Colorectal Cancer Risk Factors among the Population of South-East Siberia: A Case-Control Study

Abstract

Colorectal cancer remains one of the most widespread malignancies in the world. However, there is a lackof comprehensive studies considering colorectal cancer risk factors among Russian populations, particularlyin Siberia. The aim of this investigation was to determine the impact of various lifestyle, dietary, family, andsocioeconomical factors on colorectal cancer risk in South-East Siberia. We recruited 185 Russian colorectal cancercases and 210 gender-, age-, and ethnicity-matched asymptomatic controls with no history of any malignant tumor,using a specially designed questionnaire to obtain relevant information. After the statistical analysis, we definedseveral significant factors affecting colorectal cancer risk. Among these were smoking (OR=2.13, 95%CI=1.4-3.24, P=0.0004), being overweight (BMI between 25-30, OR=2.45, 95%CI=1.49-4.03, P=0.0004), alcohol drinking(OR=8.73, 95%CI=5.49-13.87, P<0.0001), beer drinking (OR=9.24, 95%CI=5.14-16.61, P<0.0001), consumptionof hard liquor (OR=9.37, 95%CI=5.92-14.82, P<0.0001), excessive red meat consumption (P<0.0001), excessiveintake of red meat products (P<0.0001), excessive intake of dairy products (P<0.0001), excessive sour cream andcheese consumption (P<0.0001 and 0.0002, respectively), spicy food consumption (OR=2.87, 95%CI=1.9-4.33,P<0.0001), family history of gastrointestinal malignant tumors (OR=3.99, 95%CI=2.09-7.59, P<0.0001), andincome exceeding twice the subsistence minimum (OR=5.34, 95%CI=3.35-8.53, P<0.0001). Certain factors, suchas high concentration of salt in the food and precancerous colonic lesions, demonstrated borderline significance(OR=3.45, 95%CI=1.68-7.1, P=0.0008, and OR=5.25, 95%CI=1.94-14.22, P=0.001, respectively). Some factorswere established as protective, like consumption of rye bread and both rye and wheat bread (OR=0.32,95%CI=0.21-0.5, P<0,0001, and OR=0.07, 95%CI=0.02-0.21, P<0.0001, respectively), and also low concentrationof salt in the food, although this was of borderline significance (OR=0.43, 95%CI=0.26-0.69, P=0.0006). ABOand Rhesus blood antigens were not associated with increased colorectal cancer risk. These results should bedefinitely applied for elaboration of programs of colorectal cancer prevention in Russia, particularly in Siberia.