Study Reveals Higher Mortality Risks for Rare Skin Cancer Patients

A recent study conducted by researchers at Karolinska Institutet and Karolinska University Hospital has revealed alarming mortality rates among patients diagnosed with rare skin cancers, specifically mycosis fungoides (MF) and Sézary syndrome (SS). The research, published in the *British Journal of Dermatology* on June 19, 2025, indicates that individuals with these conditions face a significantly heightened risk of death due to lymphoma and infections compared to the general population.

The study tracked over 600 patients diagnosed between 2000 and 2019 and compared their outcomes with more than 6,000 age- and sex-matched individuals without these diseases. The findings indicate that patients with MF or SS have a 56% increased risk of dying from any cause, with the risk of dying from lymphoma being nearly 180 times higher and the risk of dying from infections almost three times higher than that of the general population.

According to Dr. Hanna Brauner, a researcher at the Department of Medicine Solna at Karolinska Institutet and a dermatologist at Karolinska University Hospital, “Lymphoma was the leading cause of death, especially among patients with more severe disease. We also saw that infections, although less common, contributed to increased mortality.”

The researchers identified patients who required hospital care or systemic treatment shortly after diagnosis to assess the severity of the disease. Those with more severe cases had a median survival of only 4.5 years, compared to 14.2 years for patients with milder forms of the disease.

The study underscores the critical need for early diagnosis and careful monitoring of patients with MF and SS. Dr. Brauner emphasized the variability of the disease, stating, “Our results show how varied the disease can be. Patients with mild MF often live many years, while those with severe forms of MF or SS need more intensive care and support.”

Furthermore, the research suggests that proactive management of infections could improve outcomes, given that both the disease and its treatments can compromise the immune system. The study received support from various organizations, including the Swedish Society for Medical Research and the Swedish Cancer Foundation.

Dr. Lina U. Ivert, a co-author of the study and affiliated with Karolinska Institutet, highlighted the implications of these findings: “Increased mortality due to lymphoma and infections in patients with mycosis fungoides or Sézary syndrome: A Swedish nationwide, population-based cohort study” aims to inform clinicians about the urgent need for vigilant patient care.

This research adds to the growing body of evidence that highlights the severe health risks associated with rare skin cancers. As the medical community continues to grapple with the complexities of these diseases, ongoing studies and improved patient monitoring strategies will be essential in improving survival outcomes for affected individuals.