ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Epidemiologic studies on dioxin, specifically 2,3,7,8-tetra-chlorodibenzo-p-dioxin (TCDD), have not consistently found an increased cancer risk. This study examines mortality rates for 754 employees at a chemical plant after an accident in 1949 in which 122 workers developed chloracne from high exposure to TCDD. We also examined exposure to 4-aminobiphenyl, a potential bladder carcinogen. Although the numbers are small, and confounding factors cannot be ruled out, workers exposed to 4-aminobiphenyl who developed chloracne from the accident had increased mortality rates from soft tissue sarcoma, bladder cancer, and respiratory cancer. All soft tissue sarcomas occurred among workers with potential 4-aminobiphenyl exposure, whereas no soft tissue sarcomas occurred among workers with TCDD exposure alone. In these workers, exposure to TCDD alone at levels great enough to cause chloracne was not associated with increased cancer rates.

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Identification of soft tissue sarcomas (STSs) in epidemiologic mortality studies is complicated by nosologic coding rules that require that STSs arising in a visceral organ must be coded in the International Classification of Diseases (ICD) category for that organ, rather than in the ICD category for malignant neoplasms of connective tissue. Moreover, prior studies have shown poor agreement between diagnoses recorded on death certificates compared with those in hospital records for these tumors. We reviewed deaths from STS among workers in a registry of 6,716 dioxin-exposed workers at the National Institute for Occupational Safety and Health (NIOSH) and in a NIOSH cohort mortality study of 10,240 workers exposed to chlorinated naphthalenes. We identified 19 subjects with STSs. Of these, 17 (89%) were identifiable by reading the entries on selected death certificates, and two (11%) were found only by reviewing medical records of cases coded to ICD categories likely to have contained STS. Of the 17 STSs identified from death certificates, only nine (53%) had been coded as underlying cause of death to the ICD category “malignant neoplasms of soft and connective tissue.” Medical records were obtained for 14 of the 17 cases (82%), and in each case, the STS diagnosis was verified. Tissue blocks from tumors were available for review in nine of the 17 cases identified from death certificates, and the diagnosis of STS was verified in seven (78%). Nosologic rules reduce the sensitivity of cohort mortality studies to detect excesses of STS. Development of referent rates based on histologic coding, such as the International Classification of Diseases for Oncology (ICD-O) system, would allow better study of tumors such as STS.

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We conducted a case-control study to evaluate the effect of replacement estrogen use alone, and the combined effect of estrogen and progesterone use, on the risk for endometrial cancer. We studied women age 50–64 years at Group Health Cooperative of Puget Sound. We identified 172 incident cases of endometrial cancer diagnosed during the years 1979–1989, and controls of similar age and duration of membership in the plan. Women who had used conjugated estrogens alone for 5 or more years were at increased risk for developing endometrial cancer compared with nonusers [adjusted rate ratio (RR) = 22.0; 95% confidence interval (CI) = 6.5–74.1]. Users of unopposed estrogens of 3–4 years' duration had a relative risk of 1.9 (95% CI = 0.4–8.7). Women who had used medroxyprogesterone acetate in combination with the estrogen therapy for 3 or more years had a risk near that of nonusers (adjusted RR = 1.3; 95% CI = 0.5–3.4) and that of users of unopposed estrogens for less than 5 years. There were insufficient women who used estrogen and progesterone together for 5 or more years to derive a separate risk estimate for these women.

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We used data from a study of racial differences in cancer patient survival to examine the association between estrogen receptor status and the intake of nutrients and food groups among 689 black and white women, ages 20–79, with breast cancer newly diagnosed in 1985 and 1986. We reviewed medical records and collected interview data, including a 34-item food frequency questionnaire. Consistent with published reports, we found positive estrogen receptor status to be positively associated with age and inversely associated with parity and oral contraceptive use. Whites were more likely than blacks to have estrogen receptor-positive tumors. We examined eight nutrients and six food groups in multivariate analyses for association with estrogen receptor status. After adjusting for age, race, usual body mass index, and parity, a high percentage of calories from fat was associated with estrogen receptor-positive cancer, and a high percentage of calories from carbohydrates was associated with estrogen receptor-negative breast cancer. These findings indicate that women with breast cancer who are on diets with a high percentage of calories from fat may be more likely to develop estrogen receptor-positive cancers.

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The distinction between additive risk models and additive relative risk models is important when nonadditivity is used as a criterion for interdependence of causal effects (causal interaction). I show here that, in stratified studies, additive relative risk models do not provide the often-assumed correspondence between additivity and absence of causal inter action. Under the causal models of Rothman and others, complete assessment of causal interaction requires that one fit additive risk models; in matched case-control studies, such fitting may require external information.

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The sufficient causes model of disease occurrence leads to a specific conception of how the risk of disease resulting from exposure to an agent combines with background risks. From this conception, one can derive a method for quantifying in populations the respective effects of the agent and background, using either rates or risks. This method differs from the usual difference or ratio measures of effect by taking into account the probability that the sufficient cause of disease involving the agent of interest and that not involving it will both occur during the observation period. The method leads to: (1) measures of the risks or rates of completion of sufficient causes involving or not involving the agent of interest; (2) a measure of the proportion of cases preventable by removing or blocking the agent, based on observed risks of disease. This proportion varies as a function of the duration of exposure; (3) a measure of the proportion of cases caused by the agent, based on observed rates of disease. This proportion is constant over time, if the rates are; (4) a causal interpretation of a constant rate ratio, when the rates vary over time.

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

To assess the role of surveillance bias in the observed threefold excess of cutaneous malignant melanoma (CMM) at the Lawrence Livermore National Laboratory (LLNL) in California, we examined the thickness of CMMs among all 20 laboratory employees who were members of a large prepaid health plan and whose CMM was diagnosed from 1970 through 1984. For comparison, we reviewed slides of 36 other members of the same health plan matched (usually 2:1) to the laboratory case by age, sex, facility, and year of diagnosis. Three expert dermatopathologists read the slides using a multiheaded microscope to reach a consensus; they were blind to the laboratory employment status of the subjects. We found that from 1970 to 1976, before there was widespread publicity about the excess incidence of CMM at LLNL, lesion thickness was greater for non-LLNL employees (mean difference =1.5 mm; 95% confidence interval 0.1–2.9). From 1977 through 1984, however, there was no appreciable difference [mean difference = −0.3 mm; 95% confidence limits (CL) = −1.4, 0.9]. Dropping the matching to adjust for histologic type of melanoma as well as gender, year, and age at diagnosis yielded substantially the same results. These data are compatible with an effect of surveillance bias up to around 1976, but in this health plan population, they do not support a role for surveillance bias in the continuing excess incidence observed since that time.

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

We conducted a population-based case-control study, using the 1984–1989 linked Washington State birth and death certificate data, to determine whether maternal prior spontaneous pregnancy loss was associated with the risk of sudden infant death syndrome (SIDS). We identified 87Z autopsied SIDS cases and 3,704 controls matched to cases on year of birth. To reduce the confounding from unmeasured socio-economic and behavioral factors, we analyzed the data separately for infants with and without father's race provided on the birth certificate. Among infants whose father's race was known, those of multiparous women with a prior spontaneous pregnancy loss before 20 weeks gestational age were at reduced risk of SIDS, after adjustment for maternal age, prenatal smoking, and gravidity. An increased number of prior pregnancy losses was associated with a further reduction in the risk of SIDS: one prior pregnancy loss was associated with a 25% decrease [odds ratio (OR) = 0.75; 95% confidence interval (CI) = 0.52–1.08], and two or more prior pregnancy losses was associated with a 47% decrease (OR = 0.53; 95% CI = 0.30–0.94). There was no such association, however, among infants of women with no prior livebirth. Similar associations were observed between prior spontaneous pregnancy loss during the entire gestational period and the risk of SIDS in offspring. To explain the different associations between maternal prior pregnancy loss and the risk of SIDS observed among infants of women with and without a prior livebirth, we hypothesize an upward bias resulting from the presence of a larger proportion of infants of human leukocyte antigen-compatible couples among first liveborn infants.

ISSN:1044-3983    

出版商:OVID    

年代:1993

数据来源: OVID