Data Sheet 1_Case Report: Pembrolizumab in a patient with preexisting paraneoplastic dermatomyositis and sarcomatoid urothelial carcinoma. Searching for balance.pdf

Dermatomyositis (DM) is an uncommon systemic autoimmune disorder classified as one of the idiopathic inflammatory myopathies (IIM). DM could also represent a manifestation of an underlying neoplasm with a relative risk of cancer globally ranging from 3% to 8%. Owing to the strong connection between immunosurveillance and cancer progression, the management of paraneoplastic DM represents a challenging issue. To complicate matters is the advent of cancer immunotherapy, that might interfere with self-tolerance with a true risk of previous autoimmune disorders re-exacerbation. We report the case of a 50-year-old patient with advanced urothelial bladder cancer and preexisting paraneoplastic DM treated with pembrolizumab. On the basis of our experience, previous paraneoplastic DM might not necessarily represent an absolute contraindication for ICIs treatment. Furthermore, this case might suggest a role of intravenous immunoglobulins (IVIG) in preventing DM reactivation, underling the importance of a multidisciplinary approach.

皮肌炎（Dermatomyositis, DM）是一种罕见的全身性自身免疫性疾病，归属于特发性炎性肌病（idiopathic inflammatory myopathies, IIM）范畴。DM亦可作为潜在恶性肿瘤的临床表现，全球范围内其伴发癌症的相对风险为3%至8%。鉴于免疫监视与癌症进展间存在紧密关联，副肿瘤性皮肌炎的临床管理堪称一项极具挑战性的难题。更棘手的是，癌症免疫治疗的问世可能会干扰自身耐受，存在使既往自身免疫性疾病再度加重的实际风险。我们报告1例50岁晚期尿路上皮膀胱癌合并既往副肿瘤性皮肌炎的患者，该患者接受帕博利珠单抗（pembrolizumab）治疗。基于本次临床经验，既往副肿瘤性皮肌炎未必是免疫检查点抑制剂（immune checkpoint inhibitors, ICIs）治疗的绝对禁忌证。此外，该病例或可提示静脉注射免疫球蛋白（intravenous immunoglobulins, IVIG）在预防皮肌炎复发中的作用，凸显多学科协作诊疗模式的重要性。