Impact of Preoperative MRI on Surgical and Long-term Outcome in Patients With Invasive Lobular Carcinoma (ILC): A Retrospective Cohort Study.

[BACKGROUND] Preoperative MRI is used for staging breast cancer and is considered particularly useful in invasive lobular carcinoma (ILC).

[PURPOSE] The aim of this retrospective study was to compare diagnostic, operative and long-term outcomes in ILC patients who underwent preoperative breast MRI to those who did not.

[MATERIAL AND METHODS] Between 2010 and 2012, 361 patients with postoperative diagnosis of ILC were enrolled in this study.

[RESULTS] Preoperative MRI was performed for 245 (67.9%) women. MRI identified 21 additional cancers and resulted in 62 benign findings. Reoperation rate due to insufficient margins was lower in the MRI group 11 (8.8%) compared to no-MRI group 14 (21.9%), P = .014. Mastectomy rates were equal, 131 (53.5%) and 62 (53.4%), P = 1.000. No statistical difference was found in local recurrences; 2 (1.8%) versus 2 (3.8%), P = .596, nor in 10-year disease-free survival, 88.5% compared to 84.5%, P = .295. The 10-year overall survival was 79.0% and 74.5%, P = .351. Preoperative MRI did not decrease the risk of breast cancer recurrence nor increase survival in ILC patients. The reoperation rate was lower in the MRI-group, but the preoperative MRI had a large proportion of false positive findings.

[CONCLUSION] Preoperative MRI did not affect long-term outcomes in ILC patients; however, recurrence rates were low in both groups. ILC patients may benefit from preoperative MRI, as the reoperation rate was lower.