Does Low-grade Follicular Lymphoma With a High Proliferation Index Require a Different Treatment Strategy? A Single Center Experience.

Background/aim: Follicular lymphoma (FL) is the most common indolent non-Hodgkin lymphoma worldwide. Patients can have a wide range of clinical features and behavior which does not necessarily correlate to histologic grade or Ki-67 proliferation index. We hypothesized that patients with low grade but high proliferative index (LG/HP) FL have a more aggressive disease course. The aim of this study was to determine the role of LG/HP on the outcomes of FL patients.

Patients and methods: A retrospective single center study of FL patients treated within the Allegheny Health Network was conducted from January 2011 to December 2021. Patients were divided into three groups: low grade/high proliferation index (PI) (LG/HP), low grade/low PI (LG/LP), and high grade (HG). Cox regression models looking at variables including age, sex, race, Ann Arbor staging, PET SUV_max, FLIPI score, and treatment details were used to analyze predictors of progression. Survival estimates were calculated using the Kaplan-Meier method and compared using the Log-rank test.

Results: A total of 145 patients were treated for FL during the study period. Most were males and fell into the LG/LP group. We determined that the median progression-free survival in the LG/HP group was numerically worse than the LG/LP group; however, this did not meet statistical significance.

Conclusion: Our data suggest that a different treatment approach may not be warranted for LG/HP FL patients.