Third Department of Surgery, Attikon University Hospital, 12462 Athens, Greece.
Second Department of Pathology, Attikon University Hospital, 12462 Athens, Greece.
Oncol Rep. 2021 Jun;45(6). doi: 10.3892/or.2021.8043. Epub 2021 Apr 13.
Colorectal cancer (CRC) is one of the most frequently encountered neoplasms and has a high rate of morbidity and mortality. Recent findings showing that tumor immune evasion is an important mechanism underlying propagation of a cancer have changed the landscape of medical oncology through identification of Programmed‑Death receptor 1 and its ligand (PD‑1 and PD‑L1) as novel targets for oncological immune therapies. PD‑1 is primarily expressed on peritumoral lymphocytes and when activated, it suppresses its immune functions. Conversely, PD‑L1 is primarily expressed on the tumor infiltrating front with the purpose of deregulating physiological cytotoxic immune responses. Numerous studies have linked PD‑L1 overexpression to specific adverse clinicopathological features, such as poor differentiation, lymphovascular invasion and worse overall survival in CRC patients. Nevertheless, there is no concrete evidence showing which patients may exhibit the maximal beneficial effects of PD‑1/PD‑L1 blockade therapy, and how these novel molecular targets may be optimally integrated into therapeutic regimens for management of CRC patients with resectable and generalized disease.
结直肠癌（CRC）是最常见的肿瘤之一，发病率和死亡率都很高。最近的研究发现，肿瘤免疫逃逸是癌症发生的重要机制，通过鉴定程序性死亡受体 1 及其配体（PD-1 和 PD-L1）作为肿瘤免疫治疗的新靶点，改变了肿瘤医学的格局。PD-1 主要表达在肿瘤周围的淋巴细胞上，当被激活时，它会抑制其免疫功能。相反，PD-L1 主要表达在肿瘤浸润前沿，目的是使生理细胞毒性免疫反应失活。大量研究将 PD-L1 过表达与特定的不良临床病理特征联系起来，如分化不良、血管淋巴管侵犯和 CRC 患者总体生存率较差。然而，目前尚无确凿证据表明哪些患者可能从 PD-1/PD-L1 阻断治疗中获得最大的益处，以及这些新的分子靶点如何最佳地整合到治疗方案中，以管理可切除和全身性疾病的 CRC 患者。
