Smoking and Cancer - a new link?

A new mechanism has been identified that might possibly explain howsmoking can cause breast, bowel and lung cancer.A team at the Christie Hospital, Manchester, found that smokers havesignificantly higher levels of insulin-like growth factors (IGFs) in theirblood than non-smokers. Cigarette smoking histories were taken fromover 400 individuals aged between 55-65 years who were attending a bowel cancer screening trial in Manchester.The findings were presented at Europe's largest annual meeting ofhormone specialists (endocrinologists). They found that long-term smoking significantly affected levels of IGFs and that this was related to the duration and quantity of cigarette use. The findings were dose-related and were statistically significant. There was a 20 to 25 percent difference in IGF levels between the heaviest smokers and the non-smokers.It was found that growth factors do encourage cancer cell growth andprotect abnormal cells against natural death. However a much larger study is required to prove that smoking, levels of IGF and cancer risk are interlinked. This research indicates that there is possibly a new mechanism that can explain the development of some cancers. This has potential implications for cancer risk assessment and prevention strategies in the future.