Physician-scientist taps into microbiome to fight cancer

The lowest point in the nascent career of Neelendu Dey, MD, helped seal his fate as a physician-scientist.

He had just started his first year as a resident at University of California, San Francisco. One of his patients was a 30-year-old woman who was dying of metastatic colorectal cancer. “I was in my mid-20s interacting with an individual just a few years older than I am, going through one of the most terrible health outcomes one could imagine,” Dr. Dey said.

He remembers asking the patient what he could do for her, how he could make her feel more comfortable. “That feeling of helplessness, particularly as we think about young people developing cancer, it really stuck with me through the years,” he said.

Dr. Dey, a graduate of the AGA Future Leaders Program, is now a gastroenterologist and researcher at the Fred Hutch Cancer Center in Seattle. In an interview, he talked about his dual role as a physician and scientist, and how those two interests are guiding his research in precancerous conditions of the colon.

Cases like that of the young woman with colon cancer “really help drive the urgency of the work we do, and the research questions we ask, as we try to move the ball forward and help folks at earlier stages,” he said.

Q: Why did you choose GI?

When you think about what sorts of chronic diseases really impact your quality of life, gut health is one of the chief contributors among various aspects of health. And that really appealed to me — the ability to take someone who is essentially handicapped by a series of illnesses and symptoms that derive from the GI tract and enable them to return to the person they want to be, to be productive in the way that they want to be, and have a rewarding life.

As I thought about how I wanted to contribute to the future of medicine, one of the ways in which I’ve always thought that I would do that is through research. When I considered the fields that really appealed to me, both from that clinical standpoint and research standpoint, GI was one that really stood out. There has been a lot of exciting research going on in GI. My lab currently studies the microbiome, and I feel like this is an area in which we can contribute.
 

Q: What role does digestive health play in overall health?

Obviously, the direct answer is gut health is so critical in something like nutritional intake. Some GI symptoms, if your gut health has gone awry, can really be detrimental in terms of quality of life. But one less obvious role that digestive health plays is its long-term effects. We’re starting to appreciate that gut health, the gut microbiome, and gut immune education are probably long-term players. Some experiences in early life might shape our immunity in ways that have consequences for us much later in life. Whether we get early life antibiotics, for example, may potentially contribute to colorectal cancer down the line. Thinking about the long-term players is more challenging, but it’s also an appealing opportunity as we think about how we can shape medicine moving forward.

Q: What practice challenges have you faced in your career?

First, being a physician-scientist. It’s challenging to be either a physician alone or to be a researcher alone. And trying to do both includes the challenges of both individual worlds. It just takes more time to get all the prerequisite training. And second, there are just challenges with getting the opportunities to contribute in the ways that you want — to get the research funding, to get the papers out, things like that.

Q: Tell me about the work you’ve been doing in your lab to develop microbiome-based strategies for preventing and treating cancer.

The microbiome presents several opportunities when it comes to cancer prevention. One is identifying markers of cancer risk, or of general good health down the line. Some of those biomarkers could — potentially — feed directly into personalized risk assessment and maybe even inform a future screening strategy. The second opportunity the microbiome presents is if we identify a microbe that influences your cancer risk, can we then understand and exploit, or utilize, that mechanism to mitigate cancer risk in the future? Our lab has done work looking at subspecies levels of microbes that track with health or cancer. We’ve done some work to identify what these subspecies groupings are and have identified some links to certain precancerous changes in the colon. We think that there’s an opportunity here for future interventions.

Q: Have you published other papers?

We recently published another paper describing how some microbes can interact with a tumor suppressor gene and are influenced in a sex-biased manner to drive tumorigenesis in a mouse model. We think, based on what we’re seeing in human data, that there may be some relationships and we’re exploring that now as well. 

Q: What is your vision for the future in GI, and in your career?

The vision that I have is to create clinical tools that can expand our reach and our effectiveness and cancer prevention. I think that there are opportunities for leveraging microbiome research to accomplish this. And one outcome I could imagine is leveraging some of these insights to expand noninvasive screening at even earlier ages than we do now. I mean, we just dialed back the recommended age for colonoscopy for average risk individuals to 45. But I could envision a future in which noninvasive screening starts earlier, in which the first stool-based tests that we deploy to assess personalized risk are used in the pediatric clinic.

Lightning Round

Texting or talking?

Talking

Favorite city in the United States besides the one you live in?

St. Louis

Cat or dog person?

Both

If you weren’t a GI, what would you be?

Musician

Best place you went on vacation?

Borneo

Favorite sport?

Soccer

Favorite ice cream?

Cashew-based salted caramel

What song do you have to sing along with when you hear it?

Sweet Child of Mine

Favorite movie or TV show?

25th Hour or Shawshank Redemption

Optimist or Pessimist?

Optimist