Recently, we showed that short, intense caloric restriction due to the Dutch famine increased breast cancer risk in women and influenced the hormonal- and IGF-system. These systems may also affect breast density, which is one of the strongest risk factors for breast cancer. We examined the influence of the Dutch famine on breast density, using mammograms of 1,035 women.
View Article and Find Full Text PDFCancer Epidemiol Biomarkers Prev
August 2003
To assess the appropriateness of a single measurement of urinary 6-sulfatoxymelatonin (aMT6S) as a marker for long-term exposure to endogenous melatonin in epidemiological studies, we examined the reproducibility of aMT6S in first morning urine voids collected from 40 postmenopausal women. Urine specimens were collected on three different occasions, and the mean time between the first and the third urine sample was 5.1 years.
View Article and Find Full Text PDFObjective: The relationship between smoking and colorectal cancer risk and whether such effect is modified by variations in the NAT2 genotype is investigated.
Methods: In the prospective DOM (Diagnostisch Onderzoek Mammacarcinoom; 27,722 women) cohort follow-up from 1976 until 1987 revealed 54 deaths due to colon or rectal cancer, and follow-up from 1987 to 01-01-1996 revealed 204 incident colorectal cancer cases. A random sample (n = 857) from the baseline cohort was used as controls.
Higher levels of circulating Insulin-like Growth Factor (IGF)-I may be associated with higher risks for premenopausal breast cancer. We investigate the associations between circulating levels of IGF-I, its binding proteins (IGFBPs) -1, -2, -3, C-peptide and postmenopausal breast cancer. This is a prospective study nested in 2 Dutch cohorts.
View Article and Find Full Text PDFIn large studies and under field conditions common to epidemiological research, factors outside of and inside the laboratory can introduce misclassification of genetic susceptibility markers. Few reports have been made on the accuracy of genotyping individuals using DNA extracted from frozen urine that was stored for approximately 20 years. This study was performed to determine the reproducibility and accuracy of N-acetyltransferase 2 (NAT2) genotyping by RFLP analysis using DNA from stored urine.
View Article and Find Full Text PDFIn several population-based studies in the past urine samples were collected and stored for future research. We set out to determine the reliability of using such samples for genotyping DNA markers in epidemiologic research. A source of DNA extracted from exfoliated nucleated cells in urine is provided by the DOM cohort, in which specimens were collected 15-25 years ago.
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