Correlation between genetic polymorphisms within IL-1B and TLR4 genes and cancer risk in a Russian population: a case-control study.

In the last decade, a growing interest has been devoted to the evaluation of the impact of single nucleotide polymorphisms (SNP) on cancer risk. According to the results of multiple studies, among the genes that have a considerable influence on cancer risk are those encoding pattern recognition receptors, cytokines, and antioxidant defense enzymes. Nonetheless, the effect of numerous SNPs within these genes on cancer risk has been scarcely investigated. A case-control study of 401 cases and 300 sex- and age-matched controls was performed in order to explore the role of IL1B_1473G/C (rs1143623), SOD1_7958A/G (rs4998557), TLR4_1196C/T (rs4986791), IL10_1082A/G (rs1800896), IL17A_197G/A (rs2275913), and TLR4_896A/G (rs4986790) polymorphisms in the susceptibility to colorectal cancer (n = 244), gastric carcinoma (n = 72), and ovarian cancer (n = 85). The analysis revealed a significant relationship between the presence of heterozygous genotypes for IL1B_1473G/C and TLR4_896A/G polymorphisms and higher risk of rectal cancer (codominant model, OR = 1.67; 95% CI, 1.06-2.63; p = 0.048 and OR = 2.25; 95% CI, 1.26-4.02; p = 0.014, respectively). In addition, the variant G/G genotype of the IL10_1082A/G SNP was associated with a 2.5-fold increase in ovarian cancer risk with a borderline significance (codominant model, OR = 2.45; 95% CI, 1.14-5.25; p = 0.069). Similarly, the carriers of the C/T genotype for the TLR4_1196C/T polymorphism were more susceptible to rectal cancer with a borderline significance (codominant model, OR = 1.42; 95% CI, 0.80-2.51 p = 0.06). No statistically significant associations were found when stratifying the sample by subgroups of age, sex, and clinicopathological characteristics. Finally, we observed six combinations of haplotypes for the examined SNPs, each of which either profoundly increased or decreased cancer risk. The results from our study provided evidence that IL1B_1473G/C and TLR4_896A/G SNPs are implicated in rectal cancer development in a Russian population. Further research should be addressed to clarify the role of the abovementioned polymorphisms in cancer etiology.

Colorectal cancer risk factors among the population of South-East Siberia: a case-control study.

Colorectal cancer remains one of the most widespread malignancies in the world. However, there is a lack of comprehensive studies considering colorectal cancer risk factors among Russian populations, particularly in Siberia. The aim of this investigation was to determine the impact of various lifestyle, dietary, family, and socioeconomical factors on colorectal cancer risk in South-East Siberia. We recruited 185 Russian colorectal cancer cases 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 defined several 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), consumption of hard liquor (OR=9.37, 95%CI=5.92-14.82, P<0.0001), excessive red meat consumption (P<0.0001), excessive intake of red meat products (P<0.0001), excessive intake of dairy products (P<0.0001), excessive sour cream and cheese 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), and income exceeding twice the subsistence minimum (OR=5.34, 95%CI=3.35-8.53, P<0.0001). Certain factors, such as 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 factors were 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 concentration of salt in the food, although this was of borderline significance (OR=0.43, 95%CI=0.26-0.69, P=0.0006). ABO and Rhesus blood antigens were not associated with increased colorectal cancer risk. These results should be definitely applied for elaboration of programs of colorectal cancer prevention in Russia, particularly in Siberia.

Analysis of cancer incidence and mortality in the industrial region of South-East Siberia from 1991 through 2010.

Kemerovo is an industrial region of the Russian Federation characterized by highly developed mining, chemical, metallurgical and power industries. Many of the factories were closed down due to the socioeconomical crisis in the early 90's, and economic potential of the survivors has also decreased significantly. Paradoxically, this has led to the improvement of the ecological situation in the region and elimination of exposure to many chemical carcinogens. This factor, in combination with the improvement of oncological care, might be expected to have lead to a decline of cancer incidence and mortality in the region. To assess trends of cancer incidence and mortality in Kemerovo Region, we therefore carried out an analysis of relevant epidemiological data during 1991-2010. In fact, a significant increase of cancer incidence overall was revealed during 2001-2010. Male cancer incidence was significantly higher than female cancer incidence. Regarding gastric cancer incidence, statistically significant differences during 2001-2010 were found only for men, and male incidence exceeded female incidence. Concerning colorectal cancer incidence, it was lower during 2001-2005 and 2006-2010 as compared to the period of 1991-1996. Lung cancer incidence was significantly higher during 1991-2000 compared to 2001-2010. Among urban populations, cancer incidence was higher in comparison with rural population, but a gradual steady convergence of trends of cancer incidence among urban and rural populations was noted. Lung cancer, breast cancer, colorectal cancer, non-melanoma skin cancer, and gastric cancer are the most prevalent cancer forms in Kemerovo Region. There were no differences in cancer mortality between 2001-2005 and 2006-2010; however, male cancer mortality exceeded female cancer mortality. A similar situation was observed for gastric cancer, colorectal cancer, and lung cancer. Cancer mortality among urban populations exceeded mortality among rural population, for both genders. We suggest that these data can be used for development of modern programs of cancer prevention and early diagnostics in industrial regions of Siberia.