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Biomedical subjects

F De Waard

Publications and source records attributed to F De Waard.

11 recordsLinked to original sources
PubMed1995

Validity of urinary biomarkers of exposure to tobacco smoke following prolonged storage.

BACKGROUND: The utility of using biomarkers of smoking in epidemiological studies depends not only on the validity and precision of the laboratory procedure but often on the long-term stability of the analytes of interest in stored biological samples. METHODS: We retrieved urine samples collected in 1976-1977 from women included in a cohort study in Utrecht and for whom information on smoking status was available. Creatinine and thiocyanate were measured in 1976-1977 on fresh samples. Cotinine and creatinine were analysed in 1988 on urine stored at -20 degrees C. RESULTS: Measurements of creatinine more than 10 years apart showed a correlation of 0.95 and equal means. Cotinine measurements made in 1988 allowed a clear separation of smokers and non-smokers (sensitivity 92%, specificity 100%), suggesting that concentrations retained their discriminant value even after 10 years of storage. CONCLUSION: These results emphasize the possibilities offered by long-term storage, under proper conditions, of biological samples for subsequent determination of analytes which may emerge as the study progresses.

Biomarkers↗
PubMed1992

Preventive intervention in breast cancer, but when?

After an introductory note on primary preventive intervention of breast cancer during adulthood, the author defends and extends a hypothesis that relates most of the known risk factors for this disease to the development of preneoplastic lesions in the breast. If changes in lifestyle concerning nutritional and/or reproductive risk factors during puberty and adolescence would turn out to be unacceptable socially, an alternative approach might be found in chemoprevention based on cell differentiation.

Adolescent↗
PubMed1991

Endocrine aspects of cancer: an epidemiological approach.

Over the last 2 decades epidemiologists have increasingly used parameters of endocrine function in their studies. Prospective cohort studies offer methodological advantages in view of the latency between the relevant hormonal exposure and the clinical onset of cancer. Examples from the author's experience are provided. Evidence is mounted for an important "time window" for breast cancer development between menarche and the birth of a first child.

Adult↗
PubMed1988

Breast cancer screening, with particular reference to the concept of 'high risk' groups.

An overview is presented of the salient aspects of the DOM-project of breast cancer screening carried out in the city of Utrecht, the Netherlands. Results on stage at diagnosis, case-fatality, and mortality rates suggest that the program has been effective. Attention is devoted to the issue whether knowledge about risk factors for breast cancer is helpful in making a screening program more effective or efficient. It is concluded that such knowledge is of limited importance.

Breast Neoplasms↗
PubMed1981

[Screening for breast cancer (author's transl)].

This is a report on the breast cancer screening project carried out in the city of Utrecht/Netherlands. Women aged 50 to 64 were examined by clinical examination and xeromammography. The predictice value of recommendation for biopsy was 42% (sensitivity 94%, specificity 99%). The prevalence rate of breast cancer at the first screening was 7.2 (0/00). Comparing the situation before and during the screening program the number of tumors less than 3 cm in diameter and the number of cases with negative axillary lymph nodes have increased in breast cancer patients detected by screening.

Breast Neoplasms↗
PubMed1977

Breast cancer incidence according to weight and height in two cities of the Netherlands and in Aichi prefecture, Japan.

A study was made in the cities of Rotterdam and The Hague, the Netherlands, and in Aichi prefecture, Japan, to assess the effect of weight and height (and their combinations) on the age-specific incidence of breast cancer. It is based on a comparison between 1006 cases of breast cancer and 4201 women from the general population, 33-69 years old. The results suggest that about one-half of the differences in incidence between the regions in Holland and Japan can be attributed to differences in body weight and height. In breast cancer patients in Rotterdam and The Hague those with metastases in axillary involvement. A hormonal factor related to body weight and/or height might be responsible for the increased incidence and the more rapid course of breast cancer in women with a large body mass.

Adult↗