Response to therapy

Burkitt lymphoma: Historically, response to the initial prophase treatment was considered an important predictive factor. Poor responders (i.e., <20% resolution of disease) had an event-free survival (EFS) rate of 30%.[25,26] However, poor response to initial treatment was not found to be an adverse prognostic factor in the Inter B-NHL Ritux 2010 (NCT01516580) trial, in which patients were treated with more effective therapy.[27]

Lymphoblastic lymphoma: The presence of a residual mediastinal mass at day 33 or at the end of induction was not found to be associated with decreased survival in the BFM 90-95 studies. However, all patients with less than 70% reduction at the end of induction had therapy intensified.[28]

Burkitt lymphoma: One study suggested an inferior outcome for patients with Burkitt lymphoma who had detectable MRD after induction chemotherapy.[30] However, other studies found that detectable MRD at the end of induction was not prognostic, possibly because of the low number of relapses in patients with disease detected in the blood or bone marrow at diagnosis.[31,32]

Anaplastic large cell lymphoma: A retrospective analysis of a collaborative European study showed that after induction, MRD-negative patients had a relapse risk of approximately 20% and an overall survival (OS) rate of approximately 90%. By contrast, MRD-positive patients had a relapse risk of 81% and an OS rate of 65% (P < .001). The presence of MRD is significantly associated with uncommon histological subtypes containing small cell and/or lymphohistiocytic components.[33][Level of evidence B4]