Profile of HER2 +ve Gastric Cancers in Brunei Darussalam

Gastric cancer is the second most common gastrointestinal cancer and is still associated with significant morbidity and mortality due to late presentation and diagnosis at advanced stages. Studies have reported that a variable proportion of gastric cancer is positive for the human epidermal growth factor receptor 2 (HER2) and patients with HER2 positive (HER2 +ve) lesions can benefit from targeted therapy. This study was conducted to assess the prevalence of HER2 +ve gastric cancers in Brunei Darussalam, a developing Southeast Asian nation.

Patients were identified from the Department of Pathology registry and retrospectively reviewed. HER2 expression was assessed by immunohistochemistry and only those staining 3+ were considered positive.

Our study included 103 cases (66 males and 37 females) with a mean age of 65.1 ± 14.8 years old. There were 14 cases positive for HER2 (10 males and 4 females) giving a prevalence of 13.6%. The HER2 +ve cases were significantly older (70.6 ± 19.3 years old) than the negative cases (64.2 ± 13.8, p=0.041) and had significantly more advanced disease (stages 3 and 4, p=0.026). There were no significant differences in gender distribution, presence of intestinal metaplasia, EBV status, Helicobacter pylori status, tumor location (proximal vs. distal) and degree of tumor differentiation (all p values >0.05).

Our study showed that 13.6% of our gastric cancers are positive for HER2, the affected patients being older and having more advanced disease at diagnosis.