Controversial drug Herceptin may still help women who have almost lost the battle with breast cancer, according to a study.
Adding Herceptin to conventional chemotherapy delays progression of the cancer by nearly three months compared with chemotherapy alone - an improvement of 46%, a study has shown.
Survival is extended from 20.4 months to 25.5 months on average. However, this result is not statistically significant.
Herceptin - the antibody drug trastuzumab - is only effective in women with the HER-2 gene, who account for about 20% of breast cancer patients.
In 2006, the NHS watchdog the National Institute for Health and Clinical Excellence (NICE) backed the use of Herceptin in early stage patients after coming under enormous pressure to make the drug more accessible.
But many doctors and health experts have questioned whether the NHS can afford the drug, which costs £20,000 per patient per year.
The new research, presented at the annual meeting of the American Society for Clinical Oncology in Chicago, suggests that women on Herceptin benefit from continuing with the drug after their disease stops responding to traditional chemotherapy.
Dr Rob Stein, consultant oncologist at University College London Hospitals, said: "It is important for patients and clinicians to know that trastuzumab keeps working in women whose aggressive HER 2-positive breast cancer comes back."