FRI0456 Risk of Malignancy in Anca-Associated Vasculitis Patients

Background Recent studies indicate that patients with ANCA-associated vasculitis (AAV) have a significantly higher risk of developing malignancies1, that the mortality in AAV patients is 2.6 times higher than that of the general population, and that malignancies are the second cause of death after the first year of diagnosis2. Drawbacks from these studies are a relatively short follow-up, and possibly, under-reportage due to lack of access to registries. Objectives To assess the risk of developing at least one malignancy after diagnosis of AAV. Methods We investigated the occurrence of malignancies in 187 histologically confirmed AAV patients after diagnosis at our center between 1982 and 2011 by performing a search in PALGA, a Dutch national pathology database which covers all the histologically confirmed malignancies diagnosed in The Netherlands. Results One hundred and thirty-six patients with AAV had a follow-up of at least 1 year; 46 of those developed 93 malignancies during a mean follow-up of 12.3 years. There were 63 non-melanoma skin cancers (NMSC) of the skin. Thirteen malignancies occurred more than once: four of the bladder, four of the prostate, three of colon/rectum and two of the lung. There was a variety of one time occurring malignancies. The mean age of AAV patients developing a malignancy was similar to patients without a malignancy (58 years). Conclusions This study shows a higher incidence of malignancies than was reported for a European study group. One explanation for this discrepancy could be the accurate data reporting through the Dutch PALGA system by which virtually no malignancy could have been missed. There was no significant age difference between patients with and without malignancies. Notably, there was a high number of NMSCs which is most likely related to the immunosuppressive therapy these patients receive. In the management and treatment of patients with AAV, it is of major importance to monitor closely for developing malignancies. References Heijl C., Harper L., Flossmann O., and al. Incidence of malignancy in patients treated for antineutrophil cytoplasm antibody-associated vasculitis: follow-up data from European Vasculitis Study Group clinical trials Ann Rheum Dis 2011; 70: 1415-1421. Flossmann O., Berden A., de Groot K., and al. Long-term patient survival in ANCA-associated vasculitis Ann Rheum Dis 2011; 70: 488-494. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.5700