Interim PET-CT Result Is Not Predictive of Survival in Patients with MYC-Rearranged Non-Burkitt Aggressive B Cell Lymphoma

Abstract

Abstract Background Patients with a diagnosis of MYC-rearranged non–Burkitt aggressive B-cell lymphoma (MYC-R), including those with double hit lymphoma, are at high risk of developing relapsed/refractory disease, even if treated with intensive front-line immunochemotherapy. It is common in clinical practice and clinical trials to perform an interim positron emission tomography (PET)/computed tomography (CT) scan (iPET) during front-line therapy for diffuse large B-cell lymphoma. However, the utility of the iPET result for MYC-R patients for predicting outcomes is unclear. Patients and Methods We performed a single-center retrospective study with centralized pathologic review and PET/CT image acquisition and interpretation for 28 MYC-R patients. The patients received front-line therapy with R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin [doxorubicin], Oncovin [vincristine], prednisone) or intensive immunochemotherapy. Results Eight patients had iPET-positive (iPET+) and 20 patients had iPET-negative (iPET−) results using the Deauville visual assessment criteria. At a median follow-up length of 30.4 months, progression-free survival was 65% and overall survival was 76%, neither of which differed significantly between the iPET− and iPET+ patients. The positive predictive value of iPET for progression at 30 months was 25%, and the negative predictive value was 65%. Conclusion Although patients with MYC-R lymphoma have been reported to be at high risk of primary treatment failure, this was not predicted by iPET+ results. Thus, the iPET result should not be used to guide changes in front-line or consolidative therapy for these patients.