HER2 aberrations and heterogeneity in cancers of the digestive system: Implications for pathologists and gastroenterologists

Figure 2 HER2 alterations frequencies from public datasets accessible from cBioPortal[16] in the most common tumors occurring in the digestive system compared to breast cancer. Overall, HER2 amplifications occur more frequently in gastric, esophageal, and pancreatic cancers, whereas gallbladder cancer and cholangiocarcinoma characteristically show HER2 mutations (10% and 6% of cases, respectively). The domain structure of the erbB2 protein and gene alterations identified in primary carcinomas of the digestive system available from cBioPortal[16] (reported the top) show the presence of hotspot somatic mutations in the furin-like (binding site) and protein kinase domains. Mutation types are color-coded on the basis of the legend on the bottom right.