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Biomedical subjects

L R Wilkens

Publications and source records attributed to L R Wilkens.

At least 19 recordsLinked to original sources

Comparison of long-term dietary recall between cancer cases and noncases.

A quantitative history of current dietary intake based on 83 food items was administered by interview to a representative sample of 4,809 subjects in Hawaii in 1977-1979. In 1983-1987, this history was readministered to the 131 original respondents who had subsequently developed cancer, as well as 413 randomly selected subjects who remained cancer free. A surrogate was interviewed when the original subject was unavailable. The repeat interview elicited information about diet at the time of the original interview. The authors found that recall values for macronutrients were consistently higher than original levels for both cases and noncases, which may be due in part to a modification in the administration of the repeat questionnaire. Although there were no marked differences overall between cases and noncases in the ability to recall past diet, differences between the two groups were seen in certain subsets of the sample. In the subgroup with the longest recall interval (8-10 years), cases were not able to recall their diets as well as noncases. Also, the difference between original and recall values was larger for cases with colorectal cancer and all cases diagnosed with distant stage disease, compared with noncases. This was not true for cases of breast and prostate cancer and those with localized or regional disease. The following variables were found to have no significant effect on recall for cases or noncases: sex, age, education, and type of respondent (surrogate or subject). Of the five major ethnic groups included in the study, Japanese had the best recall of their past diets, while respondents reporting a diet change between the interviews had poorer recall than did those who reported no change. These results suggest that differential misclassification in dietary case-control studies may pose a significant problem in certain instances, but that these studies can yield meaningful results with certain constraints on the study population.

Aged

Attributable risk of breast, prostate, and lung cancer in Hawaii due to saturated fat.

The dietary data from case-control studies of breast, prostate, and lung cancer in Hawaii revealed that saturated fat was a risk factor for these malignancies. The dietary intakes from the three studies were used to calculate the attributable risk (AR) due to saturated fat. For all ethnic groups combined, the ARs for the highest quartiles of intake were 14.9 percent for female breast cancer, 13.0 percent for prostate cancer, and 23.1 percent for male lung cancer. Our results suggested that a reduction of saturated fat to the lowest quartiles of intake could result in a 10 to 20 percent decrease in risk for these three cancers in Hawaii. We also examined the ethnic-specific risks associated with saturated fat consumption among the Japanese and the Caucasians in the three studies. The ARs for the highest quartiles of intake were notably higher among the Caucasians than the Japanese, primarily due to the difference in their dietary patterns. Although the calculated AR due to saturated fat was higher among the Caucasians than among the Japanese, all persons in the population would derive considerable benefit by reducing their intake of this nutrient.

Adult

Obesity in youth and middle age and risk of colorectal cancer in men.

To investigate an association between colon cancer and obesity during early adulthood--a potentially important period in the etiology of this disease--the authors assembled, by computer linkage, a population-based historical cohort of 52,539 men born between 1913 and 1927 residing in Hawaii (USA), for whom weight and height had been recorded in 1942-43 and 1972. Linkage of this cohort to the Hawaii Tumor Registry resulted in the identification of 737 incident cases of colorectal cancer for 1972-86. An average of 3.8 cancer-free controls were matched to each case on month and year of birth and ethnicity of the parents. A case-control analysis in each anatomic subsite of the large bowel revealed that both early and middle-age body mass increased the risk of sigmoid cancer in men in a dose-dependent fashion. The odds ratios (OR) for sigmoid cancer for the highest compared with the lowest tertiles of Quetelet index were: 2.1 (95 percent confidence interval [CI] = 1.4-3.2) and 1.7 (CI = 1.1-2.5), at ages 15-29 and in prediagnostic years, respectively. These associations were additive and independent of socioeconomic status. Men who were above the median Quetelet index in 1942 and 1972 had an OR of 2.7 (CI = 1.8-4.0), compared with those who were below the median in both periods. This study provides further evidence for an association of obesity with colon cancer in men and suggests that this association is limited to the sigmoid colon and may be related to both early and late events of colon carcinogenesis.

Adolescent

The logistic modeling of interobserver agreement.

An approach to the logistic modeling of interobserver agreement is described that allows for the estimation of a commonly employed measure of agreement. The dependent variable is defined to be 1 if the two raters agree, and 0 otherwise. Covariates may be included in the regression equation in order to obtain adjusted or subgroup-specific estimates of percent agreement. As an empirical example, logistic models were fitted to data from a validation study of the agreement between interview information and physician records on the history of post-menopausal estrogen use, from a case-control study of breast cancer conducted on Oahu, Hawaii. Variables found to be related to agreement in previous univariate analyses were examined as covariates in the logistic model. The directly calculated estimates of percent agreement agreed well with the modeled estimates derived from the regression coefficients. Thus, the logistic model may provide a useful alternative to existing methods for the description of interobserver agreement.

Breast Neoplasms

Dietary factors in lung cancer prognosis.

A hypothesis-generating analysis of the role of diet on survival was conducted among a sample of 463 men and 212 women with histologically-confirmed lung cancer. Interview information was obtained from two population-based case-control studies of lung cancer conducted on the Island of Oahu, Hawaii, between 1979 and 1985. The interview consisted of a quantitative dietary history to assess the usual intake of foods 1 year prior to diagnosis, a complete tobacco history, and other demographic and lifestyle information. Records from the Hawaii Tumor Registry were reviewed for data on stage, histology, and follow-up status of these patients. A food group analysis showed a significant reduction in the risk of death with increasing consumption of all vegetables combined among women (P for trend = 0.03), but not among men. The covariate-adjusted median survival times for women from the highest to the lowest quartiles of vegetable intake were 33, 21, 15, and 18 months, respectively. The results also suggested an association of fruit intake and survival among women (P for trend = 0.02), although a similar effect was not found among men. Increased consumption of certain foods, such as tomatoes and oranges among men, and broccoli and, perhaps, tomatoes among women, appeared to improve survival. This exploratory analysis provides mixed indications that certain components of vegetables and fruits may prolong survival in lung cancer patients.

Adult

The association of body size, reproductive factors and thyroid cancer.

A population-based case-control study of the association of diet and other factors and thyroid cancer was conducted between 1980 and 1987 on Oahu, Hawaii. Study participants included 51 men and 140 women with thyroid cancer, and 113 male and 328 female controls matched on age (+/- 5 years) and sex. A significant, positive monotonic dose-response relation of weight in late adulthood (5 years prior to interview) and the risk for thyroid cancer was found for men and women. A greater than five-fold increase in the risk for thyroid cancer among men, and more than a two-fold increase in risk among women, was found for subjects in the highest compared with the lowest quartile of weight in late adulthood. Height was significantly related to the risk for thyroid cancer among men, but not women. Among men, there was a significant dose-response relation of weight in early adulthood (20-29 years of age) and the odds ratios (ORs) for thyroid cancer, although the trend was not significant after adjustment for height. Among women, there was also a positive relation of adult weight gain and thyroid cancer, with an OR of 2.6 associated with more than a 14% increase in weight. The effects of relative weight and weight gain on thyroid cancer risk were stronger in post-menopausal women than in premenopausal women. There was a significant positive interaction between fertility drug use and early adult weight and the risk for thyroid cancer in women. Odds ratios were also significantly elevated for women above the median weight in early adulthood who experienced a miscarriage or stillbirth at first pregnancy. In summary, these data show an association of weight, particularly in late adulthood, and the risk for thyroid cancer in men and women, and further suggest a positive interaction between weight in young adulthood and fertility drug use on thyroid carcinogenesis in women.

Adult

High-fat foods and the risk of lung cancer.

We conducted a population-based case-control study of the association of dietary cholesterol and fat with lung cancer between 1983 and 1985 on Oahu, Hawaii. The study population included 226 men and 100 women with lung cancer, and 597 male and 268 female community controls matched for age (+/- 5 years) and sex. There was a positive dose-response relation between the consumption of processed meats (luncheon meats, bacon, sausage), dairy foods (whole milk, regular ice cream), eggs, and particular desserts (fruit pies, custard/cream pies) and the risk of lung cancer in men. We also found a positive trend in the risk of lung cancer in women with increasing intake of some processed meats (bacon, Spam) and desserts (cakes, custard/cream pies). The dose-response relation tended to be stronger among men who were heavy smokers and who were diagnosed with squamous cell cancer of the lung. A positive trend in risk was found for nitrite intake in men and dimethylnitrosamine intake in men and women. These data indicate that smokers with a high intake of foods rich in fat and animal protein or who have a preference for cured meats are at increased risk of lung cancer.

Adult

Use of breath hydrogen and methane as markers of colonic fermentation in epidemiologic studies: circadian patterns of excretion.

Fermentation in the large bowel has been postulated to play a protective role against colon cancer. Hydrogen and methane are end products of this fermentation process and are absorbed into the bloodstream and excreted via expired air in the breath. Breath levels of hydrogen and, to a lesser extent, methane correlate strongly with colonic fermentation and may serve as useful biomarkers for this process. In a preliminary study to assess the usefulness of these two markers in epidemiologic studies, we followed the hourly excretion of the two gases in expired alveolar air for 48 hr in 20 healthy subjects, using a Quintron gas chromatograph equipped with a solid-state detector specific for reducing gases. All subjects excreted hydrogen, but 71% did not excrete methane. Possible atmospheric contamination of the samples was corrected for on the basis of breath carbon dioxide levels. A clear circadian pattern of excretion was observed for breath hydrogen, with a decrease during the early morning followed by a progressive increase during the rest of the day. Methane excretion was constant throughout the day. This study shows that four samples collected at convenient times (0600, 1300, 1800, and 2200 hr) are optimal to characterize individuals by their breath excretions of hydrogen and methane during a 24-hr period.

Biomarkers

Early-age body size, adult weight gain and endometrial cancer risk.

To further characterize the association of obesity and endometrial cancer, in particular with regard to the role of early-age obesity and adult weight gain, the authors assembled by computer linkage a population-based historical cohort of 30,266 women born between 1913 and 1932, for whom weight and height had been recorded in 1942-43 and 1972. Linkage of this cohort to the Hawaii Tumor Registry resulted in the identification of 214 (mainly post-menopausal) incident cases of endometrial cancer for 1972-1986. An average of 37 cancer-free controls were matched to each case on month and year of birth and ethnicity. A case-control analysis, conducted in each 5-year birth cohort, revealed no clear association of endometrial cancer with weight, height or body mass at ages 10 to 29 years. However, positive associations with adult body weight and gain in body mass since 1942 were observed for women diagnosed at age 60 or older. This association with obesity was strongest in women whose body mass was below the median in 1942 and equal to or above the median in 1972. No association with body size was detected in women diagnosed before age 60. Parity, age at first birth and socioeconomic indicators for 1942 and 1972 did not confound the analysis. These findings suggest that obesity affects the late stages of endometrial carcinogenesis, and the possibility that one or more determinants of weight gain may be independently associated with endometrial cancer risk.

Aged

Validation of a quantitative diet history method in Hawaii.

The validity of a quantitative diet history method was evaluated among 262 men and women from the five major ethnic groups of Hawaii (Japanese, Caucasian, Chinese, Filipino, and Hawaiian) in 1984-1987. The reference data included four 1-week food records obtained at approximately 3-month intervals. The diet history was administered 6 months after the fourth week of food records and included 47 foods that were major sources of protein, fat, cholesterol, vitamins A and C, and beta-carotene. Photographs showing three portion sizes were utilized for quantifying intakes in the food records and the diet history. Generally, among all ethnic-sex groups, intakes from the diet history were greater than those from the record sets, particularly for the vitamins. Agreement was measured by the intraclass correlation coefficient (rl) and the weighted kappa statistic (kappa w), and consistency was measured by Spearman's rank correlation (rho). For the total group, the rl's ranged from 0.48 for vitamin A to 0.61 for cholesterol. The kappa w's were generally lower than the rl's, whereas the rho's were higher, ranging from 0.52 for vitamin C to 0.64 for cholesterol. Agreement among the ethnic-sex groups varied, with the Chinese females and the Japanese males having the higher rl's, and the Hawaiian males and females having the lowest values. The results provide evidence that the quantitative diet history gives reasonably accurate estimates of the usual dietary intakes among the major ethnic groups of Hawaii.

Aged

Vegetable and fruit consumption in relation to prostate cancer risk in Hawaii: a reevaluation of the effect of dietary beta-carotene.

This is a further analysis of a case-control study of 452 prostate cancer cases and 899 population controls that was conducted in 1970-1983 among the multiethnic population of Hawaii. Because a previous analysis had shown a positive association with intake of beta-carotene, a nutrient presently being tested for chemoprevention, the authors reexamined the data for consistency among the main food sources of beta-carotene. Vegetables and fruits containing other phytochemicals suspected to be cancer inhibitors were also examined. With the exception of papaya, which was positively associated with risk among men aged 70 years and older, consumption of other yellow-orange fruits and vegetables, tomatoes, dark green vegetables, and cruciferous vegetables was not associated with prostate cancer risk. These results suggest that: 1) the positive association with beta-carotene intake among older men that the authors previously reported was essentially due to the greater papaya consumption of cases compared with controls; and 2) intake of beta-carotene, lycopene, lutein, indoles, phenols, or other phytochemicals is not associated with prostate cancer risk.

Aged

Dietary patterns of female nonsmokers with and without exposure to environmental tobacco smoke.

The relationship of passive smoking to diet was examined in 82 female nonsmokers who provided a quantitative diet history in 1986. Exposure to environmental tobacco smoke (ETS) was assessed by urinary cotinine measurement. Mean values for each dietary variable, adjusted for age, ethnicity, education, and last week's ethanol intake, were compared among unexposed women and women with low or high ETS exposure. Linear relationships with amount of ETS exposure were also sought. Intakes of beta-carotene and cholesterol were found to be inversely related to ETS exposure. Since these nutrients have been associated with lung cancer risk, they are potential confounders of the passive-smoking/lung-cancer relationship. Although we estimate the confounding effect of these dietary factors to be modest, they should be measured carefully in future studies of this relationship.

Age Factors

Relation of body size to prognosis in lung cancer patients.

A survival analysis was conducted among a sample of 463 men and 212 women with histologically confirmed lung cancer. Interview information from these patients was obtained from two population-based case-control studies of lung cancer conducted on the island of Oahu, Hawaii, between 1979 and 1985. The interview consisted of a complete tobacco history, and other demographic and lifestyle information. Records from the Hawaii Tumor Registry were reviewed for data on stage, histology, and follow-up status of these patients. Height, weight in early adulthood, and weight five years prior to diagnosis were inversely related to survival among women, after adjustment for age at diagnosis, stage, histology, ethnicity, and smoking status. No relationship of these variables to survival was found among men. The association of body size and the relative risk of death among women was strongest for patients with small cell cancer, although the association was not restricted to this cell type. The covariate-adjusted median survival times for female never-smokers below the 50th percentile of weight in early- and late-adulthood was at least twice as long as that for any other group (46 cf 17-23 months). There was no evidence for an interaction between weight in early adulthood and weight five years prior to diagnosis on the risk of death among women. Stage at diagnosis and education did not modify the association of the anthropometric variables and survival. These data suggest that weight and height may be associated with prognosis for women with lung cancer.

Adenocarcinoma

Smoking history and survival among lung cancer patients.

Two population-based case-control studies of lung cancer were conducted on the Island of Oahu, Hawaii, between 1979 and 1985. Interview information concerning smoking habits and other characteristics was obtained from a total of 463 men and 212 women with histologically confirmed lung cancer. Records from the Hawaii Tumor Registry were reviewed for information on the stage, histology, and follow-up status of these patients. Cigarette smoking was found to be positively related to the age-adjusted risk of death among women (relative risk (RR) = 1.6; 95 percent confidence interval (CI) = 1.0-2.4), but not among men (RR = 0.8; 95 percent CI = 0.5-1.2). Among women, the age-adjusted median survival time for never smokers was 33 months (n = 53) compared with a median survival of 18 months (n = 159) for smokers. Both past and current female smokers were at greater risk of death than never-smokers, and there was a significant trend in the risk of death by the number of cigarettes smoked per day (P = 0.04), and the age at which the subjects started smoking (P = 0.01). The effects of tumor stage and histology upon the association between tobacco smoking and survival were also explored.

Adenocarcinoma

An epidemiologic study of thyroid cancer in Hawaii.

A population-based case-control interview study was designed to test the hypothesis that dietary iodine or the consumption of goitrogenic vegetables increases the risk of thyroid cancer. A total of 191 histologically confirmed cases (64 percent female) and 441 matched controls from five ethnic groups in Hawaii were available for analysis. Among women, intake of seafood (especially shellfish), harm ha (a fermented fish sauce), and dietary iodine were associated with an increased risk of cancer, whereas consumption of goitrogenic (primarily cruciferous) vegetables was associated with a decreased risk. Non-dietary risk factors included miscarriage (especially at first pregnancy), use of fertility drugs, family history of thyroid disease, obesity, and work as a farm laborer. The odds ratio for the combined effect of a high iodine intake and a first-pregnancy miscarriage was 4.8 (95 percent confidence interval [CI] = 1.2-19.2); and for high iodine intake and use of fertility drugs 7.3 (95 percent CI = 1.5-34.5). Among men, positive associations were found for obesity, work as a farm laborer, and a past history of benign thyroid disease. Although this study identified several dietary and non-dietary risk factors for thyroid cancer, it could not fully explain the exceptionally high incidence rates among Filipino women in Hawaii.

Adult

Vasectomy and non-fatal acute myocardial infarction: a hospital-based case-control study in Seoul, Korea.

One hundred and sixty-three Korean men aged 35-64 who were admitted to a university-affiliated hospital diagnosed for the first time with acute myocardial infarction (AMI) were compared with 326 matched non-AMI patients hospitalized with a diagnosis considered unrelated to vasectomy. When other potentially confounding variables were controlled for, vasectomized men were found to be 2.6 times (adjusted odds ratio) more likely to have had an AMI as compared to the non-vasectomized men (95% CL: 1.1, 6.1). The adjusted odds ratio of AMI for subjects having had a vasectomy less than or equal to 9 years ago was the same as those who had a vasectomy greater than or equal to 15 years (OR = 2.5), although those who had had a vasectomy 10-14 years ago were associated with a higher odds ratio of 4.2. Among those subjects with vasectomies who were also cigarette-smokers and/or hypertensive, the risk of development of AMI increased multiplicatively compared with those with none of these conditions. We suspect that our finding of this positive association may be spurious due to possible bias introduced during selection of controls and during the process of data collection. Cancer patients may have been less likely to undergo an elective surgical procedure such as vasectomy prior to the admission. When multivariate analysis included only controls who were non-cancer patients (N = 241 controls), the adjusted odds ratio between vasectomy and hospitalization for AMI was reduced to 2.1, (95% CL: 0.8, 5.7), which is no longer statistically significant. When the analysis was further limited to only those control subjects admitted with a diagnosis of digestive system problems, the adjusted odds ratio was reduced to close to unity (1.1). Recognizing the importance of the study topic and the fact that all previous epidemiological studies showed no association between vasectomy and cardiovascular diseases, we urge further studies. A historical cohort study in the Korean setting is considered feasible and is recommended.

Adult

Vasectomy and cardiovascular deaths in Korean men: a community-based case-control study.

This community-based case-control study was carried out in four cities in South Korea to examine whether vasectomy is associated with a long-term increased risk of cardiovascular death in Korean men. Our results coincide with those from epidemiological studies conducted in Western countries as well as the one study conducted in China and do not support the vasectomy--atherosclerosis hypothesis originating from animal research.

Adult

Agreement between interview information and physician records on history of menopausal estrogen use.

A case-control study of the association between replacement estrogen use and breast cancer risk was conducted between 1975 and 1980 on Oahu, Hawaii. Data from this study were used to compare menopausal estrogen histories obtained through a personal interview with information from the subject's physician(s) or clinical records. The sample included 344 breast cancer cases, 344 hospital controls, and 344 neighborhood controls. Study participants included Japanese and white women aged 45-74 years who were residents of Oahu. Interviewers asked participants whether they had ever used replacement or menopausal estrogens for 1 month or longer. The month and year of initial use and the duration of use for each preparation were recorded for the users. Questions were also asked about a number of other medications. Information on estrogen use from the users and nonusers was then verified by the physician(s) or clinic(s) named by the study subject. The results showed moderate to substantial agreement between users and physicians on ever/never use of estrogens (kappa = 0.74), duration of estrogen use (intraclass correlation coefficient (rI) = 0.54), and age at initial use of estrogens (rI = 0.57). There was no differential misclassification by the case-control status of the subject. Agreement tended to be better for Japanese subjects, younger subjects, nonsmokers, and those of higher socioeconomic status, as measured by two indicators, college education and home ownership. Agreement was also negatively influenced by the duration of estrogen use and length of recall. These results suggest that women can recall estrogen use with a high degree of accuracy and support the use of a personal interview for obtaining information on replacement estrogens in case-control studies.

Age Factors