A recent study suggests a variable that should be used as a standard outcome measure for clinical trials of patients with follicular lymphoma, published in the British Journal of Hematology (online August 7, 2017; doi:10.1111/bjh.14831).
Follicular lymphoma is a relatively rare type of non-Hodgkin lymphoma. Limited data exists regarding the risk factors associated with histological transformation in patients with such disease, as well as the role of treatment and response on survival following transformation.
A group of Spanish researchers led by Armando López-Guillermo, MD, department of hematology, Clinical Hospital of Barcelona, conducted a retrospective observational study to investigate the cumulative incidence of histological transformation in patients with follicular lymphoma, risk factors associated with transformation, and any potential associations between the role of treatment and response on survival following transformation. A total of 1734 patients with grade I-IIIA follicular lymphoma were enrolled and received varying first-line therapies.
The High Follicular Lymphoma International Prognostic Index (FLIPI) and Revised International Prognostic Index (R-IPI) were utilized to predict prognosis.
Researchers observed complete responses or uncertain responses in 75% of the patient cohort; partial response in 18%; and refractory disease, progressed disease, or death in 6%.
Overall survival after 10 years was 72% (95% CI, 69%-75%). After a median follow-up of 6.2 years, 106 patients had developed histological transformation. Researchers noted the median time to transformation was 2.5 years after the initial diagnosis.
Cumulative incidence of histological transformation at 5 years and 10 years were 5% and 8%, respectively. Low-, intermediate-, and high-risk FLIPI assessment scores were associated with cumulative incidence of 7%, 9%, and 14%, respectively. Additionally, non-responsiveness to first-line therapy was associated with histological transformation.
Five-year survival following transformation was 26% among the patients who developed histological transformation. Factors associated with survival following transformation were response to histological transformation first-line therapy, autologous stem cell transplantation, and R-IPI score.
After reviewing the results of their study, researchers concluded that inclusion of histological transformation in clinical trials for follicular lymphoma with new agents should be mandatory.—Zachary Bessette