Prognostic indices for peripheral T-cell lymphoma - not otherwise specified and adult T-cell leukemia/lymphoma: From past to future.

Several prognostic indices have been reported for peripheral T-cell lymphoma (PTCL) and adult T-cell leukemia/lymphoma (ATL). The clinical features and prognosis of PTCL differ in a specified pathological diagnosis, whereas those of ATL are more diverse, even in the same clinical subtypes of acute, lymphoma, chronic, and smoldering. The establishment of a prognostic index is important not only for a risk-stratified treatment approach, but also for the preliminary evaluation of therapeutic findings by novel modalities, particularly in rare and aggressive diseases such as ATL. Five prognostic indices for PTCL-not otherwise specified and 6 prognostic indices for ATL are discussed herein. Recent advances in molecular analyses have facilitated prognostication using molecular profiles. In addition to the external validation of these prognostic indices, which are mostly established by clinical information, the development of novel indices by incorporating molecular profiles is warranted to improve the outcomes of patients through the selection of optimal treatments.