Survival for melanoma patients with pre-existing chronic lymphocytic leukemia.

Abstract

e19057 Background: Recent successes in melanoma drug development have rekindled interest in immunotherapy for melanoma (MM). Patients (pts) with chronic lymphocytic leukemia (CLL), a malignant expansion of B-lymphocytes, have an impaired immune system and not uncommonly develop secondary MM. We hypothesized that MM pts with pre-existing CLL are more likely to die than MM pts without a second malignancy. Methods: Pts were identified in the updated Surveillance Epidemiology and End Results (SEER) (1973-2008) database with MM only (MEL) or with primary CLL and secondary MM (MELpCLL). Time between diagnosis and death or last follow up and other demographic SEER data were recorded. The Chi-Square Test was used to make unadjusted comparisons between group death rates. A Cox proportional hazards regression model, adjusted for patient characteristics, predicted the risk of death by group. Results: 8,294 SEER pts were included (8,115 in MEL, 179 in MELpCLL). With a median follow-up time of 7 years, 2,454 pts (30%) died. There was a significant difference in mortality rates between the groups: MEL 29% / MELpCLL 71%; p<0.001 by Chi-Square. In the multivariate Cox model (Table), MELpCLL pts were significantly more likely to die than MEL pts (HR = 1.22, 95% CI = 1.02-1.46, p = 0.034). Higher risk of death was also significantly associated with older age and male gender (p<0.001) but not MM location (data not shown). MM data like thickness and ulceration were only available in more recent SEER records, precluding survival analysis. Conclusions: MELpCLL pts had a 22% increased risk of death compared to MEL pts in multivariate analysis, consistent with the hypothesis. [Table: see text]