Geographical distribution of the incidence of gastric cancer in Bhutan

• Published in: World journal of gastroenterology : WJG 2015-10, Vol.21 (38), p.10883-10889
• Main Authors: Dendup, Tashi, Richter, James M, Yamaoka, Yoshio, Wangchuk, Kinley, Malaty, Hoda M
• Format: Article
• Language: English
• Subjects: Aged; Bhutan - epidemiology; cancer; Mortality; Epidemiology; Bhutan; Female; Gastric; Gastrointestinal Neoplasms - epidemiology; Geographic Mapping; Humans; Incidence; Male; Middle Aged; Retrospective Study; Stomach Neoplasms - epidemiology
• ISSN: 1007-9327; 2219-2840
• DOI: 10.3748/wjg.v21.i38.10883

AIM: To estimate the prevalence of gastric cancer(GC) in a cohort of patients diagnosed with GC and to compare it with patients diagnosed with all other types of gastro-intestinal(GI) cancer during the same period.METHODS: Between 2008 and 2013,five-year period,the medical records of all GI cancer patients who underwent medical care and confirm diagnosis of cancer were reviewed at the National Referral Hospital,Thimphu which is the only hospital in the country where surgical and cancer diagnosis can be made. Demographic information,type of cancer,and the year of diagnosis were collected.RESULTS: There were a total of 767 GI related cancer records reviewed during the study period of which 354(46%) patients were diagnosed with GC. There were 413 patients with other GI cancer including; esophagus,colon,liver,rectum,pancreas,gall bladder,cholangiocarcinoma and other GI tract cancers. The GC incidence rate is approximately 0.9/10000 per year(367 cases/5years per 800000 people). The geographic distribution of GC was the lowest in the south region of Bhutan 0.3/10000 per year compared to the central region 1.4/10000 per year,Eastern region 1.2/10000 per year,and the Western region 1.1/10000 per year. Moreover,GC in the South part was significantly lower than the other GI cancer in the same region(8% vs 15%; OR = 1.8,95%CI: 1.3-3.1,P = 0.05). Among GC patients,38% were under the age of 60 years,mean age at diagnosis was 62.3(± 12.1) years with male-to-female ratio 1:0.5. The mean age among patients with all other type GI cancer was 60 years(± 13.2) and male-tofemale ratio of 1:0.7. At time of diagnosis of GC,342(93%) were at stage 3 and 4 of and by the year 2013; 80(23%) GC patients died compared to 31% death among patients with the all other GI cancer(P = 0.08).CONCLUSION: The incidence rate of GC in Bhutan is twice as high in the United States but is likely an underestimate rate because of unreported and undiagnosed cases in the villages. The high incidence of GC in Bhutan could be attributed to the high prevalence of Helicobacter pylori infection that we previously reported. The lowest incidence of GC in Southern part of the country could be due to the difference in the ethnicity as most of its population is of Indian and Nepal origin. Our current study emphasizes on the importance for developing surveillance and prevention strategies for GC in Bhutan.