Clinical outcomes and prognostic factors in patients with Richter's syndrome treated with chemotherapy or chemoimmunotherapy with or without stem-cell transplantation

Purpose: The purpose of this study was to assess the incidence, presenting characteristics, and treatment outcomes of Richter's syndrome (RS) and factors predicting response and survival. Patients and Methods: An electronic database search of patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) who presented at The University of Texas M.D. Anderson Cancer Center (Houston, TX) between January 1975 and June 2005 was performed, and patient medical records were reviewed. Results: Of the 3,986 patients with CLL/SLL, 204 patients (5.1%) had possible RS, and 148 patients (3.7%) had biopsy- or fine-needle aspiration-proven RS. Treatment included chemotherapy alone and chemoimmunotherapy with rituximab. The overall response rate for the 130 assessable patients was 39% (chemotherapy, 34%; chemoimmunotherapy, 47%; P = .2). In multivariate analysis, factors predicting prolonged survival were Zubrod performance status 0-1 (P = .006), lactate dehydrogenase ≤ 1.5x the upper limit of normal (P = .003), platelet count ≥ 100,000 (P = .01), tumor size ≤ 5 cm (P = .02), and fewer than two prior therapies (P = .02). The five adverse factors predicting shorter survival were used to design a model to predict an individual patient's risk of death: the RS score. A total of 20 patients underwent stem-cell transplantation (SCT). Patients who underwent allogeneic SCT as postremission therapy had longer survival than patients who achieved remission and received no additional therapy or patients who underwent allogeneic or autologous SCT as salvage therapy (P = .019). Conclusion: A score to predict an individual patient's risk of death is proposed. Chemotherapy and rituximab combinations are effective in RS. Patients with available donors may be considered for allogeneic SCT as postremission therapy.