Are Poly (ADP-Ribose) Polymerase Inhibitors Safe in Paraneoplastic Dermatomyositis due to High-Grade Serous Carcinoma of the Ovary? A Case Report and a Review of the Literature.

Introduction: Dermatomyositis (DM) is a chronic autoimmune disorder characterized by noninfectious inflammation of the muscles and skin [Curr Treat Options Neurol. 2003;5(5):349-56]. An interesting aspect of DM is its correlation with cancer, particularly as paraneoplastic syndrome, in up to 30% of all cases [Int J Mol Sci. 2020;21(6):2178]. There is a notable association with specific cancers, such as lung cancer in men and breast or ovarian cancer (OC) in women. OC is responsible in up to 13.3%-21.4% of DM cases in women. Thus, it is important to explore whether poly (ADP-ribose) polymerase inhibitors (iPARP), a key component of OC maintenance treatment, are safe to use in patients with paraneoplastic DM especially since iPARP could be associated with an immunomodulatory effect with unknown impact on paraneoplastic syndromes.

Case presentation: A 69-year-old patient without significant comorbidities was undergoing dermatological investigations for a persistent skin rash suspect of DM. In her preplanned appointment, bilateral ovarian masses were detected. The skin biopsy confirmed a DM. The DM was associated with an underlying advanced FIGO IIIC high-grade serous ovarian cancer (HGSOC) not amendable to a primary debulking surgery. Following perioperative chemotherapy and a macroscopically complete interval debulking surgery, the patient was to receive iPARP. On immunosuppressive treatment, DM was in near complete remission; thus, the safety of iPARP needed to be reviewed before treatment initiation.

Conclusion: This article reports on a case of HGSOC receiving iPARP maintenance following standard of care interval debulking surgery. On this treatment, the patient did not experience DM flair and remains in complete oncological response.