Thursday, January 10, 2013

'Drug holidays' beat cancer drug resistance in mice

Introducing medication-free spells to some cancer treatments may keep patients alive for longer, studies in mice with skin cancer suggest.

The animals had melanoma, which can rapidly become resistant to treatments.

However, a study in the journal Nature showed tumours also became dependent on the drug to survive. Withdrawing treatment caused tumours to shrink.

Experts said the findings were exciting, but still needed testing in people.

The tumours gain resistance by changing the chemistry of the inside of a cell. However, the researchers showed this process left the cancer cells dependent on the drug - like an addict.

When the mice were no longer given the drug, the tumours began to shrink.

The scientists used this knowledge to test a new way of prescribing the medication. Instead of giving the drug every day, the mice were given drugs for four weeks and then had a two week "drug holiday" before starting the pattern over again.

Efim Guzik, professor of cancer biology at University of California, San Francisco, said: "Remarkably, intermittent dosing with vemurafenib prolonged the lives of mice with drug-resistant melanoma tumours.

Whether the same effect would be seen in people given the same medication is uncertain.

Prof Mark Middleton, director of Cancer Research UK's Experimental Cancer Medicine Centre in Oxford, said: "We still need to test the idea in the clinic, but these results suggest a way in which this important new treatment might be able to increase the benefit to patients and their families.

Prof Marais said the same effect is possible in other forms of targeted cancer drug treatment.

Source: http://www.bbc.co.uk/news/health-20956179

No comments: