Current status of prognostication in classical Hodgkin lymphoma.

Classical Hodgkin lymphoma (cHL) is characterized by a paucity of neoplastic Hodgkin/Reed Sternberg (HRS) cells within a complex cellular milieu that is rendered immunologically incapable of reacting against CD30(+) HRS cells due to a plethora of immune escape mechanisms initiated by the neoplastic cells. Accounting for 25% of all lymphomas and nearly 95% of all Hodgkin lymphomas, patients with cHL are typically young adults. Besides traditional prognostic factors, such as the International Prognostic Index (IPI), newer imaging and ancillary biomarkers (CD68, Galectin-1 and plasma microRNA) have shown promise. Furthermore, the evolution of gene expression profiling (GEP) in recent years has enabled the development of several practically feasible GEP-based predictors with prognostic relevance. This review discusses the current status of clinical prognostication in cHL, the critical role of histological evaluation in light of several mimicking entities, and the relevance of tissue as well as serum biomarkers pertaining to immune escape mechanisms and recent GEP studies.