Tumor angiogenesis change estimated by using diffuse optical spectroscopic tomography: Demonstrated correlation in women undergoing neoadjuvant chemotherapy for invasive breast cancer?

Purpose: To investigate if changes in tumor angiogenesis associated with complete pathologic response (pCR) or partial pathologic response (pPR) to treatment can be demonstrated by using diffuse optical spectroscopic (DOS) tomography. Materials and Methods: All participants in this prospective, HIPAA-compliant, institutional review board-approved study provided written informed consent. Eleven women with invasive breast carcinoma were imaged with DOS tomography prior to, during, andat completion of neoadjuvant chemotherapeutic regimens. By using region of interest (ROI) analysis, the DOS measure of total tissue hemoglobin (Hb T ) was temporally correlated with quantitative measures of existing (CD31-expressing) and tumor-induced (CD105-expressing) vessels, in pretreatment and posttreatment tissue specimens, to assess change. Results: Quantifi ed angiogenesis alone in pretreatment core biopsy specimens did not predict treatment response, but mean vessel density (MVD) and mean vessel area (MVA) of CD105-expressing vessels were signifi cantly decreased in women with pCR ( n = 7) ( P < .001 and P = .003, respectively). MVA of CD105-expressing vessels was also signifi cantly reduced at comparison of pre- and posttreatment residual tumor for women with pPR ( n = 4) ( P = .033). A longitudinal analysis showed signifi cant decreases ( P = .001) in mean Hb T levels during neoadjuvant chemotherapy in breast abnormality ROIs for women with pCR but not women with pPR. For women with pCR, but not women with pPR, pretreatment MVD of CD105-expressing vessels correlated with pretreatment Hb T ( P < .001). Conclusion: DOS tomographic examinations in women with breast cancer who are receiving neoadjuvant chemotherapy show a mean decrease in Hb T with time in patients with pCR only. Observed pretreatment and posttreatment correlates with quantifi ed angiogenesis markers confi rm the likely biologic origin for this DOS signature and support its potential to predict angiogenic tissue response early in the treatment cycle.