Dr. Xu is working to develop blood-based biomarkers that can be used to detect and monitor kidney cancer. He is mentored in this work by Dr. Matthew L. Freedman (Dana-Farber Cancer Institute), and is also mentored closely by Dr. David McDermott (Beth Israel Deaconess Medical Center) and Dr. Toni K. Choueiri (Dana-Farber Cancer Institute). In this project, Dr. Xu will assess the performance of two blood-based tests, plasma kidney injury molecule-1 (KIM-1) and cfMeDIP-seq. KIM-1 is a transmembrane protein which is overexpressed in clear cell and papillary kidney cancer, and has a cleavable extracellular domain which circulates in plasma. cfMeDIP-seq is a technique that uses differential methylation patterns to sensitively detect small amounts of circulating tumor DNA. By detecting two different components of kidney cancer, these tests might overcome the limited precision of prior blood tests. First, Dr. Xu will measure KIM-1 in blood collected prior to surgery from patients with suspicious kidney masses, to test whether KIM-1 and cfMeDIP-seq can predict which patients have kidney cancer. Second, he will measure KIM-1 in patients who completed surgery for kidney cancer, and determine whether patients with higher plasma KIM-1 have higher chance of cancer recurrence and may benefit from additional treatment. Third, he will measure KIM-1 in blood samples from patients with advanced kidney cancer to test whether KIM-1 can help to predict survival in these patients, and whether decrease in KIM-1 after treatment predicts response to treatment. This project, if successful, could lead to the first minimally invasive blood tests that can guide the diagnosis and treatment of kidney cancer.