https://orcid.org/0000-0001-5391-9537
Key Points
Involvement of ≥2 EN sites or skin/soft tissue on PET/CT represent predictors of PFS and OS in newly diagnosed follicular lymphoma (FL).
We developed a PET-based prognostic index for untreated FL, without need for bone marrow biopsy. This index did not outperform FLIPI-2.
Abstract
Parameters detected by positron emission tomography (PET) are not included in the usual predictive indices for follicular lymphoma (FL). Data is lacking regarding PET extranodal factors that predict outcomes in FL. PET exams from 258 patients with untreated grade 1-3a FL included in the E2408 randomized phase II trial were reviewed. Validation of the prognostic significance of PET factors identified in a previous retrospective study was performed. PET factors with a significant impact on survival outcomes were combined with significant FL International Prognostic Index-2 (FLIPI-2) factors to evaluate the predictive value of a PET-based prognostic index. Presence of two or more EN sites and skin/soft tissue involvement on PET were validated as predictors of overall survival. These factors were combined with all FLIPI-2 factors except “positive BMB” to form a PET-based prognostic score. This novel score identified a group of patients at high risk of progression of disease at 24 months. This PET-based score did not perform better than the traditional FLIPI-2 on additional analysis. Presence of two or more EN sites and skin/soft tissue involvement on PET predict poor outcomes in untreated FL. Further studies should be performed to determine the validity of a PET-based prognostic index in FL.
Author notes
Funding: Robert H. Lurie Comprehensive Cancer Center
Acknowledgments: This study was coordinated by the ECOG-ACRIN Cancer Research Group (Peter J. O’Dwyer, MD and Michelle D. Schnall, MD, PhD, Group Co-Chairs); Supported by the National Cancer Institute of the National Institutes of Health under award numbers: U10CA180820, U10CA180794, UG1CA233320, and UG1CA233339; The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Data Availability: The data that support the findings of this study are available upon request by email to the corresponding author.
