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🌱 來自: gastric cancer

Pathology or biomarkers-of-gastric cancer

Lauren’s histologic classification Intestinal: Tumor cells arranged in tubular or glandular formations, spreads through gastric wall as part of a tumor mass Diffuse: Defective intercellular adhesion molecules allow tumor cells to invade w/o formation of tubules or glands; spreads as discohesive cells throughout stomach wall; highly metastatic; signet-ring histology is a poor prognostic factor WHO classification: Tubular, papillary, mucinous, poorly cohesive incl. signet ring, adenosquamous, small cell, undifferentiated, squamous cell The CA genome atlas 4 subtypes: EBV-positive (w/ recurrent PIK3CA muts, higher prevalence of DNA hypermethylation), microsatellite instability (MSI), chromosomal instability (CIN) (↑ receptor tyrosine kinases incl. VEGFR2), genomically stable (GS) Biomarkers w/ clinical implications HER2 overexpression: Determined by HER2 IHC (3+), IHC equivocal (2+), & FISH amp, or HER2 gene amplification; 10-20% of gastric adenoCAs MMR: Determined by IHC for MLH1, MSH2, MSH6, PMS2 proteins PD-L1: Positive if combined positive score (CPS) ≥1; unclear utility as responses seen w/ checkpoint inhibition in PD-L1 (-) tumors & significant interobserver variability EBV: Gold standard is EBV-encoded RNA in situ hybridization (EBER-ISH) NGS: Tumor sequencing for other targets (eg, NTRK)