Skin Cancer Risk Persists for 30 Years after Blood Cancer Diagnosis

Survivors of chronic lymphocytic leukemia and all other blood cancers need to be watchful for the signs of skin cancer, according to a Dutch study. For at least 30 years after the initial diagnosis of cancer, the risk for skin cancer is two-fold higher than the general population.

Previously, it was known that survivors of chronic lymphocytic leukemia had an increased risk for any type of secondary cancer, including melanoma and cutaneous squamous cell carcinoma. However, it was not clear whether survivors of other types of leukemia, lymphoma, or multiple myeloma were also at increased risk or not. It was also unclear whether any risk for basal cell carcinoma or Merkel cell carcinoma development was affected.

The Dutch researchers used a national cancer registry with 210,794 patients diagnosed with a blood cancer between 1989 and 2020, all without any history of skin cancer. Within the data, 8,140 patients who survived a blood cancer developed a skin cancer: 1,040 with basal cell carcinoma, 5,802 with squamous cell carcinoma, 1,187 with melanoma, and 111 with Merkel cell carcinoma.

They found that chronic lymphocytic leukemia was among the most common blood cancers for individuals who later developed skin cancer (12% of the total). Survivors of diffuse large B-cell lymphoma (16%) and multiple myeloma (14%) had a larger cohort of individuals with skin cancer diagnoses.

Trends observed with data from the U.S. population were consistent with these results. Using a registry from the U.S. National Institutes of Health, there is a three-fold increased risk of skin cancer for non-Hodgkin lymphoma survivors and a seven-to-eightfold increased risk for survivors of chronic lymphocytic leukemia.

Although the reasons are uncertain why survivors of blood cancers have a higher risk for skin cancer, there is an idea to explain it. First, many individuals who develop cancer have reduced functioning of their immune system, and there is a strong link to immune regulation with skin cancer. Second, immunosuppressive medications and direct effects from cancer treatment with chemotherapy and radiation therapy may drive subsequent cancer development. Therefore, immune dysfunction is thought to be the underlying reason for the increase in skin cancers among survivors of blood cancers.

The theory that immune suppression is involved also fits with another finding from the study. Patients who received hematopoietic stem cell transplantation as first-line therapy have a higher risk of developing cutaneous squamous cell carcinoma. The study speculates that a complication arising in half of these patients requiring long-term immunosuppression is to blame. Many patients are prescribed the immunosuppressants azathioprine or cyclosporine, which increases sensitivity to UV as well.

The study suggests that survivors of blood cancers and their clinicians be educated about the increased long-term risk of skin cancers. The authors also recommend vigilance and UV-protection. Self-awareness and skin self-examinations can help prevent a late-stage skin cancer diagnosis, too. Know your skin.

This summary was based on the article, “Skin cancer risk in over 200.000 patients with haematologic malignancies in 30 years; a nationwide population-based study in the Netherlands” published in the January 2025 edition of the British Journal of Dermatology and written by Celeste J Eggermont and colleagues.