Protein loss could hold key to death rates among patients

THE loss of a cell repair protein in large numbers of women battling breast or ovarian cancer could explain why they die early, research in Yorkshire suggests.

Scientists at Leeds University found the loss of the protein MCPH1 in cancer cells correlated with significant numbers of women who undergo surgery and chemotherapy to kill residual cancer cells but die early because of resistance to treatments.

The protein helps cells to repair DNA damage and influences the function of two key genes, certain variations of which are linked with an increased risk of the cancers.

The scientists, funded by the charities Yorkshire Cancer Research and the Breast Cancer Campaign, found that 29 per cent of 319 breast cancer sufferers and 19 per cent of 47 women with ovarian cancer who underwent treatment were deficient in the protein. This was the case particularly in those with fast-developing ovarian cancer and those resistant to chemotherapy.

Sandra Bell, of the Leeds Institute of Molecular Medicine, said: "This is an exciting discovery. We have found that the reduced levels of MCPH1 in these breast and ovarian cancer patients are associated with increasing tumour grade and poor survival."

She said the protein also regulated resistance to two chemotherapy drugs so the fact it was not in patients' cancer cells opened a new therapeutic window.

"Yorkshire Cancer Research is now funding the use of a new technology to rapidly identify molecules which selectively kill cancer cells which have lost the MCPH1 protein but do not kill cells which contain it," she added.

"The identification of these molecules should allow new chemotherapy drugs to be developed that are tailored for women with breast and ovarian cancers who are dying earlier than expected because they are resistant to current chemotherapies."