Feasibility of allogeneic hematopoietic stem cell transplantation for follicular lymphoma undergoing transformation to diffuse large B-cell lymphoma.

The transformation of follicular lymphoma (FL) to high-grade histology occurs in up to 70% of FL patients. Studies reporting outcomes of transformed FL patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) are scant. Eight FL patients with histologically confirmed transformation to diffuse large B-cell lymphoma underwent HSCT at our institution. The median age was 56 years (range 44-63 years). Median follow-up is 60 months. Progression free survival and overall survival at 4-years for patients undergoing allogeneic HSCT is 56% and 66%, respectively. Four patients developed grade II-IV acute GVHD, whereas four patients had extensive chronic GVHD. Day 100 and overall non-relapse mortality rate was 12.5% and 25%, respectively. Allogeneic HSCT appears feasible in patients with transformed FL and is associated with acceptable treatment-related mortality and low relapse rates.