Positron-emission tomography-based staging reduces the prognostic impact of early disease progression in patients with follicular lymphoma.

•Early progression after first-line treatment in follicular lymphoma is a marker of poor prognosis.•Positron-emission tomography (PET) staging possibly identifies patients with highest risk of poor outcomes.•PET staging reduces the prognostic impact of early progression likely by excluding patients with early transformation.•Patients with early progression and early transformation have the highest risk of poor outcomes.