Patients with chronic lymphocytic leukemia (CLL), a blood cancer affecting white blood cells, face nearly double the risk of developing skin cancer compared to the general population, according to a large new study. Over a 10-year period, about 13.5% of CLL patients developed skin cancer versus 6.9% of people without the disease, a significant difference that researchers say demands closer attention and preventive care .

Why Are CLL Patients at Such High Risk for Skin Cancer?

The connection between chronic lymphocytic leukemia and skin cancer risk stems from the disease's impact on the immune system. CLL weakens the body's natural defenses by affecting lymphocytes, a type of white blood cell crucial for fighting infections and abnormal cell growth. Additionally, the immunosuppressive treatments used to manage CLL further compromise immune function, making it harder for the body to detect and eliminate cancerous cells before they develop into full-blown tumors .

Researchers from Denmark conducted a comprehensive registry-based study following 8,352 patients diagnosed with CLL between 1990 and 2020, alongside 41,760 matched individuals without the disease. This large sample size and long follow-up period provide strong evidence for the findings. The study tracked participants from the time of CLL diagnosis until skin cancer occurred, death, emigration, or the end of the study period .

What Types of Skin Cancer Are Most Common in CLL Patients?

The increased skin cancer risk in CLL patients wasn't limited to one type. The study found elevated rates across most skin cancer subtypes, with particularly striking increases in two common forms:

• Basal Cell Carcinoma: The most common type of skin cancer, occurring in 8.6% of CLL patients compared to 5.4% of controls, representing a 59% higher risk.
• Squamous Cell Carcinoma: The second most common form, developing in 4.7% of CLL patients versus 1.4% of the general population, more than triple the rate.
• Other Skin Cancers: The study documented elevated risks across additional skin cancer types, though basal and squamous cell carcinomas accounted for the majority of cases.

These two non-melanoma skin cancers are generally more treatable than melanoma when caught early, but the higher incidence in CLL patients underscores the importance of regular skin checks .

Does Skin Cancer Spread More Aggressively in CLL Patients?

Perhaps most concerning, the study revealed that CLL patients don't just develop skin cancer more often; they also experience worse outcomes when they do. Over the 10-year follow-up period, CLL patients had a 0.7% risk of skin cancer metastasis, meaning the cancer spread to other parts of the body, compared to just 0.1% in the general population. This represents a sevenfold increase in the likelihood of cancer spread .

The mortality data painted a similarly troubling picture. CLL patients faced a 0.3% risk of dying from skin cancer-related causes versus 0.1% in matched controls. While these absolute numbers remain relatively low, the threefold difference highlights how the compromised immune system in CLL patients may allow skin cancers to progress more rapidly and aggressively .

How Should CLL Patients Protect Their Skin?

Given these findings, dermatological surveillance and preventive strategies become critical for anyone living with chronic lymphocytic leukemia. The research team emphasized that increased awareness and enhanced monitoring can help catch skin cancers at earlier, more treatable stages.

• Regular Self-Examinations: CLL patients should perform monthly skin checks using the ABCDE method, looking for asymmetry, irregular borders, color variation, diameter larger than a pencil eraser, and evolving or changing moles.
• Professional Dermatology Visits: Annual or semi-annual full-body skin examinations by a dermatologist are recommended for CLL patients, more frequent than the standard screening for the general population.
• Sun Protection Practices: Consistent use of broad-spectrum sunscreen with SPF 30 or higher, protective clothing, and limiting sun exposure during peak hours (10 a.m. to 4 p.m.) can reduce skin cancer risk.
• Coordination with Oncology Team: CLL patients should discuss skin cancer screening protocols with their hematologist or oncologist to ensure preventive care is integrated into their overall treatment plan.

The researchers concluded that patients with CLL represent a high-risk group for skin cancer and its complications, warranting a more proactive approach to dermatological care than currently standard .

What Does This Mean for Overall Health in CLL Patients?

While the skin cancer findings are significant, it's important to maintain perspective. During the study follow-up period, more than half of CLL patients (56.3%) died from any cause, compared to 39.3% of matched controls. This means that while skin cancer risk is substantially elevated, the overall mortality burden from CLL itself remains the primary health concern for these patients .

Nevertheless, the study underscores an important message: CLL patients need enhanced dermatological surveillance and preventive strategies to support earlier detection and improved outcomes. By working closely with both their oncology and dermatology teams, patients can take meaningful steps to reduce their skin cancer risk and catch any cancers that do develop at the earliest, most treatable stages.