Protective effect of fish consumption on colorectal cancer risk. Hospital-based case-control study in Eastern Europe.

BACKGROUND/AIMS: Current epidemiologic studies investigating the effect of fish intake on colorectal cancer (CRC) risk are scarce. Therefore, the aim of this study was to elucidate the relationship between fish consumption and CRC risk.

METHODS

This hospital-based case-control study was performed in 548 CRC patients (Surgery Clinic, University Hospital in Krakow, Poland) between November 2000 and May 2008. Histological findings, information on anatomic location and stage of cancer were available for all the patients enrolled in this study. The control group consisted of 745 patients of the same hospital with no history of cancer admitted for treatment of non-neoplastic conditions. During the 5-year study period, the food frequency questionnaire used focused on the reference period that was defined as 1-5 years prior to CRC diagnosis for the CRC cases and the date of hospital admission for the controls.

RESULTS

The crude odds ratio (OR) was inversely related to fish consumption (z for trend in quartiles of intake= -2.31, p=0.021; OR=0.89; 95% confidence interval, CI: 0.81-0.98). The risk of CRC increased with intake of stewed or cooked meat (z for trend in quartiles of intake=2.14; p=0.032; OR=1.11; 95% CI: 1.01-1.23). The adjusted OR showed a significant reduction in CRC already at the moderate fish intake of one or two servings per week (OR=0.70; 95% CI: 0.51-0.94), but it was even lower at higher fish intake (OR=0.56; 95% CI: 0.39-0.86). All multivariate statistical models employed in the analysis considered potential confounders, such as demographic characteristics of subjects, body mass index, smoking status, leisure time physical activity, energy consumption and intake of meat products.

CONCLUSIONS

The study results indicate that increased fish intake may have a preventive effect on CRC and modulate the effect of meat consumption. To our knowledge, this is the first large epidemiologic study on dietary habits and CRC incidence in Eastern Europe.