Single-institutional retrospective analysis of Japanese patients with chronic lymphocytic leukemia

Unlike in Western countries, chronic lymphocytic leukemia (CLL) is a rare lymphoid malignancy in Japan, and its clinical features remain to be elucidated in the Japanese population. Therefore, we retrospectively analyzed 29 Japanese CLL patients newly diagnosed at our institute. Seventeen (59%) were male, and their median age was 62 years. With a median follow-up period from diagnosis of 69 months (range, 3-170 months), 9 patients received some form of treatment for CLL. Three patients died of disease progression with or without infection (n=2) or skin cancer (n=1). Five-year overall and treatment-free survival rates were 83% (95%CI, 46-96%) and 67% (95%CI, 45-81%), respectively. Two patients received allogeneic hematopoietic stem cell transplantation for refractory disease, and both were alive without disease relapse at 53 and 110 months, respectively, after transplantation. These results suggest the clinical courses of Japanese patients with CLL to be comparable to those in Western countries. However, future studies of larger numbers of patients are needed to further elucidate the features and long-term clinical courses of CLL in the Japanese population.