Department of Public Health, Aarhus University, 8000 Aarhus C, Denmark.
Institute of Global Public Health, University of Strathclyde at the International Prevention Research Institute, Lyon 69570, France.
Eur J Public Health. 2022 Aug 1;32(4):630-635. doi: 10.1093/eurpub/ckac047.
Reductions in breast cancer mortality observed over the last three decades are partly due to improved patient management, which may erode the benefit-harm balance of mammography screening.
We estimated the numbers of women needed to invite (NNI) to prevent one breast cancer death within 10 years. Four scenarios of screening effectiveness (5-20% mortality reduction) were applied on 10,580 breast cancer deaths among Norwegian women aged 50-75 years from 1986 to 2016. We used three scenarios of overdiagnosis (10-40% excess breast cancers during screening period) for estimating ratios of numbers of overdiagnosed breast cancers for each breast cancer death prevented.
Under the base case scenario of 20% breast cancer mortality reduction and 20% overdiagnosis, the NNI rose from 731 (95% CI: 644-830) women in 1996 to 1364 (95% CI: 1181-1577) women in 2016, while the number of women with overdiagnosed cancer for each breast cancer death prevented rose from 3.2 in 1996 to 5.4 in 2016. For a mortality reduction of 8.7%, the ratio of overdiagnosed breast cancers per breast cancer death prevented rose from 7.4 in 1996 to 14.0 in 2016. For a mortality reduction of 5%, the ratio rose from 12.8 in 1996 to 25.2 in 2016.
Due to increasingly potent therapeutic modalities, the benefit in terms of reduced breast cancer mortality declines while the harms, including overdiagnosis, are unaffected. Future improvements in breast cancer patient management will further deteriorate the benefit-harm ratio of screening.
过去三十年中，乳腺癌死亡率的降低部分归因于患者管理水平的提高，这可能会削弱乳房 X 线筛查的获益-危害平衡。
我们估计了需要邀请的女性人数（NNI），以在 10 年内预防一例乳腺癌死亡。对 1986 年至 2016 年期间挪威 50-75 岁年龄组的 10580 例乳腺癌死亡病例进行了四种不同的筛查效果（降低 5%-20%的死亡率）的模拟。我们使用了三种不同的过度诊断情况（筛查期间会出现 10%-40%的额外乳腺癌）来估计每例乳腺癌死亡预防的过度诊断乳腺癌的比例。
在 20%乳腺癌死亡率降低和 20%过度诊断的基础案例中，NNI 从 1996 年的 731（95%CI：644-830）名女性增加到 2016 年的 1364（95%CI：1181-1577）名女性，而每例乳腺癌死亡预防的过度诊断乳腺癌人数从 1996 年的 3.2 例增加到 2016 年的 5.4 例。在乳腺癌死亡率降低 8.7%的情况下，每例乳腺癌死亡预防的过度诊断乳腺癌的比例从 1996 年的 7.4 例增加到 2016 年的 14.0 例。在乳腺癌死亡率降低 5%的情况下，该比例从 1996 年的 12.8 例增加到 2016 年的 25.2 例。
由于越来越有效的治疗方法，降低乳腺癌死亡率的获益减少，而包括过度诊断在内的危害则不受影响。未来乳腺癌患者管理的改善将进一步恶化筛查的获益-危害比。
