Oncologist Thomas Weber, M.D., is taking on the worrisome rise in early-onset colorectal cancer. March was Colorectal Cancer Awareness Month, and Weber spoke during an Office of the Director Seminar March 5. Linda Birnbaum, Ph.D., director of NIEHS and the National Toxicology Program, hosted the talk.

Weber is from the Zucker School of Medicine at Hofstra/Northwell and directs surgical oncology for the Northwest Region of Northwell Health. His research targets the causes of the increase in early age-onset colorectal cancer.

Weber stressed the challenge of designing studies to tease out potential risk factors. “We’re trying to…provide a platform on which we can pursue scientific questions, secure answers, and save lives.” (Photo courtesy of Michael Garske)

Weber took one step toward his goal by founding and serving as president of the Colon Cancer Challenge Foundation (CCCF). The public charity raises money to support colorectal cancer awareness, screening, and research.

Recently, CCCF has joined with other organizations to address the increasing incidence of young adult colorectal cancer. The foundation is sponsoring its fourth summit on early age onset colorectal cancer in April (see first sidebar).

On the rise worldwide

NIEHS clinical researcher Frederick Miller, Ph.D., joined in the discussion after Weber’s talk. (Photo courtesy of Michael Garske)

As with most cancers, overall incidence rates for colorectal cancer are decreasing both in the United States and worldwide, which Weber attributed to recommended screenings for those age 50 years and older. However, when looking specifically at colorectal cancer diagnoses for those younger than 50 years, the trend is exactly the opposite.

By comparing groups of individuals born in the 1950s and 1990s, Weber demonstrated that the risk of colon cancer has doubled, whereas the risk of rectal cancer has quadrupled. Nearly one-third of rectal cancer patients are younger than 55 years old.

Beyond that, projections of current trends suggest that rates among those aged 20 to 29 years will increase more than 100 percent by 2030. “[These results] have enormous clinical implications, as the current guidelines suggest regular screenings to begin at the age of 50,” Weber said.

Early-onset colorectal cancer is particularly dangerous because diagnoses tend to occur after individuals become symptomatic. By that time, the cancer has progressed to a late stage, and treatment has poorer outcomes.

Causes unknown, but not unknowable

June Dunnick, Ph.D., head of the General Toxicology and Cancer Group, highlighted links between brominated chemicals and intestinal cancers in animals, even with short-term exposures. (Photo courtesy of Michael Garske)

Weber’s group found that the trend began in the mid to late 1980s, and they are now working to discover risk factors. Their studies suggest that some of the usual players are involved, including obesity, diet, and genetics.

“We need a new set of hypotheticals,” he said. “We have to control for the usual suspects if we are going to tease out some of the innovative potential causes.”

“We need your help,” Weber added, suggesting that environmental factors play a role. He called for more research, especially on exposures in early life.

Citation: Siegel RL, Fedewa SA, Anderson WF, Miller KD, Ma J, Rosenberg PS, Jemal A. 2017. Colorectal Cancer Incidence Patterns in the United States, 1974-2013. J Natl Cancer Inst 109(8): djw322.

(Rachel Carroll, Ph.D., is a research fellow in the NIEHS Biostatistics and Computational Biology Branch.)