West Midlands Breast Screening QA Reference Centre, West Midlands Cancer Intelligence Unit, Public Health Building, The University of Birmingham, Birmingham B15 2TT, UK.
J Med Screen. 2009;16(4):186-92. doi: 10.1258/jms.2009.009040.
To examine variations in screening status category with time for 20,862 invasive breast cancers diagnosed in the West Midlands between 1989 and 2006, and to provide 10-year relative survival rates for each category.
Population-based breast screening was introduced in the West Midlands from 1988. Primary invasive breast cancers diagnosed from 1 April 1989 to 31 March 2006 in women eligible for breast screening were identified from the West Midlands Cancer Intelligence Unit's cancer registration database. A screening status was determined for each case using previously published methodology.
Screening status rates are affected initially by the gradual rollout of the screening programme and more recently by the need to wait for three years before interval cancers and cancers in lapsed and non-attenders can be identified. In the steady-state period 1994-2003, 40.6% of invasive breast cancers were screen-detected, 36.3% were interval cancers and 11.2% were cancers in non-attenders (NA). Ten-year relative survival was 89.6% for screen-detected breast cancers, 73.3% for interval cancers and 51.9% for cancers in NA.
The detection of invasive breast cancers by screening has improved over time, with an equivalent reduction in the numbers of interval cancers. This, together with a stable rate of cancers in NA and an improvement in the survival of women with interval cancers, suggests that further improvements in breast cancer mortality can be predicted. International comparisons of interval cancer rates are difficult due to interprogramme differences in the time between screens.
研究 1989 年至 2006 年间在西米德兰兹诊断出的 20862 例浸润性乳腺癌的筛查状况随时间的变化，并提供每个类别 10 年相对生存率。
西米德兰兹的人群为基础的乳腺筛查于 1988 年开始。通过西英格兰癌症智能单位的癌症登记数据库，确定了从 1989 年 4 月 1 日至 2006 年 3 月 31 日期间有资格接受乳腺筛查的女性中诊断出的原发性浸润性乳腺癌。使用先前发表的方法确定每个病例的筛查状态。
筛查状态的比率最初受到筛查计划的逐步实施的影响，最近则受到需要等待三年才能确定间隔期癌症和漏诊及不参加筛查者的癌症的影响。在 1994 年至 2003 年的稳定阶段，40.6%的浸润性乳腺癌是筛查发现的，36.3%是间隔期癌症，11.2%是不参加筛查者（NA）的癌症。筛查发现的乳腺癌 10 年相对生存率为 89.6%，间隔期癌症为 73.3%，不参加筛查者的癌症为 51.9%。
随着时间的推移，通过筛查发现的浸润性乳腺癌有所增加，间隔期癌症的数量也相应减少。这与不参加筛查者的癌症数量保持稳定以及间隔期癌症患者的生存率提高一起表明，可以预测乳腺癌死亡率的进一步降低。由于各方案之间筛查间隔时间不同，国际间间隔期癌症发生率的比较较为困难。
