New Link Between Smoking, Cancer Found
July 16th, 2009 | by admin |By Richard Woodman
04/09/2002 — LONDON (Reuters) – British researchers said on Tuesday they had identified a possible new mechanism that might explain how smoking can cause breast and bowel cancer as well as lung cancer.
The team, at the Christie Hospital, Manchester, UK, said they had found that smokers have significantly higher levels of insulin-like growth factor (IGF) in their blood than non-smokers.
“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.
Renehan said that other research had recently established that IGF is linked to breast and colorectal cancer. This had prompted his team to examine associations between smoking and IGF.
The team looked at cigarette smoking histories in over 400 individuals, aged 55 to 65, attending a bowel cancer screening trial in Manchester. The investigators found that long-term smoking significantly affected levels of IGF 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.”
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, the “cell suicide” mechanism.
However, he said that a much larger study would be needed to prove that smoking, IGF levels and cancer risk are all linked.
Three studies released last year by British and American researchers suggest that common processes involving insulin signaling control the ageing process in organisms ranging from yeast to quite possibly humans.
