Results of a prospective phase II trial evaluating interim positron emission tomography-guided high dose therapy for poor prognosis diffuse large B-cell lymphoma

Abstract

Patients with diffuse large B-cell lymphoma (DLBCL) with a poor prognosis based upon advanced stage and elevated serum lactate dehydrogenase achieve a 3–4-year progression-free survival (PFS) of only 55%. The role of interim fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) to guide use of upfront high dose chemotherapy (HDCT) and autologous stem cell transplant (ASCT) for patients with poor prognosis DLBCL is unproven. A prospective phase II clinical trial was designed to evaluate the outcomes of HDCT/ASCT for patients with poor prognosis DLBCL aged 18–65 years who had unfavorable interim restaging PET scans. Of the 70 eligible patients, 36 had unfavorable and 34 favorable interim PET responses, with 3-year PFS rates of 65.2% and 52.7%, respectively. In conclusion, favorable interim PET response as defined in this study is not associated with improved PFS rates for patients with poor prognosis DLBCL treated with RCHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone). A phase III trial evaluating this PET-guided approach is not warranted.