Rounding Up the Answers to Rise in Early-Onset Colorectal Cancer

Jimmy Zanon was just 37 years old when he learned he had advanced colorectal cancer after seeing his doctor for what they thought was a benign condition. In Jimmy’s search for the best treatment, he and his wife, Kim, found their way to the CU Cancer Center on our campus. After a whirlwind 15 weeks of chemotherapy, five weeks of five-day-a-week radiation, and surgery to remove two inches of his colon and 15 lymph nodes, the busy father of two was able to return to daily life and the outdoor activities he enjoys. 

Jimmy is among the growing number of people ages 20 to 49 diagnosed with colon and rectal cancers, many at advanced stages. The reasons are not well understood, and this trend runs counter to an overall decline in rates of colorectal cancers over the past several decades due in part to more effective treatment and screening.

Climbing Case Numbers

Colorectal cancer is the second most common cancer in people under age 50 in the United States today. Colorectal cancer deaths among young people are expected to double by 2030, becoming the number one cause of cancer death in those 20 to 49 years of age in this country. What’s more, those with early-onset colorectal cancer typically have more advanced disease at diagnosis than those diagnosed later in life.

Physician-scientists at CU Anschutz and worldwide are working to pinpoint the contributing factors ‒ examining the biology of the disease, time to diagnosis and a host of other elements including diet, genetics, antibiotic use, obesity and even birth by C section. If one thing is certain, it is that the colorectal cancer landscape is anything but. 

An Uncertain Landscape

Christopher Lieu, MD, guided Jimmy’s treatment plan. Lieu has dedicated his career to advancing progress in early identification of, and more effective treatments for, early-onset colorectal cancers, which are misdiagnosed, diagnosed late and difficult to treat.

“We have seen a significant increase in the number of early-onset colorectal cancer cases in the U.S. and many parts of the world over the past three decades,” he said. “It’s interesting that the trend is being seen in numerous countries with different diets, exposures and environmental factors.” 

He notes the gut microbiome ‒ the ecosystem of microorganisms in the human gastrointestinal tract ‒ may be an important piece of the puzzle. Alterations of the bacteria and fungi that exist in our guts may lead to an environment where cancer has a higher chance of developing, so physicians and researchers are looking at the factors that may be altering its makeup.

“It’s interesting that the trend is being seen in numerous countries with different diets, exposures and environmental factors.” - Chris Lieu, MD


Addressing Disparities

The picture becomes further clouded when accounting for disparities among young people affected. There are notable differences in early-onset colorectal cancer incidence by race and geography. Black and Hispanic populations, and those residing in specific regions of the Southern U.S., are disproportionately affected and at younger ages. 

Lieu emphasizes that the social determinants of health are essential to understanding the disease and its burden, including a complex interplay of environmental, socioeconomic and genetic factors and unequal access to screening and treatment.

“There may be multiple things going on,” he said. “We get so focused on the science that sometimes we forget about some of these other environmental, systemic and institutional topics.”

He and colleagues have called on physicians nationwide to deepen collaboration and information-sharing to better address both biological causes of early-onset colorectal cancer disparities and the contributing social determinants of health. 

Bringing Multiple Disciplines to Bear

Patients like Jimmy who are treated on our campus receive care from a comprehensive team dedicated to early-onset disease. The CU Cancer Center is one of a handful nationwide with a multidisciplinary focus on this subset of young patients ‒ a focus that enables patient-centered treatment and support, while also advancing a parallel research track. 

“My care experience was nothing short of amazing, and I was confident that the team was using cutting-edge treatments and research to get the best results,” Jimmy said. “Dr. Lieu treated me as a person who he knew would recover and go on to live a long and fulfilling life.”

“My care experience was nothing short of amazing.” - Jimmy Zanon


From surgeons and oncologists, to fertility specialists, geneticists and social workers, our providers come together to offer patients the highest-quality care unique to their specific circumstances. In the lab, samples from these patients help shed light on the underlying factors that may be at work.

“If we treat a young patient but don’t examine their blood and tumor tissue, then we learn nothing,” said Lieu. “The ability to collect samples and use them to find out what’s going on and why it’s happening ‒ and more importantly, what we can do about it ‒ that’s the real promise for the future.”

Harnessing Data

Even while numbers of early-onset cases climb, our providers see just a handful at a given time, making national and international collaboration critical in the search for answers. 

The CU Cancer Center published one of the largest genomic characterizations of early-onset colorectal cancers to date, and our teams are collaborating with an international consortium to build a robust data set on patient outcomes and survival rates. 

By combining forces, we expand the universe of data available for investigators seeking to uncover patterns and inform more effective, less toxic treatments like highly targeted immunotherapies.

“We are learning more and more about the biology of these cancers ‒ both through work done at CU Anschutz and in collaboration with centers across the country,” Lieu said. “And that’s cause for hope.”

“We are learning more and more about the biology of these cancers… that’s cause for hope.” - Chris Lieu, MD

Awareness is Key

Two years ago, the U.S. Preventive Services Task Force lowered the recommended screening age from 50 to 45 amid the alarming rise in cases. Those with a family history or other risk factors, or those who develop symptoms, are encouraged to start the conversation with their provider even earlier. 

Lieu said raising awareness among physicians and patients about the warning signs of potential disease is key. Colorectal cancer is largely preventable, as precancerous polyps can be removed during colonoscopy and early-stage cancer surgically removed before it grows or spreads. 

Jimmy Zanon remains cancer free today. He is a vocal advocate for education and screening. “If you have symptoms, don’t delay,” he said. “Listen to your body, and get yourself checked out.”

Be Well,

Don Elliman

Don Elliman

P.S. There will be no At the Forefront newsletter next month. Keep an eye on your inbox in September for our annual publication Momentum, featuring stories of progress made possible with philanthropic support.




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