Validation of prognostic indices in adult T-cell leukemia/lymphoma and their prognostic value at the start of second-line treatment.

Adult T-cell leukemia/lymphoma (ATL), a peripheral T-cell neoplasm associated with human T-cell leukemia virus type 1 (HTLV-1), carries a poor prognosis. We first confirmed the applicability of the simplified ATL-prognostic index (sATL-PI) and the Japan Clinical Oncology Group prognostic index (JCOG-PI) in the cohort of patients with aggressive ATL diagnosed between January 2009 and March 2022 at Kagoshima University Hospital. The power of stratification of survival at the start of second-line treatment, namely sATL-PI-2 and JCOG-PI-2, were then evaluated in 53 and 54 patients. The sATL-PI-2 could successfully stratify patients into high-, intermediate-, and low-risk groups with median survivals of 0.9, 5.4, and 9.6 months. The JCOG-PI-2 also stratified high- and moderate-risk groups with median survivals of 1.5 and 7.6 months. These results indicate that both indices are useful as prognostic tools at the initiation of second-line treatment in patients with ATL.