Efficacy of azathioprine in reducing recurrence in idiopathic granulomatous mastitis.

Idiopathic granulomatous mastitis (IGM) is an immune-mediated inflammatory breast disease presenting significant treatment challenges due to its varied symptoms and lack of standardized guidelines. This study aims to evaluate the efficacy and safety of immunosuppressive modalities, including corticosteroids (CS) and immunosuppressive agents such as methotrexate (MTX) and azathioprine (AZA), in managing IGM, with a focus on recurrence rates and treatment outcomes. We conducted a retrospective analysis of 505 female patients diagnosed with IGM at the Bursa Uludag University Breast Surgery Clinic between January 2011 and December 2022. Patients received various treatments, including observation, CS therapy, MTX, AZA, and surgical interventions when necessary. Recurrence rates among different therapy groups were compared using chi-square tests, with Bonferroni correction applied for multiple comparisons. Of the total patients, 29.7% received first-line conservative therapy, while 70.3% required second or third-line immunosuppressive treatments. Among those who received immunosuppressive therapy (n = 355), CS therapy alone had the highest recurrence rate at 28.8%. The addition of MTX reduced the recurrence rate to 19.8%, but this reduction was not statistically significant (p = 0.143). AZA therapy significantly lowered recurrence rates, both when used alone (4.7%) and in combination with CS (9.1%) (p < 0.005). Patients treated with a combination of MTX and AZA had a recurrence rate of 4.8%. Overall, there were significant differences in recurrence rates among the therapy groups (χ² (4, N = 352) = 25.58, p < 0.001). AZA, whether used alone or in conjunction with other immunosuppressive agents, effectively reduces recurrence rates in IGM patients. These results support its use as an alternative to CS therapy in tailored treatment plans.