Burn injuries and skin cancer: a population-based cohort study.

Development of malignant tumours in chronic burn wounds or scars is extremely rare, but a frequently reported complication. Most of these tumours are squamous cell carcinoma and, more occasionally, basal cell carcinoma and malignant melanoma are reported. The interval between the initial burn and the diagnosis of the tumour is usually long; 20-30 years or more. A large number of case reports and small series of selected patients have been published. Only one epidemiological study has been performed recently, but it could not confirm any increased risk. We conducted a historical cohort study to assess the risk of cancer in Swedish patients with burn injuries. Using the national Inpatient Registry we identified 37,095 patients who had been hospitalized for burn injuries. This cohort was linked with the Swedish Cancer Registry for a virtually complete follow-up with regard to cancer. The mean follow-up time was 16.4 years (range >0-39). The risk of developing any form of cancer was slightly increased: standardized incidence ratio (SIR) 1.11 (95% confidence interval (CI) 1.06-1.16) based on 2227 patients with cancer. However, squamous cell carcinoma: SIR 0.88 (95% CI 0.70-1.09) and malignant melanoma: SIR 0.88 (95% CI 0.68-1.12) did not occur more often than expected. Also, in a subgroup of 12,783 patients who were followed for 20-39 years, no increased risk of skin cancer could be detected. This study does not support any casual association between burn injuries and a later risk of skin cancer.