Karyotypic stability in chronic B-cell leukemia.

Twenty-one patients with B-cell chronic lymphocytic leukemia (B-CLL) have been followed for more than 2 years with serial cytogenetic studies, including 11 cases for more than 5 years and three others for more than 10 years. A chromosomally abnormal clone was present at the time of initial study in 10 of these patients, and neither these nor the 11 individuals with a normal karyotype had any cytogenetic evolution during the follow-up period, although clinical progression, requiring therapy, was observed in 13 cases. In an additional 12 B-CLL patients who had repeat chromosome studies but were followed for less than 2 years, two patients with advanced disease and multiple cytogenetic abnormalities developed minor additional karyotypic changes and died within 18 months, and two patients with a normal karyotype developed rapidly progressive disease associated with an emerging chromosomally abnormal clone and survived only 1 year. These results demonstrate that karyotypic evolution is rare in B-CLL. Its occurrence indicates a poor prognosis, but its rarity suggests that clinical progression in this disease is usually more dependent on other factors.