Corticosteroids in idiopathic granulomatous mastitis: a systematic review and meta-analysis.

Idiopathic granulomatous mastitis (IGM) is an inflammatory disease of the breasts with an unknown etiology. Corticosteroids are one the primary options for treating this disease, but the results of previous studies concerning their efficacy have been controversial. We, therefore, decided to assess the effectiveness of corticosteroids on IGM using a systematic review and meta-analysis. We conducted a systematic search using MeSH terms and all relevant keywords in PubMed, EMBASE, Cochrane Library and Web of Science until May 21, 2019. Data were analyzed using the Comprehensive Meta-Analysis (CMA) V.2 software program and presented as the event rate, risk ratio (RR) and risk difference (RD). Twelve studies including 559 IGM patients were entered into the meta-analysis. Our analysis showed that the RR and RD of recurrence in the steroid-only group compared with the surgery-only group were 2.99 (95% confidence interval [CI] 0.28-31.33) and 0.14 (95% CI - 0.01-0.30), respectively, showing no statistical significance. The meta-analysis of the steroid-only group and steroid + surgery group showed that the RR of recurrence was 6.13 (95% CI 0.41-81.62) with no significance. However, the meta-analysis of the RD showed that the risk of recurrence in the steroid group was significantly higher than that in the steroids + surgery group (RD: 0.28, 95% CI 0.11-0.44). This meta-analysis showed that managing IGM with only steroids may be less effective than the combination of steroids and surgery. This combination approach may result in a lower rate of recurrence and side effects in these patients.