Gene test may show if cancer will respond to chemotherapy

Thousands of cancer patients could be saved from unnecessary and distressing treatment by a new test that identifies those most likely to respond to chemotherapy.

About half of breast cancer patients who undergo chemotherapy obtain no benefit but suffer side effects. The treatment involves giving toxic doses of drugs to the patient but at present there is no way of telling which women will respond.

Chemotherapy is designed to shrink tumours before surgery and tumours that show shrinkage of more than 75 per cent are described as "sensitive" while those showing shrinkage of less than 75 per cent are described as "resistant".

By establishing if a patient has a sensitive tumour the NHS could save millions of pounds since the most frequently used drug docetaxel (Taxotere) costs £1,500 for a course of treatment and patients may need up to six courses. The remaining women whose tumours are resistant would also be spared unnecessary suffering.

Some 40,000 women are diagnosed with breast cancer in the UK each year, of whom about a third undergo chemotherapy. In the new study, researchers from Baylor College of Medicine in Texas studied gene expression profiles - the activity levels of certain genes - linked with responses to the therapy.

They took samples of tissue from the breasts of 24 women aged from 36 to 63 with a first occurrence of breast cancer. The tumours ranged in size from 4cm to 23cm. The women were then treated with a course of docetaxel to shrink their tumours before surgery.

Following treatment, the researchers found that of the 24 tumours, 11 (46 per cent) were sensitive and 13 (54 per cent) were "resistant".

The researchers, led by Dr Jenny Chang, found that sensitive tumours had higher expression in genes involved in the cell cycle and protein modification. The findings are published in The Lancet.

Dr Chang said: "When validated, this type of molecular profiling could have important implications in defining the optimum treatment for individual patients."

Michelle Barclay, of Breakthrough Breast Cancer, said: "We hope that one day tailor-made therapy can be available for each breast cancer patient based on their genetic make-up."