Prognosis and primary therapy in peripheral T-cell lymphomas.

Peripheral NK/T-cell neoplasms are an uncommon group of diseases that show distinct racial and geographic variation. The prognostic significance of the T-cell phenotype has been clearly defined in recent studies by using modern lymphoma classification systems. However, within this heterogenous group of neoplasms, some have a more favorable prognosis, such as ALK-positive anaplastic large-cell leukemia (ALCL) and primary cutaneous ALCL, and some have ultimately fatal courses with standard chemotherapy programs (e.g., hepatosplenic gammadelta T-cell lymphomas). Further, unlike the benefits observed with CHOP chemotherapy in the treatment of diffuse large B-cell lymphoma (DLBCL), peripheral T-cell lymphomas (PTCL), other than ALK-positive ALCL, are relatively chemoresistant to this regimen. Given disease rarity and biological heterogeneity, advances in diagnosis, prognosis and treatment have lagged behind DLBCL. Recently, however, studies are emerging that focus specifically on PTCLs with the ultimate goal of better understanding disease biology and developing more effective therapies.