Purpose

Controversy continues regarding the effect of screening mammography on breast cancer outcomes. We evaluated late-stage cancer rate and overall survival (OS) for different screening intervals using a real-world institutional research data mart.

Methods

Patients having both a cancer registry record of new breast cancer diagnosis and prediagnosis screening history between 2004 and 2019 were identified from our institutional research breast data mart. Time interval between the two screening mammograms immediately preceding diagnosis and the time to cancer diagnosis were determined. Screening interval was deemed annual if ≤15 months, biennial if >15 and ≤27 months, intermittent if >27 months, and baseline if only one prediagnosis screen was known. The primary end point was late-stage cancer (TNM stage IIB or worse), and the secondary end point was OS. The association of screening interval and late-stage cancer was analyzed using multivariable logistic regression adjusting for prediagnosis characteristics. Proportional hazards regression was used for survival analysis. Potential lead time was analyzed using survival from a uniform fixed time point.

Results

In total, 8,145 patients with breast cancer had prediagnosis screening mammography in the timeframe. The percentage of late-stage cancers diagnosed increased significantly with screening interval with 9%, 14%, and 19% late stages for annual, biennial, and intermittent groups (P < .001), respectively. The trend persisted regardless of age, race, and menopausal status. Biennial and intermittent groups had substantially worse OS than the annual screened group, with relative hazards of 1.42 (95% CI, 1.11 to 1.82) and 2.69 (95% CI, 2.11 to 3.43), respectively, and 1.39 (95% CI, 1.08 to 1.78) and 2.01 (95% CI, 1.58 to 2.55) after adjustment for potential lead time.

Conclusion

Annual mammographic screening was associated with lower risk of late-stage cancer and better OS across clinical and demographic subgroups. Our study suggests benefit of annual screening for women 40 years and older.

 目的

关于乳腺 X 线摄影筛查对乳腺癌结果的影响，争议仍然存在。我们使用真实世界的机构研究数据集市评估了不同筛查间隔的晚期癌症发生率和总生存期 （OS）。

 方法

从我们的机构研究乳腺数据集市中确定了 2004 年至 2019 年间具有新乳腺癌诊断癌症登记记录和诊断前筛查史的患者。确定了诊断前两次乳腺 X 线筛查之间的时间间隔和癌症诊断时间。如果 ≤15 个月，则认为筛查间隔为每年一次，如果 >15 和 ≤27 个月则为两年一次，如果 >27 个月为间歇性筛查，如果只知道一项诊断前筛查，则为基线。主要终点是晚期癌症 （TNM IIB 期或更差），次要终点是 OS。使用多变量 logistic 回归调整诊断前特征分析筛查间隔与晚期癌症的关联。比例风险回归用于生存分析。使用统一固定时间点的存活率分析潜在提前期。

 结果

在此期间，共有 8,145 名乳腺癌患者进行了诊断前筛查乳腺 X 光检查。筛查间隔时间延长，晚期癌症诊断百分比显著增加，年、两年和间歇组晚期分别为 9% 、 14% 和 19% （P < .001）。无论年龄、种族和更年期状况如何，这种趋势都持续存在。两年一次和间歇性组的 OS 明显差于年度筛查组，相对危险度分别为 1.42 （95% CI，1.11 至 1.82） 和 2.69 （95% CI，2.11 至 3.43），调整潜在提前期后分别为 1.39 （95% CI，1.08 至 1.78） 和 2.01 （95% CI，1.58 至 2.55）。

 结论

年度乳腺 X 线摄影筛查与临床和人口统计学亚组的晚期癌症风险降低和更好的 OS 相关。我们的研究表明，每年筛查对 40 岁及以上的女性有益。