School of Population Health, University of Adelaide, Adelaide, SA, Australia.
Cancer Causes Control. 2013 Jul;24(7):1417-26. doi: 10.1007/s10552-013-0221-1. Epub 2013 May 7.
This study aims to measure the impact of HRT use at the time of screening on rates of screen-detected invasive breast cancer (IBC) and ductal carcinoma in situ (DCIS), interval cancers and investigative procedures, within a well-established population-based mammography screening program.
Using South Australian BreastScreen data from 1998 to 2009 pertaining to 819,722 screening episodes, Poisson regression models were undertaken to estimate the incidence risk ratios (IRR) for various screening outcomes at both the first and subsequent screening rounds, among women who had been using HRT in the 6 months prior to screening compared with those who had not.
Current HRT use was associated with increased risk of recall for assessment, biopsy procedures, and breast cancer diagnosis among BreastScreen participants. Risk of screen-detected breast cancer was increased at subsequent screening rounds (IRR = 1.30, 95% confidence interval 1.18-1.34), but not at women's first screening round (1.05, 0.88-1.25). This increased risk applied to IBC (1.35, 1.27-1.45), but not to DCIS (1.04, 0.89-1.23). Interval cancer risk was elevated among HRT users following both the first screen (1.77, 1.33-2.37) and subsequent screening episodes (1.92, 1.72-2.15).
Increased risks of recall, biopsy rates, screen-detected, and interval cancers among HRT users have important implications for population-based breast cancer screening programs. Our findings support the concept that HRT use may increase the growth of preexisting cancers. Lack of effect on DCIS could imply different etiology or time frames for DCIS and IBC development or increased transition from preinvasive to invasive disease due to HRT use.
本研究旨在通过在一个成熟的基于人群的乳房 X 光筛查计划中，测量在筛查时使用 HRT 对筛查发现的浸润性乳腺癌（IBC）和导管原位癌（DCIS）、间期癌和调查程序的发生率的影响。
利用 1998 年至 2009 年南澳大利亚乳房 X 光筛查数据，涉及 819722 次筛查期，使用泊松回归模型，在首次和随后的筛查轮次中，比较了在筛查前 6 个月内使用 HRT 的女性与未使用 HRT 的女性的各种筛查结果的发病率风险比（IRR）。
在乳房 X 光筛查参与者中，当前使用 HRT 与召回评估、活检程序和乳腺癌诊断的风险增加有关。在随后的筛查轮次中，筛查发现的乳腺癌风险增加（IRR=1.30，95%置信区间 1.18-1.34），但在女性首次筛查时没有增加（1.05，0.88-1.25）。这种风险增加适用于 IBC（1.35，1.27-1.45），但不适用于 DCIS（1.04，0.89-1.23）。在首次筛查（1.77，1.33-2.37）和随后的筛查期（1.92，1.72-2.15）中，HRT 使用者的间期癌风险增加。
HRT 使用者的召回、活检率、筛查发现和间期癌风险的增加，对基于人群的乳腺癌筛查计划有重要意义。我们的研究结果支持这样一种概念，即 HRT 的使用可能会增加现有癌症的生长。对 DCIS 没有影响可能意味着 DCIS 和 IBC 发展的病因或时间框架不同，或者由于 HRT 的使用，从癌前病变到侵袭性疾病的过渡增加。
