Correlation of quantitative parameters on dynamic contrast-enhanced MRI with prognostic factors of breast carcinoma

Abstract

Objective To investigate the correlation between parameters obtained from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and prognostic factors (including enhanced morphology, tumor size, histological grade, nuclear grade) of breast carcinoma. Methods One hundred and thirteen breast cancer cases with 120 lesions confirmed histopathologically were retrospectively analyzed. All the patients underwent the DCE-MRI before the surgery, and the immunohistochemistry after the operation was performed to get the histological and nuclear grade. The volume transfer constant(Ktrans), rate constant (kep), and volume of extravascular extracellular space per unit volume of tissue(ve) were calculated through the DCE-MRI postprocessing. One hundred and three invasive ductal carcinomas were examined with the immunohistochemistry to get results of the histological and nuclear grade. Accordingly, the 103 lesions were divided in two subgroups: the tumors of histological grade Ⅰ, Ⅱ (low histological grade) and tumors of grade III (high histological grade); tumors of nuclear grade Ⅰ,Ⅱ (low nuclear grade) and tumors of grade Ⅲ (high nuclear grade). All the tumors were divided into mass-like type and non mass-like type according the enhanced morphology, as well as size ≤20 mm type and size >20 mm type respectively. Correlations between parameters and enhanced morphology, tumor size, histological grade, nuclear grade were analyzed through Mann-Whitney U test, the correlation between the tumor size and quantitative parameters was tested with Spearman correlation. Results Mean Ktrans was higher in tumors with mass-liketumors (n=92) than with non mass-like tumors(n=28), and the differences was statistically significant (P 0.05). There was no significant differences between tumor size≤20 mm(n=40) and size>20 mm (n=52) in mean Ktrans ,kep and ve respectively (P>0.05) .The mean maximal size of mass-like tumors was (2.38±0.95) cm, and there was no significant correlations between the tumors size and Ktrans (r=0.238, P=0.038), kep and ve (r values were 0.223 and 0.070, respectively, P values were 0.052 and 0.547 respectively) . Mean Ktrans, kep was higher in tumors with a high histological grade (n=22) than with a low histological grade(n=52), also was higher in tumors with a high nuclear grade(n=15) than with a low nuclear grade (n=56), with statistically significant differences (P 0.05). Conclusion There is correlation between parameters obtained from DCE-MRI and prognostic factors of breast cancers, with higher Ktrans and kep, or lower ve, indicating poor prognostic factors. Key words: Breast neoplasms; Magnetic resonance imaging; Prognostic factors