Individual response to neoadjuvant chemotherapy assessed with optical mammography in patients with breast cancer

We report an optical mammography study on eight patients with breast cancer who underwent neoadjuvant chemotherapy. Of these eight patients, six were responders (tumor size decreased by more than 50%) and two were non-responders (tumor size decreased by less than 50%). The goals of this study are (1) to characterize the temporal evolution of the hemoglobin concentration ([HbT]) and saturation (SO2) in breast tissue during the course of treatment in responders and non-responders, and (2) to define a quantitative index that is capable of identifying responders and non-responders during treatment. We found that both [HbT] and SO2 decreased by a greater amount in responders than in non-responders during therapy. This result applied to both cancerous and healthy breast, but the discrimination of responders and non-responders was more significant with SO2 measurements in the cancerous breast. A cumulative response index defined in terms of SO2 measurements in the cancerous breast achieved a 100% sensitivity and 100% specificity for the identification of responders and non-responders at therapy midpoint. These results confirm the potential of optical mammography in assessing response to neoadjuvant chemotherapy during treatment, thus offering the opportunity to consider alternative options to ineffective treatment regimens.