Hormone replacement therapy use and variations in the risk of breast cancer
Bibliographic record
Abstract
OBJECTIVE: To determine the effect of different types and formulations of hormone replacement therapy (HRT) on the risk of breast cancer in postmenopausal women. DESIGN: Population-based case-control study. SETTING: UK, 1988-2004. PARTICIPANTS: Women 50-75 years between 1998 and 2004. MAIN OUTCOME MEASURES: Breast cancer incidence to estimate the rate ratio (RR) associated with use of various HRTs over a 30-year period. RESULTS: We identified 6347 incident cases of breast cancer that were matched with 31,516 controls. Cases were on average 61 years at diagnosis and 22% had undergone a hysterectomy. The rate of breast cancer was increased with the use of opposed estrogens in oral form (adjusted RR 1.38; 95% CI 1.27-1.49) in contrast to patch form (RR 1.08; 95% CI 0.81-1.43). This rate was similarly elevated with both continuous (RR 1.29; 95% CI 1.07-1.56) and sequential (RR 1.33; 95% CI 1.21-1.46) forms of opposed estrogen. The rate of breast cancer was not increased among exclusive users of unopposed estrogens (RR 0.97; 95% CI 0.86-1.09) or of tibolone (RR 0.86; 95% CI 0.65-1.13). Users of tibolone who had switched from opposed estrogens, however, had an elevated rate (RR 1.29; 95% CI 1.09-1.52). The rate of breast cancer increased by 25% (95% CI 20-30%) with every ten prescriptions of orally administered opposed estrogen. CONCLUSIONS: The risk of breast cancer varies with the formulation and preparation of HRT. Opposed estrogens (progesterone-estrogen) in oral form are associated with an increased risk of breast cancer, which increases with use. Transdermal opposed estrogens, unopposed estrogens and tibolone do not increase this risk. However, this study is an observational study that carries risks of various biases, and thus the findings need to be interpreted with caution.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".