Risk of Malignancy Among Patients With Sarcoidosis: A Population-Based Cohort Study.

OBJECTIVE: To investigate the risk of malignancy in patients with sarcoidosis in a population-based cohort.

METHODS: A cohort of Olmsted County, Minnesota, residents diagnosed with sarcoidosis between January 1, 1976 and December 31, 2013 was identified based on individual medical record review. For each sarcoidosis subject, 2 sex- and age-matched comparator subjects without sarcoidosis were randomly selected. Cases and comparators were then cross-indexed with the Mayo Clinic Cancer Registry, which collected data on every type of malignancy except for nonmelanoma skin cancer, for malignancy ascertainment.

RESULTS: A total of 345 incident cases of sarcoidosis and 690 comparators were identified. There was no difference in the prevalence of malignancy at the index date between the 2 groups (4.3% among cases and 4.3% among comparators; P = 1.0). During followup, 36 patients with sarcoidosis and 91 subjects without sarcoidosis developed malignancy, with a cumulative incidence at 10 years of 3.8% and 7.1%, respectively. The difference corresponded to a hazard ratio (HR) of 0.72 (95% confidence interval [95% CI] 0.49-1.06). The cumulative incidences at 10 years for individual types of malignancy were also similar between the 2 groups, with nonsignificant HRs. However, subgroup analysis found that cases with extrathoracic involvement were at higher risk of incident hematologic malignancy compared with cases without extrathoracic involvement (HR 1.87 [95% CI 1.09-3.22]).

CONCLUSION: Risk of malignancy was similar among patients with sarcoidosis compared to nonsarcoidosis subjects. However, the risk of incident hematologic malignancy was significantly higher among patients with sarcoidosis with extrathoracic involvement compared to patients without extrathoracic disease.