Objective:

To examine the prognostic value of magnetic resonance imaging (MRI) characteristics for ipsilateral breast tumor recurrence (IBTR) patients following breast-conserving surgery (BCS) and the risk of distant metastasis following secondary surgery in patients with IBTR.

Methods:

A retrospective analysis was conducted on 6 807 breast cancer patients who underwent BCS in Fudan University Shanghai Cancer Center between January 2010 and December 2018. Among them

67 cases experienced IBTR and underwent preoperative MRI examination at our institution. Using a 1∶2 ratio

they were matched with 134 control patients without recurrence based on age

clinical stage

and fibro glandular density. Univariate analysis was used to compare the MRI characteristics and clinical pathological data of the two groups. Multivariate logistic regression was performed to identify independent factors for IBTR. Furthermore

among the 67 patients with IBTR

47 patients underwent secondary surgery and had MR images of the recurrent tumor. The median follow-up time was 22.0 months (range from 1.9 to 101.1 months)

with 15 cases developing distant metastasis and 32 cases without distant metastasis. Univariate and multivariate Cox regression analyses were conducted to determine independent predictive factors associated with distant metastasis following secondary surgery.

Results:

Univariate analysis revealed a significant association between histological grade

negative margin distance

molecular subtype

receipt of postoperative adjuvant radiotherapy

background parenchymal enhancement (BPE)

lesion enhancement type

suspicion of involvement of the nipple skin on preoperative MRI

and postoperative IBTR (

P

＜0.05). Additionally

multivariate logistic regression analysis demonstrated that high BPE

non-mass lesions

nipple or skin thickening with indentation

molecular subtypes of human epidermal growth factor receptor 2 (HER2) + and triple-negative breast cancer

as well as not receiving

radiotherapy after surgery

were independent risk factors for IBTR. Among the 47 patients who underwent secondary surgery and had MRI images of the recurrent tumor

univariate and multivariate Cox regression analysis indicated that negative HER2 status and high BPE levels on preoperative MRI were associated with a higher risk of distant metastasis after secondary surgery.

Conclusion:

Preoperative MRI provides valuable assistance in the auxiliary clinical management and prognostic prediction of patients undergoing breast-conserving surgery and experiencing IBTR. High BPE

non-mass lesions

and nipple or skin thickening with indentation on preoperative MRI indicate a high risk of local recurrence after breast-conserving surgery. In addition

high BPE on MRI of recurrent lesions is associated with the occurrence of distant metastasis after secondary surgery.