Current or prior tamoxifen exposure ≥5 years in a woman with intact uterus (no prior hyst...

Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.

ID	`RF-IATROGENIC-TAMOXIFEN-ENDOMETRIAL-PREVENTION`
Type	Red flag
Status	reviewed 2026-05-18 \| pending_clinical_signoff
Diseases	`DIS-ENDOMETRIAL`
Sources	`SRC-NCCN-BREAST-2025` `SRC-NCCN-UTERINE-2025`

Red Flag Origin

Definition	Current or prior tamoxifen exposure ≥5 years in a woman with intact uterus (no prior hysterectomy). Tamoxifen is a selective estrogen- receptor modulator (SERM) — antagonist in breast tissue (therapeutic for ER+ breast cancer + risk reduction) but partial agonist in endometrium → ~2-7 fold increased endometrial cancer risk (predominantly endometrioid; less commonly serous, carcinosarcoma). Cumulative risk ~1-2% over 5y treatment; higher with longer duration + post-menopausal status. Endometrial cancers in tamoxifen-exposed women often more aggressive histology than spontaneous. Population with hysterectomy: this RF does NOT fire (no at-risk organ). Patient with ER+ breast cancer (treatment-time persona) ALSO has prevention- persona considerations covered by this RF. Prevention-persona RedFlag (§20 v0.3 iatrogenic pilot).
Clinical direction	investigate
Category	other

Trigger Logic

{
  "any_of": [
    {
      "finding": "current_tamoxifen_use_ge_5y",
      "value": true
    },
    {
      "finding": "prior_tamoxifen_completion_intact_uterus",
      "value": true
    },
    {
      "finding": "tamoxifen_post_menopausal_intact_uterus",
      "value": true
    }
  ],
  "type": "lab_value"
}

Notes

Prevention-persona RedFlag for tamoxifen exposure ≥5y in women with intact uterus. ~2-7 fold endometrial cancer risk. Engine routes to PreventionPlan recommending symptom-prompted evaluation (postmenopausal bleeding → immediate workup with TVUS + endometrial biopsy). Routine asymptomatic TVUS screening NOT recommended per ACOG (false-positives from tamoxifen-related subepithelial changes). STUB pending two-Clinical-Co-Lead signoff per CHARTER §6.1 dev-mode.

Used By

Indications

IND-IATROGENIC-TAMOXIFEN-ENDOMETRIAL-PREVENTION-OBSERVATION - IND-IATROGENIC-TAMOXIFEN-ENDOMETRIAL-PREVENTION-OBSERVATION
IND-IATROGENIC-TAMOXIFEN-ENDOMETRIAL-PREVENTION-SURVEILLANCE - IND-IATROGENIC-TAMOXIFEN-ENDOMETRIAL-PREVENTION-SURVEILLANCE

Red flag

RF-IATROGENIC-COMBINED-HRT-PREVENTION - Cumulative use of combined hormone replacement therapy (estrogen + progestin / progestoge...