Early prediction of pathologic response to neoadjuvant therapy in breast cancer: Systematic review of the accuracy of MRI
The Breast, 08/08/2012
Marinovich ML et al. – Based on descriptive presentation of the data, sensitivity/specificity pairs for prediction of pathologic response were highest in studies measuring reductions in Ktrans (near–pCR), ECU (pCR, but not near–pCR) and tumour volume (pCR or near–pCR), at high thresholds (typically >50%); lower sensitivity/specificity pairs were evident in studies measuring reductions in uni– or bidimensional tumour size.
Methods- A systematic literature search (to February 2011) was performed to identify studies reporting the accuracy of MRI during NAC in predicting pathologic response, including searches of MEDLINE, PREMEDLINE, EMBASE, and Cochrane databases.
- 13 studies were eligible (total 605 subjects, range 16–188).
- Dynamic contrast-enhanced (DCE) MRI was typically performed after 1–2 cycles of anthracycline-based or anthracycline/taxane-based NAC, and compared to a pre-NAC baseline scan.
- MRI parameters measured included changes in uni- or bidimensional tumour size, three-dimensional volume, quantitative dynamic contrast measurements (volume transfer constant [Ktrans], exchange rate constant [kep], early contrast uptake [ECU]), and descriptive patterns of tumour reduction.
- Thresholds for identifying response varied across studies.
- Definitions of response included pathologic complete response (pCR), near-pCR, and residual tumour with evidence of NAC effect (range of response 0–58%).
- Heterogeneity across MRI parameters and the outcome definition precluded statistical meta-analysis.
- Based on descriptive presentation of the data, sensitivity/specificity pairs for prediction of pathologic response were highest in studies measuring reductions in Ktrans (near-pCR), ECU (pCR, but not near-pCR) and tumour volume (pCR or near-pCR), at high thresholds (typically >50%); lower sensitivity/specificity pairs were evident in studies measuring reductions in uni- or bidimensional tumour size.
