Researchers examine if there is an association between antibiotics and colon cancer. They looked into specific colon regions.
The use of antibiotics continues to rise every year, recently estimated at 70 billion individual antibiotic prescriptions in 2010. While sometimes necessary in treating bacterial infections, antibiotics have been associated with a negative impact on gut health. Antibiotics alter the balance and composition of gut bacteria, oftentimes resulting in the growth and presence of excessive bad bacteria, thereby affecting the presence of good bacteria.
Researchers worry that the negative effects on gut health can lead to larger health problems, including the development of tumours, specifically in the colon. Former studies have shown links between antibiotics and cancers; however, because many limitations were present, more studies are needed for more knowledge and awareness.
Published by the BMJ, the article titled “Oral antibiotic use and risk of colorectal cancer in the United Kingdom, 1989–2012: a matched case–control study” delves into the link between antibiotics and colon cancer. The Clinical Practice Research Datalink (CPRD) was used. The CPRD is a database that contains anonymous medical records. Using data from the CPRD, researchers looked at medical data from 11.3 million individuals in the United Kingdom from January 1989 to December 2012. Researchers were able to view detailed information on patients’ prescription intake, including specific medications, dosages, and duration.
After reviewing the data, the researchers found that antibiotic use was more likely in individuals who developed colon cancer, in comparison to those who did not. The risks appeared to be greater when looking specifically at penicillin and similar antibiotics that eradicate anaerobic bacteria (anti-anaerobic antibiotics); these antibiotics posed a greater risk on the proximal colon. The researchers found that as little as 15-30 days of any antibiotic intake puts individuals at a higher risk of colon cancer (8%), while 30 or more days equates to an even larger risk (15%), with the exception of distal colon cancer. With this being said, risks fluctuate depending on the area within the colon. Colon cancer was linked to antibiotic intake as distant as ten or more years prior to colon cancer diagnosis. Antibiotics taken as little as nine to one year prior to diagnosis posed no such risk.
More studies that focus on antibiotics and colon cancer are needed, especially ones that include patients’ lifestyle factors.
Written by Laura Laroche, HBASc, Medical Writer
Zhang, Jiajia, et al. “Oral antibiotic use and risk of colorectal cancer in the United Kingdom, 1989–2012: a matched case–control study”. BMJ. 2019.
Antibiotics exposure linked to increased colon cancer risk. 2019, https://www.eurekalert.org/pub_releases/2019-08/jhm-ae082019.php, assessed Aug 22, 2019.
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