Melanoma and Non-Melanoma Skin Cancer in Patients with Chronic Lymphocytic Leukemia.

There are reports of an increased risk of skin cancers in patients with B-Chronic Lymphocytic Leukemia (CLL). These skin cancers include basal cell and squamous cell carcinoma. This analysis was performed to more completely define the prevalence of skin cancers in patients in the Mayo Clinic Rochester CLL database and to look for contributing factors.

The Mayo Clinic Rochester CLL Database includes all patients with a diagnosis of CLL since January 1995 seen in the Division of Hematology and who have signed institutional review board approved consents for research. For this study, 2240 patients were analyzed to compare differences in characteristics between CLL patients with and without skin cancer. Chi-square statistics were used to compare qualitative variables (age categories, gender, referral status, ALC categories, CD38, ZAP-70, IgVH gene mutation status, FISH categories, Rai stage), and t-tests were used for quantitative variables (age at diagnosis, ALC values). Overall survival (OS) and time to first treatment (TFT) analyses were performed with results being displayed using Kaplan-Meier curves and p-values calculated using a log-rank test. Prevalence of melanoma among CLL patients was compared to the age-adjusted prevalence of melanoma in individuals in the Iowa SEER registry.

Median follow-up for the 2240 patients diagnosed between 1/1/1995 and 8/11/2009 was 4.6 years. In aggregate, 293 (13.1%) patients were found to have non-melanoma skin cancer (squamous cell carcinoma or basal cell carcinoma) cancer. The diagnosis of non-melanoma skin cancer occurred before the CLL diagnosis in 39% and at or after the diagnosis of CLL in 61%. There were 57 (2.5%) cases of melanoma in association with CLL. The diagnosis of melanoma occurred before the CLL diagnosis in 38% and at or after the diagnosis of CLL in 62%.The prevalence of non-melanoma skin cancer and melanoma skin cancer were both higher in non-referred (geographically regional) CLL patients than referred CLL patients (16.6% vs. 11.4%, p<0.001 for non melanoma; 2.0% vs. 3.6%, p=0.03 for melanoma). The prevalence of melanoma in CLL patients was higher than that of age-adjusted prevalence for individuals in the Iowa SEER registry (2.5% vs. 0.03%; p<0.001).

We next evaluated the relationship between CLL patients with skin cancer and demographic characteristics, prognostic parameters, and CLL related treatment. The risk of non-melanoma skin cancer in CLL was found to be associated with age (median age at diagnosis with skin cancer 67.6 vs. without skin cancer 63.3, p<0.001) and with sex (males 15.1% vs females 8.9%, p <0.001). There was no statistical significant difference in frequency of non-melanoma skin cancer associated with absolute lymphocyte count (ALC), Rai stage, CD 38, Zap 70, IgVH gene mutation status, FISH, or treatment history. The risk of melanoma in CLL was found to be associated with age at diagnosis (median age with melanoma 69.9 vs. without melanoma 63.8, p=0.002) and CD38 (positive 1.3% vs negative 3.1%, p=0.03). There was no statistically significant difference associated with gender, ALC, Rai stage, Zap 70, IgVH gene mutation status, FISH, or treatment history.

Since the presence of skin cancer could be a marker of immune dysregulation we hypothesized skin cancer may be associated with clinical outcome of CLL. Accordingly, we evaluated the relationship between non-melanoma skin cancer and melanoma skin cancer and TFT and OS. Contrary to our hypothesis, TFT (median 6.0 years vs. 4.9; p=0.04) and OS (median 10.8 years vs. 9.7; p=0.02) of patients with non-melanoma skin cancer were both longer than those without non-melanoma skin cancer. No differences in TFT (p=0.06) or OS (p=0.66) were observed among patients with melanoma compared to those without melanoma.

We find in our cohort of CLL patients a higher prevalence of melanoma than the general population. Risk of melanoma and non-melanoma skin cancer among patients with CLL does not appear to be related to CLL characteristics, with the exception of CD 38, or CLL outcome. The diagnosis of melanoma and non-melanoma skin cancer in patients with CLL does not appear to be a risk factor for either CLL specific outcomes (TFT) or shorter survival.

Kay:Biogenc-Idec, Celgene, Genentech, genmab: Membership on an entity's Board of Directors or advisory committees; Genentech, Celgene, Hospira, Polyphenon Pharma, Sanofi-Aventis: Research Funding. Zent:Genentech, Bayer, Genzyme, Novartis: Research Funding. Shanafelt:Genentech: Research Funding; Hospira: Membership on an entity's Board of Directors or advisory committees, Research Funding; Polyphenon E International: Research Funding; Celgene: Research Funding; Cephalon: Research Funding; Bayer Health Care Pharmaceuticals: Research Funding.