Abstract P2-08-28: Association between rim enhancement on magnetic resonance imaging and response of chemo therapy
Authors: Motonari T , Yoshida A , Tsunoda H , Hayashi N , Yagata H , Yamauti H 
Published: May 2016

Background: Triple-negative breast cancers (TNBC) are defined as tumors that lack expression of estrogen receptor (ER), progesterone receptor (PR), and HER2. TNBC is characterized as a cancer with a high malignancy potential and a poor prognosis. Systemic therapy that is effective in TNBC is only chemotherapy. On magnetic resonance imaging (MRI), rim enhancement was frequently seen in TNBC. It is reported that rim enhancement on MRI may associated with long-term outcome of patients with triple-negative breast cancer and may potentially serve as a prognostic biomarker in these patients. It is not well known about the relationship of rim enhancement on the MRI and treatment effectiveness of TNBC.

Purpose: We investigated the relationship between rim enhancement on MRI and response of chemo therapy and outcome in patients with TNBC.

Methods: MRI findings of 144 consecutive female TNBC patients, who underwent surgery from 2007 to 2012 in our hospital, were retrospectively reviewed. All patients have taken the MRI in our hospital before treatment, and had undergone chemotherapy before or after surgery. Presence of rim enhancement on MRI was assessed. Rim enhancement was defined more pronounced at the periphery of the mass at early phase.

Association of the presence of rim enhancement on MRI and the pathological complete response (pCR) rate in patients who underwent neo adjuvant chemotherapy (NAC) was assessed using two-sided Pearson's Chi squared tests. Disease free survival (DFS) rates were calculated by the Kaplan-Meier method. Univariate analysis was performed using the log rank test. pCR was defined as the disappearance of invasive cancer.

Results: The median age was 51yo (26-82), and the median observation period was 49 months (5-92). Eighty-one patients (56.2%) underwent NAC and 63 patients (43.7%) underwent adjuvant chemotherapy. Twenty-six cases (18.0%) occurred recurrence or distance metastasis. The presence of rim enhancement were observed 68 cases (42.3%), and non-rim enhancement were 66 cases (57.6%). DFS were not significantly different according to the presence of rim enhancement on MRI(P=0.31).

In NAC patients, 28 patients (34.5%) were led to pCR and 53 (63.4%) were non-pCR. The presence of rim enhancement were observed 44 cases (54.3%), and non-rim enhancement were 37 cases (45.6%). In pCR rate, rim enhancement is higher than non-rim enhancement (40.9%, 27.0%, respectivrly). However, the presence of rim enhancement on MRI was not significantly associated with pCR in TNBC patients (p= 0.190).

Table1. Association between rim enhancement and pCR pCR(%)non-PCR (%)P-valuerim enhancement18 (40.9)26 (59.1) non-rim enhancement10 (27.0)27 (72.9)0.19

Conclusion: The presence of rim enhancement on MRI showed high pCR rate. While, it is not a significant predictor of pCR in TNBC patients.

Citation Format: Motonari T, Yoshida A, Tsunoda H, Hayashi N, Yagata H, Yamauti H. Association between rim enhancement on magnetic resonance imaging and response of chemo therapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-28.