Eliminating H pylori Lowers CRC Incidence, Mortality Risk

TOPLINE:

Being positive for Helicobacter pylori is associated with a higher risk for colorectal cancer (CRC) incidence and CRC mortality, new data show; however, a 2-week course of antibiotics to eliminate the bacterial infection can reduce the risk of developing and dying from CRC.

METHODOLOGY:

• H pylori is a known cause of peptic ulcers and stomach cancer and has been classified as a group I carcinogen by the World Health Organization›s International Agency for Research on Cancer.
• Studies showed that H pylori increases the risk for gastric cancer and may increase the risk for CRC, but evidence supporting the CRC connection remains inconsistent.
• To investigate a possible H pylori-CRC link, investigators reviewed CRC incidence and mortality in a nationwide cohort of 812,736 veterans tested for H pylori at Veterans Health Administration facilities; of the 205,178 (25.2%) who tested positive for H pylori, 134,417 (34%) were treated.
• Patients were followed from their first H pylori test, and researchers tracked subsequent CRC diagnoses as well as CRC-related and non-CRC–related deaths.

TAKEAWAY:

• H pylori infection was associated with an 18% higher risk for CRC (adjusted hazard ratio [aHR], 1.18) and a 12% higher risk for CRC mortality (aHR, 1.12).
• Untreated patients had a 23% higher risk for CRC (aHR, 1.23) and a 40% higher risk for CRC mortality (aHR, 1.40) than treated individuals.
• Over the 15-year follow-up, receiving treatment for H pylori infection vs no treatment was associated with a lower risk of developing and dying from CRC (absolute risk reduction, 0.23%-0.35%). For context, among individuals receiving a screening colonoscopy, the invasive test was associated with a 0.84%-1.22% absolute risk reduction in CRC incidence and a 0.15-0.30% absolute risk reduction in CRC mortality.
• Excluding patients diagnosed with CRC within a year of H pylori testing did not change the associations in the study.

IN PRACTICE:

“We would like to highlight the potentially exciting clinical implications of these findings,” the authors of an accompanying editorial wrote. “Although the mechanistic connection between H pylori and colorectal cancer is not fully resolved,” the finding that eliminating H pylori “could reduce both gastric and colorectal cancers is incredibly potent and should be considered in clinical care for individuals at high risk for GI [gastrointestinal] cancers.”

SOURCE:

The work, led by Shailja C. Shah, MD, of the University of California San Diego, was published in the Journal of Clinical Oncology, alongside the accompanying editorial by Julia Butt, PhD, of the German Cancer Research Center, Heidelberg, Germany, and Meira Epplein, PhD, of Duke University in Durham, North Carolina.

LIMITATIONS:

The study was limited to US veterans, which means generalizability to other populations needed to be confirmed. There may have been differences in CRC risk factors between treated and untreated patients.

DISCLOSURES:

The work was funded by the Veterans Health Administration, the National Cancer Institute, and others. Investigators reported ties to numerous companies, including AstraZeneca, Novartis, Guardant Health, and Medscape Medical News, publisher of this article. The editorialists had no disclosures.

A version of this article appeared on Medscape.com.