Anastrozole (breast-cancer chemoprevention context)
Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.
| ID | DRUG-ANASTROZOLE-CHEMOPREVENTION |
|---|---|
| Type | Drug |
| Aliases | AI chemoprevention — anastrozoleAnastrozole (breast-cancer chemoprevention)ArimidexАнастрозол (хіміопрофілактика раку молочної залози) |
| Status | reviewed 2026-05-18 | pending_clinical_signoff |
| Diseases | None declared |
| Sources | SRC-NCCN-BREAST-2025 SRC-NCCN-GENETIC-FAMILIAL-BREAST-OVARIAN-2025 SRC-USPSTF-BREAST-2024 |
Drug Facts
| Class | Aromatase inhibitor (non-steroidal, third-generation) |
|---|---|
| Mechanism | Reversible non-steroidal inhibitor of cytochrome P450 aromatase (CYP19A1), reducing peripheral conversion of androgens to estrogens (estradiol, estrone). In postmenopausal women aromatase activity in adipose, breast, and other peripheral tissue is the dominant estrogen source — anastrozole 1 mg/day suppresses circulating estradiol by ~80-95%. Cancer-prevention rationale: estrogen exposure is the dominant driver of HR-positive breast carcinogenesis, and near-complete suppression of postmenopausal estrogen production reduces incidence of ER-positive breast cancer (and DCIS). IBIS-II RCT (Cuzick Lancet 2014, 12-year follow-up Lancet 2020): in 3,864 postmenopausal high-risk women, anastrozole 1 mg/day for 5 years reduced breast-cancer incidence by ~49% vs. placebo (HR 0.51) with durable benefit out to 12 years. |
| Typical dosing | Breast-cancer chemoprevention (off-label, NCCN Breast / NICE): 1 mg PO once daily for 5 years. Indicated for POSTMENOPAUSAL women at increased breast-cancer risk (e.g., 5-year IBIS/Tyrer-Cuzick ≥3%, or ≥1.7% Gail; LCIS, atypical hyperplasia, BRCA carriers not pursuing surgery, prior thoracic RT). Baseline DEXA + lipid panel; supplement vitamin D + calcium per bone-health protocol. Re-image bone density every 1-2 years. Discontinue and refer to endocrinology if osteoporotic fracture develops. Avoid in premenopausal women (ineffective; ovarian aromatase escape). |
| Ukraine registered | True |
| NSZU reimbursed | True |
| Ukraine last verified | 2026-05-18 |
Notes
STUB — v0.2 chemoprevention-workstream authoring (batch 2); pending two-Clinical-Co-Lead signoff per CHARTER §6.1 dev-mode. BREAST-CANCER CHEMOPREVENTION CONTEXT — distinct from generic DRUG-ANASTROZOLE (treatment indications for postmenopausal HR+ early/metastatic breast). Alternative to exemestane (DRUG-EXEMESTANE-CHEMOPREVENTION not yet authored; MAP.3 trial — exemestane 25 mg/day, 65% reduction in invasive breast cancer at 3 years). Anastrozole evidence: IBIS-II (Cuzick Lancet 2014/2020) — 5-year course, ~49% reduction sustained at 12-year follow-up. USPSTF 2024 (Grade B) supports offering risk- reducing medication to postmenopausal women ≥35 y with ≥3% 5-year Tyrer-Cuzick or ≥1.7% Gail risk. NCCN Breast 2025 lists tamoxifen, raloxifene, exemestane, anastrozole as options; AI agents preferred in postmenopausal women without contraindication due to lower VTE and endometrial-cancer risk than tamoxifen. Engine should surface this option only when (a) postmenopausal confirmed, (b) high-risk calculator met, (c) baseline bone-health assessment done, (d) patient declined or completed prophylactic mastectomy. Primary IBIS- II RCT not yet ingested as standalone SRC-* — cited sources co...
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