Ma Wenjie, Wang Molin, Wang Kai, Cao Yin, Hertzmark Ellen, Ogino Shuji, Ng Kimmie, Willett Walter C, Giovannucci Edward L, Song Mingyang, Chan Andrew T
Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston.
Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston.
JAMA Oncol. 2022 Jul 1;8(7):986-993. doi: 10.1001/jamaoncol.2022.0883.
In the past 4 years, the American Cancer Society and the US Preventive Services Task Force updated recommendations to initiate colorectal cancer (CRC) screening at 45 years of age to address the increasing incidence of CRC among adults younger than 50 years. However, empirical evidence evaluating the potential benefits of screening in younger populations is scant.
To examine the association between endoscopy initiation at different ages and risk of CRC among US women.
DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study used data from the Nurses' Health Study II, which included US female health professionals followed up from 1991 through 2017. Data analysis was performed from August 2020 to June 2021.
Age at initiation of sigmoidoscopy or colonoscopy for screening (routine screening or because of family history) or symptoms.
Incident CRC, confirmed by medical records, pathology reports, and the National Death Index. Cumulative incidence of CRC in each group was estimated with age as the time scale, and the absolute risk reduction associated with endoscopy initiation at different ages through 60 years was calculated. Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% CIs, stratified by age and calendar year of questionnaire cycle and adjusted for CRC risk factors in the multivariable models.
Among 111 801 women aged 26 to 46 years (median, 36 years) at enrollment, 519 incident CRC cases were documented over 26 years, encompassing 2 509 358 person-years of follow-up. In the multivariable analysis, compared with no endoscopy, undergoing endoscopy was associated with a significantly lower risk of incident CRC for age at initiation before 45 years (HR, 0.37; 95% CI, 0.26-0.53), 45 to 49 years (HR, 0.43; 95% CI, 0.29-0.62), 50 to 54 years (HR, 0.47; 95% CI, 0.35-0.62), and 55 years or older (HR, 0.46; 95% CI, 0.30-0.69). The absolute reduction in the estimated cumulative incidence of CRC through 60 years of age was 72 per 100 000 persons for initiation of endoscopy at 45 to 49 years of age vs 50 to 54 years of age. Compared with no endoscopy, initiation of endoscopy before 50 years of age was also associated with a reduced risk of CRC diagnosed before 55 years of age (<45 years: HR, 0.45 [95% CI, 0.29-0.70]; 45-49 years: HR, 0.43 [95% CI, 0.24-0.76]).
In this cohort study, compared with no endoscopy, initiation of endoscopy before 50 years of age was associated with a reduced risk of CRC, including CRC diagnosed before 55 years of age. Screening before 50 years of age was associated with greater absolute reduction in CRC risk compared with initiation of CRC screening at 50 years of age or later.
在过去4年中，美国癌症协会和美国预防服务工作组更新了建议，将结直肠癌（CRC）筛查起始年龄设定为45岁，以应对50岁以下成年人中CRC发病率不断上升的情况。然而，评估在较年轻人群中进行筛查潜在益处的实证证据很少。
研究美国女性在不同年龄开始进行内镜检查与CRC风险之间的关联。
设计、设置和参与者：这项前瞻性队列研究使用了护士健康研究II的数据，该研究包括1991年至2017年期间接受随访的美国女性健康专业人员。数据分析于2020年8月至2021年6月进行。
因筛查（常规筛查或由于家族史）或症状而开始进行乙状结肠镜检查或结肠镜检查的年龄。
通过病历、病理报告和国家死亡指数确诊的新发CRC。以年龄为时间尺度估计每组中CRC的累积发病率，并计算60岁之前不同年龄开始进行内镜检查所带来的绝对风险降低。使用Cox比例风险回归计算风险比（HRs）和95%置信区间（CIs），按问卷周期的年龄和日历年份分层，并在多变量模型中对CRC风险因素进行调整。
在入组时年龄为26至46岁（中位数为36岁）的111801名女性中，26年期间记录了519例新发CRC病例，随访时间总计2509358人年。在多变量分析中，与未进行内镜检查相比，在45岁之前开始进行内镜检查（HR，0.37；95%CI，0.26 - 0.53）、45至49岁（HR，0.43；95%CI，0.29 - 0.62）、50至54岁（HR，0.47；95%CI，0.35 - 0.62）以及55岁及以上（HR，0.46；95%CI，0.30 - 0.69）时，进行内镜检查与新发CRC风险显著降低相关。45至49岁开始进行内镜检查与50至54岁相比，到60岁时估计的CRC累积发病率的绝对降低为每100000人中有72例。与未进行内镜检查相比，50岁之前开始进行内镜检查也与55岁之前诊断出CRC的风险降低相关（<45岁：HR，0.45 [95%CI，0.29 - 0.70]；45 - 49岁：HR，0.43 [95%CI，0.24 - 0.76]）。
在这项队列研究中，与未进行内镜检查相比，50岁之前开始进行内镜检查与CRC风险降低相关，包括55岁之前诊断出的CRC。与50岁及以后开始进行CRC筛查相比，50岁之前进行筛查与CRC风险的绝对降低幅度更大。
