged in at least some high-intensity exercise (OR = 0.7;95% CI = 0.4-1.1), but there was no clear decline in risk at the highest categories of duration or intensity. There was no association between any intensity exercise at ages 12-21 years and risk of breast cancer. These results indicate a weak negative association between physical activity and risk of breast cancer in middle-aged women.

Breast Neoplasms↗