A New Histology-Based Prognostic Index for Aggressive T-Cell lymphoma: Preliminary Results of the “TCL Urayasu Classification”

Background: Aggressive mature T-cell lymphoma (TCL) is a disease that carries a poor prognosis. Methods: We analyzed the expression of 22 tumor cell functional proteins in 16 randomly selected patients with TCL. Immunohistochemistry was performed in paraffin-embedded tumor tissue sections to determine the protein expression statuses in tumor cells. Results: Glucose-regulated protein 94 (GRP94), a protein that serves as a pro-survival component under endoplasmic reticulum (ER) stress in the tumor microenvironment, was significantly associated with a shortened survival. Furthermore, significant differences were observed when GRP94 was combined with six other factors. The six factors were (1) programmed cell death-ligand 1 (PD-L1); (2) programmed cell death 1 (PD-1); (3) aldo-keto reductase family 1 member C3 (AKR1C3); (4) P53, a tumor suppressor; (5) glucose-regulated protein 78 (GRP78), an ER stress protein; and (6) thymidine phosphorylase (TP). Based on the combination of GRP94 and the six other factors expressed in the tumors, we propose a new prognostic classification system for TCL (TCL Urayasu classification). Group 1 (relatively good prognosis): GRP94-negative (n = 6; median OS, 88 months; p < 0.01); Group 2 (poor prognosis): GRP94-positive, plus expression of two of the six factors mentioned above (n = 5; median OS, 25 months; p > 0.05); and Group 3 (very poor prognosis): GRP94-positive, plus expression of at least three of the six factors mentioned above (n = 5; median OS, 10 months; p < 0.01). Conclusions: Thus, the TCL Urayasu prognostic classification may be a simple, useful, and innovative classification that also explains the mechanism of resistance to treatment for each functional protein. If validated in a larger number of patients, the TCL Urayasu classification will enable a targeted treatment using selected inhibitors acting on the abnormal protein found in each patient.