Clinical Characteristics, Treatment Pattern and Outcome of Histologic Transformed Lymphoma, a Single Institution Experience

Author(s): Bolanle Gbadamosi, Yifan Pang, Daniel Ezekwudo, David Macari, John Khoury, Anish Konde, Nwabundo Anusim, Michael Stender, Ishmael Jaiyesimi, Susanna Gaikazian

Indolent lymphomas may transform into intermediate or high-grade lymphoma, a diagnosis that is usually made reached by tissue biopsy, with unfavorable prognosis. A retrospective study was performed of the clinical characteristics, treatment patterns and outcomes of 73 patients with histologic transformed lymphoma originating as follicular lymphoma (FL), chronic lymphocytic leukemia/small cell leukemia (CLL/SCL), marginal zone lymphoma (MZL), lymphoplasmacytic lymphoma (LPL), or low grade B cell lymphoma not otherwise specified (NOS). The median time to transformation was 55 months (range 1-258) and Diffuse Large B Cell Lymphoma (DLBCL) constituted the majority of HTL diagnosis diagnoses. There was a statistically significant longer time to the development of HTL in patients with CLL and LPL compared to other indolent lymphoma types (FL, MZL and low-grade B cell lymphoma NOS); however, overall survival (OS) at histologic transformation was similar regardless of the indolent lymphoma type preceding HTL. Treatment with Rituximab-containing regimens have increased overall survival in HTL compared with the pre-rituximab era. In the 63 treated cases of HTL, PET showed complete remission (CR) in the majority of patients (55%) with 15% achieving partial remission (PR) and 15% having progressive disease (PD). OS at two years was approximately 60%, and 41% of patients remained alive at 5 years. Univariate analysis identified that treatment with RCHOP conferred better OS when compared to regimens with less or greater intensity than RCHOP, p=0.001. Multivariate analysis confirmed that achievement of CR and LDH level within the normal range statistically predicted better OS. On-going clinical trials may suggest novel therapeutics and provide for more evidence-based management of HTL.