[Prognostic factors in Hodgkin and non-Hodgkin lymphomas]

Hodgkin's and non-Hodgkin's lymphomas are frequent and represent a heterogenic group of haematologic diseases. Prognostic factors allow to classify patients into homogeneic risk groups, to adapt treatment proposal to disease's risk and, in some cases, to avoid over-treatment. For all lymphomas, the first step is to determine the stage of the disease in Ann Arbor's classification, using physical examination, radiological and functional imaging. However, this classification is not optimal to predict disease evolution. Specific scores corresponding to the histological subtype of the lymphoma have been determined: IPI (international prognostic index) for aggressive lymphomas, FLIPI (follicular lymphoma international prognostic index) for indolent lymphomas and IPS (international prognostic score) for advanced Hodgkin's lymphomas. Functional imaging by PET (position emission tomography) is of prognostic significance in aggressive and Hodgkin lymphomas to evaluate early response to treatment, before autografting and at the end of the treatment. Several kinds of molecular prognostic markers have been studied: circulating rates of proteins, over expression of genes, presence of specific cells in the tumour... But these factors are not yet used in clinical practice, as they have not been validated on large cohorts and their interactions with other prognostic factors and between them are not well known. Although molecular biology has made some recent progress, only classical prognostic factors (physical examination, radiological and functional imaging) are used by now.