Objective To characterize the epidemiology of temporal artery biopsy–positive (TAB+) giant cell arteritis (GCA), including trends in incidence, seasonal variation, and prevalence in Skåne, the southernmost region of Sweden. Methods All histopathology reports of TABs from 1997 through 2019 were reviewed to identify patients diagnosed with TAB+ GCA. Incidence rates based on the 23-year period and the point-prevalence at 31 December, 2014 were determined. An alternative prevalence calculation included only TAB+ GCA patients living in the study area and receiving immunosuppressant therapy on the point-prevalence date. Results 1360 patients were diagnosed with TAB+ GCA (71% female). The average annual incidence 1997–2019 was 13.3 (95% CI 12.6–14.0) per 100 000 inhabitants aged ≥50 years and was higher in females (17.8; 95% CI 16.7–18.9) than in males (8.2; 95% CI 7.4–9.0). The age- and sex- standardized incidence declined from 17.3 in 1997–8.7 in 2019, with incidence ratio (IR) of 0.98 per year (95% CI 0.98–0.99). A seasonal variation was observed with higher incidence during spring than winter [IR 1.19 (95% CI 1.03–1.39)]. The overall point-prevalence of TAB+ GCA was 127.1 per 100 000 (95% CI 117–137.3) and was 75.5 (95% CI 67.7–83.3) when including only patients receiving immunosuppressants. Conclusions Over the past two decades, the incidence of biopsy-confirmed GCA has decreased by ∼2% per year. Still, a high prevalence of GCA on current treatment was observed. More cases are diagnosed during spring and summer than in the winter.

ObjectiveTo 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.

Giant cell arteritis (GCA) and Takayasu Arteritis (TAK) are two systemic granulomatous vasculitides affecting medium- and large-sized arteries. Similarities in GCA and TAK regarding the clinical presentation, the systemic inflammatory response and the distribution of the arterial lesions, have triggered a debate over the last decade about whether GCA and TAK represent two different diseases, or are age-associated different clinical phenotypes of the same disease. On the other hand, there are differences regarding epidemiology, several clinical features (eg, polymyalgia rheumatica in GCA) and treatment. The aim of this review is to present the latest data regarding this question and to shed some light on the differences and similarities between GCA and TAK regarding epidemiology, genetics, pathogenesis, histopathology, clinical presentation, imaging and treatment. The existing data in literature support the opinion that GCA and TAK are different clinical entities.