Verheus Martijn, Peeters Petra H M, Kaaks Rudolf, van Noord Paulus A H, Grobbee Diederick E, van Gils Carla H
Julius Center for Health Sciences and Primary Care, University Medical Center, Room Str 6.131, P. O. Box 85500, Utrecht 3508 GA, the Netherlands.
Cancer Epidemiol Biomarkers Prev. 2007 Mar;16(3):451-7. doi: 10.1158/1055-9965.EPI-06-0642.
A high proportion of glandular and stromal tissue in the breast (percentage breast density) is a strong risk factor for breast cancer development. Insulin-like growth factor-I (IGF-I) is hypothesized to influence breast cancer risk by increasing breast density.
We studied the relation between premenopausal circulating IGF-I levels and premenopausal and postmenopausal, absolute nondense and dense area, and percentage breast density as well as changes in these measures over menopause.
Mammograms and blood samples of 684 premenopausal participants of the Prospect-European Prospective Investigation into Cancer and Nutrition cohort were collected at baseline. A second mammogram of these women was collected after they became postmenopausal. Premenopausal IGF-I levels were measured in serum. Premenopausal and postmenopausal breast measures were assessed using a computer-assisted method. Mean values of breast measures were calculated for quartiles of serum IGF-I using linear regression analysis.
Women with higher premenopausal IGF-I levels showed a slightly smaller decrease in dense area over menopause (-12.2 cm2 in the highest versus -12.9 cm2 in the lowest quartile; P trend = 0.58) and, at the same time, a smaller increase in the nondense (fat) area (P trend = 0.09). Due to the changes over menopause, high premenopausal IGF-I serum levels were associated with lower nondense area (P trend = 0.05), somewhat higher dense area (P trend = 0.66), and consequently higher percentage breast density (P trend = 0.02) after menopause.
Women with higher premenopausal IGF-I levels have a smaller increase in nondense area and also a slightly smaller decrease in absolute dense area during menopause, resulting in higher breast density after menopause.
乳腺中腺组织和基质组织比例较高（乳腺密度百分比）是乳腺癌发生的一个重要危险因素。胰岛素样生长因子-I（IGF-I）被认为可通过增加乳腺密度来影响乳腺癌风险。
我们研究了绝经前循环IGF-I水平与绝经前、绝经后乳腺绝对非致密区和致密区、乳腺密度百分比之间的关系，以及这些指标在绝经过程中的变化。
在基线时收集了欧洲癌症与营养前瞻性调查队列中684名绝经前参与者的乳房X光片和血液样本。这些女性绝经后又收集了一次乳房X光片。在血清中测量绝经前IGF-I水平。使用计算机辅助方法评估绝经前和绝经后乳腺指标。通过线性回归分析计算血清IGF-I四分位数对应的乳腺指标平均值。
绝经前IGF-I水平较高的女性，绝经期间致密区的减小幅度略小（最高四分位数为-12.2平方厘米，最低四分位数为-12.9平方厘米；P趋势=0.58），同时，非致密（脂肪）区的增加幅度也较小（P趋势=0.09）。由于绝经期间的变化，绝经前IGF-I血清水平较高与绝经后较低的非致密区（P趋势=0.05）、略高的致密区（P趋势=0.66）相关，因此乳腺密度百分比更高（P趋势=0.02）。
绝经前IGF-I水平较高的女性，绝经期间非致密区增加幅度较小，绝对致密区减小幅度也略小，导致绝经后乳腺密度更高。
