Giving women with certain breast cancers the drug Herceptin improves survival rates two years on, a study reports today. Previous research has shown that Herceptin stops breast cancers returning for the 15-25% of women who have a type of early breast cancer called HER2-receptor positive. But this is the first time a reduction in the number of deaths has been recorded.
The drug has been hailed as a "miracle" treatment for women who can use it and is available on the NHS at the cost of £20,000 a year after the National Institute for Clinical Excellence fast-tracked approval.
But the Herceptin Adjuvant (HERA) study, reporting in today's Lancet, also found further evidence that the drug can cause cardiac damage in some women. Two out of every 100 women who take the drug will experience heart damage, some severely, though the damage is not fatal after two years. Doctors do not yet know whether the damage is permanent.
Ian Smith, lead researcher, of the Royal Marsden hospital, said: "Our results indicate that trastuzumab [Herceptin] shows a significant overall survival benefit in early breast cancer over observation alone after chemotherapy ... The survival benefit that has emerged over such a short period emphasises the potential of this approach and underlines the importance of developing further specific targeted therapies in breast and other cancers."
During the trial, 1,703 women were randomised to receive Herceptin one year after surgery and chemotherapy and 1,698 women were assigned to the control group, for observation alone after chemotherapy.
The researchers report that after two years 59 women on Herceptin had died, compared with 90 in the control group.
Though the study is only two years old, Dr Smith said he expected the benefit of the drug to be much higher over time. But he conceded that the researchers had no evidence whether Herceptin might store up other problems for the future.
"Time will tell as to whether there are any other long-term side-effects, but the trials so far haven't found any problems other than the cardiac damage," Dr Smith said.
Pamela Goldberg, the Breast Cancer Campaign's chief executive, said the trial results "show that using Herceptin significantly improves overall survival rates, further confirming its effectiveness".
Maria Leadbeater, a breast cancer nurse specialist at Breast Cancer Care, said: "Clearly there remains the need for further research into the long-term effects of Herceptin, which will enable us to establish the ideal duration of treatment along with a more thorough understanding of its side-effects."
