Retrospective study assessing the role of MRI in the diagnostic procedures for early breast carcinoma: a correlation of new foci in the MRI with tumor pathological features.

BACKGROUND: Use of breast magnetic resonance imaging (MRI) to detect breast cancer has generated significant debate. We analyze the role of breast MRI in the detection of additional disease and the need to perform additional biopsies in early breast carcinoma patients. In addition, we correlate the detection of new foci with tumor pathological features.
METHODS: Early breast carcinoma patients that had undergone an MRI as well as a mammography as diagnostic procedures were included in the study. The following pathologic features were studied: carcinoma type, histological grade, estrogen receptors (ER), progesterone receptors (PR), HER2 and Ki67. Univariate analysis was conducted to ascertain significant correlation among detection of new foci and each of the tumor pathological features.
RESULTS: Data from 98 patients have been analyzed: median age 49 years (range 35-79); carcinoma type: (a) infiltrative ductal carcinoma (n = 73, 74 %), (b) infiltrative lobular cancer (n = 12, 12 %), (c) ductal carcinoma in situ (n = 6, 6 %); amplified HER2 (n = 18, 18 %); grade III (n = 33, 33 %); Ki67 ≥ 25 % (n = 33, 33.67 %); positive ER and PR (n = 79, 80 %); triple negative tumors (n = 8, 8 %). MRI detected additional disease in 38 cases (39.58 %), and 20 led to an additional biopsy (20.4 %). Thirty-eight patients (39 %) underwent mastectomy. We found a statistically significant correlation between new foci in MRI and high Ki67 ≥ 25 % (p < 0.005). No other statistically significant correlation was established.
CONCLUSION: MRI detected additional disease in 39 % cases, requiring an additional biopsy 20 %. Tumors with high proliferative index were significantly correlated with the detection of new foci in MRI.