HER-2 Overexpression in Gastric and Gastroaesophageal Cancer: A Different Disease among Gastric Adenocarcinoma Subtypes

Gastric cancer and gastroesophageal junction adenocarcinoma is a common malignancy worldwide, in particular in Japan and in the Pacific coast of Latin America. Unless early diagnosis is performed, this disease carries a bad prognosis with a high mortality rate regardless of the use of standard treatments. A subgroup of this patients, probably close to a 20 percent, carry HER 2 mutations that result in HER 2 overepression. Targeted treatment to block HER 2 in the first line of treatment in the metastatic setting has resulted in positive outcomes when adding trastuzumab to standard chemotherapy, nonetheless no other HER 2 targeted treatments have reported benefit in this malignancy. Clinical trials are currently ongoing to evaluate the benefit of HER 2 blockade as perioperative treatment for patients that overexpress HER 2.