为了评估客观测量的乳腺X线压力和片负倾斜度与同期筛查的乳腺癌（BC）、随后筛查或筛查间隔期的关系，我们在英国以人群为基础的筛查计划中对80495次乳腺X线检查进行了自动化压力和片负倾斜度估算。应用调整后的逻辑回归模型进行分析，以估计压力参数与同期筛查发现的乳腺癌之间的关联关系（777例病例）。通过构建嵌套式病例对照设计，应用条件逻辑回归分析估计了压力和倾斜度与：（a）筛查间隔期癌症（148例病例/625例与其年龄匹配的对照组）和（b）随后筛查发现的癌症（344例病例/1436例），的关联关系。结果显示，压力的增加与同期筛查发现的乳腺癌的几率呈负相关（压力分布的最高三分之一与最低三分之一之间的几率比（OR）为0.74；95% CI为0.60, 0.92；线性趋势P值（Pt）= 0.007）。有某种程度的证据表明，适中的压力与间隔期癌症的几率下降有关（中间三分之一与最低三分之一之间的几率比为0.63；95% CI为0.38, 1.05；p = 0.079），但在压力和随后筛查发现的乳腺癌几率之间并没有发现关联。没有证据表明片负倾斜度与同期、随后筛查或间隔期癌症检测的几率相关。研究结果表明，压力对于乳腺X线筛查的性能产生影响，而片负倾斜度则没有。筛查期间不足或过度的压力可能会导致检测乳腺癌的能力下降，从而导致更多的间隔期癌症发生。

To assess the associations between objectively measured mammographic compression pressure and paddle tilt and breast cancer (BC) detected at the same ("contemporaneous") screen, subsequent screens, or in-between screens (interval cancers).Automated pressure and paddle tilt estimates were derived for 80,495 mammographic examinations in a UK population-based screening programme. Adjusted logistic regression models were fitted to estimate the associations of compression parameters with BC detected at contemporaneous screen (777 cases).Nested case-control designs were used to estimate associations of pressure and tilt with: (a) interval cancer (148 cases/625 age-matched controls) and (b) subsequent screen-detected cancer (344/1436), via conditional logistic regression.Compression pressure was negatively associated with odds of BC at contemporaneous screen (odds ratio (OR) for top versus bottom third of the pressure distribution: 0.74; 95% CI 0.60, 0.92; P-for-linear-trend (Pt) = 0.007). There was weak evidence that moderate pressure at screening was associated with lower odds of interval cancer (OR for middle versus bottom third: 0.63; 95% CI 0.38, 1.05; p = 0.079), but no association was found between pressure and the odds of BC at subsequent screen. There was no evidence that paddle tilt was associated with the odds of contemporaneous, subsequent screen or interval cancer detection.Findings are consistent with compression pressure, but not paddle tilt, affecting the performance of mammographic screening by interfering with its ability to detect cancers.Inadequate or excessive compression pressure at screening may contribute to a reduced ability to detect cancers, resulting in a greater number of interval cancer cases.