In a study with 70 cases of ILC, preoperative MRI reduced re-excision rates, particularly in young women with dense breasts [82]. In another study with 369 women, preoperative breast MRI was also associated with a reduction in repeat surgery (OR, 0.140; P < . 001), without increasing mastectomy rates [76]. Although MR does lead to increased cancer detection, there is limited evidence that preoperative MRI improves survival or decreases recurrence, including data from multicenter analyses [61,68,83-85]. In 3,180 affected breasts in 3,169 women (median age, 56.2 years), 8-year disease-free survival did not differ between the MRI (97%) and the non-MRI (95%) groups (P = . 87), and the multivariable model showed no significant effect of MRI on disease- free survival: hazard ratio (HR) for MRI (versus non-MRI) was 0.88 (95% CI, 0.52-1.51; P = . 65); age, margin status, and tumor grade were associated with disease-free survival (all P < . 05) [85]. Of the 31,756 patients included in a survival cohort (70% non-MRI and 30% MRI), breast MRI was not significantly associated with overall survival (HR, 0.91; 95% CI, 0.74-1.11, P = . 35) or with disease-free survival (HR, 1.16; 95% CI, 0.81-1.67), even among the different histological subtypes. The lack of survival benefit extends also to patients with ILC, despite improved surgical outcomes in this population as described above [83]. One recent study did show lower recurrences (locoregional, distant and contralateral) in women who received a preoperative MRI, with a nonsignificant trend toward MR improving disease-free survival (P = . 057) [86], and another study of 1,199 subjects did show improved overall survival in the group who received MRI [87]. Given these data, benefits of preoperative MRI for additional cancer detection or delineating extent of disease should be balanced with the possibility of a false-positive diagnosis leading to additional biopsy, unnecessary additional imaging, and potential delays in definitive treatment.
Imaging of Invasive Breast Cancer. In a study with 70 cases of ILC, preoperative MRI reduced re-excision rates, particularly in young women with dense breasts [82]. In another study with 369 women, preoperative breast MRI was also associated with a reduction in repeat surgery (OR, 0.140; P < . 001), without increasing mastectomy rates [76]. Although MR does lead to increased cancer detection, there is limited evidence that preoperative MRI improves survival or decreases recurrence, including data from multicenter analyses [61,68,83-85]. In 3,180 affected breasts in 3,169 women (median age, 56.2 years), 8-year disease-free survival did not differ between the MRI (97%) and the non-MRI (95%) groups (P = . 87), and the multivariable model showed no significant effect of MRI on disease- free survival: hazard ratio (HR) for MRI (versus non-MRI) was 0.88 (95% CI, 0.52-1.51; P = . 65); age, margin status, and tumor grade were associated with disease-free survival (all P < . 05) [85]. Of the 31,756 patients included in a survival cohort (70% non-MRI and 30% MRI), breast MRI was not significantly associated with overall survival (HR, 0.91; 95% CI, 0.74-1.11, P = . 35) or with disease-free survival (HR, 1.16; 95% CI, 0.81-1.67), even among the different histological subtypes. The lack of survival benefit extends also to patients with ILC, despite improved surgical outcomes in this population as described above [83]. One recent study did show lower recurrences (locoregional, distant and contralateral) in women who received a preoperative MRI, with a nonsignificant trend toward MR improving disease-free survival (P = . 057) [86], and another study of 1,199 subjects did show improved overall survival in the group who received MRI [87]. Given these data, benefits of preoperative MRI for additional cancer detection or delineating extent of disease should be balanced with the possibility of a false-positive diagnosis leading to additional biopsy, unnecessary additional imaging, and potential delays in definitive treatment.