Gastrointestinal cancers are a specific group of oncological diseases in which the location and nature of growth are of key importance for clinical symptoms and prognosis. At the same time, as research shows, they pose a serious threat to a patient’s life, especially at an advanced stage of development. The type of therapy used depends on the anatomical location of the cancer, its type, and the degree of progression. One of the modern forms of therapy used to treat gastrointestinal cancers is PDT, which has been approved for the treatment of esophageal cancer in the United States. Despite the increasingly rapid clinical use of this treatment method, the exact immunological mechanisms it induces in cancer cells has not yet been fully elucidated. This article presents a review of the current understanding of the mode of action of photodynamic therapy on cells of various gastrointestinal cancers with an emphasis on colorectal cancer. The types of cell death induced by PDT include apoptosis, necrosis, and pyroptosis. Anticancer effects are also a result of the destruction of tumor vasculature and activation of the immune system. Many reports exist that concern the mechanism of apoptosis induction, of which the mitochondrial pathway is most often emphasized. Photodynamic therapy may also have a beneficial effect on such aspects of cancer as the ability to develop metastases or contribute to reducing resistance to known pharmacological agents.
胃肠道癌症是一类特定的肿瘤性疾病，其发生部位和生长特性对临床症状及预后具有关键影响。研究表明，这类疾病对患者生命构成严重威胁，尤其在进展期阶段。治疗方案的选择取决于肿瘤的解剖位置、病理类型及进展程度。光动力疗法是目前用于治疗胃肠道癌症的现代疗法之一，已在美国获批用于食管癌治疗。尽管该疗法在临床中的应用日益广泛，但其在癌细胞中诱导的确切免疫学机制尚未完全阐明。本文综述了当前对光动力疗法作用于各类胃肠道癌细胞（重点关注结直肠癌）机制的认识。光动力疗法诱导的细胞死亡类型包括凋亡、坏死和焦亡。其抗癌效应还源于对肿瘤血管系统的破坏以及免疫系统的激活。现有大量研究关注凋亡诱导机制，其中线粒体通路最受重视。光动力疗法还可能对癌症转移能力产生抑制作用，并有助于降低对已知药物的耐药性。
Photodynamic Therapy and Immunological View in Gastrointestinal Tumors
肿瘤(癌症)患者之家