Spontaneous regression of chronic lymphocytic leukemia

Immune therapy and graft-versus-tumor effect seen after allogeneic hematopoietic stem cell transplantation provide proof-of-principle of the ability of human immune system to control cancer. Spontaneous regression of cancer is another dramatic evidence of the existence of powerful immune surveillance in human body. We report a 54-year-old man with 13q14 deleted chronic lymphocytic leukemia and diffuse lymphadenopathy, who had spontaneous normalization of leukocytosis and resolution of lymphadenopathy thirteen years after the diagnosis of chronic lymphocytic leukemia. Better understanding of spontaneous regression may help elucidate body’s immune response against tumor cell. This may further enhance the development of immune therapies and provide insight towards tumorigenesis.