Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
N Engl J Med. 2012 Jun 21;366(25):2345-57. doi: 10.1056/NEJMoa1114635. Epub 2012 May 21.
The benefits of endoscopic testing for colorectal-cancer screening are uncertain. We evaluated the effect of screening with flexible sigmoidoscopy on colorectal-cancer incidence and mortality.
From 1993 through 2001, we randomly assigned 154,900 men and women 55 to 74 years of age either to screening with flexible sigmoidoscopy, with a repeat screening at 3 or 5 years, or to usual care. Cases of colorectal cancer and deaths from the disease were ascertained.
Of the 77,445 participants randomly assigned to screening (intervention group), 83.5% underwent baseline flexible sigmoidoscopy and 54.0% were screened at 3 or 5 years. The incidence of colorectal cancer after a median follow-up of 11.9 years was 11.9 cases per 10,000 person-years in the intervention group (1012 cases), as compared with 15.2 cases per 10,000 person-years in the usual-care group (1287 cases), which represents a 21% reduction (relative risk, 0.79; 95% confidence interval [CI], 0.72 to 0.85; P<0.001). Significant reductions were observed in the incidence of both distal colorectal cancer (479 cases in the intervention group vs. 669 cases in the usual-care group; relative risk, 0.71; 95% CI, 0.64 to 0.80; P<0.001) and proximal colorectal cancer (512 cases vs. 595 cases; relative risk, 0.86; 95% CI, 0.76 to 0.97; P=0.01). There were 2.9 deaths from colorectal cancer per 10,000 person-years in the intervention group (252 deaths), as compared with 3.9 per 10,000 person-years in the usual-care group (341 deaths), which represents a 26% reduction (relative risk, 0.74; 95% CI, 0.63 to 0.87; P<0.001). Mortality from distal colorectal cancer was reduced by 50% (87 deaths in the intervention group vs. 175 in the usual-care group; relative risk, 0.50; 95% CI, 0.38 to 0.64; P<0.001); mortality from proximal colorectal cancer was unaffected (143 and 147 deaths, respectively; relative risk, 0.97; 95% CI, 0.77 to 1.22; P=0.81).
Screening with flexible sigmoidoscopy was associated with a significant decrease in colorectal-cancer incidence (in both the distal and proximal colon) and mortality (distal colon only). (Funded by the National Cancer Institute; PLCO ClinicalTrials.gov number, NCT00002540.).
结直肠癌筛查中内镜检查的获益尚不确定。我们评估了乙状结肠镜筛查对结直肠癌发病率和死亡率的影响。
1993 年至 2001 年，我们将 154900 名年龄在 55 至 74 岁的男性和女性随机分配至筛查组（接受乙状结肠镜筛查，可在 3 或 5 年后重复筛查）或对照组（常规护理）。结直肠癌病例和因该病死亡的情况得以确定。
在随机分配至筛查组（干预组）的 77445 名参与者中，83.5%接受了基线乙状结肠镜检查，54.0%在 3 或 5 年后接受了筛查。中位随访 11.9 年后，干预组结直肠癌的发病率为每 10000 人年 11.9 例（1012 例），而对照组为每 10000 人年 15.2 例（1287 例），发病率降低 21%（相对风险，0.79；95%置信区间 [CI]，0.72 至 0.85；P<0.001）。在远端结直肠癌（干预组 479 例 vs. 对照组 669 例；相对风险，0.71；95%CI，0.64 至 0.80；P<0.001）和近端结直肠癌（干预组 512 例 vs. 对照组 595 例；相对风险，0.86；95%CI，0.76 至 0.97；P=0.01）的发病率方面也观察到了显著降低。干预组每 10000 人年有 2.9 例结直肠癌死亡（252 例死亡），而对照组为每 10000 人年 3.9 例（341 例死亡），死亡率降低 26%（相对风险，0.74；95%CI，0.63 至 0.87；P<0.001）。远端结直肠癌死亡率降低了 50%（干预组 87 例 vs. 对照组 175 例；相对风险，0.50；95%CI，0.38 至 0.64；P<0.001）；近端结直肠癌死亡率无变化（分别为 143 例和 147 例；相对风险，0.97；95%CI，0.77 至 1.22；P=0.81）。
乙状结肠镜筛查与结直肠癌发病率（远端和近端结肠均如此）和死亡率（仅远端结肠）的显著降低相关。（美国国家癌症研究所资助；PLCO 临床试验。gov 编号，NCT00002540。）
