Article Text
PDF
Abstract
Background Previous studies on the association between sarcoidosis and malignancy yielded conflicting results.
Objectives This study was aimed to investigate the risk of malignancy in patients with sarcoidosis in a population-based cohort.
Methods An inception cohort of patients with incident sarcoidosis in 1976–2013 in a geographically well-defined population was identified based on comprehensive individual medical record review. Inclusion required physician diagnosis supported by histopathologic evidence of non-caseating granuloma, radiographic evidence of intrathoracic sarcoidosis, compatible clinical presentation, and exclusion of other granulomatous diseases. For each sarcoidosis subject, two sex and aged-matched comparator subjects without sarcoidosis were randomly selected. Cases and comparators were then cross-indexed with the Cancer Registry of the institution, which collected data on every type of malignancy except for non-melanoma skin cancer, for malignancy ascertainment.
Results 345 incident cases of sarcoidosis and 690 comparators were identified. The median duration of follow-up was 12 years. There was no difference in the prevalence of malignancy at sarcoidosis incidence/index date between the 2 groups (14 cases, 3.8% among cases and 30 cases, 4.3% among comparators, P=0.87) compared to non-sarcoidosis subjects. During follow-up, 37 patients with sarcoidosis and 91 subjects without sarcoidosis developed malignancy with a cumulative incidence at 10 years of 4.1% and 7.1%, respectively. The difference corresponded to a hazard ratio of 0.74 (95% confidence interval (CI), 0.50 -1.09). The cumulative incidences at 10 years for individual types of malignancy were also similar between patients with sarcoidosis and non –sarcoidosis comparators, with non-significant hazard ratios. However, subgroup analysis found that cases with extra-thoracic involvement were at higher risk of incident hematologic malignancy compared with cases without extra-thoracic involvement (HR 1.87; 95% CI 1.09–3.22)
Conclusions Risk of malignancy was similar among patients with sarcoidosis compared to non-sarcoidosis subjects. However, the risk of incident hematologic malignancy was significantly higher among patients with sarcoidosis with extra-thoracic involvement compared to patients without extra-thoracic disease.
Disclosure of Interest None declared