RT Journal Article SR Electronic T1 Malignancies in Giant Cell Arteritis: A Population-based Cohort Study JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.190236 DO 10.3899/jrheum.190236 A1 Pavlos Stamatis A1 Carl Turesson A1 Minna Willim A1 Jan-Åke Nilsson A1 Martin Englund A1 Aladdin J. Mohammad YR 2019 UL http://www.jrheum.org/content/early/2019/10/08/jrheum.190236.abstract AB Objective To investigate the risk of cancer in patients with biopsy-proven giant cell arteritis (GCA) from a defined population in southern Sweden. Methods The study cohort consisted of 830 patients (mean age at GCA diagnosis was 75.3 yrs, 74% women) diagnosed with biopsy-proven GCA between 1997 and 2010. Temporal artery biopsy results were retrieved from a regional database and reviewed to ascertain GCA diagnosis. The cohort was linked to the Swedish Cancer Registry. The patients were followed from GCA diagnosis until death or December 31, 2013. Incident malignancies registered after GCA diagnosis were studied. Based on data on the first malignancy in each organ system, age- and sex-standardized incidence ratios (SIR) with 95% CI were calculated compared to the background population. Results One hundred seven patients (13%) were diagnosed with a total of 118 new malignancies after the onset of GCA. The overall risk for cancer after the GCA diagnosis was not increased (SIR 0.98, 95% CI 0.81–1.17). However, there was an increased risk for myeloid leukemia (2.31, 95% CI 1.06–4.39) and a reduced risk for breast cancer (0.33, 95% CI 0.12–0.72) and upper gastrointestinal tract cancer (0.16, 95% 0.004–0.91). Rates of other site-specific cancers were not different from expected. Conclusion In this Swedish population-based cohort of GCA, the overall risk for cancer was not increased compared to the background population. However, there was an increased risk for leukemia and a decreased risk for breast and upper gastrointestinal tract cancer.