Role of frontline autologous stem cell transplantation in young, high-risk diffuse large B-cell lymphoma patients

Background/Aims: Several studies have demonstrated the effect of autologous hematopoietic stem cell transplantation (auto-HSCT) as a salvage treatment for patients with relapsed diffuse large B-cell lymphoma (DLBCL). However, the role of auto-HSCT as a frontline treatment has not been fully investigated in the rituximab era. We validated the age-adjusted International Prognostic Index (aaIPI) score for high-risk DLBCL patients and identified a possible role for frontline auto-HSCT. Methods: We recommended frontline auto-HSCT for high-risk DLBCL patients who satisfied the criteria of both a higher Ann-Arbor stage (III to IV) and an elevated lactate dehydrogenase (LDH) level at diagnosis with an aaIPI $score{\geq}2$. From 2006 to 2011, among the 150 DLBCL patients aged ${\leq}60$ years who were treated with six cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP), 23 high-risk patients with a complete response (CR) were treated with auto-HSCT. For comparison, we selected 35 well-matched high-risk patients with CR who completed R-CHOP treatment alone. In addition, there were 81 low-risk patients and 11 refractory patients. Results: DLBCL patients with an aaIPI $score{\geq}2$ showed inferior overall survival (OS; p = 0.040) and progression-free survival (PFS; p = 0.007) compared to the aaIPI score 0 to 1. Between the two treatment arms among the high-risk DLBCL patients, the clinical parameters were not different. The high-risk group treated with frontline auto-HSCT showed similar OS (p = 0.392) and PFS (p = 0.670) to those in the low-risk group. Thus, frontline auto-HSCT showed superior PFS (p = 0.004), but only a trend towards favorable OS (p = 0.091) compared to R-CHOP alone. Conclusions: We identified the possible role of frontline auto-HSCT for high-risk DLBCL with a higher stage (III to IV) and elevated LDH level.