通过测量一名妇女的骨密度，可以提供额外的信息，从而更准确地判定该名妇女罹患乳腺癌的风险。这是即将于9月1日在美国癌症学会期刊《癌症》（Cancer）上发表的一项最新研究得出的结论。该项研究认为，在当前的风险评估中纳入骨密度测试，也许可显著提高医生预测绝经后中老年妇女罹患乳腺癌风险的能力。
骨密度测试用于骨质疏松症诊断，并可帮助评估骨折风险。骨密度低一般与较高的骨折风险密切相关，而正常的骨密度也意味着较低的骨折风险。女人一生中，因为造成高骨密度的激素和其他因素，而导致罹患乳腺癌的更高风险是可能的。研究发现，在高骨密度和高乳腺癌风险间存在关联，因此骨密度测试被提议作为乳腺癌风险模型的附加内容。在美国礼来公司的支持下，该研究首先调查了骨密度、传统乳腺癌评估工具的结果及同一组绝经后妇女的乳腺癌发病率这几者之间的关系。
为了调查这些关系，美国亚利桑那大学公共卫生学院赵晨（音译）博士及其同事对参与“妇女健康倡议”的近10000名绝经后妇女（平均年龄为63岁）进行了研究，“妇女健康倡议”由美国国立卫生院心脏、肺和血液研究所赞助，在全美40个临床中心进行。研究人员评估了这些妇女的初始骨密度水平及盖尔（Gail）风险模型系数。盖尔风险模型是一个用来预估35岁及以上年龄妇女罹患侵入性乳腺癌后5年预后寿命的常用工具。随后，他们对这些妇女进行了平均约8年的跟踪调查，观察哪些妇女最后发展成乳腺癌。
研究发现，具有高盖尔系数的妇女与低盖尔系数的妇女相比，罹患乳腺癌的风险要高35%。研究还发现，总的髋部骨密度T值每增加一个单位，发展成乳腺癌的风险就增加25%。而上述两个值是相互独立的，那些两个评估分值都很高的妇女罹患乳腺癌的风险就要高得多。
调查结果显示，在目前采用的风险评估工具中增加骨密度测试，可显著改进乳腺癌的风险预测。研究人员表示，未来的研究中将调查是否将骨密度和盖尔系数与其他风险因子一起纳入，如乳腺密度，这将能进一步提高识别妇女罹患乳腺癌高风险的能力。（生物谷Bioon.com）
生物谷推荐原始出处：
Cancer，doi：10.1002/cncr.23674，Zhao Chen，Rowan Chlebowski
Hip bone density predicts breast cancer risk independently of Gail score
Zhao Chen, PhD, MPH 1 *§, Leslie Arendell, MS 1, Mikel Aickin, PhD 2, Jane Cauley, PhD 3, Cora E. Lewis, MD, MSPH 4, Rowan Chlebowski, MD, PhD 5¶
1Division of Epidemiology and Biostatistics, University of Arizona College of Public Health, Tucson, Arizona
2Department of Family and Community Medicine, University of Arizona, Tucson, Arizona
3Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
4Division of Preventive Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama
5Los Angeles Biomedical Research Institute at Harbor-University of California at Los Angeles Medical Center (LABioMed), Torrance, California
Abstract
BACKGROUND.
The Gail model has been commonly used to estimate a woman's risk of breast cancer within a certain time period. High bone mineral density (BMD) is also a significant risk factor for breast cancer, but it appears to play no role in the Gail model. The objective of the current study was to investigate whether hip BMD predicts postmenopausal breast cancer risk independently of the Gail score.
METHODS.
In this prospective study, 9941 postmenopausal women who had a baseline hip BMD and Gail score from the Women's Health Initiative were included in the analysis. Their average age was 63.0 ± 7.4 years at baseline.
RESULTS.
After an average of 8.43 years of follow-up, 327 incident breast cancer cases were reported and adjudicated. In a multivariate Cox proportional hazards model, the hazards ratios (95% confidence interval [95% CI]) for incident breast cancer were 1.35 (95% CI, 1.05-1.73) for high Gail score (1.67%) and 1.25 (95% CI, 1.11-1.40) for each unit of increase in the total hip BMD T-score. Restricting the analysis to women with both BMD and a Gail score above the median, a sharp increase in incident breast cancer for women with the highest BMD and Gail scores was found (P < .05).
CONCLUSIONS.
The contribution of BMD to the prediction of incident postmenopausal breast cancer across the entire population was found to be independent of the Gail score. However, among women with both high BMD and a high Gail score, there appears to be an interaction between these 2 factors. These findings suggest that BMD and Gail score may be used together to better quantify the risk of breast cancer. Cancer 2008. © 2008 American Cancer Society.
