Studies Assess PET Scans as Tool for Guiding Therapy in Lymphoma

Though much of the lymphoma research presented at the Annual Meeting of the American Society of Hematology (ASH) in December 2014 focused on the growing number of novel therapies for this disease, a subset of presentations focused on the impact of non-pharmaceutical treatment issues such as patient quality of life, maintenance scans, and the presence or absence of various risk factors. These studies, a selection of which are summarized below, demonstrate that research beyond pharmaceutical trials is a crucial component of continuing to improve survival rates in lymphoma.

Two studies at ASH investigated the effectiveness of using positron emission tomography (PET) scans to guide treatment for lymphoma patients. Researchers on the PETAL trial in Germany initiated a randomized study, in which 107 patients (out of a group of 926) who had an unfavorable PET scan after 2 cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) were randomized to either move to a more intensive therapy regimen or receive an additional 6 cycles of R-CHOP. Although the PET scan did prove to be an effective predictor of poor outcomes, the researchers found that there was no significant difference in treatment outcomes for those that switched to the more aggressive therapy midway through their treatment. The abstract on this study may be viewed here.

A separate study examined diffuse large B-cell lymphoma (DLBCL) patients who received a PET scan after 3 cycles of R-CHOP; those with positive scans (showing continued disease progression) were moved to a more aggressive R-ICE regimen (rituximab, ifosfamide, carboplatin, and etoposide). Similar to the PETAL trial, the researchers found that, though the scans were effective at predicting poor outcomes, the switch to R-ICE did not significantly improve patient outcomes. The researchers, including LRF Scientific Advisory Board members Laurie H. Sehn, MD, MPH and Randy Gascoyne, MD, as well as former SAB member Joseph M Connors, MD all of British Columbia Cancer Agency in Vancouver, suggested that R-ICE may not be sufficient to overcome the inherent resistance to chemotherapy in the group with poorer outcomes. The abstract on this study may be viewed here.