Staging and prognosis of chronic lymphocytic leukemia: the Manitoba experience

Three hundred ninety-one cases of chronic lymphocytic leukemia (CLL) from the Tumour Registry of Manitoba, spanning a 20-year period from January 1960 to December 1979, were reviewed. Survival curves were developed using the staging systems of Rai and Binet. A clear separation in survival was found utilizing the system of Binet. Also, there was a significant increase in the development of secondary malignancies (observed, 53; expected, 31, p less than 0.01). However, there was no significant increase in secondary malignancies if only those malignancies occurring at least six months after the diagnosis of chronic lymphocytic leukemia was made were analyzed (observed, 38; expected, 29, p = 0.26). This suggests that the increase in secondary malignancies is not treatment-related, and may be due to the underlying disease.