Abstract 1922: Tamoxifen detection by molecular fluorescence in breast cancer patients as a screening for metabolizer classification

Abstract

Abstract Breast cancer patients with polymorphic changes in the CYP2D6 gene show considerable variations in tamoxifen (TMX) bioavailability due to the need for bioactivation of this drug. Therefore, patients with such allelic changes have a worse prognosis compared to controls. Biospectroscopy allows the analysis of biofluids, providing the complete characterization of all molecules present in the biological matrix. Among spectroscopic techniques, molecular fluorescence stands out for its high analytical sensitivity in the broad identification of information obtained by the excitation-emission fluorescence matrix (EEM). This allows the specific measurement of fluorescent species in the sample. Quantification of TMX by fluorescence spectroscopy provides a phenotypic assessment of the patient's pharmacological metabolizing status, leading to a personalized and effective pharmacological therapy. We applied fluorescence spectroscopy to blood samples from n=20 women, who had genotyping of the CYP2D6*4_g.1846G>A allele, which confers decreased protein activity. We were able to demonstrate that the fluorescence signal generated by the TMX structure in plasma solution could be detected using our methodology. The data collected exhibited signal interference due to the numerous molecular species present in this matrix. However, using multivariate statistical algorithms we could extract relevant information from the analyte, improving the signal / noise of the emission-excitation matrix. Finally, we were able to demonstrate that low cost method, which can be performed rapidly, may allow for a simple point of care stratification of patients by the CYP2D6 status, which in turn may allow for increased personalization of tamoxifen therapy for breast cancer patients. Citation Format: Lorenna Larissa Ferreira Costa, Daniel Lucas Dantas de Freitas, Kassio Michell Gomes de Lima, Tirzah Braz Petta Lajus. Tamoxifen detection by molecular fluorescence in breast cancer patients as a screening for metabolizer classification [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1922.