Cancer-associated dermatomyositis provides a unique opportunity to explore the relationship between autoimmunity and cancer. In this review, we describe the related epidemiological issues, considering the various currently accepted myositis phenotypes, their link with cancer, and the possible mechanisms leading to this relationship. We discuss current evidence regarding the role of molecular mimicry, somatic DNA tumor mutations, and the PD-1/PD-L1 pathway in the association between cancer and myositis. We also review tumor-infiltrating lymphocytes as a relevant factor to be evaluated in cancer-associated myositis, their interaction with tumor neoantigens, and the tumor mutational burden, all of which have implications for the treatment of these patients with immunotherapy. Finally, we discuss clinical scenarios related to the relationship between cancer and myositis, delineating a comprehensive theory linking autoimmunity and cancer.

中文翻译：

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恶性肿瘤和肌炎，从分子模拟到肿瘤浸润淋巴细胞

癌症相关性皮肌炎为探索自身免疫与癌症之间的关系提供了独特的机会。在这篇综述中，我们描述了相关的流行病学问题，考虑了目前公认的各种肌炎表型、它们与癌症的联系以及导致这种关系的可能机制。我们讨论了关于分子模拟、体细胞 DNA 肿瘤突变和 PD-1/PD-L1 通路在癌症和肌炎之间关联中的作用的当前证据。我们还回顾了肿瘤浸润淋巴细胞作为癌症相关肌炎评估的相关因素、它们与肿瘤新抗原的相互作用以及肿瘤突变负荷，所有这些都对免疫疗法治疗这些患者有影响。最后，