Journal of the National Cancer Institute
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J. Natl. Cancer Inst. · Dec 1996
Risk of basal cell and squamous cell skin cancers after ionizing radiation therapy. For The Skin Cancer Prevention Study Group.
Human evidence that ionizing radiation is carcinogenic first came from reports of nonmelanoma skin cancers (NMSCs) on the hands of workers using early radiation devices. An increased risk of NMSC has been observed among uranium miners, radiologists, and individuals treated with x rays in childhood for tinea capitis (ringworm of the scalp) or for thymic enlargement; NMSC is one of the cancers most strongly associated with the atomic bombing of Hiroshima and Nagasaki. Although exposure to ionizing radiation is a known cause of NMSC, it is not yet clear whether therapeutic radiation causes both major histologic types of NMSC, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Additionally, the potentially modifying effects, such as latency, age when treated, and type of treatment, are not well understood. ⋯ Our data suggest that exposure to therapeutic radiation is associated with BCC but not with SCC.
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J. Natl. Cancer Inst. · Dec 1996
Randomized Controlled Trial Multicenter Study Clinical TrialPostchemotherapy adjuvant tamoxifen therapy beyond five years in patients with lymph node-positive breast cancer. Eastern Cooperative Oncology Group.
Data from a pilot study published in 1984 suggested that tamoxifen administration (as adjuvant hormonal therapy) for more than 5 years after initial breast cancer surgery might have therapeutic benefit. ⋯ Our results suggest that further evaluation of adjuvant tamoxifen therapy beyond 5 years in women with axillary lymph node-positive, estrogen receptor-positive breast cancer who have also been treated with adjuvant chemotherapy would be appropriate.
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J. Natl. Cancer Inst. · Dec 1996
Randomized Controlled Trial Clinical TrialMeasurement error and results from analytic epidemiology: dietary fat and breast cancer.
International correlational analyses have suggested a strong positive association between fat consumption and breast cancer incidence, especially among post-menopausal women. However, case-control studies have been taken to indicate a weaker association, and a recent, pooled cohort analysis reported little evidence of an association. Differences among study results could be due to differences in the populations studied, differences in the control for total energy intake, recall bias in the case-control studies, and dietary measurement error biases. Existing measurement error models assume either that the sample data used to validate dietary self-report instruments are without measurements error or that any such error is independent of both the true dietary exposure and other study subject characteristics. However, growing evidence indicates that total energy and, presumably, both total fat and percent energy from fat are increasingly underreported as percent body fat increases. ⋯ Dietary self-report instruments may be inadequate for analytic epidemiologic studies of dietary fat and disease risk because of measurement error biases.