The Burden of Multiple Basal Cell Carcinomas: A Population-wide Study

Area of Science:

• Dermatology
• Oncology
• Epidemiology

Background:

• Basal cell carcinoma (BCC) is a prevalent skin cancer.
• Patients with BCC have an elevated risk of developing subsequent primary tumors.
• Previous research on BCC multiplicity is limited by a lack of national registration.

Purpose of the Study:

• To analyze the incidence of multiple BCCs in Sweden.
• To identify risk factors associated with subsequent primary BCC development.
• To estimate the cumulative risk of developing additional BCCs.

Main Methods:

• Registry-based cohort study utilizing data from the Swedish BCC Registry (2004-2017).
• Inclusion of all histopathologically verified, primary BCC tumors.
• Cox regression analysis to assess risk factors for subsequent BCCs.
• Estimation of cumulative BCC development risk after prior diagnoses.

Main Results:

• 39.9% of individuals with a registered BCC had at least two tumors.
• Increased risk of subsequent BCCs observed in males, older individuals, and residents of southern Sweden.
• Cumulative 5-year risk of an additional BCC was ~30% for males and ~27% for females after initial diagnosis.
• Risk of subsequent BCCs significantly increased with a history of multiple previous BCCs.

Conclusions:

• A history of multiple BCCs is associated with an increased cumulative risk of developing further BCCs.
• Specific demographic and geographic factors (male sex, older age, southern Sweden residence) are linked to higher subsequent BCC risk.
• Clinical surveillance is crucial for individuals with a history of multiple BCCs.