Breast radiologic complete response

Breast radiologic complete response is associated with favorable survival outcomes after neoadjuvant chemotherapy in breast cancer:

Publication date: Available online 14 September 2020
Source: European Journal of Surgical Oncology
Author(s): Jinsun Woo, Jai Min Ryu, Sung Mi Jung, Hee Jun Choi, Se Kyung Lee, Jonghan Yu, Jeong Eon Lee, Seok Won Kim, Seok Jin Nam, Byung Joo Chae

Abstract
Background
The aim of this study was to examine the accuracy of radiologic complete response (rCR) in predicting pathologic complete response (pCR), and determine whether rCR is a predictor of favorable survival outcomes.

Materials and methods
We retrospectively reviewed breast cancer patients treated with neoadjuvant chemotherapy (NAC) followed by surgery from September 2007 to June 2016. Breast lesions and axillary nodes were measured by MRI and categorized into either disappeared (breast rCR) or residual disease (breast non-rCR) and either normalized (axillary rCR) or abnormal findings (axillary non-rCR) in the axillary nodes. Correlation between rCR and pCR were compared using Cohen's Kappa statistics, and the recurrence-free survival (RFS) and overall survival (OS) rates were calculated by the Kaplan-Meier method.

Results
Out of the 1017 eligible patients, 287 (28.2%) achieved breast pCR, 165 (16.2%) achieved breast rCR, 529 (52.0%) had axillary pCR, and 274 (26.9%) achieved axillary rCR. The correlation between a breast rCR and pCR showed a Cohen's Kappa value of 0.459, and between axillary rCR and pCR, the value was 0.384. During a median follow-up time of 48.0 months, the 5-year RFS rates were 90.6% for breast rCR, and 69.2% for breast non-rCR. The 5-year RFS rates were 82.3% for axillary rCR, and 68.8% for axillary non-rCR. Patients without breast rCR had a 2.4-fold significant increase in the risk of recurrence (p = 0.004) compared to patients with breast rCR.

Conclusion
Although rCR correlated with pCR by only moderate to fair degrees, breast rCR was a strong predictor for a favorable RFS outcome.

Keywords
Breast cancerNeoadjuvant chemotherapyRadiologic complete responseSurvival outcome