Evaluation of Effective Factors in Incidence of Colorectal Cancer

Colorectal cancer is considered as the third prevalent malignancy worldwide. Investigation of information on cancers in Iran during 1985-1996 showed an increase in the incidence and prevalence of colorectal cancer. Its rank in Iran has increased from 9 to 5th during 10 years. It was reported as high prevalent cancer in Iranian people aged less than 40 years among Asian countries.

In this cases-control study patients with a pathologic report of colorectal cancer were recruited among those cases registered in Ardabil Cancer Registry. Control group were selected from neighbors, frequency matched for age and gender. Subjects were interviewed using a questionnaire consisting information on age, gender, smoking, drugs and alcohol consuming, diet, family history of cancer and serum IgM and IgG level for H. pylori. Data were analyzed using SPSS v16.

In the current study, 43 persons (53.8%) were male and 37 (46.2%) were female. In the case group, 10 persons (12.5%) were under 40, 34 cases (42.5%) in age group of 41- 60 and 36 persons (45%) were more than 61 years. In the control group 12 persons (15%) were under 40, 36 persons (45.5%) in age group of 41-60 and 40 persons (68%) were more than 61 years. In the control group 3 cases had BMI less than 19, 36 cases (45%) between 19-24.9, 31 cases (38.8%) between 25-29.9 and 10 cases (12.5%) were more than 30, whereas this variable was 2.5, 32.5, 46.2 and 18.8% respectively in the case group. Positive history of smoking found to increase the risk of cancer around 1.8 times (OR= 1.78; CI: 0.91- 5.85). However, significant difference was not observed between two groups regarding alcoholic beverage consumption (p=0.385). There were significant differences between two groups in terms of vegetables and carbohydrates intake. Difference was also significant between two groups regarding positive level of IgG. Among studied persons, 19 and 13 patients in case and control group had positive IgM respectively.

Our finding showed an increased risk colorectal cancer in those consuming low vegetable and fruits and high carbohydrate consuming, having smoking history, positive family history of cancer and serum IgG level.