Towards a personalized approach to aromatase inhibitor therapy: a digital microfluidic platform for rapid analysis of estradiol in core-needle-biopsies

Despite advances in breast cancer prevention and treatment, variability in patient-response has revealed the need for a more personalized approach to medicine, in which treatments are tailored to each patient's biology. Motivated by this idea, we introduce a technique that allows for quantification of small-molecule analytes directly from core needle biopsy (CNB) tissue samples on a miniaturized platform. The new technique, powered by digital microfluidics, integrates tissue-liquid extraction and magnetic bead-based competitive immunoassay for quantification of estradiol in milligram-sized CNB samples. Each measurement (from start to finish) requires similar to 40 minutes, a duration consistent with a visit to a doctor's office. The performance of the new technique was validated by the gold-standard analysis method (high performance liquid chromatography coupled to tandem mass spectrometry), and was applied to evaluate human patient samples before and after a course of treatment with aromatase inhibitor therapy. We propose that the new technique has great potential for eventual use for fast, automated, and quantitative analysis of bio-markers in tissue samples, towards a personalized medicine approach.