Study Links Hidden Virus in Gut Bacteria to Colorectal Cancer Risk

The recent deaths of actors Catherine O’Hara and James Van Der Beek from colorectal cancer have put the disease squarely in the spotlight. Experts with Baptist Health Cancer Care say they’ve seen a definite increase in patients asking about colonoscopies and other colorectal screening methods. It’s not unlike the heightened awareness created in 2020 following Chadwick Bozeman’s death at age 43 of colon cancer.

“If anything good can come from this kind of a tragedy, it’s that there is definitely a greater awareness of the risks and the dangers of colorectal cancer—particularly in younger people and African American communities,” says Jordan Seth Moseson, D.O., a Baptist Health surgeon specializing in minimally invasive colorectal and general surgery.

The trend of younger people such as Mr. Van Der Beek being diagnosed with colon cancer in more advanced stages continues to be a concern, Dr. Moseson adds. But at the same time, he reports he’s been seeing younger people showing up for screening exams—even if it may not be the right time for them. “I’ve actually had to turn a few people away and say, ‘Hey, you’re not quite at that age yet but I’m glad you’re thinking about it.’”

Current U.S. Preventive Services Task Force guidelines recommend screening for colorectal cancer begin at age 45 unless one has a personal or family history of the disease, inflammatory bowel disease (IBD) or other known risk factors. Screenings should continue at regular intervals until age 76, at which point the decision should be made on an individual basis with one’s physician.

A Leading Cause of U.S. Cancer Deaths

Colorectal cancer remains one of the most diagnosed cancer types in the U.S. and a leading cause of cancer-related death, according to the Colorectal Cancer Alliance.

Historically, around 150,000 new cases are diagnosed each year in the U.S. Approximately 55,000 deaths per year occur from colorectal cancer, making it the second leading cause of cancer-related death in the U.S. for men and women combined.

While overall cancer death rates have declined, the incidence of colorectal cancer in adults under 50 has been steadily climbing. In fact, the Alliance notes, the disease has become the leading cause of cancer death in adults under 50.

The shift toward younger patients — including those in their 20s, 30s, and 40s — presents a unique challenge. Unlike older patients, these individuals are in the prime of their lives, often raising young families or perhaps trying to start one.

A Possible Cause of Colorectal Cancer?

A recent study suggests a virus hiding inside a common gut bacterium may play a role in colorectal cancer.

Researchers studying Bacteroides fragilis—a bacterium normally found in the human gut—discovered that some strains carry a previously unknown virus. The study found that people with colorectal cancer were about twice as likely to have this virus present in their gut bacteria.

Scientists think the virus may alter the bacterium in ways that increase its cancer-promoting effects. However, the virus has also been detected in healthy people, so researchers emphasize that the findings show a possible link, not proof that the virus causes cancer.

The discovery could help explain why B. fragilis, which is common in healthy guts, is sometimes associated with colorectal cancer. It may also support earlier detection of colorectal cancer and guide new ways to treat and prevent this disease, suggests Luis Hernandez, M.D., a colorectal surgeon at Baptist Health Miami Cancer Institute.

“Historically, gut flora has been looked at separately for bacterium and viruses, and this study demonstrates their role together in colorectal cancer,” says Dr. Hernandez. “These findings can provide a new way for potentially screening patients for colorectal cancer development, as well as maybe intervening before dysbiosis, an imbalance of the gut microbiome, can occur.”

Treatment Options for Colorectal Cancer

Treatment protocols for colorectal cancer are well established and highly effective, according to Dr. Hernandez.

“Depending on how advanced their cancer is, patients may require chemotherapy, radiation therapy or surgery—or perhaps a combination of these,” Dr. Hernandez says. “Survival is much better the earlier it’s found but even in more advanced cases, the treatment protocols we have now work very well.”

The order of treatments is determined by the patient’s particular cancer type and stage, explains Dr. Hernandez. “If surgery is required, the patient may undergo chemotherapy first in order to shrink the tumor and make it easier to surgically remove, or resect,” he explains. “Our oncologists have excellent results even when a patient needs advanced therapy like chemotherapy or radiation or some sort of combination of the two.”

Proton Therapy Offers Greater Precision, Fewer Side Effects

If radiation is required for treatment, proton therapy may offer advantages for young rectal cancer patients, says Michael Chuong, M.D., medical director of the department of radiation oncology at Miami Cancer Institute.

“Because proton therapy is so precise, we can substantially reduce radiation exposure to normal pelvic tissues such as bowel, bladder, pelvic bone marrow and reproductive organs compared with x-ray–based therapy,” Dr. Chuong explains.

In younger individuals with longer life expectancy, he says this reduction is especially meaningful because it has the potential to better preserve long-term quality of life and survivorship outcomes.

“Proton therapy may lower the lifetime risk of late toxicities including chronic bowel or urinary dysfunction, infertility or impaired sexual function, pelvic insufficiency fractures and treatment-related secondary malignancies,” Dr. Chuong notes. “This is particularly important for patients expected to live many decades after treatment.”

The Importance of Colorectal Cancer Screenings

Screening is still the most important way of preventing colon cancer as it identifies polyps before they can convert to cancers, emphasizes Dr. Moseson.

“What I want people to take away from this is to get screened. Period. Full stop,” Dr. Moseson says. “Colonoscopies are the gold standard for colorectal cancer screening but I don’t care what method you use – just get screened. If we find a polyp or even an early cancer, we can remove it right then and there and prevent it from becoming a bigger problem.”

Lifestyle Modifications Can Prevent Colorectal Cancer

The best way to treat colorectal cancer is to not get it in the first place, says Dr. Moseson.

“While you can’t change your racial background or your age, there are some modifiable risk factors with colorectal cancer,” he says. I advise my patients to quit smoking, limit alcohol intake, stick to a high-fiber, low-fat diet and exercise regularly. These are really the best things we know of that can help prevent colorectal cancer and pretty much every other cancer, too.”

Click here for more information about colorectal cancer and the services and specialists available at Baptist Health Miami Cancer Institute.