Prior history of non-melanoma skin cancer is associated with increased mortality in patients with chronic lymphocytic leukemia.

We investigated whether a previous diagnosis of non-melanoma skin cancer among chronic lymphocytic leukemia patients is a predictor of poor outcome. Using the Swedish Cancer Registry, we conducted a population-based study to evaluate the survival patterns among chronic lymphocytic leukemia patients with and without non-melanoma skin cancer. Cox proportional hazards regression models were used and Kaplan-Meier curves were constructed. Of a total of 12,041 chronic lymphocytic leukemia cases identified, 236 cases, including 111 squamous cell cancer, had a prior history of non-melanoma skin cancer. Chronic lymphocytic leukemia patients with a prior history of non-melanoma skin cancer had a 1.29-fold (95% CI 1.10-1.52; p=0.0024) increased risk of dying; and those with a history of squamous cell cancer had a further elevated 1.86-fold (95% CI 1.46-2.36; p<0.0001) risk of dying. Kaplan-Meier plots showed that patients with a history of non-melanoma skin cancer, particularly those with squamous cell cancer, had significantly poorer survival than chronic lymphocytic leukemia patients without non-melanoma skin cancer (p<0.0001; log-rank test). Non-melanoma skin cancer may be a novel clinical predictor of worse chronic lymphocytic leukemia outcome.