GNAS R201 mutations are detected in ~40–70% of IPMNs (predominantly main-duct and mixed-t...
Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.
| ID | BMA-GNAS-IPMN |
|---|---|
| Type | Actionability |
| Status | reviewed 2026-05-04 | pending_clinical_signoff | actionability review required |
| Diseases | DIS-PDAC |
| Sources | SRC-ESMO-PANCREATIC-2024 SRC-NCCN-PANCREATIC-2025 |
Actionability Facts
| Biomarker | BIO-GNAS |
|---|---|
| Variant | GNAS R201 activating mutation (R201C, R201H) in pancreatic cyst fluid or tissue — intraductal papillary mucinous neoplasm (IPMN); diagnostic/risk-stratification marker for cyst malignant potential |
| Disease | DIS-PDAC |
| ESCAT tier | IIB |
| Recommended combinations | Pancreaticoduodenectomy or distal pancreatectomy — for IPMN with high-risk stigmata (obstructive jaundice, mural nodule ≥5 mm, main duct dilation ≥10 mm, positive cytology) regardless of GNAS status, Surveillance (MRI/MRCP or EUS q6m–3yr depending on size/features) — for IPMN without high-risk stigmata; GNAS + KRAS positivity informs more frequent surveillance |
| Evidence summary | GNAS R201 mutations are detected in ~40–70% of IPMNs (predominantly main-duct and mixed-type) and in a subset of GNAS-driven mucinous cystic neoplasms (MCNs). GNAS mutation is a key component of multi-analyte pancreatic cyst fluid analysis (alongside KRAS mutation, CEA level, cytology) used to classify cysts as mucinous vs non-mucinous and to stratify malignant potential. Clinical utility: (1) Diagnostic: GNAS R201 mutation in cyst fluid confirms mucinous neoplasm (IPMN or MCN) with high specificity (>95%). Used in Pancrasite and other commercial cyst analysis panels. (2) Risk stratification: GNAS + KRAS double-positive cysts have higher malignant risk than GNAS or KRAS single-positive. Per NCCN/IAP (International Association of Pancreatology) 2022 guidelines, worrisome features and high-risk stigmata drive surgical referral, but molecular markers (GNAS + KRAS + TP53/SMAD4/CDKN2A) in cyst fluid are increasingly incorporated into risk models. (3) No treatment is directed at GNAS per se — management is surgical resection for high-risk features. GNAS mutation does not select systemic t... |
Notes
ESCAT IIB: GNAS mutation is a diagnostic/risk-stratification tool in IPMN management, not a therapeutic target. The disease_id DIS-PDAC is used as the closest match, since IPMN is a pre-malignant precursor to PDAC; no dedicated IPMN disease entity exists in the KB. Clinical workflow for pancreatic cysts: (1) Imaging characterization: MRI/MRCP (preferred), CT for mural nodule detection. (2) EUS-FNA with cyst fluid analysis for cysts ≥2 cm or with concerning features. (3) Cyst fluid CEA (>192 ng/mL = mucinous), amylase (low in serous), cytology (atypical/ malignant cells = immediate surgery), GNAS/KRAS NGS panel. (4) GNAS+ (or KRAS+) confirms mucinous → enter IAP/NCCN surveillance protocol. (5) Additional molecular markers (TP53, SMAD4, CDKN2A mutations in cyst fluid) may indicate high-grade dysplasia requiring resection even without imaging high-risk stigmata. GNAS R201 testing: requires dedicated pancreatic cyst fluid NGS panel (e.g., Pancrasite by LabCorp, or institutional panel); not covered by standard tumor tissue NGS panels.
Used By
No reverse references found in the YAML corpus.