Environmental Risk Factors and Plasma Concentration of Lead and Copper in Colorectal Cancer Patients in Alexandria, Egypt: A case-control study

AbstractBackground:Colorectal canceris the third most commonly diagnosed cancer in both men and women. It is thought to result from a complex interaction between several genetic 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 compare the plasma levels of lead and copper in colorectal cancer between patients and healthy subjects and to estimate the relation between the exposure to some environmental risk factors and colorectal cancer.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 about possible environmental risk factors were collected by a pre-designed structured interviewing questionnaire. Levels of lead (Pb) and copper (Cu) of all participants were measured by graphite furnace atomic absorption spectrometry.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 Living nearby solid waste collecting sites, followed by exposure to environmental tobacco smoke (ETS), then plasma Lead level (>0.164 mg /L), and lastly living in house with old oily painting(OR = 83.25, 95% CI = 1.28-5419.13; OR = 32.20, 95% CI = 1.53-678.07; OR = 31.06, 95% CI = 1.55-622.59; OR = 9.35, 95% CI = 1.02-85.79, respectively).Conclusion:There was a significant difference in the plasma levels of Pb and Cu between colorectal cancer patients and healthy subjects. This may be due to prolonged exposure to environmental pollutants. Chronic exposure to environmental pollutants may have important role in the pathogenesis of the colorectal cancer. However, further studies are needed to enhance our understanding of this relationship between heavy metals and their role in cancer progression.