Department of Radiology, University of Colorado-Denver, School of Medicine, 12700 E 19th Ave, Mail Stop C278, Aurora, CO 80045, USA.
AJR Am J Roentgenol. 2012 Mar;198(3):723-8. doi: 10.2214/AJR.11.7146.
The purpose of our study was to estimate the number of women needed to screen (NNS) to prevent one breast cancer death and the number needed to screen per life-year gained (NNS/LYG) with annual or biennial screening mammography and to compare NNS to the number needed to invite (NNI) to a screening trial to prevent one breast cancer death.
Cancer Intervention and Surveillance Modeling Network (CISNET) modeling results commissioned by the United States Preventive Services Task Force (USPSTF) for their 2009 update of breast cancer screening recommendations were used to estimate NNS and NNS/LYG with annual or biennial screening mammography. NNS values were compared with NNI as reported by USPSTF, which used the CISNET results to aid their 2009 recommendation of starting age and screening interval.
For women between the ages of 40 and 49 years undergoing annual screening mammography, CISNET modeling results estimate an NNS of 746, 39% of the NNI of 1904 estimated by USPSTF on the basis of randomized controlled trial (RCT) data. The NNS based on CISNET results for women between 50 and 59 years is 351 (26% of the NNI of 1339 estimated by USPSTF from RCT data), for women between 60 and 69 years is 233 (62% of the NNI of 377 estimated by USPSTF from RCT data), and for women between 70 and 79 years is 377. Annual screening of women between 40 and 84 years yields an NNS of 84 and an NNS/LYG of 5.3. Biennial screening of women ages 50-74 yields an NNS of 144 and an NNS/LYG of 9.1.
The NNS based on CISNET modeling results is much smaller than the NNI based on RCT data. Eighty-four women need to be screened annually between 40 and 84 years to save one life from breast cancer and 5.3 need to be screened annually to gain 1 life-year from breast cancer.
我们的研究目的是估计每年需要筛查的人数（NNS）以预防一例乳腺癌死亡，以及每年每获得一个生命年需要筛查的人数（NNS/LYG），以此比较年度或两年一次的筛查乳腺 X 光检查来预防一例乳腺癌死亡。
美国预防服务工作组（USPSTF）委托癌症干预和监测建模网络（CISNET）对其 2009 年更新的乳腺癌筛查建议进行建模，以估计年度或两年一次的筛查乳腺 X 光检查的 NNS 和 NNS/LYG。将 NNS 值与 USPSTF 报告的 NNI 进行比较，USPSTF 使用 CISNET 结果来帮助其推荐的起始年龄和筛查间隔。
对于 40-49 岁接受年度筛查乳腺 X 光检查的女性，CISNET 建模结果估计 NNS 为 746，USPSTF 根据随机对照试验（RCT）数据估算的 NNI 为 1904 的 39%。50-59 岁女性基于 CISNET 结果的 NNS 为 351（USPSTF 基于 RCT 数据估算的 NNI 为 1339 的 26%），60-69 岁女性为 233（USPSTF 基于 RCT 数据估算的 NNI 为 377 的 62%），70-79 岁女性为 377。对 40-84 岁女性进行年度筛查可获得 84 的 NNS 和 5.3 的 NNS/LYG。对 50-74 岁女性进行两年一次的筛查可获得 144 的 NNS 和 9.1 的 NNS/LYG。
基于 CISNET 建模结果的 NNS 远小于基于 RCT 数据的 NNI。40-84 岁的女性每年需要筛查 84 次才能预防一例乳腺癌死亡，每年需要筛查 5.3 次才能获得 1 个生命年以预防乳腺癌。
