Aggressive B-cell Lymphomas : Studies of Treatment, FDG-PET Evaluation and Prognostic Factors

Sammanfattning: To improve outcome in young, high-risk lymphoma patients, treatment was intensified, adding etoposide and rituximab to standard CHOP treatment. Granulocyte-colony stimulating factor (G-CSF) enabled treatment bi-weekly. Results were promising: overall (OS) and event-free survival (EFS) 79% and 60% respectively, median follow up 27 months. Single infusion Ara-C, contrary to expectations, did not prevent relapse in CNS. DLBCL were classified as germinal center (GC) or non-GC derived, using immunohistochemical markers, CD10, BCL6 and MUM1. We investigated the outcome for both phenotypes after adding rituximab to chemotherapy. For 106 patients treated with CHOP alone, the GC phenotype displayed significantly better OS and EFS. In contrast, GC phenotype did not predict outcome in 95 patients treated with immunochemotherapy . Thus, addition of rituximab seems to eliminate the prognostic value of immunohistochemically defined GC phenotypes in DLBCL. To improve evaluation and find non-responders, mid-treatment FDG-PET CT was incorporated into clinical routine for patients with high-risk aggressive lymphoma. For those with positive PET, biopsy followed by treatment intensification was recommended. Twenty-five patients were examined, five with positive PET. Two of these had lymphoma in the biopsy. Two had a negative biopsy, and one had a false positive investigation. Seven patients had increased uptake of uncertain significance. Two patients with uncertain PET, and two with negative PET have relapsed, giving a negative predictive value of 85%. In case of relapse of aggressive lymphoma or if not obtaining CR, high dose chemotherapy with autologous stem cell support (HDT) is standard treatment. HDT outcome for 38 patients with transformed follicular lymphoma was compared to outcome for 79 patients with de novo B-cell lymphoma. At median follow-up of 11.5 years both OS and EFS were superior in the transformed group, OS 67% and 33%, EFS 55% and 27% respectively. Treatment related mortality was less than reported in other studies.