Association of Advanced Leukemic Stage and Skin Cancer Tumor Stage With Poor Skin Cancer Outcomes in Patients With Chronic Lymphocytic Leukemia

IMPORTANCE Although it has been well established that patients with chronic lymphocytic leukemia (CLL) have an increased risk of developing skin cancer, few studies have investigated the effect of CLL stage on the risk of poor skin cancer outcomes. The present study of CLL staging assesses outcomes of melanoma, squamous cell carcinoma, and Merkel cell carcinoma in this high-risk population. OBJECTIVE To determine if progression of CLL measured by advanced Rai stage (III or IV) is associated with worse skin cancer outcomes. DESIGN, SETTING, AND PARTICIPANTS Twenty-year retrospective study at 2 academic centers in Boston, Massachusetts, of adults with CLL and either melanoma, squamous cell carcinoma, or Merkel cell carcinoma. MAIN OUTCOMES AND MEASURES Hazard ratios (HRs) for the development of poor skin cancer outcomes (local recurrence, nodal metastasis, distant metastasis, or death from skin cancer). RESULTS In total, 133 patients with 377 primary skin cancers and a median follow-up of 41 months were included. Squamous cell carcinoma predominated (92.0%). The risk of death from skin cancer was equivalent to the risk of death from CLL (13.5%). On multivariate analysis, advanced Rai stage (III or IV) at the time of the first skin cancer diagnosis (HR, 4.5; 95% CI, 2.3-8.9) and a high skin cancer tumor (T) stage (HR, 4.9; 95% CI, 2.2-10.8) were associated with poor skin cancer outcomes. Those with both a low skin cancer T stage and a low Rai stage (n = 265) had a low risk (5.3%; 95% CI, 3.2%-8.7%) of poor skin cancer outcomes. Those with a low T stage and a high Rai stage (n = 89) had a significantly higher risk of poor skin cancer outcomes (16.9%; 95% CI, 10.9%-26.0%). The 23 patients with a high T stage had high risks of poor outcomes regardless of CLL status (27.3% if a low Rai stage and 50.0% if a high Rai stage, with wide 95% CIs). CONCLUSIONS AND RELEVANCE In patients with CLL and non-basal cell carcinoma skin cancer, mortality is as high from skin cancer as from CLL. The Rai stage and skin cancer T stage should be considered when risk-stratifying patients with skin cancer. Regular communication between dermatologists and oncologists will help facilitate the identification of patients with CLL who are at high risk of having poor skin cancer outcomes.