ERBB2 and colorectal cancer: Richman SD et al. [15] analyzed HER2 amplification/overexpression in 3256 patients from three colorectal cancer trials in the UK and found that the overexpression of HER2 was observed in 25 of 1914 (1.3%) stage II-III tumors and 29 of 1342 (2.2%) stage IV tumors.