Major advances in cancer immunotherapy have dramatically expanded the potential to manipulate immune cells in cancer patients with metastatic disease to counteract cancer spread and extend patient lifespan. One of the most successful types of immunotherapy is the immune checkpoint inhibitors, such as anti-CTLA-4 and anti-PD-1, that keep anti-tumour T cells active. However, not every patient with metastatic disease benefits from this class of drugs and patients often develop resistance to these therapies over time. Tremendous research effort is now underway to uncover new immunotherapeutic targets that can be used in patients who are refractory to anti-CTLA-4 or anti-PD-1 treatment. Here, we discuss results from experimental model systems demonstrating that modulating the immune response can negatively affect metastasis formation. We focus on molecules that boost anti-tumour immune cells and opportunities to block immunosuppression, as well as cell-based therapies with enhanced tumour recognition properties for solid tumours. We also present a list of challenges in treating metastatic disease with immunotherapy that must be considered in order to move laboratory observations into clinical practice and maximise patient benefit.

癌症免疫疗法的重大进展极大地扩展了操纵患有转移性疾病的癌症患者的免疫细胞以抵抗癌症扩散并延长患者寿命的潜力。最成功的免疫疗法之一是免疫检查点抑制剂，例如抗 CTLA-4 和抗 PD-1，它们可以保持抗肿瘤 T 细胞的活性。然而，并非所有患有转移性疾病的患者都能从此类药物中受益，并且随着时间的推移，患者常常会对这些疗法产生耐药性。目前正在进行大量研究工作，以发现可用于抗 CTLA-4 或抗 PD-1 治疗难治性患者的新免疫治疗靶点。在这里，我们讨论实验模型系统的结果，证明调节免疫反应会对转移形成产生负面影响。我们专注于增强抗肿瘤免疫细胞的分子和阻断免疫抑制的机会，以及增强实体瘤肿瘤识别特性的细胞疗法。我们还提出了一系列使用免疫疗法治疗转移性疾病的挑战，必须考虑这些挑战，以便将实验室观察结果转化为临床实践并最大限度地提高患者利益。