Background Breast magnetic resonance imaging (MRI) is more accurate than ultrasound and mammography in estimating local extension of both invasive breast cancer and ductal carcinoma in situ (DCIS) and it is part of a breast cancer patient's preoperative management. Purpose To verify if time interval between breast biopsy and preoperative MRI, lesion margins, and biopsy technique can influence tumor sizing on MRI. Material and Methods By a database search, we retrospectively identified all women with a newly diagnosed, biopsy-proven, primary breast cancer who underwent MRI before surgery. The time interval between biopsy and MRI, the type of biopsy procedure, and various pathological features of tumors were collected. We defined the concordance between MRI and pathology measurements as a difference of <5 mm in lesion sizing. Results One hundred and sixty-six women (mean age, 51.4 ± 10.4 years) were included. The time interval between biopsy and MRI showed only a weak correlation with the absolute MRI-pathology difference (r = 0.236). Stratifying the whole cohort of patients using a cutoff value of 30 days, we found that the MRI-pathology discordance was significantly higher in patients with a biopsy-MRI time interval >30 days ( P < 0.05). By means of multivariate analysis, we found that DCIS subtype and the presence of poorly defined margins on MRI are the only two factors independently and strongly associated with MRI-pathology discordance in lesion sizing. Conclusion Size, histology, and margins of tumors may affect the accuracy of MRI measurements. The type of biopsy procedure and the time interval between biopsy and preoperative MRI are not independently associated to MRI-pathology discordance.
Keywords: Magnetic resonance imaging (MRI); breast; core biopsy; ductal carcinoma in situ (DCIS); fine needle aspiration cytology (FNAC); vacuum-assisted breast biopsy.