December 9, 2022

Antibiotics associated with increased risk of colon cancer in some patients


New research presented at the ESMO World Gastrointestinal Cancer Congress suggests that the use of antibiotics may increase the risk of colon cancer, especially in people under the age of 50. Investigators warn that unnecessary use of antibiotics could potentially put patients at risk.

The study used a Scottish primary care database to examine nearly 8,000 bowel cancer patients matched with people without bowel cancer. Through this analysis, the researchers found that the use of antibiotics was associated with an increased risk of colon cancer in all age groups. In addition, the risk increased by almost 50% in patients under 50, while the increase was only 9% in those over 50.

“To our knowledge, this is the first study to link the use of antibiotics to the increasing risk of early-onset colon cancer, a disease that has increased at a rate of at least 3% per year for the past two decades, ”said Sarah Perrott. , University of Aberdeen, in a data presentation. “Junk food, sugary drinks, obesity and alcohol probably played a role in this increase, but our data underscores the importance of avoiding unnecessary antibiotics, especially in children and young adults.”

The researchers found that the antibiotics were linked to cancers in the first part of the colon, the right side, and in younger patients. Specifically, the development of these right-sided cancers was associated with quinolones and sulfonamides / trimethoprim, which are used to treat a number of infections. According to investigators, the contents of the right side of the colon are more liquid, and as such, the microbiome in this section of the colon may be different than in other areas of the colon.

“We now want to know if there is a link between the use of antibiotics and changes in the microbiome, which can make the colon more susceptible to cancer, especially in young people,” said Leslie Samuel, MSc, in a Press release. “It’s a complex situation because we know that the microbiome can quickly return to its previous state, even after the intestine has been emptied for a diagnostic procedure such as endoscopy. We don’t yet know if antibiotics can induce effects on the microbiome that could directly or indirectly contribute to the development of colon cancer.

To further compound the cause for concern, younger colon cancer patients, aged 20 to 40, tend to have a poorer prognosis than older people, as they are often diagnosed later. .

“Doctors are less likely to investigate a patient with abdominal discomfort for colon cancer if they are in their 30s than if they are 70, and younger patients are not eligible for cancer screening of the intestine, ”Alberto Sobrero, MD, said in the release. . “As a result, their cancer is usually diagnosed at a later stage, when it is more difficult to treat.”


Bowel cancer data reinforces need to reduce unnecessary antibiotic use [news release]. EurekAlert; July 2, 2021. Accessed July 6, 2021.