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

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.

Pre-treatment MRI tumor features and post-treatment mammographic findings: may they contribute to refining the prediction of pathologic complete response in post-neoadjuvant breast cancer patients with radiologic complete response on MRI?

PURPOSE

Radiologic complete response (rCR) in breast cancer patients after neoadjuvant chemotherapy (NAC) does not necessarily correlate with pathologic complete response (pCR), a marker traditionally associated with better outcomes. We sought to verify if data extracted from two important steps of the imaging workup (tumor features at pre-treatment MRI and post-treatment mammographic findings) might assist in refining the prediction of pCR in post-NAC patients showing rCR.

METHODS

A total of 115 post-NAC women with rCR on MRI (2010-2016) were retrospectively assessed. Pre-treatment MRI (lesion morphology, size, and distribution) and post-treatment mammographic findings (calcification, asymmetry, mass, architectural distortion) were assessed, as well as clinical and molecular variables. Bivariate and multivariate analyses evaluated correlation between such variables and pCR. Post-NAC mammographic findings and their correlation with ductal in situ carcinoma (DCIS) were evaluated using Pearson's correlation.

RESULTS

Tumor distribution at pre-treatment MRI was the only significant predictive imaging feature on multivariate analysis, with multicentric lesions having lower odds of pCR (p = 0.035). There was no significant association between tumor size and morphology with pCR. Mammographic residual calcifications were associated with DCIS (p = 0.009). The receptor subtype remained as a significant predictor, with HR-HER2 + and triple-negative status demonstrating higher odds of pCR on multivariate analyses.

CONCLUSIONS

Multicentric lesions on pre-NAC MRI were associated with a lower chance of pCR in post-NAC rCR patients. The receptor subtype remained a reliable predictor of pCR. Residual mammographic calcifications correlated with higher odds of malignancy, making the correlation between mammography and MRI essential for surgical planning. Key Points • The presence of a multicentric lesion on pre-NAC MRI, even though the patient reaches a radiologic complete response on MRI, is associated with a lower chance of pCR. • Molecular status of the tumor remained the only significant predictor of pathologic complete response in such patients in the present study. • Post-neoadjuvant residual calcifications found on mammography were related to higher odds of residual malignancy, making the correlation between mammography and MRI essential for surgical planning.

Retrospective analysis of multiparametric MRI in predicting complete pathologic response of neo-adjuvant chemotherapy in bladder cancer

BACKGROUND

Muscle invasive bladder cancer (MIBC) treatment combines systemic therapy and radical cystectomy (RC) or local (chemo-)radiotherapy. Response to systemic therapy is an important outcome predictor but is difficult to assess pre-operatively.

METHODS

We analyzed multiparametric MRI (mpMRI) in consecutive MIBC patients receiving cisplatin-based neo-adjuvant chemotherapy at our institution. Two readers, blinded for pathological outcome, independently scored mpMRI before and after 2 and 4 cycles using both a qualitative 3-step method and nacVI-RADS. We analyzed accuracy of mpMRI scores to predict pathologic complete response (pCR) and inter-observer agreement.

RESULTS

We analyzed 46 patients receiving NAC, 6 patients did not undergo RC after NAC and were excluded. Eleven out of 40 (28%) patients showed a pCR. mpMRI could be assessed in over 90% of patients. Radiologic complete response (rCR) using both methods was significantly associated with pCR, with an overall specificity of 96% and sensitivity of 36% and a high inter-observer agreement. rCR as assessed by the 3-step score was significantly associated with disease free survival (DFS) benefit.

CONCLUSION

The use of nacVI-RADS can predict pCR after NAC with high specificity but low sensitivity and a high inter-observer agreement. A 3-step score adds value in determining local residual disease, rCR assessed by this method could correlate with DFS benefit. mpMRI scores should be prospectively assessed in future trials of multimodal management of MIBC and can be a predictive asset in routine clinical management.