Abstract OT3-2-07: Predicting hormonal therapy response in breast cancer using diffuse optical spectroscopic imaging (DOSI): Ongoing clinical study

Background: The goal of this multi-site prospective study is to validate a safe, painless imaging method to measure the change in breast density caused by hormonal chemotherapy treatments such as tamoxifen. Recent studies have demonstrated that hormonal therapies are more effective at reducing risk in women who exhibit >10% reduction in breast density compared to women who had little or no density change, suggesting that breast density is a predictor of tamoxifen effectiveness. Current methods to measure breast density include MRI and mammography, however frequent applications of these modalities are limited due to cost and x-ray exposure, respectively. Alternatively, we are testing an imaging method that uses safe near-infrared light to measure breast tissue physiology called diffuse optical spectroscopic imaging (DOSI). Trial Design and Eligibility: The primary aim of the study is to determine whether the percentage change in the DOSI measurement of water correlates with the change in the MRI measurement of breast density after 18 months of treatment in the contralateral normal breast of breast cancer patients receiving tamoxifen. Other DOSI-derived parameters such as lipid content and hemoglobin concentration will be examined in secondary aims. Two groups of women are being recruited for the study: Pre-menopausal subjects receiving tamoxifen (treatment group) and pre-menopausal subjects not receiving chemoprevention agents (control group). Participants are measured with DOSI and non-contrast MRI before, and 6, 12 and 18 months after beginning tamoxifen. Eligible subjects are pre- and peri-menopausal females older than 21 years of age who have not and do not intend to receive chemotherapy, radiation, or surgical cancer treatment to the imaged breast, and are not pregnant or nursing. Study sites include the University of California, Irvine and San Francisco campuses. Statistical Methods: At a 5% significance level, the pre-determined power of the study is sufficient to detect the difference between the treatment and control groups by measuring the percentage change of breast tissue water concentration with DOSI. The research hypothesis is that the mean difference from baseline for tissue water concentration from DOSI will be greater for the tamoxifen-treated group than the control group. For water concentration and for MRI breast density, a two-sided independent sample t-test will be used to test the null hypothesis that the mean difference from baseline is the same for the tamoxifen-treated and control groups. As a secondary analysis, a multivariate mixed effects model will be built using the observed DOSI parameter or MRI breast density measured from each patient as the outcome variable, and predictor variables to include treatment group and measurement time, in addition to relevant clinical and demographic variables. Accrual Update: Out of the target accrual of 36, 11 subjects (6 treatment and 5 control group) have been enrolled to date. Enrollment is open until 11/30/2015. Citation Format: Thomas D OSullivan, Anais Leproux, Alice M Police, Dorota Wisner, Christine McLaren, Wen-Pin Chen, Albert E Cerussi, Min-Ying Su, Bruce J Tromberg. Predicting hormonal therapy response in breast cancer using diffuse optical spectroscopic imaging (DOSI): Ongoing clinical study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT3-2-07.