Diabetes, Epstein-Barr virus and extranodal natural killer/T-cell lymphoma in India: Unravelling the plausible nexus

The International Diabetes Federation Diabetes Atlas estimates a staggering 590 million people affected with diabetes mellitus (DM) within the next two decades globally, of which Type 2 DM will constitute more than 90%. The associated insulin resistance, hyperinsulinemia, and hyperglycemia pose a further significant risk for developing diverse malignant neoplasms. Diabetes and malignancy are multifactorial heterogeneous diseases. The immune dysfunction secondary to Type 2 diabetes also reactivates latent infections with high morbidity and mortality rates. Epstein-Barr virus (EBV), a ubiquitous human herpes virus-4, is an oncogenic virus; its recrudescence in the immunocompromised condition activates the expression of EBV latency genes, thus immortalizing the infected cell and giving rise to lymphomas and carcinomas. Extranodal natural killer/T-cell lymphoma (ENKTCL), common in South-East Asia and Latin America; is a belligerent type of non-Hodgkin lymphoma (NHL) almost invariably associated with EBV. An analysis of articles sourced from the PubMed database and Google Scholar web resource until February 2014, suggests an increasing incidence of NHL in Asia/India and of ENKTCL in India, over the last few decades. This article reviews the epidemiological evidence linking various neoplasms with Type 2 DM and prognosticates the emergence of ENKTCL as a common lymphoreticular malignancy secondary to Type 2 diabetes, in the Indian population in the next few decades.