The Impact of H pylori Testing on Colorectal Cancer Detection

This study published in JAMA evaluated the effectiveness of adding a Helicobacter pylori stool antigen test to fecal immunochemical testing (FIT) for colorectal cancer screening in a population of adults aged 50 to 69 in Taiwan. The researcher divided 240,000 participants into two groups: one received invitations for H pylori testing and FIT. At the same time, the other was invited to FIT alone.
Out of the total, 63,508 participants were invited for the combined test (H pylori plus FIT), and 88,995 were invited for FIT only. Among those invited, the screening participation rates were 49.6% (31,497 out of 63,508) for HPSA plus FIT and 35.7% (31,777 out of 88,995) for FIT alone. Among the 12,142 participants (38.5%) who tested positive for HPSA, 8,664 (71.4%) underwent antibiotic treatment, achieving a 91.9% eradication rate. The incidence of gastric cancer was .032% in the HPSA plus FIT group and .037% in the FIT only group (mean difference, −.005% (95% CI, −.013% to .003); P = .23).

The study was conducted from January 1, 2014, to September 27, 2018, with final follow-up occurring on December 31, 2020. The primary outcomes evaluated were the incidence of gastric cancer and mortality associated with gastric cancer, with all invited individuals analyzed according to their assigned groups.

Mortality rates were .015% in the HPSA + FIT group and .013% in the FIT-only group (mean difference of .002%, 95% CI: -.004% to .007%; P = .57). After adjusting for screening participation, follow-up duration, and patient characteristics, HPSA + FIT was associated with a lower incidence of gastric cancer (.79, 95% CI: .63-.98) but not with gastric cancer mortality (1.02, 95% CI: .73-1.4) compared to FIT alone. Among those treated with antibiotics, the most common side effects were abdominal pain or diarrhea (2.1%) and dyspepsia or poor appetite (.8%).

The study has several limitations that may impact its findings. Notably, 38,792 individuals were unreachable, and 48,705 did not receive an invitation, contributing to significant exclusion rates. Additionally, low participation rates, particularly in the FIT-only group (35.7%), could skew the results. The follow-up period may not have been sufficient to capture all gastric cancer outcomes, and the small differences in cancer incidence and mortality rates raise concerns about statistical power.

In August, the introduction of new diagnostic tests, Rapid H pylori Antigen Test Card, by MP Biomedicals is an in-vitro qualitative assay for detecting H pylori antigens in human stool specimens. It aids in diagnosing H pylori infection, monitoring therapeutic effectiveness, and confirming eradication in peptic ulcer patients.² This alignins with the goal of evaluating H pylori testing as part of a broader colorectal cancer screening strategy.

In conclusion, while adding H pylori testing to FIT did not lead to a significant reduction in gastric cancer rates or mortality compared to FIT alone, it did suggest some potential for lowering cancer incidence when accounting for confounding variables. This highlights the complexity of screening strategies and the need for further research to optimize cancer prevention methods.

References

Lee Y, Chiang T, Chiu H, et al. Screening for Helicobacter pylori to Prevent Gastric Cancer: A Pragmatic Randomized Clinical Trial. JAMA. Published online September 30, 2024. Accessed October 2, 2024. doi:10.1001/jama.2024.14887

MP Biomedicals announces the launch of advanced gastrointestinal diseases diagnostic kits. NewsMedical. August 27, 2024. Accessed October 2, 2024. https://www.news-medical.net/news/20240827/MP-Biomedicals-announces-the-launch-of-advanced-gastrointestinal-diseases-diagnostic-kits.aspx