Absolute lymphocyte counts (ALCs) following fludarabine, cyclophosphamide, and rituximab (FCR) are prognostic for survival among patients with chronic lymphocytic leukemia (CLL), according to a study published in Hematological Oncology.1

FCR, a standard treatment for CLL, is linked to lymphocyte depletion, which may indicate therapy success. While minimal residual disease (MRD) testing has high prognostic value in CLL, it can be prohibitively expensive.

For this retrospective study, researchers evaluated data from 99 patients to determine whether ALC testing, which is less costly than MRD testing, has prognostic value in CLL.

Patients without lymphocytosis who had a partial response or better to treatment were evaluated at 3, 6, 9, and 12 months post–frontline FCR. ALCs were measured against overall survival (OS) and event-free survival (EFS).

At 3 months post-FCR, an ALC of less than 1 x 103 cells/μL was linked to a 5-year OS of 91% vs 64% for a higher ALC. This improved OS was also seen among patients with lower ALCs at the 6- and 9-month time points.

“Normal-range” ALCs at 12 months, defined as 4 or lower x 103 cells/μL, correlated with a 5-year OS of 91%.

At 9 months post-FCR, a shorter EFS was seen among patients with ALCs higher than 1.8 vs .7 or lower (27 months vs not reached, respectively).

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The authors concluded that ALC levels are prognostic for survival among FCR-treated patients with CLL, noting that ALCs may indicate cancer clonal suppression or T cell subpopulation depletion.

They added that “[while] ALC levels may be a cheap and widely available prognostic marker, with the increasing implementation of MRD monitoring, the added value for clinical practice should be further explored.”

Reference

  1. Joffe E, Arad N A, Bairey O, et al. Persistently low lymphocyte counts after FCR therapy for chronic lymphocytic leukemia are associated with longer overall survival. Hematol Oncol. 2017 Jun 22. doi: 10.1002/hon.2444 [Epub ahead of print]