Lung cancer screening is a proven method to detect cancers early, resulting in reduced morbidity and mortality. Guidelines regarding lung cancer screening have been published by a few groups, including the American Cancer Society (ACS) who, since 2010, have recommended for low-dose computed tomography screening for those who meet the criteria. One such criterion is years since quitting (YSQ). The 2023 update¹ incorporates significant evolutions that reflect an updated evidence base, in particular related to YSQ. In recognizing that genomic alterations from combustible tobacco exposure do not reliably reverse over time, the guideline update expands the population of those eligible for screening. Furthermore, it serves as a cautionary tale to current episodic smokers regarding the common assumption that quitting smoking removes the risk of lung cancer, particularly with the passage of time.

The rationale for this change is explained as follows: the individual risk of lung cancer does indeed decrease over time once someone quits smoking, but this reduction is relatively lower only if compared with a similar person who continues to smoke. Compared with a person who never smoked, the risk for lung cancer appears to remain three times greater, even at 20 and 30 YSQ. This introduces an entirely new cohort of people now eligible for lung cancer screening, some of whom we may not visualize when imagining the patient who should be contacted for annual screening. For example, picture a business executive in her 50s who previously smoked two packs per day throughout high school and into young adulthood, quitting when she became a parent at age 30 years. She smoked during college and graduate school, but that is now in the distant past. Because of her previous smoking history of 20 pack-years, she is now—for the first time ever—considered a prime candidate for lung cancer screening to reduce the potential morbidity and mortality from lung cancer.

Embedded within this update are acknowledgments of the limitations of available data. For example, large trials used in this analysis did not routinely report on race or ethnicity; and, where race was captured, the vast majority of individuals were White study volunteers. Whether the same eligibility criteria for lung cancer screening applies across races is not clear, but some data suggest that race matters, with lung cancer onset at a younger age among Black people compared to White people, and with a higher proportion of those who did not meet the critical 30 pack-year threshold to initiate lung cancer screening (compared with White people). Finally, how to identify nonsmokers who may benefit from screening is not known. This is important because it accounts for 20% of all diagnoses of lung cancer. We agree that further work into who they are is urgent.

For now, this important update is one that requires swift action at the individual, community, state, and national levels. Since the initial screening recommendation by the American Cancer Society in 2010, uptake of lung cancer screening across eligible populations has been low; in many states, the rate is in the single digits. Because the 2023 update expands the population eligible for screening and notes that smoking of any duration or amount has negative health consequences, the implementation of screening and smoking-cessation programs must accelerate. Furthermore, such programs must embed themselves in communities that particularly face lung cancer disparities, such as in racial minority and rural populations. We know that screening saves lives, and the recent updated guidelines further highlight the crucial need to solve for greater access to screening for all.

肺癌筛查是一种经过验证的早期发现癌症的方法，可降低发病率和死亡率。包括美国癌症协会 (ACS) 在内的一些团体已发布了有关肺癌筛查的指南，自 2010 年以来，该协会建议对符合标准的患者进行低剂量计算机断层扫描筛查。其中一项标准是戒烟年数(YSQ)。 2023 年更新¹包含了反映更新证据基础的重大演变，特别是与 YSQ 相关的证据基础。认识到可燃烟草暴露引起的基因组改变不会随着时间的推移而可靠地逆转，指南更新扩大了符合筛查资格的人群。此外，它对当前偶尔吸烟的人来说是一个警示，提醒人们普遍认为戒烟可以消除患肺癌的风险，尤其是随着时间的推移。

这一变化的理由解释如下：一旦戒烟，个体患肺癌的风险确实会随着时间的推移而降低，但只有与继续吸烟的类似人相比，这种降低才相对较低。与从不吸烟的人相比，即使 YSQ 为 20 和 30，患肺癌的风险似乎仍高出三倍。这引入了一个全新的人群，现在有资格进行肺癌筛查，其中一些人在想象应该联系进行年度筛查的患者时可能无法想象。例如，想象一下一位 50 多岁的企业高管，她从高中到成年初期每天每天吸两包烟，并在 30 岁时为人父母后戒烟。她在大学和研究生期间吸烟，但那已经是遥远的过去了。由于她之前有 20 包年的吸烟史，她现在有史以来第一次被认为是肺癌筛查的主要候选人，以降低肺癌的潜在发病率和死亡率。

此更新中包含对可用数据局限性的确认。例如，本分析中使用的大型试验通常不会报告种族或民族；而且，在记录种族情况时，绝大多数人都是白人研究志愿者。相同的肺癌筛查资格标准是否适用于不同种族尚不清楚，但一些数据表明种族很重要，与白人相比，黑人患肺癌的年龄更年轻，而且未接受肺癌筛查的人比例更高达到启动肺癌筛查的关键 30 包年阈值（与白人相比）。最后，如何识别可能从筛查中受益的非吸烟者尚不清楚。这很重要，因为它占所有肺癌诊断的 20%。我们一致认为，迫切需要进一步了解他们的身份。

目前，这一重要更新需要个人、社区、州和国家层面迅速采取行动。自 2010 年美国癌症协会首次提出筛查建议以来，符合条件的人群对肺癌筛查的接受度一直很低；在许多州，这一比率只有个位数。由于 2023 年更新扩大了符合筛查资格的人群，并指出任何持续时间或数量的吸烟都会对健康产生负面影响，因此必须加快筛查和戒烟计划的实施。此外，此类计划必须融入特别面临肺癌差异的社区，例如少数族裔和农村人口。我们知道筛查可以拯救生命，最近更新的指南进一步强调了解决全民筛查问题的迫切需要。