There are 2 major phenotypic groups in diffuse large B-cell lymphoma, activated B-cell (ABC) and germinal center B-cell (GCB). The GCB phenotype responds well to up front therapy, while the ABC phenotype has worse overall and progression-free survival rates, Myron Czuczman, MD, explains. The utilization of technologies, such as nanostring, allow clinicians to identify which patients have the ABC subtype, which allows for stratification to an optimal treatment, Thomas J. Kipps, MD, states.

Lenalidomide has demonstrated improvements in outcomes for patients with the difficult-to-treat ABC phenotype, when combined with R-CHOP. Czuczman adds that activity has also been observed with ibrutinib in the ABC phenotype. Richard Furman, MD, describes a large national study looking at R-CHOP plus bortezomib to further define and close the treatment gap between GCB and ABC. Preliminary data suggest that the addition of bortezomib may help to overcome some of the negative prognostic value of the ABC phenotype. Another approach using CD30 expression and the use of CD30 antibodies as therapy in the DLBCL, is under exploration, notes Czuczman.

Regardless of the phenotype, patient outcomes may change when treatments are based on PET scan results, suggests Additionally, Shuo Ma, MD, PhD. In this approach, treatment would be escalated based on a positive PET scan. However, studies presented at the 2014 ASH meeting do not demonstrate that this approach improves outcomes. However, if patients remain PET-positive after a couple of cycles of R-CHOP, it could indicate that they are chemo-refractory. In this situation, there is a shortage of viable treatment options.