Melanoma in patients with chronic lymphocytic leukemia and non-Hodgkin lymphoma

Background: The relationship between melanoma and chronic lymphocytic leukemia (CLL) or non-Hodgkin lymphoma (NHL) has been minimally investigated. Objective: The objective of this study was to examine the incidence of melanoma in patients with a history of CLL or NHL, and their associated mortality. Methods: Cohorts of Kaiser Permanente Southern California members with a history of CLL and NHL were identified. Age-adjusted incidence density rates of melanoma among patients with CLL or NHL were compared with rates of melanoma among the general population of Kaiser Permanente Southern California patients. The mortality of patients with melanoma was examined using Cox proportional hazards modeling. Results: The age-adjusted incidence rate per 100,000 person-years for melanoma among patients with either CLL or NHL was 107 (95% confidence interval 84.4-129.6) versus 25.9 among the general population (95% confidence interval 84.4-129.6, P < .001). Patients with melanoma and a history of CLL or NHL had 2.46 greater odds of death compared with those without CLL or NHL (95% confidence interval 1.77-3.41). Limitations: This study was retrospective in nature; the International Classification of Diseases, Ninth Revision codes used may contain diagnostic errors; and only overall survival was used in our analysis. Conclusions: Patients with a history of CLL or NHL have a higher incidence of melanoma. Patients with CLL or NHL who are subsequently given the diagnosis of melanoma have a higher mortality than patients with melanoma without a preceding diagnosis of CLL.