Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905.
Department of Health Sciences Research, Mayo Clinic, Rochester, MN.
AJR Am J Roentgenol. 2021 May;216(5):1193-1204. doi: 10.2214/AJR.20.23854. Epub 2021 Mar 3.
Background parenchymal uptake (BPU) on molecular breast imaging (MBI) was identified in a case-control study as a breast cancer risk factor beyond mammographic density. To our knowledge, this finding has not yet been confirmed in a cohort study. The objectives of this study were to examine the association of BPU with breast cancer and to estimate the absolute risk and discriminatory accuracy of BPU in a cohort study. A retrospective cohort was established that included women without a history of breast cancer who underwent MBI from 2004 to 2015. Radiologists who were blinded to future breast cancer diagnoses assessed BPU on baseline MBI examinations as low (photopenic or minimal) or elevated (mild, moderate, or marked). Associations of BPU with breast cancer were estimated using multivariable Cox proportional hazards models of the time to diagnosis. The 5-year absolute risk was calculated for study subgroups. The discriminatory accuracy of BPU was also assessed. Among 2992 women (mean age, 56.3 years; SD, 10.6 years) who underwent MBI, breast cancer events occurred in 144 women (median follow-up, 7.3 years). Median time to diagnosis after MBI was 4.2 years (range, 0.5-11.6 years). Elevated BPU was associated with a greater breast cancer risk (hazard ratio [HR], 2.39; 95% CI, 1.68-3.41; ≤ .001). This association remained in postmenopausal women (HR, 3.50; 95% CI, 2.31-5.31; < .001) but was not significant in premenopausal women (HR, 1.29; 95% CI, 0.72-2.32; = .39). The 5-year absolute risk of breast cancer was 4.3% (95% CI, 2.9-5.7%) for women with elevated BPU versus 2.5% (95% CI, 1.8-3.1%) for those with low BPU. Postmenopausal women with dense breasts and elevated BPU had a 5-year absolute risk of 8.1% (95% CI, 4.3-11.8%) versus 2.8% (1.8-3.8%) for those with low BPU. Among postmenopausal women, discriminatory accuracy for invasive cancer was improved with the addition of BPU versus use of the Gail risk score alone (C statistic, 65.1 vs 59.1; = .04) or use of the Breast Cancer Surveillance Consortium risk score alone (C statistic, 66.4 vs 60.4; = .04). BPU on MBI is an independent risk factor for breast cancer, with the strongest association observed among postmenopausal women with dense breasts. In postmenopausal women, BPU provides incremental discrimination in predicting breast cancer when combined with either the Gail model or the Breast Cancer Surveillance Consortium model. Observation of elevated BPU on MBI may identify a subset of women with dense breasts who would benefit most from supplemental screening or preventive options.
背景实质摄取（BPU）在分子乳腺成像（MBI）中的表现被病例对照研究确定为一种超越乳腺密度的乳腺癌危险因素。据我们所知，这一发现尚未在队列研究中得到证实。本研究的目的是检验 BPU 与乳腺癌的相关性，并估计 BPU 在队列研究中的绝对风险和判别准确性。我们建立了一个回顾性队列，包括 2004 年至 2015 年间未患乳腺癌的女性，进行 MBI 检查。对基线 MBI 检查中的 BPU 评估为低（透光或轻微）或高（轻度、中度或明显）。使用多变量 Cox 比例风险模型估计 BPU 与乳腺癌的相关性。研究亚组计算了 5 年的绝对风险。还评估了 BPU 的判别准确性。在 2992 名接受 MBI 检查的女性中（平均年龄 56.3 岁；标准差 10.6 岁），有 144 名女性发生乳腺癌（中位随访时间 7.3 年）。MBI 后诊断的中位时间为 4.2 年（范围为 0.5-11.6 年）。BPU 升高与乳腺癌风险增加相关（风险比 [HR]，2.39；95%CI，1.68-3.41； ≤.001）。这种关联在绝经后妇女中仍然存在（HR，3.50；95%CI，2.31-5.31； <.001），但在绝经前妇女中不显著（HR，1.29；95%CI，0.72-2.32； =.39）。BPU 升高的女性 5 年乳腺癌绝对风险为 4.3%（95%CI，2.9-5.7%），而 BPU 降低的女性为 2.5%（95%CI，1.8-3.1%）。绝经后乳腺致密且 BPU 升高的女性 5 年乳腺癌绝对风险为 8.1%（95%CI，4.3-11.8%），而 BPU 降低的女性为 2.8%（1.8-3.8%）。在绝经后妇女中，与单独使用 Gail 风险评分（C 统计量为 65.1 比 59.1； =.04）或单独使用乳腺癌监测联盟风险评分（C 统计量为 66.4 比 60.4； =.04）相比，增加 BPU 可提高浸润性癌症的判别准确性。MBI 上的 BPU 是乳腺癌的一个独立危险因素，在乳腺致密的绝经后妇女中观察到最强的相关性。在绝经后妇女中，当与 Gail 模型或乳腺癌监测联盟模型联合使用时，BPU 提供了对乳腺癌的增量判别。观察 MBI 上的 BPU 可能会发现乳腺致密的女性亚组，她们最受益于补充筛查或预防性选择。
