A new study published in the journal Gastroenterology reports that the bacterium Helicobacter pylori, a risk factor for gastric cancer infection may also be associated with an increased risk of colorectal cancer (CRC) in some ethnic and racial groups, particularly among African Americans.
“The link between infection and cancer is intriguing, particularly if we can eradicate it with a simple round of antibiotics,” said lead author Meira Epplein, Ph.D., co-leader of Cancer Control and Population Sciences at Duke Cancer Institute. “Our study provides strong evidence that we need to pursue this research to establish a definitive cause-and-effect.”
Julia Butt and associates assembled a large consortium of cohorts representing diverse populations in the United States to thoroughly evaluate the potential association of H pylori antibodies with CRC risk.
The researchers collected data from 10 large regional and national studies and analyzed blood samples from more than 8,400 ethnically and regionally diverse study participants — half who went on to develop colorectal cancer and the other half with no such diagnosis.
Key study findings:
- H.pylori infections were equally common in both cancer and non-cancer group, with 4 in 10 patients in both groups testing positive for exposure to the bacterium.
- White patients had below average H. pylori infection rates, and Asian Americans had average rates. For black and Latino patients, however, the rates were much higher.
- Among African Americans, 65 percent of the non-cancer patients and 71 percent of the colorectal cancer patients had pylori antibodies; among Latinos, 77 percent of the non-cancer group and 74 percent of the cancer group had antibodies.
- Further analysis showed that antibodies to four pylori proteins were most often present among the different ethnic groups with colorectal cancer.
- One pylori protein, in particular, VacA, had the strongest association with increased odds of colorectal cancer among the African American patients in the study, and, specifically, high levels of antibodies to this protein were associated with colorectal cancer incidence in both African Americans and Asian Americans.
“In an analysis of a large consortium of cohorts representing diverse populations, we found serologic responses to H pylori VacA to associate with increased risk of CRC risk—particularly for African Americans. Future studies should seek to understand whether this marker is related to virulent H pylori strains carried in these populations.”write the authors.
For reference log on to 10.1053/j.gastro.2018.09.054