Proton pump inhibitors (PPIs), both over-the-counter medications and those typically prescribed by physicians to help treat symptoms of acid reflux, may have a role in the prevention of colorectal cancer (CRC).
Research Professor Zora Djuric, Ph.D., of the Department of Family Medicine, is among a national team of researchers who evaluated the risk of common obesity-related cancers -- breast, colorectal (CRC), and endometrial -- with the use of PPI and histamine-2 receptor antagonists (also called H2RA or H2-blockers). H2-blockers are typically used to treat and prevent duodenal and gastric ulcers, as well as other diseases that arise because of too much stomach acid.
Besides their use in reducing stomach acid, PPI influences a critical enzyme implicated in cancer growth. Study results were recently published in the paper, “Proton pump inhibitor use and obesity-associated cancer in the Women’s Health initiative,” in the journal Nutrition and Cancer.
“There is a critical need to determine whether commonly used, generally safe medications can be repurposed as chemopreventive agents,” the authors write, particularly those that influence enzymes known to affect cancer growth.
The team evaluated the role of these two classes of drugs on risk rates of several common cancers including breast, endometrial, and colorectal. In total, the study team evaluated diagnostic records of almost 125,000 postmenopausal women. Their analysis found that while the use of either PPIs or H2-blockers had no effect on the risk of breast cancers, women who had used PPIs were at significantly lower risk of developing colorectal cancers later in life. Data were suggestive that PPI may also protect against endometrial cancer. This protection from risk was not found among women who used HR-blockers, indicating that PPI was protective via pathways other than by reducing stomach acid.
This relationship was found even when the researchers controlled for BMI and non-steroidal anti-inflammatory drug (NSAID) use. Additionally, risk rates for colorectal cancer were slightly improved the longer women had used PPIs and the higher the PPI potency (dosages of 20 mg or higher were found to offer the most protection).
“Study results add to a growing evidence base that shows that PPIs may have a role in reducing risk of colorectal cancer,” Djuric said. “In fact, our results corroborate the findings of a preclinical study, which we cite it the publication, that shows that PPIs can reduce cancer development. We are hoping to test PPIs as a preventive agent within the Early Phase Clinical Cancer Prevention Consortium, which is part of the Cancer Prevention-Clinical Trials Network (CP-CTNet). There is a lot of promise in our study results, and we are looking forward to following them up with further research since it is a fairly non-toxic approach to prevention.”
Article citation: Ballinger, T. J., Djuric, Z., Sardesai, S., Hovey, K. M., Andrews, C. A., Brasky, T. M., Zhang, J. T., Rohan, T. E., Saquib, N., Shadyab, A. H., Simon, M., Wactawski-Wende, J., Wallace, R., &; Kato, I. (2022). Proton pump inhibitor use and obesity-associated cancer in the Women’s Health initiative. Nutrition and Cancer, 1–11. https://doi.org/10.1080/01635581.2022.2108467