Do autoimmune diseases influence the onset and progression of ovarian cancer? A systematic review and meta-analysis.

OBJECTIVE: Ovarian cancer remains the fifth leading cause of cancer-related deaths in women. The immune system influences the onset and progression of ovarian cancer. Therefore, we aimed to study the behavior of ovarian cancer in patients with a pre-existing immune dysfunction, more specifically autoimmune disease. METHODS: For this systematic review we carried out a systematic search of four electronic databases (MEDLINE, Embase, CENTRAL, Web of Science) with the two main search terms "autoimmunity" and "ovarian cancer" up to May 10, 2020. We included 36 different autoimmune diseases in our search. From the 4799 screened records, we identified 53 relevant articles for our review, of which 48 were used in our meta-analysis. RESULTS: The incidence of ovarian cancer was significantly lower in patients with multiple sclerosis (standardized incidence ratio (SIR) 0.76, 95% CI 0.60 to 0.96). There was a tendency towards a lower risk of ovarian cancer in patients with systematic lupus erythematosus (SIR 0.89, 95% CI 0.68 to 1.15) and a tendency towards a higher risk in those with type 1 diabetes mellitus (SIR 1.49, 95% CI 0.98 to 2.28); however, this was not statistically significant. No conclusions could be drawn on mortality or the influence of immunosuppressive drugs used in the treatment of autoimmune diseases and the incidence of ovarian cancer. CONCLUSIONS: Our study showed a decreased incidence of ovarian cancer in patients with multiple sclerosis. However, further investigation on the role of the immune system in the development of ovarian cancer in women with autoimmune diseases remains necessary.