Wang Sabrina, Sultana Farhana, Kavanagh Anne, Nickson Carolyn, Karahalios Amalia, Gurrin Lyle C, English Dallas R
Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia.
Cancer Epidemiology Division, Cancer Council Victoria, Melbourne, Victoria, Australia.
Cancer Med. 2023 Sep;12(17):18120-18132. doi: 10.1002/cam4.6373. Epub 2023 Aug 7.
Quantifying the benefits and harms of breast cancer screening accurately is important for planning and evaluating screening programs and for enabling women to make informed decisions about participation. However, few cohort studies have attempted to estimate benefit and harm simultaneously.
We aimed to quantify the impact of mammographic screening on breast cancer mortality and overdiagnosis using a cohort of women invited to attend Australia's national screening program, BreastScreen.
In a cohort of 41,330 women without prior breast cancer diagnosis, screening, or diagnostic procedures invited to attend BreastScreen Western Australia in 1994-1995, we estimated the cumulative risk of breast cancer mortality and breast cancer incidence (invasive and ductal carcinoma in situ) from age 50 to 85 years for attenders and non-attenders. Data were obtained by linking population-based state and national health registries. Breast cancer mortality risks were estimated from a survival analysis that accounted for competing risk of death from other causes. Breast cancer risk for unscreened women was estimated by survival analysis, while accounting for competing causes of death. For screened women, breast cancer risk was the sum of risk of being diagnosed at first screen, estimated using logistic regression, and risk of diagnosis following a negative first screen estimated from a survival analysis.
For every 1,000 women 50 years old at first invitation to attend BreastScreen, there were 20 (95% CI 12-30) fewer breast cancer deaths and 25 (95% CI 15-35) more breast cancers diagnosed for women who attended than for non-attendees by age 85. Of the breast cancers diagnosed in screened women, 21% (95% CI 13%-27%) could be attributed to screening.
The estimated ratio of benefit to harm was consistent with, but slightly less favourable to screening than most other estimates from cohort studies.
Women who participate in organised screening for breast cancer in Australia have substantially lower breast cancer mortality, while some screen-detected cancers may be overdiagnosed.
准确量化乳腺癌筛查的益处和危害对于规划和评估筛查项目以及使女性能够做出关于参与筛查的明智决策至关重要。然而，很少有队列研究试图同时估计益处和危害。
我们旨在利用受邀参加澳大利亚国家筛查项目“乳房筛查”（BreastScreen）的一组女性，量化乳房X线筛查对乳腺癌死亡率和过度诊断的影响。
在1994 - 1995年受邀参加西澳大利亚州“乳房筛查”的41330名未曾有过乳腺癌诊断、筛查或诊断性检查的女性队列中，我们估计了50至85岁时参加者和未参加者的乳腺癌死亡累积风险以及乳腺癌发病率（浸润性癌和原位导管癌）。数据通过链接基于人群的州和国家健康登记处获得。乳腺癌死亡风险通过生存分析估计，该分析考虑了其他原因导致死亡的竞争风险。未筛查女性的乳腺癌风险通过生存分析估计，同时考虑死亡的竞争原因。对于筛查女性，乳腺癌风险是首次筛查时被诊断的风险（使用逻辑回归估计）与首次筛查为阴性后诊断的风险（通过生存分析估计）之和。
对于首次受邀参加“乳房筛查”时年龄为50岁的每1000名女性，到85岁时，参加筛查的女性比未参加者的乳腺癌死亡人数少20例（95%置信区间12 - 30），诊断出的乳腺癌多25例（95%置信区间15 - 35）。在筛查女性中诊断出的乳腺癌，21%（95%置信区间13% - 27%）可归因于筛查。
估计的利弊比与队列研究的大多数其他估计结果一致，但对筛查的有利程度略低。
在澳大利亚参加有组织的乳腺癌筛查的女性乳腺癌死亡率显著降低，而一些筛查发现的癌症可能被过度诊断。
