Breast cancer drug combination could stop cancer “in its tracks”

By Dr. Ananya Mandal, MDSep 26 2011

The results of a new study revealed that treatment for women with HER2-positive breast cancer – an aggressive form of the disease which is diagnosed in 10,000 British women each year – slowed the progression of tumors by 40 per cent compared with conventional drugs. Tests on 137 women showed that the new therapy – called T-DM1 – which combines the drug Herceptin with an antibody drug, instead of with standard chemotherapy, appeared to stop the cancer “in its tracks”.

Patients who were given the new treatment lived for 14 months without their cancer getting worse, compared with nine months for those on normal chemotherapy. It also resulted in fewer patients suffering dangerous side-effects compared with standard treatments, doctors said.

Presenting their results at the European Multidisciplinary Cancer Congress conference in Stockholm, researchers said results from more trials were needed before the drug could be considered as a viable treatment.

Prof Paul Ellis, of Guy's Hospital in London said, “This is an incredible drug. We've been looking for something like this for 20 years and it is the first of its kind. A drug like this which increases survival with far less side effects is the holy grail of cancer medicine.” The drug consists of a protein which seeks out tumors and a toxin which is only released once inside cancer cells, reducing the damage to healthy tissue.

Trials were carried out at hospitals across the world including three in the UK: the Christis Hospital in Manchester, the Freeman Hospital in Newcastle-upon-Tyne and the Royal Bournemouth General Hospital.

Experts are currently carrying out a further clinical trial on at least 1,000 women in more than 20 countries, including Britain, and results are expected within two years.

Nell Barrie of Cancer Research UK said, “This approach combines two effective treatments but until we have results from larger, longer term trials we won't know for sure how beneficial this could be for patients with this particular type of breast cancer.”

Dr Rachel Greig of the Breakthrough Breast Cancer charity said, “This new drug may keep cancer at bay for longer than standard treatments with fewer side effects which crucially could offer patients a better quality of life. It’s important to emphasize this drug is still in trials and some years away from potentially being made available on the NHS.”

Around 10,000 women in Britain are diagnosed with HER2-positive cancer each year, making up around 20 to 30 per cent of all breast cancer cases. The diagnosis means women have been found to have large quantities of a protein known as HER2 on the surface of the tumor cells, which makes the disease more aggressive. In recent years, Herceptin, which targets this protein, had been hailed as the best solution for such women. The new trial appears to show that the addition of the antibody DM1 prevents the cell division which spreads cancer. The combination drug is not yet licensed, and could take three to five years to be available.