Concomitant association of giant cell arteritis and malignancy: a multicenter retrospective case-control study.

Introduction: Some studies suggest that there is an increased risk of malignancies in giant cell arteritis (GCA). We aimed to describe the clinical characteristics and outcomes of GCA patients with concomitant malignancy and compare them to a GCA control group.
Method: Patients with a diagnosis of GCA and malignancy and with a maximal delay of 12 months between both diagnoses were retrospectively included in this study and compared to a control group of age-matched (3:1) patients from a multicenter cohort of GCA patients.
Results: Forty-nine observations were collected (median age 76 years). Malignancies comprised 33 (67%) solid neoplasms and 16 (33%) clonal hematologic disorders. No over-representation of a particular type of malignancy was observed. Diagnosis of GCA and malignancy was synchronous in 7 (14%) patients, while malignancy succeeded GCA in 29 (59%) patients. Malignancy was fortuitously diagnosed based on abnormalities observed in laboratory tests in 26 patients, based on imaging in 14 patients, and based on symptoms or clinical examination in the nine remaining patients. Two patients had a concomitant relapse of both conditions. When compared to the control group, patients with concomitant GCA and malignancy were more frequently male (p < 0.001), with an altered general state (p < 0.001), and polymyalgia rheumatica (p < 0.01).
Conclusions: This study does not indicate an over-representation of any particular type of malignancy in GCA patients. Initial follow-up dictated by vasculitis may have led to an early identification of malignancy. Nevertheless, GCA male patients with an altered general state and polymyalgia rheumatica might more frequently show concomitant malignancies.