Other malignancies in chronic lymphocytic leukemia/small lymphocytic lymphoma

Other malignancies have been reported to occur with increased frequency in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The aim of this study was to determine the frequency, outcomes, and factors associated with other cancers in patients with CLL/SLL.

We reviewed the records of consecutive patients with previously untreated CLL/SLL seen at The University of Texas M. D. Anderson Cancer Center from 1985 to 2005. The number of second cancers observed was compared with the number expected from the Surveillance, Epidemiology, and End Results database.

Among 2,028 patients, 324 (16%) had a history of other cancers and 227 (11.2%) developed other malignancies during the follow-up period. Overall, 625 cancers were observed in 551 patients, including skin (30%), prostate (13%), breast (9%), melanoma (8%), lymphoma (8%), gastrointestinal (9%), lung (6%), and other cancers (17%). The risk of a second cancer was 2.2 times higher than the expected risk. The response rates in patients with and without a history of other cancers were 86% and 92%, respectively (P = .04), and the 5-year survival rates were 70% and 82%, respectively (P < .001). In Cox analysis, independent factors predicting development of new cancers were older age, male sex, and elevated levels of beta2-microglobulin, lactate dehydrogenase, and creatinine. In patients who were treated for CLL/SLL, the treatment regimen did not affect the risk of subsequent cancer (P = .49).

Patients with CLL/SLL have more than twice the risk of developing a second cancer and an increased frequency of certain cancer types. Awareness of risk factors could permit early detection.