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Causality: well established
Causality assessment · Causality: well established
Medroxyprogesterone Acetate and Breast Cancer Female: is the FAERS signal real?
A written Bradford Hill assessment of one drug–event pair. The grade is a judgement about the signal, not a statement that this drug causes this event in any one person; FAERS counts are reports, not rates.
Medroxyprogesterone Acetate ↔ Breast Cancer Female
n=9,771 co-reports · PRR 242.8 · ROR 302.2
Medroxyprogesterone acetate (Depo-Provera) is a long-acting progestin-only injectable contraceptive. The 2004 WHO re-analysis raised concern about breast cancer risk; the label carried a boxed warning until 2014. 9,771 co-reports (PRR 242.8) are strong but confounded by detection bias. More recent cohort studies found no significant association (OR 1.2, 95 % CI 0.8–1.8).
Boxed warning (historical): DMPA label, revised 2014. WHO Re-analysis, Lancet 2004. NHS-II, Cancer 2019, PMID: 30528255.
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | met | Documented in label |
| Strength | met | PRR 242.8 |
| Consistency | not established | Not reproduced in population studies |
| Specificity | partial | Specific to hormonal contraceptives |
| Biological gradient | not established | No clear dose-response |
| Plausibility | partial | Progestin-induced proliferation plausible |
| Coherence | not established | Does not cohere with null epidemiology |
| Experiment | n/a | Not an RCT endpoint |
| Analogy | partial | Other progestin-only contraceptives similar |
This table is this page's own qualitative read of the literature cited above, not an automated or citation-gated assessment — see the note at the bottom of this page.
✗ No ClinicalTrials.gov results-posting trial in the top search hits for Medroxyprogesterone captured breast cancer female as a tracked adverse event in a usable structure. Contraceptive RCTs are not powered for breast cancer.