Familial Mediterranean Fever and Incidence of Cancer

Objective Familial Mediterranean fever (FMF) is an autoinflammatory disease manifested with recurrent serosal inflammation. The association between FMF and malignancy has not been described. The aim of this study was to estimate cancer risk in a large single-institution cohort of FMF patients. Methods The study cohort consisted of 8,534 FMF patients registered in the Israel National FMF Center at Tel Hashomer, Israel. We linked the study cohort to the database of the Israel National Cancer Registry using the national identity number. Cancer incidence in FMF patients was determined and stratified by age and gender. Standardized incidence ratios (SIR) for cancers were calculated. Results Among 8,534 FMF patients (4,400 men, 4,134 women), 350 developed cancer during the years 1970-2011. Overall cancer risk among patients with FMF was significantly lower than that expected in the following gender and ethnic groups of the Israeli population: males of Jewish ethnicity SIR 0.66, CI 95% [0.55-0.77], p<0.001; females of Jewish ethnicity SIR 0.75 CI 95% [0.64-0.86], p<0.001; males of Arab ethnicity SIR 0.34, CI 95% [0.07-0.99], p=0.024. Conclusion FMF patients have a significantly lower incidence of cancer than the general population. This pattern was demonstrated in two ethnic populations, Jewish and Arab. We speculate that the lower cancer incidence could be attributed to a direct physiological effect of FMF or to the anti-FMF treatment. This article is protected by copyright. All rights reserved.