Background: Colorectal cancer is the third most commonly diagnosed cancer in both men and women. It is thought to result from a complex interaction between several genetic factors and environmental factors. Recognizing these factors that trigger the disease occurrence and progression is essential to apply more effective measures of prevention and risk reduction.
Objectives: The main objectives of this study were to detect the plasma levels of lead and copper in colorectal cancer patients and healthy subjects and to estimate the effect of exposure to some environmental risk factors. In addition, a booklet was designed for health education and prevention of colorectal cancer based on the results of the research. Methods: A case control study was performed at the clinical oncology department clinic of Alexandria Main University Hospital. The study sample consisted of 25 colorectal cancer patients, and 25 healthy controls, who matched the cases on age and sex. Data were collected by a pre-designed pre-coded structured interviewing questionnaire; levels of lead and copper of all participants were measured by graphite furnace atomic absorption spectrometry. In addition, lead and copper levels in the drinking water by participants were measured to detect whether they were associated with the risk of colorectal cancer.
Results: Higher levels of Pb and Cu were detected in colorectal cancer patients compared to healthy subjects, these findings were statistically significant (p<0.05). The multivariate stepwise logistic regression model revealed that four factors had significant association with colorectal cancer , the first rank was lead levels ≥ 0.164 mg/L, Passive smoking, living nearby the solid waste collecting dustbins and old oily wall paints in houses (OR =31.057, 95% CI =1.549-622. 588, OR =32.20, 95%CI =1.529-678.069, OR =83.247, 95%CI =1.279-5419.134, OR =9.354, 95%CI =1.020-85.786, respectively).
Conclusion: According to the findings of this study, there was a significant difference in the levels of Pb and Cu levels between healthy subjects and colorectal cancer patients. Therefore, environmental risk factors and chronic exposure to lead sources such as lead in old deteriorating household paints could have a very important role in the elevated lead level due to the high rate of pollution in the environment. However, further studies are needed to enhance our understanding of this relationship between heavy metals and their role in cancer progression