Previous studies evaluating whether risk factors for gastric cancer are also associated with colorectal cancer (CRC) have shown inconsistent results. We prospectively examined the association of atrophic gastritis, a pre-malignant condition for gastric cancer and long-term sequelae common to many exposure factors, and the risk of incident CRC.
Methods: A total of 20,928 Finnish male smokers, aged 50-69, who were participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC) had serum pepsinogen I (SPGI) levels measured. Participants with low SPGI levels (< 25 microg/l; n = 1,665) were invited for gastroscopy. Of these, 1,059 (63.6%) participants underwent gastroscopy and atrophic gastritis was histologically confirmed in 1,006 (95.0%) participants. We used Cox proportional hazards regression to evaluate the risk of incident CRC.
Results: During a mean follow-up of 11.3 years (236,258 person-years), 425 incident CRCs were diagnosed. The incidence rates were 1.82, 1.48, and 1.82 per 1,000 person-years of follow-up for participants with normal SPGI (> or =25 microg/l), low SPGI, and histologically confirmed atrophic gastritis, respectively. Compared to subjects with normal SPGI, there was no increased risk of CRC among subjects with low SPGI (Adjusted Hazard Ratio (HR) = 0.71; 95% CI: 0.47-1.05) and among those with histologically confirmed atrophic gastritis (Adjusted HR = 0.86; 95% CI: 0.55-1.34).
Conclusion: Atrophic gastritis is not associated with an increased risk of colorectal cancer among male smokers.