Researchers at the University of Edinburgh have shown that hormone therapy can extend life in ovarian cancer patients, giving women a new alternative to chemotherapy.

The study, published today in Clinical Cancer Research, has proved for the first time that the targeted use of an anti-oestrogen drug could prolong the life of some patients by up to three years, and delay the use of chemotherapy in others.

Letrozole hormone therapy – already used with great success in the treatment of breast tumours - attacks cancer by turning off its oestrogen supply. But scientists now believe that in those ovarian cancers which are highly sensitive to oestrogen, this blocking mechanism could slow the growth and spread of disease.

The study was funded by Cancer Research UK and involved 44 women with high oestrogen receptor (ER) levels, whose cancer had relapsed after surgery and chemotherapy.

Scientists used a blood-borne tumour marker, CA-125, to track the progress of tumours during hormone treatment. They discovered that one quarter of the women showed no tumour growth after six months of anti-oestrogen therapy, and 33 per cent of the group with the greatest ER values showed a positive response which delayed the use of chemotherapy.

John F. Smyth, Professor of Medical Oncology at the University of Edinburgh, led the research programme.

He said: “This is an important landmark in the research and treatment of ovarian cancer. Despite intense scientific research over the past 20 years, there have been few new leads in our understanding of how this disease operates. But this study suggests that the addition of hormone therapy to our treatment strategy could extend and improve the lives of women with cancer.”

Ovarian cancer is the most commonly fatal of gynaecological cancers, affecting 1 in 48 women. Nearly 7,000 new cases are diagnosed in the UK each year.

Current treatment involves surgery and chemotherapy, but most ovarian cancers return within two years. Until now, further treatment options have been limited to a second course of chemotherapy, with serious implications for quality of life. It is hoped hormone treatment could offer life-extension with negligible side effects.

Dr Simon Langdon, senior lecturer in cancer research at the University of Edinburgh and the lead scientist behind this trial, said: “Ovarian cancer can be a devastating disease, so this new discovery is particularly exciting. We still have a lot to do, but this research has furthered our understanding of the hormone control of ovarian cancer, which could provide less gruelling treatments for cancer patients. It presents new possibilities for tailor-made cancer therapy and demands further investigation.”