Q&A: Dr. Wenxin (Vincent) Xu, 2026 KCA Grant Winner
Dr. Wenxin (Vincent) Xu received the KCA’s 2026 Dr. Anthony Marzoni Papillary RCC Focus Award supported by Joy and Zack Pearlman. Dr. Xu’s will research “KIM-1 as a Circulating Biomarker in Papillary RCC and Translocation RCC”. Dr. Xu is a genitourinary medical oncologist and clinical translational investigator at Dana-Farber Cancer Institute and Harvard Medical School. We spoke with him about his research and the impact it can have on people with kidney cancer.
Describe your project and how you developed the idea.
In this project, we evaluate a blood test to help detect and monitor less common subtypes of kidney cancer, including papillary kidney cancer. This is an area of unmet need because there are currently no blood tests that can reliably detect papillary kidney cancer, which comprises about 20% of all kidney cancers. If available, blood tests could help us to more accurately diagnose and monitor this disease and to know sooner whether treatments are working.
Our research group has been working on a protein called KIM-1 which is released into the blood by several types of kidney cancer. This protein was first discovered by Dr. Joseph Bonventre’s laboratory as a biomarker for kidney injury. However, it turns out that the blood levels of KIM-1 are many times higher among kidney cancer patients. Initially, a lot of our effort focused on developing KIM-1 as a blood test among patients with clear cell kidney cancer, because that cancer type is more common and banked blood specimens from clear cell kidney cancer are readily available. However, we also noticed that in mixed cohorts of patients, those with papillary kidney cancer also had very high levels of KIM-1. We therefore propose in this project to work using blood specimens from a trial that specifically enrolled papillary kidney cancer (PAPMET). This will allow us to determine, specifically in papillary kidney cancer, whether high KIM-1 levels are associated with higher risk, and whether decrease in KIM-1 levels after treatment predicts better cancer outcomes.
Why are biomarkers, especially ones you can use blood tests for, so difficult to identify for diagnosing kidney cancer?
Kidney cancer has never had a routinely available tumor marker. This makes it inherently more difficult to diagnose, monitor and treat compared to other cancer types, such as prostate cancer, which can be evaluated using a simple blood test. While some other cancer types can be detected easily using circulating tumor DNA (ctDNA), this is challenging in kidney cancer because it has fewer mutations compared to other cancer types, and therefore fewer differences between cancer DNA and normal DNA. As an example, cancer detection tests like the Galleri blood test are sensitive for liver cancer and pancreatic cancer, but are have very low sensitivity for detecting kidney cancer.
What makes papillary RCC better for studying a potential biomarker like KIM-1 than a the most common type of kidney cancer, clear cell RCC?
The existing data suggests that KIM-1 is potentially a helpful blood test for both pRCC and ccRCC. As it turns out, both pRCC and ccRCC, as well as some other cancer types including tRCC, originate from the same kidney cell (a proximal tubule cell) which overproduces KIM-1 when it transforms into cancer. What is unique about pRCC is that due to the rarity of this subtype, it is very difficult to obtain large cohorts of blood samples from specifically pRCC patients. The PAPMET trial, which was led by Dr. Monty Pal through the SWOG Cancer Research Network, represents one such cohort. That makes these samples extremely precious. Fortunately, we now have available tests that can detect KIM-1 in very small volumes of blood, less than one drop, at concentrations that are relevant for kidney cancer patients. This makes the KIM-1 test easier to evaluate since we are not using up the limited samples that are available.
What is the most exciting thing about your research for patients and families?
I am most excited about the opportunity to personalize kidney cancer treatment. In the future, I hope that blood tests like KIM-1 will help us to avoid unnecessary surgeries (for example among patients with benign tumors), to give the right amount of adjuvant treatment after surgery (not too much and not too little), and to get the right patient to the right treatment more efficiently (and to avoid continuing treatments that are ineffective). Another fascinating area which is just starting to emerge, is learning about personalized biology using blood tests. While this work is still in early stages, it is possible that combining KIM-1 with other proteins and DNA changes in the blood can help to build a profile of an individual patient, including their normal biology, immune system, response to tumor, and likelihood of side effects. This could let us choose treatments in a personalized way rather than relying on clinical trial and error. We rely on patients and families, who have already been so generous by participating in trials such as PAPMET, to continue to participate in research so that we can learn how to treat kidney cancer more wisely and effectively.
What motivates you?
Seeing patients in clinic is the strongest motivator any oncologist can have. Every day, I work with patients and families who are navigating a cancer diagnosis. We see spectacular successes and also devastating failures of our current technologies. Science moves so quickly nowadays, that when we see a problem, there is an opportunity to try to change that outcome for our future patients. We have the incredible privilege of being able to work on something in the lab and then, if it works, to bring it to patients within a few years. Many of these problems are very, very difficult, but I am also surrounded by amazing mentors and colleagues who have shown that difficult problems can be solved. If I work on a problem and don’t succeed, I also know that our efforts add to the field and will one day help someone else succeed. It is a contagious environment of hope.
What else do you want others to know about you or your research?
I want to thank the patients and families who make this work possible. Every data point in kidney cancer research comes from someone who chose to share their samples and information so that future patients could do better. Organizations like KCA bring the kidney cancer community together and help us coordinate our efforts. Kidney cancer is a terrible disease but by working together, the field has already made incredible progress, and I’m excited to see what we will accomplish in the years ahead.