The discovery by US scientists points to ways in which the disease may be prevented and could open up a new direction in cancer research. It adds to evidence that dietary changes and prophylactic treatment with hormonal drugs such as tamoxifen may help ward off the cancer.
The hormone, insulin-like growth factor (IGF-1), is part of the body's defence system and is also known to be raised in prostate cancer. Experts believe that amplifying the body's defences instead of tackling the causes of cancer could turn out to be a more effective strategy against the disease.
Previous studies have shown that levels of IGF-1 are raised in women with breast cancer, but it was unclear whether the high levels were caused by the presence of the disease.
The new study, published in The Lancet, compared 400 women from whom blood samples were taken in 1989 to 1990 and who developed breast cancer up to five years later with 620 women from whom blood was taken at the same time but who did not develop cancer.
The results showed that among pre-menopausal women those with the highest IGF-1 concentrations had twice the risk of developing breast cancer of those with the lowest concentrations. For pre-menopausal women under 50 the difference in risk between the highest and lowest concentrations rose to 4.5 times and, when the presence of a binding protein IGFBP-3 was taken into account, the difference in risk rose to 7.3 times.
Dr Susan Hankinson and colleagues at the Brigham and Women's hospital in Boston, in the US, said a blood test to measure IGF-1 concentrations could be a way of providing women with an early warning that they should attend for regular breast screening or be given prophylactic treatment. A large US study of tamoxifen given to pre-menopausal women was stopped last month after early results showed it reduced the incidence of breast cancer in high-risk women by 45 per cent.
Professor Jeff Holly, of the University Division of Surgery at Bristol Royal Infirmary, said tamoxifen was known to lower the the level of IGF- 1 and this could explain how it prevented breast cancer. Levels of IGF- 1 are determined by nutrition and set early in life - a high-protein, high-energy diet increases the levels and therefore the risk of cancer - so changes in diet to include more carbohydrate and fruit and vegetables could help prevent the disease.
Eight cancer patients have been recalled to hospital after a computer fault led to the administration of lower levels of potentially life-saving chemotherapy treatment than should have been used, it emerged today.
A total of 670 kidney function tests carried out at London's Middlesex Hospital have had to be recalculated for a range of medical conditions and the correct results forwarded to the relevant consultant doctors, an inquiry report has revealed.
Hospital investigators found a set-up fault in a computer which resulted in an under-estimation of 10 to 20 per cent in kidney-function tests.
Although the hospital has stressed that treatment in the vast majority of cases was unaffected by the computer error, doctors dealing with eight cancer patients said they would have adjusted the levels of chemotherapy drug treatment if they had been given the correct test results.
Dr Tony Goldstone, medical director of UCL Hospitals, said it was impossible to determine whether this may have any effect on the outcome of treatment.
A helpline (0808 100 1486) has also been set up for any patients who believe they were tested for kidney function at the Hospital between July and December 1997 but have not been contacted.Reuse content