癌症免疫疗法的进步正在提高许多不同癌症类型的治疗成功率。尽管如此，大多数肿瘤未能做出反应。年龄是大多数癌症的最大风险，全球人口中位年龄正在上升。年龄的增长与免疫细胞类型、丰度和功能的多种变化有关，而不是这些指标的简单下降，其后果仍未完全确定。我们对宿主年龄对免疫治疗机制、疗效和不良事件影响的理解仍然不完整。需要更深入地了解年龄对所有这些领域的影响。大多数癌症免疫治疗临床前研究都检查年轻受试者，未能评估年龄的贡献，考虑到年龄对免疫细胞以及介导癌症免疫监视和免疫治疗功效的因素的已知重要性，这是一个显着的缺陷。值得注意的是，一些癌症免疫疗法对老年宿主比年轻宿主更有效，而另一些癌症免疫疗法尽管对年轻人有效，但仍失败。在这里，我们回顾了目前对年龄对免疫和相关非免疫细胞、肿瘤微环境、癌症免疫治疗和相关不良反应的影响的理解。我们强调重要的知识差距，并建议需要深入研究的领域，包括癌症免疫监测、治疗反应、不良事件结果及其缓解措施。©2023 美国癌症研究协会。

Advances in cancer immunotherapy are improving treatment successes in many distinct cancer types. Nonetheless, most tumors fail to respond. Age is the biggest risk for most cancers, and the median population age is rising worldwide. Advancing age is associated with manifold alterations in immune cell types, abundance, and functions, rather than simple declines in these metrics, the consequences of which remain incompletely defined. Our understanding of the effects of host age on immunotherapy mechanisms, efficacy, and adverse events remains incomplete. A deeper understanding of age effects in all these areas is required. Most cancer immunotherapy preclinical studies examine young subjects and fail to assess age contributions, a remarkable deficit given the known importance of age effects on immune cells and factors mediating cancer immune surveillance and immunotherapy efficacy. Notably, some cancer immunotherapies are more effective in aged versus young hosts, while others fail despite efficacy in the young. Here, we review our current understanding of age effects on immunity and associated nonimmune cells, the tumor microenvironment, cancer immunotherapy, and related adverse effects. We highlight important knowledge gaps and suggest areas for deeper enquiries, including in cancer immune surveillance, treatment response, adverse event outcomes, and their mitigation.©2023 American Association for Cancer Research.