Affiliation:
1. Department of Hematology Ren Ji Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
2. Surgical, Medical and Dental Department of Morphological Sciences related to Transplant, Oncology and Regenerative Medicine University of Modena and Reggio Emilia Modena Italy
3. Department of Medical and Surgical Sciences for Children and Adults University of Modena and Reggio Emilia Modena Italy
4. Hospital Universitario Central de Asturias ‐ Insituto de investigación Sanitaria del Principado de Asturias (ISPA) Oviedo, Asturias Spain
Abstract
AbstractIntroductionThe histological transformation (HT) of follicular lymphoma (FL) is a crucial biological event. The study aimed to evaluate the incidence, clinicial characteristics, prognosis and impact of HT time on survival of FL transforming to diffuse large B‐cell lymphoma in population‐based large‐scale cohorts.MethodsA retrospective cohort study of FL with HT was performed in the Surveillance, Epidemiology, and End Results database. The Hematological Malignancy Research Network FL cohort and Aristotle study FL cohort were used to assess the external validity.ResultsAmong 44,127 FL cases from the Surveillance, Epidemiology, and End Results database, 1311 cases were pathology‐proven recorded to transform to diffuse large B‐cell lymphoma. The cumulative rates of HT at 5, 10, and 15 years after FL diagnosis were estimated to be 1.19%, 2.93%, and 5.01%, respectively. Significantly worse overall survival and cancer‐specific survival were exhibited in patients with HT than those without HT. Early HT (transformation of FL within 48 months after FL diagnosis [TOD48]) was an independent predictor for adverse overall survival of HT patients, regardless of treatment modalities before transformation. The adverse prognostic effect of TOD48 was validated in the Hematological Malignancy Research Network cohort and Aristotle study cohort. Older age (>75 years) and B symptoms within FL at diagnosis were the independent risk factors of TOD48. Furthermore, a novel prognostic model combining TOD48 with Follicular Lymphoma International Prognostic Index (TOD48‐FLIPI) was constructed and validated for risk stratification.ConclusionTOD48 was a risk indicator of HT, and the novel prognostic model "TOD48‐FLIPI" for HT patients was proposed.