This large study suggests that molecular alterations in SBA are closer to those in colorectal cancer (CRC) than those in gastric cancer, with low levels of HER 2 overexpression and high frequencies of KRAS mutations.
Thus, routine immunohistochemical and/or FISH testing for HER2 for potential targeted anti-HER2 therapy may not be beneficial for patients with primary small intestinal adenocarcinoma.