Malignancy Risk in Patients With Giant Cell Arteritis: A Population-Based Cohort Study

Objective. To determine the incidence of cancer in a population-based cohort of patients with giant cell arteritis (GCA) compared with age- and sex-matched referent subjects. Methods. Using the resources of the Rochester Epidemiology Project, all incident cases of GCA diagnosed between January 1, 1950 and December 31, 2004 were identified. For each GCA patient, 2 subjects without GCA of the same sex and similar age and length of medical history were selected. Diagnosis of malignancy was made by histopathology. Patients were followed until death, last contact, or December 31, 2006. Results. Our study included 204 GCA patients and 407 non-GCA subjects. The GCA cohort had 163 (79%) women and 41 (21%) men, a mean +/- SD age of 76.0 +/- 8.2 years, and a median followup of 7.7 years. The non-GCA cohort consisted of 325 (80%) women and 82 (20%) men, a mean +/- SD age of 75.6 +/- 8.4 years, and a median followup of 8.1 years. During followup, 46 GCA patients and 76 non-GCA subjects developed cancer (hazard ratio [HR] 1.26, 95% confidence interval [95% CI] 0.87-1.83). Adjustment for smoking did not alter the results. The 1-, 10-, and 20-year cumulative incidences of any malignancy were 5.9%, 33.6%, and 50.0% among GCA patients and 2.6%, 27.0%, and 47.0% among non-GCA patients, respectively. There were no differences in hematologic or solid malignancies between both groups. Colon cancer appeared more commonly in the GCA group (P = 0.07). Mortality following cancer was similar in both cohorts (HR 0.80, 95% CI 0.52-1.24). Conclusion. GCA patients are not at an increased risk of first cancer after diagnosis.