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R A Goldbohm

Publications and source records attributed to R A Goldbohm.

87 records · Page 5Linked to original sources
PubMed1994

Socioeconomic status and breast cancer incidence: a prospective cohort study.

BACKGROUND: To gain more insight into the relation between socioeconomic status (SES) and breast cancer risk, we have studied that association, before and after adjustment for traditional risk factors for breast cancer, in a prospective cohort study on lifestyle and cancer that started in 1986 in the Netherlands amongst 62,573 women aged 55-69 years. METHODS: At baseline, data on SES, diet, reproductive factors and other covariates were collected by means of a self-administered questionnaire. For data-analysis a case-cohort approach was used. After 3.3 years of follow-up, 471 incident cases were available for analysis. RESULTS: We did not find a higher age-adjusted risk of breast cancer for those with a higher level of education (RR highest/lowest level of education = 0.94, 95% confidence interval [CI]: 0.63-1.39, trend-P = 0.15). Although upper white-collar workers had a slightly higher breast cancer risk than blue-collar workers (RR = 1.16, 95% CI: 0.83-1.62, trend-P = 0.34), women with a profession of higher social standing did not have a higher risk (RR highest/lowest social standing = 0.73, 95% CI: 0.24-2.23, trend-P = 0.86). Additional adjustment for traditional risk factors did not alter the association between SES and breast cancer risk. CONCLUSIONS: We did not find an association between SES and breast cancer risk. This is not in agreement with studies conducted in other European countries and North America.

Aged↗
PubMed1994

Validation of a dietary questionnaire used in a large-scale prospective cohort study on diet and cancer.

OBJECTIVE: The study was conducted to assess the validity of a self-administered 150-item food frequency questionnaire (FFQ), used in a cohort study on diet and cancer (120,852 men and women, aged 55-69). DESIGN & SUBJECTS: The study was carried out in a subgroup of the cohort (59 men and 50 women) 2 years after the baseline FFQ was completed. A dietary record, kept over three 3-day periods, 4-5 months apart, served as reference method. To evaluate the representativeness of the study population for the entire cohort, a comparison was made with the baseline questionnaire of a random sample of the cohort. RESULTS: Pearson correlation coefficients between nutrient intakes assessed by the record and the FFQ that was completed afterwards ranged from 0.40 (95% CI: 0.22-0.54) for vitamin B1 to 0.86 (95% CI: 0.80-0.90) for alcohol intake, with correlations for most nutrients between 0.6 and 0.8. Adjustment for energy intake and sex did not materially affect these correlations, except the correlation for fat intake, which changed from 0.72 to 0.52. Correlation coefficients were only slightly modified when the results were extrapolated to the cohort at large. Correction of correlation coefficients for attenuation by day-to-day variance in the record data improved them by 0.07 on average. CONCLUSIONS: It is concluded that the FFQ is able to rank subjects according to intake of food groups and nutrients. Despite a better performance of validation study participants, this conclusion also applies to the cohort at large.

Aged↗
PubMed1994

Agreement between interview data and a self-administered questionnaire on dietary supplement use.

OBJECTIVE: To study the relative validity of an open-ended question on the consumption of dietary supplements in the preceding five-year period, incorporated in a self-administered questionnaire used in the NLCS, The Netherlands Cohort Study on diet and cancer (120,852 men and women aged 55-69 years). DESIGN: Questionnaire data were compared with reference information from three personal interviews carried out within a period of 10 months. SETTING AND SUBJECTS: A randomly selected subgroup (59 men and 50 women) of the cohort living in 12 municipalities in the eastern and western regions of The Netherlands. RESULTS AND CONCLUSIONS: The overall sensitivity of the questionnaire concerning the use of any dietary supplement was 65.9%, the specificity was 98.5%; kappa as measure of agreement was estimated at 0.69. A high percentage recall was observed among women, users of at least three types of dietary supplements, long-term supplement users and those in the oldest age group. Recall of intake of specific supplements ranged from 77.8% for garlic preparations to 11.8% for 'other' supplements. Estimates of consumption of specific supplements (garlic and vitamin preparations) may provide enough precision to correctly classify individuals as users or non-users of those supplements.

Aged↗
PubMed1993

A prospective cohort study on selenium status and the risk of lung cancer.

Selenium has been suggested to be anticarcinogenic and to play a role in the cellular defense against oxidative stress. The association between toenail selenium (a marker of long-term selenium status) and lung cancer was investigated in a cohort study of diet and cancer that started in 1986 among 120,852 Dutch men and women aged 55-69 years. After 3.3 years of follow-up, 550 incident cases of lung carcinoma were detected. Toenail selenium data were available for 370 lung cancer cases and 2459 members of a randomly selected subcohort. The rate ratio of lung cancer for subjects in the highest compared to the lowest quintile of toenail selenium, after controlling for age, gender, smoking, and education, was 0.50 (95% confidence interval, 0.30-0.81), with a significant inverse trend across quintiles (P = 0.006). The protective effect of selenium was concentrated in subjects with a relatively low dietary intake of beta-carotene or vitamin C. The rate ratio in the highest compared to the lowest quintile of selenium was 0.45 in the low beta-carotene group (95% confidence interval, 0.22-0.92; trend P = 0.028) and 0.36 in the low vitamin C group (95% confidence interval, 0.17-0.75; trend P < 0.001). The results of this study support an inverse association between selenium status and lung cancer and suggest a modification of the effect of selenium by the antioxidants beta-carotene and vitamin C.

Adenocarcinoma↗
PubMed1993

Cholecystectomy and colorectal cancer: evidence from a cohort study on diet and cancer.

The association between cholecystectomy and subsequent risk for colorectal carcinoma was investigated in a prospective cohort study on diet and cancer (n = 120,852), which is being conducted in the Netherlands from 1986 onwards among 120,852 men and women, aged 55 to 69. After a follow-up period of 3.3 years, 478 incident cases of colorectal cancer (258 men and 220 women) were identified in the cohort, 64 of whom reported at baseline to have undergone previous gall-bladder surgery (21 men and 43 women). After adjustment for age and familial history of large-bowel cancer, the relative rate (RR) for colorectal cancer in subjects who had undergone cholecystectomy compared with those who had not was 1.81 in men (p = 0.02) and 1.47 in women (p = 0.05). Additional adjustment for parity. Quetelet index, alcohol intake and other dietary variables resulted in a RR of 1.78 in men and 1.51 in women. In women, the highest RR was detected in the right colon (RR = 1.89), whereas in men, no site within the large bowel accounted specifically for the increased relative rate. In both men and women, the rate appeared to increase from approximately 6 years after cholecystectomy onward. According to the TNM stage of the disease, cholecystectomized patients were not detected at an earlier stage than the other patients. It is concluded that in this study the positive association between colorectal cancer and cholecystectomy cannot be explained by detection bias or ascertainment bias and is not confounded by risk factors for gallstone disease or dietary factors.

Aged↗
PubMed1993

A prospective cohort study on toenail selenium levels and risk of gastrointestinal cancer.

BACKGROUND: Various animal studies and ecologic studies suggest an inverse association between low dietary selenium intake and risk of various types of cancer. PURPOSE: The goal of this prospective cohort study was to investigate the association between toenail selenium levels and risks of stomach cancer and colorectal cancer. METHODS: Our cohort study on diet and cancer started in The Netherlands in 1986 with enrollment of 120,852 subjects aged 55-69 years. Of this number, 58,279 were men and 62,573 were women. Following the case-cohort approach for analysis of the data, we randomly selected from the cohort a subcohort of 3500 subjects (1688 men and 1812 women). After 3.3 years of follow-up, 155 incident cases of microscopically confirmed stomach cancer, 313 cases of colon cancer, and 166 cases of rectal cancer had been detected in the cohort. Toenail selenium data were available for 104 patients with stomach cancer, 234 with colon cancer, and 113 with rectal cancer and for 2459 subjects from the subcohort. RESULTS: In a multivariate analysis, the relative rates (RRs) of stomach cancer for subjects in increasing quintiles of toenail selenium level were 1.00, 0.44, 0.59, 0.84, and 0.64 (trend, P = .491). For men, there was some evidence for an inverse association between toenail selenium levels and stomach cancer: The RR for those in the highest compared with the lowest quintile of toenail selenium was 0.40 (95% confidence interval = 0.17-0.96), but the trend was not statistically significant (P = .136). For stomach cancer in women, there was no negative association with toenail selenium levels. Toenail selenium level was not associated with the risk of colon or rectal cancer. After exclusion of cases diagnosed in the 1st year of follow-up, the RRs of colon cancer for increasing quintiles of toenail selenium were 1.00, 1.27, 1.17, 0.75, and 1.07 (trend, P = .544); for rectal cancer, RR estimates were 1.00, 1.73, 0.83, 1.58, and 1.12 (trend, P = .890). CONCLUSIONS: These data support a suggestive but inconsistent inverse association between selenium levels and risk of stomach cancer. Our findings, like those of other studies, do not suggest an inverse association with risk of colorectal cancer.

Aged↗
PubMed1993

A prospective cohort study on dietary fat and the risk of postmenopausal breast cancer.

In 1986 a prospective cohort study on diet and cancer was started in the Netherlands among 62,573 women ages 55-69 years. Baseline information on diet and other risk factors was collected with a questionnaire. Cancer incidence was measured by record linkage with cancer registries and a pathology register. A case-cohort approach was used, in which the accumulated person time in the cohort was estimated by follow-up of a randomly selected subcohort (n = 1812). After 3.3 years of follow-up, 471 incident breast cancer cases were available for analysis. Questionnaire data for these cases and the 1716 female subcohort members without a history of cancer other than skin cancer were analyzed. In a multivariate analysis, controlling for traditional risk factors, the relative rates for breast cancer in increasing quintiles of energy-adjusted total fat intake were 1.00, 1.00, 1.34, 1.22, 1.08 (P-trend, 0.32). For saturated fat there was some evidence for a weak positive association when quintiles were used (relative rates in quintiles 1-5, 1.00, 1.22, 1.22, 1.38, 1.39; P-trend, 0.049). The 95% confidence interval (CI) for the top quintile was 0.94-2.06, however; and when saturated fat was used as a continuous variable, the effect was no longer significant (P = 0.20). Relative rate estimates for the highest versus lowest quintiles of monounsaturated fat, polyunsaturated fat, and cholesterol intake were 0.75 (95% CI, 0.50-1.12), 0.95 (95% CI, 0.64-1.40) and 1.09 (95% CI, 0.74-1.61), respectively, with no evidence for significant trends. This prospective study does not support a major role of dietary fat in the etiology of postmenopausal breast cancer.

Aged↗
PubMed1993

Garlic and its significance for the prevention of cancer in humans: a critical view.

Recently published results of epidemiologic case-control studies in China and Italy on gastric carcinoma in relation to diet suggest that consuming garlic may reduce the risk of gastric cancer. Chemical constituents of garlic have been tested for their inhibiting effect on carcinogenesis, using in vitro and in vivo models. In most experiments inhibition of tumour growth was established using fresh garlic extract, garlic compounds or synthetically prepared analogs. In this review the strengths and weaknesses of the experiments are discussed and the outcomes are evaluated to assess the possible significance of garlic or garlic compounds for the prevention of cancer in humans. It is concluded that evidence from laboratory experiments and epidemiologic studies is presently not conclusive as to the preventive activity of garlic. However, the available evidence warrants further research into the possible role of garlic in the prevention of cancer in humans.

Antineoplastic Agents↗
PubMed1993

The use of vitamins, minerals and other dietary supplements in The Netherlands.

By means of a two-day dietary record, information on the use of dietary supplements has been collected in 1987 and 1988 in a representative sample of the Dutch population aged 1-75 years. More than 17 percent of the population had been using at least one dietary supplement on at least one day of the survey. Age, sex, season, social class, alternative food habits, smoking and diet were related to the use of supplements. In young persons mainly fluoride and vitamin AD preparations were used, while a shift towards other supplements, like garlic and brewer's yeast preparations, was observed as age progresses. The use of single vitamin C supplements was not related to the level of mean daily vitamin C intake by food consumption.

Adolescent↗
PubMed1991

Comparison of questionnaire information and pharmacy data on drug use.

Information on chronic drug use at any time in the past was collected with a self-administered questionnaire as part of a prospective cohort study on diet, other life-style factors and cancer among subjects aged 55-69 years. The validity of the questionnaire information on drug use was evaluated among 207 subjects by comparing it to pharmacy records of dispensed drugs. The comparison could be made for the 2.5-year period preceding the questionnaire administration. Since the study subjects did not mention prescription drugs that were not dispensed by their pharmacy, indicating no errors of commission, the analyses were focused on the estimation of sensitivity of drug recall and its correlates. Questionnaire recall of drug use amounted overall to 61.2% of drugs prescribed to the subjects for at least 6 months. Drug recall decreased with increasing age and with increasing number of prescribed chronic use of drugs per subject. No difference in recall was observed between men and women. Recall tended to improve with increasing duration of use and varied with type of drug. When only long-term drug use at the time of questionnaire administration was considered, overall recall of drug use was 68.8%.

Age Factors↗
PubMed1990

A large-scale prospective cohort study on diet and cancer in The Netherlands.

In 1986, a prospective cohort study on diet and cancer was started in The Netherlands. The cohort (n = 120, 852) of 55-69 year old men (48.2%) and women (51.8%) originates from 204 computerized municipal population registries. At baseline, participants completed a self-administered questionnaire on diet and potential confounding variables. In addition, about 67% of the participants provided toenail clippings. Cancer follow-up consists of record linkage to a pathology registry and to cancer registries. The initial interest is in stomach, colorectal, breast and lung tumors. A case-cohort approach is applied, in which detailed follow-up information of a random subcohort (n = 5000) provides an estimate of the person-time experience of the cohort. Exposure data of the subcohort will be combined with those of incident cases, yielding exposure-specific incidence rate ratios. The intraindividual variation in determinants is estimated by annually repeated measurements (n = 250) within the subcohort. The rationale, efficiency aspects and study characteristics are discussed.

Aged↗
PubMed1990

Development of a record linkage protocol for use in the Dutch Cancer Registry for Epidemiological Research.

A method has been developed to determine the optimal linkage key for record linkage between the cancer registry and a large-scale prospective cohort study in the Netherlands. The proposed linkage procedure is a two-stage process in which the initial computerized linkage using a particular linkage key is followed by visual inspection with additional information to separate the computer matches into true and false positives. In the determination of the optimal key, both informativeness and susceptibility to error of personal identifiers were taken into account. The performance of the various keys in the linkage was expressed in terms of sensitivity and predictive value of a reported computer match. The key, consisting of date of birth, first four characters of the family name and gender was the optimal choice, with a sensitivity of 98% and an initial predictive value of a computer match of 98%. When additional information on migration, place of birth and first initial was collected in the second stage, it was possible to eliminate the false positives from the reported computer matches without loss of true positives. Thus, the sensitivity remained constant whereas the secondary predictive value of accepted matches was maximized.

Databases, Factual↗
PubMed1990

Cross-sectional versus longitudinal investigations of the diet-cancer relation.

Within a prospective cohort study on diet and cancer, information was collected on cancer prevalence and baseline meat consumption. A nested case-control study on meat and cancer was conducted with 656 prevalent colorectal cases, 1,894 breast cancer cases, and 4,701 controls. When analyzed cross-sectionally, prevalence odds ratios for eating meat rarely versus regularly were 2.08 for female colorectal and 1.75 for breast cancer. In the longitudinal analysis, cases who started consuming meat rarely after diagnosis were excluded, resulting in odds ratios of 0.51 for female colorectal and 1.17 for breast cancer. These opposite findings highlight the problem of cross-sectional designs.

Aged↗
PubMedDate not supplied

Predictors of toenail selenium levels in men and women.

Potential predictors of toenail selenium levels were studied in 1211 men and 1248 women aged 55-69 years. These subjects were randomly selected cohort members without prevalent cancer (other than skin) participating in a prospective study on diet and cancer in the Netherlands. Information on the considered potential predictors (gender, age, smoking, intake of dietary selenium and alcohol, Quetelet index) was collected together with toenail specimens in 1986. The average toenail selenium concentration was significantly (P < 0.001) lower in men than in women: 0.547 +/- 0.126 microgram/g (mean +/- SD) and 0.575 +/- 0.109 microgram/g, respectively. The gender difference remained significant after adjustment for the other variables in multiple regression analyses. Age was not associated with toenail selenium levels in men or women. An inverse association was observed with current smoking but not with past smoking. The average toenail selenium values for male current smokers were 0.513 +/- 0.106 microgram/g (mean +/- SD) versus 0.571 +/- 0.133 microgram/g for male never- or ex-smokers (P < 0.001). For women these values were 0.548 +/- 0.101 and 0.581 +/- 0.109 microgram/g, respectively (P < 0.001). Dietary selenium intake was positively associated with toenail selenium levels in multivariate analyses (P < 0.001), but the association was weak (partial r = 0.09). Alcohol intake and Quetelet index were not significant independent predictors of toenail selenium. The observed associations had similar directions in men and women but were stronger in men.

Age Factors↗