New Link Between Smoking and Cancer Identified Introduction LONDON (Reuters Health) Apr 08 A new mechanism that may explain how smoking can cause breast and bowel cancer, as well as lung cancer, has been identified by British researchers. The team, at the Christie Hospital, Manchester, said they found that smokers have significantly higher levels of insulin-like growth factors (IGFs) in their blood than non-smokers do. "We are excited about the findings of this research as they indicate a possible new mechanism to explain the development of some cancers," said research leader Dr. Andrew Renehan. "This has potential implications for cancer risk assessment and cancer prevention strategies in the future," he added in a statement. The findings were presented at the British Endocrine Societies' meeting in Harrogate, Yorkshire--Europe's largest annual meeting of hormone specialists. Dr. Renehan said that other research has recently established that IGFs are linked to breast and colorectal cancer. This prompted his team to examine associations between smoking and IGFs. The team looked at cigarette smoking histories in over 400 individuals, between 55 and 65 years old, attending a colon cancer screening trial in Manchester. They found that long-term smoking significantly affected levels of IGFs and that this was related to length of use and number of cigarettes smoked. "The findings were dose-related and were statistically significant," he added in a telephone interview. "There was a 20% to 25% difference in IGF levels between the heaviest smokers and the non-smokers." When asked about the likely biological mechanism, he said it was known that growth factors could encourage cancer cell growth and protect abnormal cells against natural death caused by apoptosis. However, he said a much larger study would be needed to prove that smoking, levels of IGF, and cancer risk are all linked. Three studies released last year by British and American researchers suggest that common processes involved in insulin signaling also control the ageing process in organisms ranging from yeast to quite possibly humans. Reuters Health Information 2002. Medscape Int J Cancer, 8/02 J Clin Onc, 2/03 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.