This study investigated the utility of biomarkers, ultrasound (US) and US-guided diffuse optical tomography (DOT) in the prediction of early breast cancer response to neoadjuvant therapy (NAT).
A total of 41 patients entered the study, who were scanned with DOT and ultrasound before undergoing NAT. After completing the first three cycles of treatment as of February 2017, the participants were assessed for pathological response using the Miller-Payne grading. Receiving operating characteristic curves, or ROC curves, were derived by regression using independent variables such as: tumour operating curves, US maximum diameter, percent diameter reduction, pre-treatment (%US), maximum haemoglobin concentration (HbT) and percent reduction in HbT (%HbT) at different points in the treatment. The supporting ROC curves were calculated using integral calculus (AUC).
A total of 38 patients succesfully compled the study, of whom 15 were HER2 positive. In addition, 11 of these patients were ER positive. A total of 12 participants were ER positive or PR positive, but HER2 negative. Furthermore, 11 patients were ER, PR and HER2 negative.
The combination of HER2 and ER biomarkers, %US at the end of cycle 1 (EOC1) and %HbT (EOC1) gave the best early predictions (AUC=0.941 (95% CI 0.933-1.0)). An AUC of 0.910 (95% CI 0.810-1.0) can also be achieved with %HbT (EOC10) and %US (EOC1) independent of ER and HER2 status. The most accurate prediction AUC=0.974 (95% CI 0.933-1.0) was achieved using %HbT (EOC1) and %US (EOC1) independent of biomarker status.
In conclusion, it can be concluded from the study that the combined use of HER2 and ER status, ultrasound, and US-regulated DOT, may provide an accurate prediction of NAT from the completion of the first treatment cycle.