Cancer: Scenario and Relationship of Different Geographical Areas of the Globe with Special Reference to North East-India

Background: Cancer is becoming the most important public health burden around the globe. As per theGLOBOCAN 2008 estimates, about 12.7 million cancer cases and 7.6 million cancer deaths were estimatedto have occurred in 2008. The burden of cancer cases for India in the year 2020 is calculated to be 1,148,757(male 534,353; female 614,404) compared to 979,786 in 2010. The pattern of cancer incidence is varying amonggeographical regions, esophageal cancer for example being high in China, lung cancer in USA, and gallbladdercancer in Chile. The question remains why? Is it due to the diversity in genome pool, food habits, risk factorassociation and role of genetic susceptibility or some other factors associated with it? In India, the North East(NE)-India region is seeing a marked increase in cancer incidence and deaths, with a very different cancerincidence pattern compared to mainland India. The genome pool of the region is also quite distinct from the restof India. Northeastern tribes are quite distinct from other groups; they are more closely related to East Asiansthan to other Indians. In this paper an attempt was made to see whether there is any similarity among the patternof cancer incidence cases for different sites of NE-India region to South or East-Asia. Materials and
Methods:Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), Pearson Correlation coefficient testwas assessed to evaluate the linkage of North-East India region to other regions. A p value <0.05 was consideredas statistically significant.
Results: The results clearly shows that there are similarities in occurrence of cancerincidence patterns for various cancer sites of NE-India with South and East-Asian regions, which may lead tothe conclusion that there might be a genetic linkage between these regions.