Increased cancer risk in patients with cutaneous lupus erythematosus and systemic lupus erythematosus compared with the general population: A Danish nationwide cohort study

Objectives To investigate if patients with cutaneous lupus erythematosus (CLE) or systemic (SLE) have an increased risk of cancer compared the general population, and furthermore to identify specific types associated risk. Methods This is observational cohort study 5310 CLE SLE identified in Danish National Patient Register from 1 January 1995 31 December 2014. The was followed up for by linkage Cancer Registry. Based on age, sex, calendar rates population Denmark, standardised incidence ratios (SIRs) were calculated. Results 40.724 person-years, each group’s average duration follow-up being 6.9 8.1 years. SIR overall (except non-melanoma skin (NMSC)) 1.35 (95%CI 1.15 1.58) 1.45 1.30 1.62). Both groups had high risks hematological – including a 3–4-fold non-Hodgkin lymphoma –, pancreatic, lung cancers. Several cancers oncogenic viruses as liver tongue/mouth/pharynx group, while ovarian 2–4-fold only group. Conclusion significantly both SLE. SIRs hematological, pancreatic elevated groups. Extra awareness should be considered.