Risk factors for recurrent preterm birth in multiparous Utah women: a historical cohort study.

OBJECTIVE: To describe risk factors for recurrent preterm birth (PTB) in the second and third birth. DESIGN: Historical cohort study. SETTING: Utah, USA. POPULATION: Women who had their first three singleton live births in Utah between 1989 and 2007 and a preterm first or second birth were included. METHODS: Maternally linked birth records were used. Multivariable-adjusted risk ratios were calculated for recurrent PTB. Results were stratified by spontaneous and indicated PTB and by pattern of birth outcomes. MAIN OUTCOME MEASURES: Risk ratios and 95% confidence intervals for risk factors for recurrent PTB. RESULTS: Among women with PTB in their first or second live birth, recurrent PTB occurred in 21% of second live births (n = 1011/4805) and 22% of third live births (n = 1872/8468). Risk factors for recurrence included short inter-pregnancy interval, underweight prepregnancy body mass index, pre-existing maternal medical conditions, history of PTB at 28-32 weeks of gestation (versus 33-36 weeks), the presence of a fetal anomaly, and young maternal age. Risk factors for spontaneous, but not indicated PTB included young maternal age and less than appropriate gestational weight gain. Risk factors also varied in women experiencing a first versus second recurrence in their third birth. CONCLUSIONS: Risk factors may vary by the clinical subtype of the most recent PTB and the pattern of term and preterm outcomes across births 1-3; some of the risk factors identified in this study may be modifiable through interventions targeted at women in the inter-conception period.

Cancer incidence in Mormons and non-Mormons in Utah during 1967--75.

Data from the Utah Cancer Registry were used to compare cancer incidence in Mormons and non-Mormons in Utah for the period 1967--75. Church membership was identified for 97.8% of the 20,379 cases in Utah by a search of the central membership files of the Church of Jesus Christ of Latter-Day Saints (or Mormon Church). Sites associated with smoking (lung, larynx, pharynx, oral cavity, esophagus, and urinary bladder) showed an incidence in Mormons at about one-half that of non-Mormons. Rates of cancers of the breast, cervix, and ovary were low in Mormon women; the rate for cervical cancer was about one-half of that observed in non-Mormons. Cancers of the stomach, colon-rectum, and pancreas were about one-third lower in Mormons than in others who are not members of this religious group. Most of the differences seen in cancer incidence can be explained by Mormon teachings regarding sexual activity and alcohol and tobacco use, but some differences (e.g., colon and stomach) remain unexplained.

Cancer risk factors: an analysis of Utah Mormons and non-Mormons.

In a comparison of Mormons and non-Mormons in Utah, more Mormon men and women married spouses of the same faith, were religiously active, were of Northern Europe ancestry, lived in rural areas, had fewer exposures to occupational hazards, were less likely to smoke cigarettes or drink coffee, tea, and alcohol, used fats in cooking, and were more often married that was the cohort of other religions. No differences existed in occupation, but Mormon men had completed more years of schooling. Mormon women were less likely to be college graduates, had fewer sexual partners, had more pregnancies, were older at first pregnancy, were less likely to use birth control pills, had fewer miscarriages and hysterectomies, examined their breasts more often, and had more breast X-rays. For women, there was only a small difference by religion for age at first intercourse and no difference for age at which they began using birth control pills. Religious activity was examined for Mormons, and in most instances inactive Mormons were more like the non-Mormon population in respect to the variables measured.

Cancer in Utah: risk by religion and place of residence.

We compared cancer incidence during 1967--75 between Mormons and non-Mormons living in urban and rural areas of Utah. The non-Mormon urban men had a 34% higher risk of cancer compared with their rural counterparts. Most of this increase in risk occurred in sites associated with tobacco and for cancers of the stomach, colon, and prostate gland. Urban Mormon males had no significant increase in risk. The urban female population was at higher risk than was the rural regardless of religion. The increase was not as striking as that observed in non-Mormon men (8 vs. 34%); cancers of the respiratory and gastrointestinal tracts and female genitalia contributed to the elevated risk. We concluded that personal habits such as smoking and drinking and reproductive factors were possible explanations for the previously observed urban-rural gradients in cancer risk.

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.

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.

Breast cancer and reproductive history from genealogical data.

With the use of data from the Utah State Cancer Registry and Utah genealogical data, an analysis of 236 breast cancer patients and 937 controls matched on year of birth showed that a late age at the birth of the first child was most strongly associated with incidence of breast cancer (relative odds = 2.0; P less than 0.001). A strong interaction was found between age at first delivery (AFD) and age at last delivery (ALD). The association of AFD with breast cancer incidence was strongest for women with an ALD before 35 years of age even after adjustment for partly (relative odds = 4.1; P less than 0.001). Decreased parity was not significantly associated with breast cancer.

Energy intake: its relationship to colon cancer risk.

A case-control study was conducted to assess the role of diet in the etiology of colon cancer. Diet was measured by means of a comprehensive quantifiable food frequency history instrument in 246 cases and 484 controls drawn from the general population of Utah. Each subject's diet was described by major nutrient groups and total energy based on the nutritional content of foods reported. Cases reported higher daily food intake 5 years preceding diagnosis than controls [men, rate ratio (RR) = 2.5; women, RR = 3.6], as measured by total energy content of the diet. Higher risk of colon cancer with increasing energy intake was independent of stage of disease at diagnosis and obesity, as measured by body mass. Fat, protein, and carbohydrate intake all had elevated RRs but could not be assessed as risk factors independent of energy intake because of their strong correlations with total calories. Due to the higher energy intake of the cases, odds ratios for the daily intake of dietary fiber and vitamins A and C were also greater than 1. However, adjusting for caloric intake removed this effect, and dietary fiber showed a weak protective effect. Total energy intake must be evaluated before attempting to assign a causal role to any food or nutrient that may be postulated to play a role in colon cancer.

Toxic substance exposure and multiple myeloma: a case-control study.

By means of a population-based, multicenter case-control investigation, certain toxic substances were evaluated as risk factors for multiple myeloma. Interviews were completed on 698 subjects with newly diagnosed multiple myeloma, and 1,683 controls were selected from the same geographic areas as those of the cases. Respondents were asked if they had ever been "highly" exposed" to one or more of a list of toxic substances or to other substances not on the list. With the aid of a toxicologist, responses were then categorized into 20 exposure groups. Those who reported past exposure to pesticides had an estimated relative risk of 2.6 for multiple myeloma [95% confidence interval (CI) = 1.5-4.6]. Subjects exposed to a variety of compounds commonly used by painters had an estimated relative risk of 1.6 (95% CI = 1.1-2.4). An increased risk also was found for those who were exposed to sources of carbon monoxide (relative risk = 1.8, 95% CI = 1.0-3.2). Associations of borderline statistical significance were found for metals and organically high polymers (plastics and elastomers). No statistically significant associations were seen for exposure to fertilizers; dyes and inks; alkalies; acids; other caustic substances; chemical asphyxiants; aliphatic, chlorinated, or aromatic hydrocarbons; aldehydes and ketones; ethers; esters; oils; dusts; or asbestos.

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.

Infectious and noninfectious exposures in the etiology of light chain myeloma: a case-control study.

Sixty-nine subjects with light chain myeloma were interviewed in a multicenter case-control study, and their responses were compared to those of 1683 controls selected from the general population of the same geographic areas. The interview was directed at the subject's history of exposure to a variety of chemical and infectious agents. Persons with a history of a medical implant had 2.2 times the risk of other persons (95% confidence interval = 0.9-5.8), a relative risk that increased with increasing time that the implant had been present. Alkali exposure that was deemed by the subject to be unusually heavy was associated with a relative risk of light chain myeloma of 7.8 (95% confidence interval = 1.7-35.3), while similarly defined exposure to carbon monoxide increased the risk by 6.1 times (95% confidence interval = 2.0-18.2). These findings differ from those obtained in our study of the more common forms of multiple myeloma and, while the differences are plausibly due only to chance given the large number of exposures investigated, they could be an indication that light chain myeloma is an etiologically distinct entity.

Colon cancer in a low-risk population.

Data are presented on colon mortality in Utah. For the years 1950 to 1969, the state population had 34% fewer deaths from colon cancer than the average United States population. Colon cancer incidence was also studied for the years 1966 to 1970, both for the state and for a large subgroup (Mormons) who abstain from tobacco and alcohol for religious reasons; the colon cancer incidence of Mormons was 37% below the United States average, and that of non-Mormons was 18% below the United States average. A preliminary dietary survey found little difference in meat, fat, and fiber consumption between the population of Utah and that of the United States as a whole.

Dietary intake as a risk factor for cancer of the exocrine pancreas.

Data from 149 cases with pancreatic cancer and 363 control subjects in Utah were obtained from proxy respondents to assess the associations between dietary intake and the development of pancreatic cancer. After adjusting for cigarette smoking status and alcohol and coffee consumption, we observed that foods containing large amounts of fat from all sources increased risk of pancreatic cancer in men [odds ratio (OR), 3.41; 95% CI, 1.59-7.29]. Further division of fat by source of food showed that high intake of bacon and sausages (OR for upper tertile, 2.77; 95% CI, 1.34-5.72) as well as large intakes of fatty foods other than meat or dairy products (OR for upper tertile, 2.80; 95% CI, 1.33-5.89) increased risk of pancreatic cancer in men; high levels of intake of red meat, chicken, fish, and dairy foods did not increase risk of pancreatic cancer in either men or women. In women, fat from nonmeat and nondairy sources also increased risk of pancreatic cancer (OR for upper tertile, 3.44; 95% CI, 1.35-8.78). Although no protective effect was observed among men who consumed large amounts of fruits, vegetables, or high fiber foods, we did observe a protective effect in women for these foods (OR for upper tertile of fruit consumption, 0.37; 95% CI, 0.18-0.81; OR for upper tertile of vegetable consumption, 0.32; 95% CI, 0.13-0.74; and OR for upper tertile of fiber consumption, 0.28; 95% CI, 0.12-0.67). Findings from this study support the hypothesis that diets high in fat contribute to the development of pancreatic cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Nasopharyngeal cancer in a low-risk population: defining risk factors by histological type.

Nasopharyngeal cancer (NPC) is a major public health problem in parts of Southeast Asia and North Africa, but is rare among whites and blacks. Although infection with the EBV and genetic susceptibility appear to play large roles in high-incidence populations, migrant studies suggest that environmental factors may also be important. Aside from the high risks associated with ingestion of salted fish, surprisingly few other risk factors have been established from studies in endemic areas. We studied a low-incidence population to determine whether tobacco use, alcohol consumption, and certain medical conditions and treatments are related to NPC and to examine variations in risk by histology. We reasoned that new relationships might be best identified in the absence of strong causal pathways, such as intake of preserved foods and genetic susceptibility. A population-based case-control study was conducted from 1987 to 1993 at five cancer registries in the United States: western Washington, metropolitan Detroit, Connecticut, Iowa, and Utah. Controls were identified by random digit dialing and frequency matched to the gender and age distribution of cases at each registry. Telephone interviews were completed by 231 cases and 246 controls. We observed a strong dose-response relationship between cigarette smoking and risk of differentiated squamous cell carcinoma (test for trend, P < .001). The highest risk [odds ratio (OR), 6.5; 95% confidence interval (CI), 2.0-21.3] occurred among current smokers with a history of more than 60 pack-years. In contrast, there was no evidence that undifferentiated or nonkeratinizing carcinomas were associated with cigarette smoking. Similarly, a significant increase in risk was observed for the heaviest alcohol consumers (21 or more drinks/week) only for differentiated squamous cell carcinomas (OR, 2.9; 95% CI, 1.2-6.9). The associations with cigarettes and alcohol appeared to be stronger among persons 50 years or older. There was a suggestion that diagnosis with infectious mononucleosis (a marker of late infection with EBV) is linked with decreased NPC risk (OR, 0.4; 95% CI, 0.1-1.1). This report indicates that over two-thirds of differentiated squamous cell NPC cases arising in older persons in the United States can be accounted for by cigarettes and alcohol, but leaves unexplained cases arising in the young and carcinomas of undifferentiated or nonkeratinizing histology. Future studies of NPC need to take into account histology and age in evaluating these and other environmental and genetic risk factors.

Natural history of thyroid abnormalities: prevalence, incidence, and regression of thyroid diseases in adolescents and young adults.

PURPOSE: This study reports the prevalence, incidence, and regression of thyroid abnormalities in a population observed from adolescence to adulthood. PATIENTS AND METHODS: Examinations for thyroid abnormalities were performed in 4,819 school-age children, ages 11 to 18, in 1965 to 1968; two thirds of this original cohort (3,121) were re-examined 20 years later (1985 to 1986). Each subject with a thyroid abnormality detected by physical examination was studied by means of a series of re-examinations, and tests of thyroid function, imaging, and biopsy to determine the exact nature of the thyroid abnormality. RESULTS: In the initial examinations (1965 to 1968), 185 thyroid abnormalities were found (3.7%). Diffuse hypertrophy with normal function (adolescent goiter) was the most common abnormality (19.3/1,000); 12.7/1,000 had chronic lymphocytic thyroiditis, and 4.6/1,000 had thyroid nodules, including two papillary carcinomas. Hyperthyroidism or hypothyroidism was found in 1.9/1,000. In the follow-up examinations in 1985 to 1986, 298 subjects had thyroid abnormalities (10.5%), of whom 81 (28.7/1,000) had simple goiters, 145 (51.3/1,000) had chronic thyroiditis, 45 (15.9/1,000) had hypothyroidism, 11 (3.9/1,000) had hyperthyroidism, and 66 (23.2/1,000) had nodules, which included 10 carcinomas. Of the 92 subjects with simple or adolescent goiter in 1965 to 1968, 60% were normal by 1985 to 1986, 20% were unchanged, and a few had developed thyroiditis (10%) or colloid goiters (3.0%). Of 61 subjects with thyroiditis, 27% had become normal, 33% remained unchanged, and 33% had become hypothyroid. Of the 22 subjects with thyroid nodules, two had complete disappearance of the nodules, and three had nodules considered to be variants of normal. The others exhibited a variety of nodular pathologic conditions. CONCLUSIONS: The natural history of thyroid disorders, including simple goiter, chronic thyroiditis, hyperthyroidism, hypothyroidism, and nodular diseases of the thyroid, indicates they are dynamic and changeable in form, function, appearance, and disappearance.

Uncertainty in the diagnosis of histologically confirmed pancreatic cancer cases.

In doing a case-control study of cancer of the exocrine pancreas, a set of criteria was developed to classify cancer of the exocrine pancreas by pathological and diagnostic data as to the probability that the tumor arose in the pancreas. We applied these criteria to the records of 125 consecutive patients between the ages of 40-79 years who were identified as having adenocarcinomas of the exocrine pancreas from a population-based cancer registry. We found that histological confirmation by a cancer registry does not guarantee the site of origin is the pancreas. Of the histologically confirmed cases meeting our study criteria, 28.7% may not have arisen in the pancreas. Forty-seven per cent of non-histologically confirmed cases, which most studies exclude, were almost certainly of pancreatic origin based on computerized tomogram (CT) scan and/or surgical palpation and subsequent clinical course. These figures may underestimate the full extent of diagnostic misclassification, especially in older age groups. We conclude that epidemiological studies of cancer of the exocrine pancreas need more uniform criteria for defining cases, and these criteria should take into account uncertainty as to site of origin. Sufficient detail of our scheme is presented so it can be applied in other studies.

Diet and survival of patients with colon cancer in Utah: is there an association?

The extent to which diet influenced colon cancer survival was examined in 411 colon cancer cases identified in Utah between 1976 and 1981 using data from two population based case-control studies. After adjustment by proportional hazards regression models for the effects of tumour stage, age, sex, and religion, the hazard rate ratios (HRR) comparing highest to lowest quartile of intake for total calories, fat and protein were 0.60, 0.81 and 0.66 respectively, with the effect of calories being greatest for short-term survival (less than or equal to 24 months), HRR = 0.49. By contrast, the highest quartile of dietary fibre intake was associated with decreased survival (HRR = 1.53) when compared with the lowest quartile. More extensive studies are needed to verify these findings and to identify mechanisms underlying these associations.

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.

Mortality among New Zealand Maori and non-Maori Mormons.

Mortality rates for New Zealand Maori and non-Maori Mormons in the period 1970-77 have been compared with those for non-Mormons in the census year 1976 to measure the impact of the Mormon lifestyle on differences in mortality between Maoris and non-Maoris. Maori mortality was much lower among Mormons than non-Mormons suggesting that environmental, rather than genetic factors, play a predominant role in the relatively high overall Maori mortality. However the prevalence of smoking among Maori Mormons was not much lower than for the general Maori population. Reasons for the relative mortality advantage of Maori Mormons were therefore not clear, although attitudes to health and health services utilization, and the influence of strong social support networks, might be involved. Paradoxically, non-Maori Mormon mortality rates were similar to those for non-Mormons. A combination of factors appeared to contribute to this finding including the fact that 26% of non-Maori Mormons were of Pacific Island origin, non-Maori Mormons were of lower socioeconomic status than other non-Maoris, and part Maoris probably constitute a high, but unknown, proportion of Mormons classified as non-Maoris.

Maternal exposure to N-nitrosatable drugs as a risk factor for childhood brain tumours.

BACKGROUND: Animal models suggest that compounds containing a nitrosyl group (N-nitroso compounds (NNO)) can act as potent transplacental carcinogens. Many common drug formulations have the potential to undergo nitrosation in vivo. The association between maternal use of nitrosatable drugs during pregnancy and development of brain tumours in the offspring was examined in a SEER-based case-control study. METHODS: Maternal exposure to nitrosatable drugs during pregnancy was compared among 361 childhood brain tumour cases and 1083 matched controls recruited through random-digit dialing. RESULTS: There was no increase in risk observed for childhood brain tumours overall (OR = 1.15; 95% CI: 0.69-1.94) or for astrocytomas individually (OR = 1.16; 95% CI: 0.50-2.69). A slight elevation in risk was noted for medulloblastomas (OR = 1.47; 95% CI: 0.28-7.62) and 'other' tumours (OR = 1.27; 95% CI: 0.56-2.86), however, both estimates were based on small numbers. CONCLUSIONS: Our findings suggest that no increased risk of childhood brain tumours was associated with maternal exposure to nitrosatable drugs. The study results should be viewed with caution given the imprecision of the point estimates as well as the lack of data on specific timing and dosage of exposure and degree of nitrosatability of drugs taken.