Expression of HER-2/neu in Gastric Adenocarcinoma

ABSTRACT

PURPOSE: The HER-2 oncogene plays a role in cellular oncogenic transformation, and is related to the aggressive tumor behaviour. Several studies have addressed the prognostic and predictive roles of the HER-2 status in gastric cancer; however, the HER-2 gene has not been used as a therapeutic target, as the opinions relating to its prognostic role are controversial. METHODS: Between January 1994 and December 1997 (1995 group), 192 patients who underwent a curative resection for a gastric adenocarcinoma at St. Mary's Hospital, College of Medicine, The Catholic University of Korea, were retrospectively reviewed from their paraffin embedded tissues and medical records. One hundred and twenty-seven patients, with the same characteristics and operated on between January and December 2002 (2000 group) were compared. The expression of HER-2 was analyzed by means of immunohistochemistry, with regard to the clinicopathological features and survival rate. RESULTS: The average ages of patients in the 1995 and 2000 groups were 56.3 and 59.1 years, respectively. In the 1995 group, 40.1, 26.5, 24.0 and 9.4%, had stage I, II, III and IV diseases, Whereas, in the 2000 group, these figures were 57.5, 18.1, 19.7, and 4.7%, respectively. The expression of HER-2 was positive in 12/192 patients (6.3%) in the 1995 group, and in 7/127 (5.5%) in the 2000 group. There was no relation between the overexpression of HER-2 and the pathological findings. However, the 5-year survival rates of patients with negative and positive HER-2 expression were 91.7 and 75.0%, in stage I and II gastric cancers, respectively. There was a significant difference in the survival rates between the two groups (P=0.010). CONCLUSION: HER-2 overexpression is an early event in gastric cancers, appearing at all stages of the disease, and is related to the poor prognosis of stage I, and II diseases. This fact is thought to be the basis of monoclonal antibody treatment and chemotherapy following a surgical operation for early gastric cancer.