Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States of America.
PLoS One. 2013 May 7;8(5):e61969. doi: 10.1371/journal.pone.0061969. Print 2013.
Normal-appearing stromal tissues surrounding breast tumors can harbor abnormalities that lead to increased risk of local recurrence. The objective of this study was to develop a new imaging methodology to characterize the signal patterns of stromal tissue and to investigate their association with recurrence-free survival following neoadjuvant chemotherapy.
Fifty patients with locally-advanced breast cancer were imaged with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before (V1) and after one cycle (V2) of adriamycin-cytoxan therapy. Contrast enhancement in normal-appearing stroma around the tumor was characterized by the mean percent enhancement (PE) and mean signal enhancement ratio (SER) in distance bands of 5 mm from the tumor edge. Global PE and SER were calculated by averaging all stromal bands 5 to 40 mm from tumor. Proximity-dependent PE and SER were analyzed using a linear mixed effects model and Cox proportional hazards model for recurrence-free survival.
The mixed effects model displayed a decreasing radial trend in PE at both V1 and V2. An increasing trend was less pronounced in SER. Survival analysis showed that the hazard ratio estimates for each unit decrease in global SER was statistically significant at V1 [estimated hazard ratio = 0.058, 95% Wald CI (0.003, 1.01), likelihood ratio p = 0.03]; but was not so for V2.
These findings show that stromal tissue outside the tumor can be quantitatively characterized by DCE-MRI, and suggest that stromal enhancement measurements may be further developed for use as a potential predictor of recurrence/disease-free survival following therapy.
肿瘤周围看似正常的间质组织可能存在异常，从而导致局部复发风险增加。本研究旨在开发一种新的成像方法来描述间质组织的信号模式，并探讨其与新辅助化疗后无复发生存的关系。
50 例局部晚期乳腺癌患者在接受阿霉素-环磷酰胺治疗前（V1）和一周期后（V2）进行了动态对比增强磁共振成像（DCE-MRI）。通过距离肿瘤边缘 5mm 的距离带，计算正常间质组织的平均增强百分比（PE）和平均信号增强比（SER）来描述肿瘤周围正常间质组织的对比增强情况。通过对距离肿瘤 5 至 40mm 的所有间质带进行平均计算，得出全局 PE 和 SER。采用线性混合效应模型和 Cox 比例风险模型分析临近依赖性 PE 和 SER 与无复发生存的关系。
混合效应模型显示，在 V1 和 V2 时，PE 均呈现出从中心向边缘逐渐降低的径向趋势。SER 的上升趋势则不那么明显。生存分析显示，在 V1 时，全局 SER 每降低一个单位的风险比估计值具有统计学意义[估计风险比=0.058，95% Wald CI（0.003，1.01），似然比 p=0.03]；而在 V2 时则不然。
这些发现表明，DCE-MRI 可定量描述肿瘤周围的间质组织，提示间质增强测量值可能进一步开发为治疗后复发/无病生存的潜在预测指标。
