European Radiology: This MRI manifestation enables noninvasive evaluation of axillary lymph nodes in patients with early-stage breast cancer

As an important factor in breast cancer treatment decisions, axillary lymph node (ALN) status has a significant impact
on prognosis.
According to the results of the American College of Surgeons Oncology Group Z0011 (ACOSOG Z0011) clinical trial, all patients with early-stage breast cancer should undergo sentinel lymph node biopsy (SLNB) to assess ALN status and determine further surgical planning
.
However, as an invasive armpit surgery, SLNB can prolong hospital stay and anesthesia, and cause a series of complications such as lymphedema or numbness of the upper extremities.

In addition, some studies have shown a false-negative rate of 7.
8-27.
3% for SLNB, leading to inadequate
assessment of lymph node staging.
Therefore, accurate assessment of ALN load is essential
to determine the appropriate treatment modalities to improve the quality of life and prognosis of patients with early-stage breast cancer.

Several studies have shown that perimammary edema detected on T2-weighted breast MRI is one of the important predictors of
prognosis in patients with invasive breast cancer.
In addition, as a higher grade of mammedema, anterior chest and subcutaneous mammedema are generally associated
with extensive lymphatic invasion and a poorer prognosis in patients with breast cancer.
Some studies have also shown that breast cancer patients with perimammary edema have a higher proportion of ALN involvement
.
However, it remains unclear whether different degrees of mammedema are helpful in assessing ALN burden
in early-stage breast cancer.

Determining the potential clinical importance of breast tumor-associated edema under T2-weighted breast MRI for predicting ALN burden preoperatively will be helpful
.
In addition, the analysis of clinicopathological factors associated with mammary edema and the analysis of clinicopathological factors associated with mammary edema help to understand its underlying biological mechanisms
.

Recently, a study published in the journal European Radiology evaluated the value of preoperative MRI breast edema features in predicting ALN load and related clinicopathological factors in patients with early-stage breast cancer, which provides technical support
for further improving the credibility of diagnosis and assisting clinical preoperative treatment planning.

This retrospective study included women with clinical stage T1 and T2 breast cancer and preoperative MRI in two separate cohorts between May 2014 and December 2020
.
Low (<3 LNs+) and high (≥3 LNs+) pathological ALN (pALN) loads were recorded as endpoints
.
The mammary edema score (BES) was assessed
on the T2WI sequence.
Univariate and multivariate analyses
were performed by logistic regression models.
The area under the curve (AUC), NRI and IDI were used to evaluate the additional predictive value
of BES.

A total of 1092 patients
were included in this review.
BES was identified as an independent predictor of pALN load in both primary (n = 677) and validation (n = 415) cohorts.

Analysis using MRI-ALN status showed that BES significantly improved the predictive performance of pALN load (AUC
.
0.
65 vs 0.
71, p < 0.
001; IDI = 0.
045, p < 0.
001; continuous NRI = 0.
159, p = 0.
050).

These results were confirmed in the validation cohort (AUC
.
0.
64 vs 0.
69, p = 0.
009; IDI = 0.
050, p < 0.
001; Continuous NRI = 0.
213, p = 0.
047).

In addition, BES was positively correlated with aggressive clinicopathological factors (p < 0.
05).

Figure ROC curve analysis
of PAL load.
A main cohort; B Verify the queue

This study showed that MRI of tumor-associated mammary edema can be used as an important imaging predictive feature to improve the prediction performance of pathological axillary lymph node load in patients with early-stage breast cancer, and further assist in the evaluation and implementation of
preoperative treatment plans.

Original source:

Zeyan Xu,Yingying Ding,Ke Zhao,et al.
MRI characteristics of breast edema for assessing axillary lymph node burden in early-stage breast cancer: a retrospective bicentric study.
DOI:10.
1007/s00330-022-08896-z