Diffuse optical tomography changes correlate with residual cancer burden after neoadjuvant chemotherapy in breast cancer patients
Menée sur 40 patientes atteintes d'un cancer du sein de stade II-IIIC et ayant reçu une chimiothérapie néo-adjuvante, cette étude met en évidence une corrélation entre l'évolution de la concentration intratumorale d'hémoglobine, mesurée à l'aide de la tomographie optique diffuse, et un indicateur mesurant le niveau de maladie résiduelle
Purpose : Breast cancer (BC) patients who achieve a favorable residual cancer burden (RCB) after neoadjuvant chemotherapy (NACT) have an improved recurrence-free survival. Those who have an unfavorable RCB will have gone through months of ineffective chemotherapy. No ideal method exists to predict a favorable RCB early during NACT. Diffuse optical tomography (DOT) is a novel imaging modality that uses near-infrared light to assess hemoglobin concentrations within breast tumors. We hypothesized that the 2-week percent change in DOT-measured hemoglobin concentrations would associate with RCB.
Methods : We conducted an observational study of 40 women with stage II–IIIC BC who received standard NACT. DOT imaging was performed at baseline and 2 weeks after treatment initiation. We evaluated the associations between the RCB index (continuous measure), class (categorical 0, I, II, III), and response (RCB class 0/I = favorable, RCB class II/III = unfavorable) with changes in DOT-measured hemoglobin concentrations.
Results : The RCB index correlated significantly with the 2-week percent change in oxyhemoglobin [HbO2] (r = 0.5, p = 0.003), deoxyhemoglobin [Hb] (r = 0.37, p = 0.03), and total hemoglobin concentrations [HbT] (r = 0.5, p = 0.003). The RCB class and response significantly associated with the 2-week percent change in [HbO2] (p ≤ 0.01) and [HbT] (p ≤ 0.02). [HbT] 2-week percent change had sensitivity, specificity, positive, and negative predictive values for a favorable RCB response of 86.7, 68.4, 68.4, and 86.7%, respectively.
Conclusion : The 2-week percent change in DOT-measured hemoglobin concentrations was associated with the RCB index, class, and response. DOT may help guide NACT for women with BC.
Breast Cancer Research and Treatment , résumé, 2016