Study finds link between colon cancer and antibiotic use

key takeaways

  • A new study links antibiotic use to an increased risk of colon cancer.
  • Young adults who use antibiotics have a 50 percent higher risk of colon cancer than those who don’t.
  • Experts recommend using antibiotics only when needed.

Traditionally, colorectal cancer was a disease that primarily affected older adults. But it is now the third leading cause of cancer death in young adults. The exact cause has puzzled researchers for years, but a new study shows a surprising potential link: antibiotic use.

The study was published in British Journal of Cancer, analyzed primary care data for nearly 40,000 people from 1999 to 2011. The researchers looked specifically at antibiotic use and lifestyle factors in people with and without colorectal cancer.

While the overall number of cancers was low (7,903 people had colon cancer and 445 were under the age of 50), the researchers found that people under the age of 50 who used antibiotics had a 50 percent higher risk of colon cancer than those who didn’t. People 50 years and older who used antibiotics had a 9% increased risk of colon cancer. The more people use antibiotics, the greater their risk.

What is colon cancer?

Colon cancer is often referred to in the broad sense of colorectal cancer, which is an umbrella term used to refer to colon and rectal cancers. Most colorectal cancers start with growths called polyps in the lining of the colon or rectum. These polyps can become cancer over time. Colorectal cancer is the third most common cancer diagnosed in U.S. men and women

However, there appears to be no link between antibiotic use and rectal cancer.

“Our findings suggest that antibiotics may play a role in colon tumor formation in all age groups,” the researchers concluded.

Why does antibiotic use increase the risk of colon cancer?

The study itself focused only on the association — not on why antibiotic use increases colon cancer risk. However, there are some theories as to why this is the case.

Antibiotic use may interfere with bacteria in the gut microbiome, which makes up the microbes in our gastrointestinal tract, gastrointestinal oncologist Scott Kopetz, MD, of the University of Texas MD Anderson Cancer Center told VigorTip. world.

“A healthy microbiome has a mix of different types of bacteria that maintain the health of the cells in the colon’s lining,” he said. “Antibiotic use disrupts this healthy microbiome and over time may lead to a higher risk of colorectal cancer.”

Can taking antibiotics cause diarrhea?

Anton Bilchik, MD, PhD, MBA, FACS, director of the Gastrointestinal Research Program at St. John’s Cancer Institute, Providence St. John’s Health, California, agrees that the gut microbiome may be affected by antibiotic use.

“Possible explanations for why antibiotics may be associated with increased risk are not fully understood, but some bacteria in the microbiome work with the immune system to prevent colon cancer,” he told VigorTip. “Antibiotics may neutralize good bacteria and stimulate bad bacteria, increasing the chance of colon cancer.”

Sarah Hoffe, MD, chief of the Division of Gastrointestinal Radiation Oncology at Moffitt Cancer Center, told VigorTip that specific findings lend credence to these theories.

“Patients who took the most antibiotics had the highest cancer risk, but studies have shown that the risk is even slightly elevated after a course of antibiotics,” she said. “The increased risk was mostly on the right side of the colon, the proximal or The ascending colon, where bacterial activity is higher than the rest of the gut.”

what does this mean to you

Antibiotic use is associated with an increased risk of colon cancer in young adults. While no direct cause-and-effect relationship has been established, experts recommend using antibiotics only when needed to ensure safety.

How to deal with antibiotic use

Experts stress that people should not avoid antibiotics when they need them to avoid colon cancer. There’s only one link at this point — not a proven cause — and many people use antibiotics without problems.

“Antibiotic use is so common that confounding factors may contribute to an increased risk of colon cancer,” Hough said. There may also be less obvious associations that could explain the link, Kopetz said.

Eating yogurt while on antibiotics can protect your gut health

“For example, patients who were more likely to see their doctor regularly were more likely to be treated with antibiotics and were also more likely to have a colonoscopy to detect cancer,” he said.

Still, Bilchik says the findings are plausible.

“If you need antibiotics, you should take them. But obviously antibiotics are overused,” he said. “It’s just another reason why it’s important to use antibiotics wisely.”

Overall, Kopetz recommends that people do their best to maintain a healthy diet and exercise regularly to reduce their risk of colon cancer, while getting screened. “Getting recommended screening starting at age 45 can detect cancer early and prevent it by removing precancerous lesions,” he said.