Early Detection of Recurrent Breast Cancer Using Metabolite Profiling In her seminar, Leiddy Z. Alvarado talked about using metabolite profiling (or metabolomics)as an alternative method for the detection of breast cancer. She used nuclear magnetic resonance(NMR) and mass spectrometry (MS) for analyzing hundreds of small molecules in biologicalsamples. She could not analyze the biological samples with NMR or MS alone, both had to bepresent. She also explained the difference between sensitivity and specificity. Sensitivity refersto people who have the disease, and specificity refers to people who do not have the disease.Leiddy explained very well her research and made it very understandable. I loved the idea thatshe is one of the authors of the paper we read.