Antibiotics Likely Putting Young People At Greater Risk Of Developing Colon Cancer: Study

A new study found that those under 50 who used antibiotics had a 50 per cent higher risk of colon cancer than those who didn't.

Colorectal cancer, also known as colon cancer, was earlier considered a disease of the elderly, as majority of cases were diagnosed in those older than age 65. But the incidence of colorectal cancer and related mortality are gradually rising among young adults. In fact, it has now become the third leading cause of cancer death among adults younger than age 50, after breast and lung cancer, as reported by researchers. However, the reason behind its occurrence in young adults had remained unclear. A new study has found the potential culprit: antibiotic use.

The study, published in the British Journal of Cancer, found antibiotic use associated with an increased risk of colon cancer in young people.

For the study, the researchers analyzed primary care data of nearly 40,000 people. Of these, 7,903 people developed colon cancer, out of which 445 were under the age of 50. They found that those under 50 who used antibiotics had a 50 per cent higher risk of colon cancer than those who didn't. The risk developing colon cancer was 9 per cent greater in those who were 50 and over who used antibiotics. The risk increases the more people used antibiotics.

Based on their findings, the researchers concluded that antibiotics appear to play a role in colon tumour formation across all age groups. However, they didn't explain how. Also, they didn't find a link between antibiotic use and rectal cancer.

Judicious use of antibiotics is important

In 2019, a study published in the journal Gut had also highlighted the need for judicious use of antibiotics, warning that it may increase the risk of colon cancer. In addition, the researchers underlined these drugs are often frequently improperly prescribed or overprescribed.

A team of researchers at the Johns Hopkins Kimmel Cancer studied 28,890 cases of colorectal cancer and compared the records with healthy subjects who never developed this disease.

They found that those who developed colon cancer were slightly more likely to have been exposed to antibiotics than those who didn't (71.3 per cent compared to 69.1 per cent). However, antibiotic exposure was only associated with increased risk of cancer in the proximal colon (the first and middle parts of the colon) but not the distal colon (last part of the colon). Particularly, this risk was seen after exposure to classes of antibiotics that kill anaerobic bacteria, such as those in the penicillin family, the researchers had said.

They didn't find this association in those with rectal cancers.

In their paper, study leader Cynthia L. Sears, Bloomberg Kimmel Professor of Cancer Immunotherapy at the Johns Hopkins Kimmel Cancer Center, advised people to avoid treating common viral infections with antibiotics, and limit antibiotic use to shortest time possible, as well as using targeted antibiotics rather than broad-spectrum ones.

Antibiotic use and colon cancer risk

Some experts suggest that antibiotic use may disrupt the gut microbiome, and over time, raise the risk of colorectal cancer.

According to experts, some bacteria in the microbiome work with the immune system to protect against colon cancer. Antibiotics may interfere with these good bacteria, and thereby increase the chance of colon cancer.

To lower the risk of colon cancer, experts recommend people to eat a healthy diet and exercise regularly. In addition, one should start getting screened starting at the age of 45. This can result in early detection of cancer and better treatment outcomes.