Chronic Helicobacter pylori infection (positive urea breath test, stool antigen, gastric...

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

ID	`RF-CHRONIC-H-PYLORI-MALIGNANCY-PREVENTION`
Type	Red flag
Status	reviewed 2026-05-18 \| pending_clinical_signoff
Diseases	`DIS-GASTRIC`
Sources	`SRC-NCCN-BCELL-2025`

Red Flag Origin

Definition	Chronic Helicobacter pylori infection (positive urea breath test, stool antigen, gastric biopsy histology, or stool PCR) in an individual without a current gastric malignancy diagnosis. IARC Group 1 carcinogen (H. pylori) — established etiological driver of gastric adenocarcinoma (intestinal-type primarily) and gastric MALT lymphoma. Eradication therapy reduces gastric-cancer incidence (NNT ~15 in high-incidence populations per Cochrane meta-analyses) and is curative for early-stage gastric MALT lymphoma in ~70-80% of cases (Wotherspoon regression). Prevention-persona RedFlag (§20 ratification 2026-05-18).
Clinical direction	investigate
Category	other

Trigger Logic

{
  "any_of": [
    {
      "finding": "h_pylori_status",
      "value": "positive"
    },
    {
      "finding": "urea_breath_test",
      "value": "positive"
    },
    {
      "finding": "h_pylori_stool_antigen",
      "value": "positive"
    },
    {
      "finding": "h_pylori_biopsy_histology",
      "value": "positive"
    }
  ],
  "type": "lab_value"
}

Notes

Prevention-persona RedFlag (CHARTER §3 amended 2026-05-18 Path A, HCP-mediated). Fires when patient profile shows chronic H. pylori (positive UBT / stool antigen / biopsy histology / stool PCR) AND no confirmed gastric malignancy. Engine routes such patients to a PreventionPlan recommending eradication therapy (per IND-H-PYLORI-PREVENTION-ERADICATION) as the etiological-cancer- prevention pathway. Evidence for H. pylori → gastric cancer causation (IARC Group 1): multiple Cochrane meta-analyses show eradication reduces gastric adenocarcinoma incidence (RR ~0.54-0.66, NNT ~15-50 depending on population baseline incidence). Effect is stronger in high-incidence populations and in younger individuals where atrophic gastritis / intestinal metaplasia has not yet developed. Evidence for H. pylori → gastric MALT lymphoma: eradication is the first-line treatment for early-stage gastric MALT lymphoma, with Wotherspoon regression in ~70-80% of cases (especially t(11;18)- negative). This is treatment-persona territory (existing MALT lymphoma in setting of confirmed H. pylori → treatment Indication, not yet authored) — distinct from prevention persona (chronic H. pylori → prevent MALT/adenocarc...

Used By

Indications

IND-H-PYLORI-PREVENTION-ERADICATION - IND-H-PYLORI-PREVENTION-ERADICATION
IND-H-PYLORI-PREVENTION-OBSERVATION - IND-H-PYLORI-PREVENTION-OBSERVATION