Abstract:
Objective This study aims to evaluate the correlation among the findings of contrast-enhanced magnetic resonance imaging(MRI), values of mean apparent diffusion coefficient(ADCmean), and prognostic factors in mass-like and non-mass-like breast cancer with microcalcification.
Methods Preoperative X-ray examination of the breast showed 111 breast lesions in 108 calcified breast cancer cases.Contrast-enhanced MRI was conducted to analyze the dynamic manifestations of mass-like and non-mass-like lesions, ADC on diffusion weighted imaging, and correlation with histological grading of the tumor, tumor size, lymph node status, and expression of estrogen receptors(ER), progesterone receptors(PR), c-erb-B2, Ki-67, and P53.The time-signal intensity curve(TIC), early-phase enhancement rate, and the ADCmean values of the lesions with microcalcification were calculated.American Society of Clinical Oncology-College of American Pathologists guideline recommendations for immunohistochemical testing of ER and PR in breast cancer were developed in 2010.The guideline established the standard that ER and PR assays be considered positive if at least 1% of the positive tumor nuclei are observed in the sample.Correlations between MRI findings and prognostic factors were analyzed by Pearson's χ2 test and Pearson correlation.ADCmean values between groups were compared using the t test for two independent samples.
Results The 111 microcalcification lesions consisted of 74(66.7%) mass-like-lesions and 37(33.3%) non-mass-like lesions.MRI sensitivity for diagnosing the calcified lesions reached 96.4%(107/111) of the cases.Four cases with missed diagnosis were identified, including 1 intraductal carcinoma(i.e., ductal carcinoma in situ) and 3 infiltrating carcinomas.The positive rate of ER in the mass-like lesion was higher than that in the non-mass-like lesion(χ2=4.681, P= 0.038).A correlation was observed between the form and the size of the lumps(r=0.256, P=0.028).Among the ≤2 cm lumps, 54.9%(28/ 51) consisted of round lumps; among the > 2 cm lumps, 47.8%(11/23) consisted of irregular lumps.The average ADC value was(1.046 8± 0.218 05)×10-3 mm2/s in the Ki-67-positive group and(1.189 6±0.303/48)×10-3 mm2/s in the Ki-67-negative group.Significant differences were indicated between the two groups(t=-2.594, P=0.011).
Conclusion MRI findings reflect to a certain extent the biological behavior and prognosis of breast cancer with microcalcification.