新概念和药物革命性地改变了癌症的医学治疗。这些药物价格昂贵，但一般耐受性好，已经大幅改善了癌症的预后。我们必须明智地使用它们，使患者获得充分的效益。胃酸分泌抑制药物，特别是质子泵抑制剂（PPIs），颠覆了治疗胃十二指肠溃疡和严重胃食管反流的方法，但常常被滥用于对胃痛或心灼热的症状性治疗。长期抑制胃酸可能会改变许多抗癌药物（例如酪氨酸激酶抑制剂（TKIs），cyclin-dependent kinase（CDK）4/6抑制剂和免疫检查点抑制剂（ICIs））的疗效，要么通过降低胃酸分泌从而影响药物吸收，要么通过改变调节ICIs反应的肠道微生物组。因此，肿瘤学家们需要特别关注PPIs和抗癌药物的同时使用。这些相互作用会产生重大的临床影响，已经证明对一些TKIs（erlotinib，gefitinib，pazopanib）的疗效损失，并在许多其他口服药物中产生冲突的结果，包括capecitabine和CDK 4/6抑制剂。此外，使用PPIs引起的肠道微生物组的深刻改变已经表明，在接受PPIs治疗的患者中，使用ICIs的效益可能会受到压制。由于使用PPIs并非必要，我们必须应用预防原则。最近一篇《Nature》的评论中的第一句是“每天有数百万人正在服用对他们无益的药物”。我们担心每天有数百万癌症患者正在服用对他们有害的药物。虽然这可能只是关联性而非因果关系，但有足够的理由使我们暂缓行动，直到我们获得明确的答案。所有这些数据都应该鼓励医学肿瘤学家不要开处方给患者使用PPIs，并向患者解释相互作用的风险，以防止由另一位医生进行不适当的处方。 版权所有 © 2023作者。由Elsevier Ltd.出版。保留所有权利。

New concepts and drugs have revolutionized medical treatment for cancers. These drugs, which are very expensive and usually well tolerated, have dramatically improved cancer prognosis. We must use them wisely for patients to fully benefit. Gastric acid antisecretory drugs and particularly proton pump inhibitors (PPIs) revolutionized the treatment of gastroduodenal ulcers and severe gastroesophageal reflux, but are frequently overused for symptomatic treatment of epigastric pain or heartburn. Long-term acid suppression may alter the efficacy of many anticancer drugs, such as tyrosine kinase inhibitors (TKIs), cyclin-dependent kinase (CDK) 4/6 inhibitors and immune checkpoint inhibitors (ICIs), by either decreasing gastric acid secretion and thus drug absorption, or by modifying the gut microbiome that modulates the response to ICIs. Oncologists thus need to pay particular attention to the concomitant use of PPIs and anticancer drugs. These interactions translate into major clinical impacts, with demonstrated loss of efficacy for some TKIs (erlotinib, gefitinib, pazopanib), and conflicting results with many other oral drugs, including capecitabine and CDK 4/6 inhibitors. Furthermore, the profound changes in the gut microbiome due to using PPIs have shown that the benefit of using ICIs may be suppressed in patients treated with PPIs. As the use of PPIs is not essential, we must apply the precautionary principle. The first sentence of a recent Comment in Nature was "Every day, millions of people are taking medications that will not help them". We fear that every day millions of cancer patients are taking medications that harm them. While this may well be only association and not causation, there is enough to make us pause until we reach a clear answer. All these data should encourage medical oncologists to refrain from prescribing PPIs, explaining to patients the risks of interaction in order to prevent inappropriate prescription by another physician.Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.