Cancers among South-East Asian Nationals in Brunei Darussalam

Chong, Vui Heng,Telisinghe, Pemasari Upali,Lim, Edwin,Tan, Jackson,Chong, Chee Fui Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.2

Background: Worldwide, the incidence of cancers is increasing and is becoming a major public health issue, including those in the Asia Pacific region. South-East Asia is a region with diverse populations with different disease spectra. This study looked at the spectrum of cancers among South-East Asians working in Brunei Darussalam. Materials and Methods: The cancer registry from 1994 to 2012 maintained by the State Laboratory was retrospectively reviewed. Crude incidence rates were calculated based on the population census of 2010. Results: Altogether, there was a total of 418 cancer cases diagnosed among South-East Asians, giving an incidence of 5.1% (n=418/8,253). The affected nationals in decreasing frequency were Malaysians (53.1%), followed by Filipinos (25.8%), Indonesians (15.3%), Thais (3.8%), Myanmese (1.7%) and Vietnamese (0.2%) with no recorded cases for Singapore and the People's Republic of Laos. The overall mean age of diagnosis was $46.1{\pm}4.2$ years old, with an increasing trend over the years (p<0.05 ANOVA). The overall gender ratio was 42.3:57.7 (male:female), more females among the Filipinos and Indonesians, more males among the Thais, and equal representation among the Malaysians and the Myanmese. The most common were cancers of the digestive system (19.9%), followed by female reproductive/gynecologic system (16.0%), breast (15.6%), hematological/lymphatic (12.0%) and head/neck (8.1%). There were differences in the prevalence of cancers among the various nationalities with highest crude incidence rate among the Myanmese (141.2/100,000), followed by the Malaysian (88.5/100,000), and the Filipinos (40.6/100,000) and the lowest among the Thais (18.4/100,000), Indonesians (10.5/100,000) and the Vietnamese (6.3/100,000). Conclusions: Cancers among South-East Asian residing in Brunei Darussalam accounted for 5.1% of all cancers. The most common cancers were cancers of the digestive, gynecologic/female reproductive system and breast with certain types slowly increasing in proportions. There mean age of diagnoses was increasing.

Profile of HER2 +ve Gastric Cancers in Brunei Darussalam

Chong, Vui Heng,Telisinghe, Pemasari Upali,Tan, Jackson,Abdullah, Muhamad Syafiq,Chong, Chee Fui Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.5

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 $65.1{\pm}14.8$ 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 ($70.6{\pm}19.3$ years old) than the negative cases ($64.2{\pm}13.8$, 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.

Characteristics of Young Colorectal Cancer in Brunei Darussalam: an Epidemiologic Study of 29 Years (1986-2014)

Koh, Kai Shing,Telisinghe, Pemasari Upali,Bickle, Ian,Abdullah, Muhammad Syafiq,Chong, Chee Fui,Chong, Vui Heng Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Background: Colorectal cancer (CRC) is the most common gastrointestinal cancer and the incidence is increasing. CRC is more common with increasing age, but a proportion occurs in young adults, termed young CRC. This study assessed the incidence and the demographic of young CRC in Brunei Darussalam. Materials and Methods: All histologically proven CRC between 1986 and 2014 registered with the Department of Pathology cancer registry were reviewed and data extracted for analyses. Young CRC was defined as cancer in patients aged less than 45 years. The various population groups were categorized into locals (Malays, Chinese and Indigenous) and expatriates. Results: Over the study period, there were 1,126 histologically proven CRC (mean age $59.1{\pm}14.7$ years, Male 58.0%, Locals 91.8% and 8.2% expatriates). Young CRC accounted for 15.1% with the proportion declining over the years, from 29% (1986-1990) to 13.2% (2011-2014). The proportion of young CRC was highest among the indigenous (30.8%), followed by the expatriates (29.3%), Malays (14.3%) and lowest among the Chinese (10.8%). The mean age of young CRC was $35.9{\pm}6.2$; lowest among the indigenous ($33.5{\pm}6.7$), expatriate ($34.9{\pm}6.0$) groupd and the Malays ($35.6{\pm}6.5$) compared to the Chinese ($38.6{\pm}4.6$), a similar trend being observed in the non-young CRC groups. There were no difference between the genders and tumor locations (rectum or colon) between the young and the non-young CRC cases. Female young CRC was significantly younger than male (p<0.05) without any significant variation between the various population groups (p>0.05). Conclusions: Our study showed that the young CRC accounted for 15.1% of all CRC with declining trend observed over recent years. Young CRC was more common among indigenous, expatriates and Malays and least common among the Chinese. There were no differences in the gender and tumor locations.

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

Chong, Vui Heng,Telisinghe, Pemasari Upali,Bickle, Ian,Abdullah, Muhamad Syafiq,Lim, Ediwn,Chong, Chee Fui Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.12

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 $59.3{\pm}14.6$ 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.

Esophageal Cancer in Brunei Darussalam over a three Decade Period: an Epidemiologic Study of Trends and Differences between Genders and Racial Groups

Chong, Vui Heng,Telisinghe, Pemasari Upali,Chong, Chee Fui Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.9

Background: Carcinoma of the esophagus is associated with significant morbidity and mortality. The most common subtype is squamous cell carcinoma (SCC). In the past three decades, the incidence of SCC has been reported to be decreasing whereas esophageal adenocarcinoma (AC) is increasing. This study assessed the trend of esophageal cancer in Brunei Darussalam over a three decades period. Materials and Methods: The National Cancer registry was searched for esophageal cancers from 1986 to 2012. Data on age, gender, racial groups (Malays, Chinese, Indigenous and foreign nationals) and histology type were collected. The rate (ASR) and Age Specific Incidence rate (ASIR) were calculated. Results: The predominant tumor type was SCC which accounted for 89% of all esophageal cancer. The gender ratio was 2.25: 1 (male: female) and the mean age at diagnosis was $66.9{\pm}12.9$ years, significantly younger for esophageal AC ($57.2{\pm}16.0$) compared to SCC ($68.1{\pm}12.0$, p<0.05), and among the foreign nationals (p<0.05 for trend). The proportions of SCC among all esophageal cancers in the various racial groups were: Malays (87.8%), Chinese (100%), Indigenous (100%) and foreign nationals (20%). None of the Chinese and Indigenous groups were diagnosed with esophageal AC. The overall ASR for esophageal cancer was 2.1/100,000; 2.0/100,000 for SCC with a declining trend and 0.17/100,000 for esophageal AC, without any trend observed. Among the two major racial groups; the Chinese has higher ASR (3.42/100,000) compared to the Malays (ASR 0.95/100,000). Conclusions: SCC is the predominant tumor type of esophageal cancer in Brunei Darussalam and more common among the Chinese. There was a declining trend in the incidence of SCC but not for esophageal AC.

Profiles of Epstein-Barr Virus Associated Gastric Carcinomas in Brunei Darussalam

Yen, Rachel Lai Siaw,Telisinghe, Pemasari Upali,Cunningham, Anne,Abdullah, Muhd Syafiq,Chong, Chee Fui,Chong, Vui Heng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Background: Gastric cancer is the second most common gastrointestinal cancer and is largely attributed to Helicobacter pylori (H. pylori) infection. In addition, studies have also shown association with Epstein-Barr virus (EBV) in 10% of gastric cancers. This study assessed the characteristics of EBV associated gastric cancers (EBVaGC) in Brunei Darussalam. Materials and Methods: This study included gastric cancers diagnosed between 2008 and 2012, registered with the Department of Pathology RIPAS Hospital, Brunei Darussalam. Clinical case notes were systematically reviewed. Histology specimens were all stained for EBV and also assessed for intestinal metaplasia and H. pylori. Results: There were a total of 81 patients (54 male and 27 females) with a mean age of $65.8{\pm}14.8years$ included in the study. Intestinal metaplasia and active H. pylori infection were detected in 40.7% and 30.9% respectively. A majority of the tumors were proximally located (55.6%), most poorly differentiated (well differentiated 16%, moderately differentiated 30.9% and poorly differentiated 53.1%) and the stages at diagnosis were; stage I (44.4%), stage II (23.5%), stage III (8.6%) and stage IV (23.5%). EBV positivity (EBVaGC) was seen in 30.9%. Between EBVaGC and EBV negative gastric cancers, there were no significant differences (age, gender, ethnic group, presence of Intestinal metaplasia, tumor locations, stages of disease and degree of tumor differentiation). Conclusions: This study showed that a third of gastric cancers in Brunei Darussalam were positive for EBV, higher than what have been reported in the literature. However, there were no significant differences between EBVaGC and EBV negative gastric cancers. This suggests that the role of EBV in gastric cancer may be mostly incidental rather than any causal relation. However, further studies are required.

Diverticular Disease and Colorectal Neoplasms: Association between Left Sided Diverticular Disease with Colorectal Cancers and Right Sided with Colonic Polyps

Wong, E Ru,Idris, Fazean,Chong, Chee Fui,Telisinghe, Pemasari Upali,Tan, Jackson,Chong, Vui Heng Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.5

Background: Both colorectal cancer (CRC) and diverticular disease (DD) are common in the affluent West, and their prevalence is also increasing in the rest of the world with economic development. Both diseases have common epidemiologic characteristics; increasing incidence, more common with advancing age and related to specific dietary changes. However, studies of associations between the two have generated mixed results with some showing positive correlations, whilst others have shown no or negative links. Most of these studies have been from the West with study populations that were predominantly Caucasians. Here the focus was on DD and colorectal neoplasms, including CRC, in Brunei. Materials and Methods: All patients who had undergone complete colonoscopy between 2011 and 2014 were identified and retrospectively reviewed. Patients under the age of 18 years old or had previous colonic surgeries (including previous CRC resection) were excluded. Results: The total number of colonoscopies included in the study was 2,766 (mean age $53.2{\pm}14.8$ years old, male 51.8%), of which DD, CRC and colonic polyps were detected in 17.3%, 4.7% and 28.2% respectively. The proportions of DD, polyps and CRC increased proportionally with age (<30 years, 30-49, 50-69 and ${\geq}70$). Overall, there was no association between the presence of DD and CRC (3.6% vs. 5.0%, p=0.179) but there was a significant association between CRC and left sided DD (p=0.034 by trend). There were also a significant association between presence of DD and polyps (36.1% vs. 28.2%, p=0.001), in particular with right-sided and pan-DD (p=0.001 for trend). Conclusions: Our study showed that the prevalence of DD, CRC and polyps increases with age. There were significant associations between presence of left-sided DD with CRC and right-sided or pan-DD with colonic polyps. This suggests shared risk factors. Further studies are required to assess links in other countries of the Asian Pacific region.

Cancers of the Young Population in Brunei Darussalam

Mohammad, Ibnu Ayyub,Bujang, Mas Rina Wati,Telisinghe, Pemasari Upali,Abdullah, Muhd Syafiq,Chong, Chee Fui,Chong, Vui Heng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: Globally, the overall incidence of cancer is increasing as a result of ageing populations and changing lifestyles. Cancer is one of the leading causes of death, especially in the developed nations. Cancers affecting the young population are generally considered uncommon. This study assessed the demography and trends of cancers of the young in Brunei Darussalam, a small and developing Southeast Asia nation. Materials and Methods: All patients diagnosed with cancers between 2000 and 2012 were identified from the cancer registry maintained by the State Histopathology Laboratory. Cancers of the young was defined as any cancers diagnosed under the age of 40 years. Demographic data and the type of cancers were collected and analysed using SPSS Statistics 17.0. Results: Among the 6,460 patients diagnosed with cancer over the study period, 18.7% (n=1,205) were categorized as young with an overall decline in the proportion from 26.6% in 2000 to 18.8% in 2012 (p<0.001 for trend). Among all cancers of the young, the most common systems affected were gynecological (24.1%), hematological/lymphatic (15.8%), subcutaneous/dermatological/ musculoskeletal (10.5%), breast (10.5%) and gastrointestinal (9.9%). Overall, among the different systems, neurological (54.9%) had the highest proportion of cancers of the young followed by gynecological/reproductive (30.6%), hematological/lymphatic (39.9%), endocrine (38.7%), subcutaneous/dermatological/ musculoskeletal (22.3%) and the head and neck region (20.1%). There was a female predominance (66.9%) and the incidence was significantly higher among the Malays (20.1%) and expatriates (25.1%) groups compared to the Chinese (10.7%) and indigenous (16.8%) groups (p<0.001 for trend). Conclusions: Cancers of the young (<40 years) accounted for almost a fifth of all cancers in Brunei Darussalam with certain organ systems more strongly affected. There was a female preponderance in all racial groups. Over the years, there has been a decline in the overall proportion of cancers of the young. Selective screening programs should nevertheless be considered.

Rising Incidence of Primary Liver Cancer in Brunei Darussalam

Chong, Raymond Jih Yeong,Abdullah, Mohd Syafiq,Hossain, Mohammad Moshaddeque,Telisinghe, Pemasari Upali,Chong, Vui Heng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Background: Primary liver cancer (PLC) is the fifth most common malignancy worldwide and is still associated with high mortality. Hepatocellular carcinoma (HCC) and cholangiocarcinoma are the two most common PLCs, and their incidence varies across regions. Currently there are no published data available on the incidence of PLC in Brunei Darussalam. Materials and Methods: All proven PLCs between 2000 and 2009 were identified from the National Cancer Registry and reviewed. Metastatic diseases were excluded. A total of 123 cases (male 65.8%, female 34.2%) were identified and their data collected for calculation of the age standardised rate (ASR). Results: The most common type of PLC was HCC (87.8%) followed by cholangiocarcinoma (10.6%). There were two cases of hepatoblastoma. The mean age at diagnosis was 63.2 years. The overall ASR of PLC was 8.2/100,000, increasing from 4.5/100,000 population in 2000 to 11.4/100,000 population in 2009. The rates were higher among males (12.0/100,000) than females (4.7/100,000). Among the ethnic groups, Chinese had the highest rates (overall 13.1/100,000 with none recorded in 2000 to 30.3/100,000 in 2009) compared to the Malays (overall 8.5/100,000 increasing from 4.5/100,000 in 2000 to 12.3/100,000 in 2009) and the indigenous groups. The incidence increased after the age of 50 and was highest among the 75-79 age groups. Increase was seen for HCC but not for cholangiocarcinoma. Conclusions: The most common type of PLC is HCC and the annual incidence of PLC is increasing in Brunei Darussalam,rates being higher in males and Chinese.