Modifying disease therapy in multiple sclerosis and breast cancer: case report

Case report:

We report three female patients diagnosed with relapsing-remitting multiple sclerosis (RRMS) undergoing therapy with high-efficacy drugs, including Natalizumab, Ocrelizumab, and Fingolimod. During treatment, they were diagnosed with breast nodules (BN) and initially chose clinical monitoring. The first patient, aged 36, monitored a BN with a specialist since 2018, starting Ocrelizumab treatment. After three months, she was diagnosed with breast cancer. The second patient, aged 45, followed a BN with a specialist since 2015, starting Fingolimod in 2018 and undergoing a breast biopsy that year, revealing ductal hyperplasia. After partial breast resection in 2019, she relapsed, switching to Natalizumab and experiencing cancer recurrence. The third patient, aged 38, rejected conventional treatment, opting for high-dose vitamin D therapy despite medical recommendations for disease modifying drugs (DMD). Due to new relapses and increased lesion burden, she started Natalizumab, later diagnosed with ductal carcinoma in situ, leading to bilateral mastectomy.

Discussion:

Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system affecting young women globally, altered by disease modifying therapy (DMT). Despite proven efficacy, recent studies suggested potential adverse effects, including neoplasms like breast cancer. Many patients already have BN before DMT, lacking regular screening. Breast cancer is prevalent among women worldwide, and its diagnosis may result from disease progression or missed screening. Three patients with prior breast nodule follow-up, diagnosed with RRMS on high-efficacy therapy, are presented, two with malignant breast neoplasia.

Final Comments:

Although breast neoplasia occurred in the three patients, causality with disease-modifying drugs cannot be established. Further research is needed to understand their potential adverse effects. Implementing neoplasm screening protocols for patients on DMT is crucial.