Prognostic value of the Kyoto Prognostic Index in higher-risk diffuse large B-cell lymphomas treated by upfront autologous stem cell transplantation in JCOG0908 trial

Background: There is currently no standard prognostic model optimized for the patients with diffuse large B-cell lymphoma (DLBCL) treated with upfront intensive immunochemotherapy including autologous stem cell transplantation (ASCT). The Kyoto Prognostic Index (KPI) has been proposed as a novel prognostic model for DLBCL, which can accurately identify especially high-risk patients. In this study, we investigated the prognostic value of the KPI in JCOG0908 trial in which higher-risk DLBCL patients defined by the conventional International Prognostic Index (IPI) were treated with upfront high dose therapy followed by ASCT. Methods: Fifty-eight patients with DLBCL, not otherwise specified, enrolled in JCOG0908 and confirmed by the central pathological review were analyzed. The Kaplan-Meier method was used to estimate the probabilities of overall survival (OS) and progression-free survival (PFS). We compared the discrimination ability of the KPI with that of the IPI. Results: According to KPI, 3-year OS and PFS rates were 86.7% and 76.7% in low-intermediate, 73.3% and 60.0% in high-intermediate, and 61.5% and 46.2% in high-risk group. According to IPI, 3-year OS and PFS rates were 75.0% and 50.0% in low-intermediate, 82.9% and 74.3% in high-intermediate, and 63.6% and 54.5% in high-risk group. The concordance-indices of KPI and IPI were 0.642 and 0.580 for OS and 0.606 and 0.606 for PFS. Conclusions: The KPI may be a suitable predictor of outcome than the IPI for patients with higher-risk DLBCL treated with upfront intensive immunochemotherapy including ASCT.

Automated summary

The Kyoto Prognostic Index (KPI) shows better predictive value in the prognosis assessment of high-risk DLBCL patients compared to the conventional International Prognostic Index (IPI).