Gastric Cancer Classifications and Subtypes

Vocabulary flashcards covering Lauren, WHO 2019, and TCGA 2014 classifications of gastric cancer, including histology, etiology, spread patterns, and prognosis.

Lauren Classification

Traditional histopathologic system dividing gastric adenocarcinoma into intestinal, diffuse, and mixed types.

Intestinal Type Gastric Cancer

Gland-forming gastric adenocarcinoma, usually in the antrum of older adults; linked to H. pylori infection and diet; spreads hematogenously and has a relatively better prognosis.

Diffuse Type Gastric Cancer

Poorly cohesive or signet-ring cell carcinoma without gland formation, often involving the entire stomach, occurring in younger patients, associated with CDH1 mutations, peritoneal/lymphatic spread, and worse prognosis.

Mixed Type Gastric Cancer

Tumor showing combined intestinal and diffuse histologic features as defined by the Lauren classification.

WHO Classification 2019

Histologic scheme categorizing gastric carcinoma into tubular, papillary, mucinous, poorly cohesive, and mixed types.

Tubular Gastric Adenocarcinoma

WHO subtype composed of glandular or tubule-forming malignant epithelium; parallels the intestinal type and is the most common WHO pattern.

Papillary Gastric Adenocarcinoma

WHO subtype characterized by finger-like epithelial projections supported by fibrovascular cores.

Mucinous Gastric Adenocarcinoma

WHO subtype in which more than 50% of the tumor contains abundant extracellular mucin pools.

Poorly Cohesive Gastric Carcinoma

WHO subtype made up of isolated or signet-ring cells with minimal cellular adhesion, corresponding to diffuse histology.

TCGA Molecular Classification 2014

Genomic framework dividing gastric cancer into EBV-positive, MSI-high, genomically stable, and chromosomal instability (CIN) subtypes.

EBV-positive Gastric Cancer

TCGA subtype driven by Epstein–Barr virus infection, often showing PIK3CA mutations and DNA hypermethylation.

MSI-high Gastric Cancer

TCGA subtype with defective DNA mismatch repair and high microsatellite instability; generally associated with a better prognosis.

Genomically Stable Gastric Cancer

TCGA subtype enriched in diffuse histology and CDH1 or RHOA mutations; tends to have poorer outcomes.

Chromosomal Instability (CIN) Gastric Cancer

TCGA subtype characterized by widespread aneuploidy and frequent TP53 mutations; the most common molecular class, often showing intestinal/tubular morphology.

Helicobacter pylori Infection

Chronic bacterial infection that promotes intestinal-type gastric cancer through longstanding inflammation and intestinal metaplasia.

CDH1 Mutation

Loss-of-function alteration in the E-cadherin gene linked to diffuse-type and genomically stable gastric cancers.

TP53 Mutation

Tumor-suppressor gene alteration commonly driving the chromosomal instability (CIN) subtype of gastric cancer.

Hematogenous Spread

Metastatic pathway primarily used by intestinal-type gastric cancer, involving dissemination via the bloodstream.

Peritoneal/Lymphatic Spread

Dissemination route typical of diffuse-type gastric cancer, leading to peritoneal carcinomatosis and extensive nodal involvement.

Prognosis: Intestinal vs. Diffuse

Intestinal-type generally carries a better outcome, whereas diffuse-type is associated with a worse prognosis due to aggressive spread.

Age Distribution in Gastric Cancer

Intestinal-type predominates in older adults, whereas diffuse-type often presents in younger patients; molecular subtypes can occur at any age.