Recurrent vertebrobasilar stroke in giant cell arteritis associated with progressive prostate carcinoma: a case report and literature review.

Giant cell arteritis (GCA) is the most prevalent large-vessel vasculitis in patients ≥ 50 years, with a frequent but poorly defined association with malignancy. We present a 71-year-old patient with progressive prostate cancer and a deleterious presentation of GCA, manifesting as repeated vertebrobasilar ischemia. Diagnostic delay occurred because of an atypical disease presentation and the assumed rarity of concurrence of GCA and cancer. Drug interactions between prednisolone and enzalutamide delayed optimal treatment. A literature review was performed to detail the incidence, clinical characteristics, and disease course of patients with GCA and solid malignancy in order to provide practical recommendations for patients with solid tumors and GCA. Concurrence of GCA and cancer is prevalent, with approximately 10% of GCA patients diagnosed with malignancy within 1 year. However, well-controlled studies do not suggest a heightened incidence of cancer in GCA. Retrospective case-control studies suggest no relevant differences in symptoms and disease course between GCA patients with and without cancer. Specifically, no difference in ischemic complications is reported. A paraneoplastic course with GCA subsiding shortly after tumor removal was reported in four cases. Most patients received standard immunosuppression; only two cases were identified in whom cancer treatment without immunosuppression resolved vasculitis. In conclusion, this report underscores that GCA and cancer concur frequently. Although this appears largely coincidental or surveillance-related, GCA sporadically occurs as a paraneoplastic phenomenon. Standard immunosuppressive treatment of GCA should not be withheld in oncology patients, although drug interactions with anticancer drugs are frequent and could warrant dose adjustments of anti-inflammatory drugs.