The Role of Hormones in the Differences in the Incidence of Breast Cancer between Mongolia and the United Kingdom
Bibliographic record
Abstract
BACKGROUND: There are striking differences in breast cancer incidence between Asian and western women. Rates vary substantially within Asia also, with Mongolia's even lower than China's. These profound differences have been speculated to be due in part to diet, mediated by circulating hormone concentrations. METHODS: Sex steroid hormone concentrations were measured in women living in Ulaanbaatar, Mongolia and the United Kingdom (U.K.). Diet was obtained by interview and national survey data. Mean hormone differences were compared by country, and systematic variation by number of days since last menstrual period was modeled and adjusted for age and parity; difference in overall area under the curves was assessed. FINDINGS: The diet in Mongolia was higher in meat and dairy than in the U.K. Mean testosterone concentrations were 18.5% lower (p<0.0001) while estradiol concentrations were 19.1% higher (p = 0.02) in Mongolian than British women, adjusted for age and parity. Progesterone was almost 50% higher in Mongolian women (p = 0.04), particularly during the follicular phase and early luteal surge. Hormone concentrations generally were similar in Mongolian women born in Ulaanbaatar compared with those born in rural areas, although there was a decreasing progesterone trend by degree of westernization (rural Mongolia; urban Mongolia; U.K.). Mean hormone differences were similar when restricted to parous women, and with further adjustment for body mass index, height, and smoking status. INTERPRETATION: These data augment accumulating evidence that circulating estrogens are unlikely to explain reduced breast cancer rates in Asia compared with the west, and suggest casting a wider net with respect to biomarkers. Lower testosterone and higher progesterone in Mongolian women raise the possibility that these hormones may be important to consider. In addition, the almost exclusive dietary reliance of Mongolians on meat and dairy argues against beneficial effects of a low-fat diet on circulating hormones explaining international breast cancer differences.
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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 | 0.000 |
| 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".