Profile of HER2 +ve Gastric Cancers in Brunei Darussalam.

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Increasing Incidence of Colorectal Cancer, Starting at a Younger Age for Rectal Compared to Colon Cancer in Brunei Darussalam.

BACKGROUND: Colorectal cancer (CRC) is the most common gastrointestinal malignancy and is a significant cause of mortality. Its incidence is generally increasing in Asia. Reports from the West have indicated that the incidence of rectal cancer is increasing in the younger population. This study assessed the time trend of CRC in Brunei Darussalam specifically assessing the different age groups at which the incidences start to increase. MATERIALS AND METHODS: The National Cancer registry was reviewed (1991 to 2014). The age standardized rate (ASR) and the age specific incidence rates (ASIRs) for three time periods (1991-1998), (1999-2006) and (2007-2014) were calculated. RESULTS: The mean age of diagnosis was 59.3±14.6 years old, incidences being slightly higher amongst men (57.6%) and Malays (67.1%). The most common tumor type was adenocarcinoma (96.4%). Rectal cancers accounted for 35.2% (n=372/1,056) of all cancers of the large bowel; more men were affected than women. The proportion of rectal cancer was also high among the indigenous group. In the three time periods, the ASR for CRC increased from 16 per 100,000 (1991-1998) to 19.6 per 100,000 (1999-2006) and 24.3 per 100,000 (2007-2014). The ASIRs for CRC increased markedly between the time periods 1998-2006 and 2007-2014, beginning in the 40-44 years age group. For rectal cancers, the ASIRs started to increase in the 25-29 age group onward whereas for colon cancers, the increase was observed at a later age, starting from the 45-49 age group. CONCLUSIONS: Our study showed an increase in the incidence of CRC including in the younger age groups. The increase was seen earlier in rectal cancer compared to colon cancer. These data mirror the trends reported from the West.