The first Indian study on incidence of cancers among ethnic populations in the north eastern state of Sikkim has revealed that the Bhutias, early immigrants from the Tibetan province of Khams, account for the highest number of cancer affected. British interdisciplinary scientific journal, Nature has highlighted this in one of its recent articles.
Researchers studied 13 ethnic groups with diverse lifestyle and dietary habits. Age-adjusted incidence rates (AARs) per 100 000 person-years were calculated by direct method using the world standard population, and analysed by ethnic group.
They reported the incidence and patterns of cancer including the ethnic variation observed during the first 6 years (2003–2008) of a Population-Based Cancer Registry (PBCR) set up in 2003 under the National Cancer Registry Programme (NCRP) of the Indian Council of Medical Research (ICMR). The registry was started following higher incidence of cancer reported in the north eastern states under a project to develop an atlas of cancer in India.
A total of 1148 male and 1063 female cases of cancer were reported between 2003 and 2008 on the Sikkim PBCR. The overall AARs were 89.4 and 99.4 per 100 000 person-years in males and females, respectively.
Incidence rates were highest amongst the Bhutia group (AAR=172.4 and 147.4 per 100 000 person-years in males and females, respectively), and the largest difference in rates were observed for stomach cancers with AARs being 12.6 and 4.7 times higher in the Bhutia group compared with other ethnic groups in males and females, respectively.
The observations call for further epidemiological investigations and the introduction of screening programmes, the researchers say.
Verma, Y. et al. Population-based cancer incidence in Sikkim, India: report on ethnic variation. Brit. J. Cancer 106, 962-965 (2012)