Cancer Registry of Norway, Oslo, Norway.
Br J Radiol. 2012 Dec;85(1020):e1226-32. doi: 10.1259/bjr/15168178. Epub 2012 Sep 19.
The aim of this study was to examine the sensitivity and specificity of screening mammography as performed in Vermont, USA, and Norway.
Incident screening data from 1997 to 2003 for female patients aged 50-69 years from the Vermont Breast Cancer Surveillance System (116 996 subsequent screening examinations) and the Norwegian Breast Cancer Screening Program (360 872 subsequent screening examinations) were compared. Sensitivity and specificity estimates for the initial (based on screening mammogram only) and final (screening mammogram plus any further diagnostic imaging) interpretations were directly adjusted for age using 5-year age intervals for the combined Vermont and Norway population, and computed for 1 and 2 years of follow-up, which ended at the time of the next screening mammogram.
For the 1-year follow-up, sensitivities for initial assessments were 82.0%, 88.2% and 92.5% for 1-, 2- and >2-year screening intervals, respectively, in Vermont (p=0.022). For final assessments, the values were 73.6%, 83.3% and 81.2% (p=0.047), respectively. For Norway, sensitivities for initial assessments were 91.0% and 91.3% (p=0.529) for 2- and >2-year intervals, and 90.7% and 91.3%, respectively, for final assessments (p=0.630). Specificity was lower in Vermont than in Norway for each screening interval and for all screening intervals combined, for both initial (90.6% vs 97.8% for all intervals; p<0.001) and final (98.8% vs 99.5% for all intervals; p<0.001) assessments.
Our study showed higher sensitivity and specificity in a biennial screening programme with an independent double reading than in a predominantly annual screening program with a single reading.
This study demonstrates that higher recall rates and lower specificity are not always associated with higher sensitivity of screening mammography. Differences in the screening processes in Norway and Vermont suggest potential areas for improvement in the latter.
本研究旨在检验美国佛蒙特州和挪威进行的筛查性乳房 X 光检查的敏感性和特异性。
对比了 1997 年至 2003 年期间佛蒙特州乳腺癌监测系统（116996 次后续筛查检查）和挪威乳腺癌筛查计划（360872 次后续筛查检查）中年龄在 50-69 岁之间的女性患者的发病筛查数据。采用 5 年年龄间隔，对初始（仅基于筛查性乳房 X 光检查）和最终（筛查性乳房 X 光检查加任何进一步的诊断性影像学检查）解释的敏感性和特异性估计值进行直接调整，对佛蒙特州和挪威合并人群进行调整，并计算 1 年和 2 年的随访结果，随访截止到下一次筛查性乳房 X 光检查的时间。
在 1 年的随访中，佛蒙特州的初始评估的敏感性在 1 年、2 年和>2 年的筛查间隔内分别为 82.0%、88.2%和 92.5%（p=0.022）。对于最终评估，相应的值分别为 73.6%、83.3%和 81.2%（p=0.047）。在挪威，2 年和>2 年间隔的初始评估敏感性分别为 91.0%和 91.3%（p=0.529），最终评估的敏感性分别为 90.7%和 91.3%（p=0.630）。在每个筛查间隔以及所有筛查间隔的组合中，佛蒙特州的特异性均低于挪威，在初始评估中，所有间隔的特异性分别为 90.6%和 97.8%（p<0.001），在最终评估中，所有间隔的特异性分别为 98.8%和 99.5%（p<0.001）。
本研究表明，在有独立双读的两年一次的筛查项目中，敏感性和特异性更高，而在只有单次阅读的主要年度筛查项目中则较低。
本研究表明，较高的召回率和较低的特异性并不总是与筛查性乳房 X 光检查的敏感性升高相关。挪威和佛蒙特州在筛查过程中的差异表明后者存在改进的潜力。
