Study: chemo has better outcomes in low doses
Managing cancer with low doses of chemotherapy could be more effective than attempting to kill the disease, scientists believe.
The controversial approach suggests that cancer patients may have a better chance of survival if they live with their illness long-term.
Current cancer treatments often involve aggressive treatment with high doses of chemotherapy in an attempt to wipe out as many tumour cells as possible.
But complete eradication of cancer is rare, and the toxic side-effects of chemotherapy can be highly destructive - not only leading to hair loss, nausea and extreme fatigue, but also crippling the body's immune system or triggering anaemia.
Some experts believe high-dose chemotherapy may actually worsen cancer by exerting a natural selection pressure that helps drug-resistant tumour cells to become more abundant, which means if cancer returns it will be fatal.
The new strategy is designed to prevent drug-resistant tumour cells getting the upper hand. Rather than trying to eradicate a tumour, the treatment stabilises it by deliberately allowing a small population of drug-sensitive tumour cells to survive.
A team of US scientists led by Dr Robert Gatenby, from the H Lee Moffitt Cancer Centre and Research Institute in Tampa, Florida, conducted tests using paclitaxel, a chemotherapy drug, to treat mice with two different kinds of breast cancer.
Standard chemotherapy initially shrank the mouse tumours, but as soon as the treatment stopped they grew back. However, giving an initial high dose followed by regular lower doses controlled cancer growth.
In fact the treatment was so effective that the majority of the mice were weaned off the drug completely over an extended period of time without suffering relapses.
Writing in the journal 'Science Translational Medicine', Dr Gatenby said: "Our results suggest that this adaptive therapeutic strategy can be adapted to clinical imaging and can result in prolonged progression-free survival in breast cancer.
"Finally, we note that the evolutionary principles that govern AT may be applicable to a wide range of breast cancer treatments including hormonal manipulation and immunotherapy, although they will need to undergo further testing in those settings."
Rachel Rawson, senior clinical nurse specialist from the charity Breast Cancer Care, said the proposed treatment was "an exciting avenue to explore".
"The potential to reduce gruelling side-effects of chemotherapy, while increasing the treatment's effectiveness, could dramatically improve the lives of people with breast cancer. This is an exciting avenue to explore," she added.
"Chemotherapy can mean women live with debilitating sickness, fatigue and extremely distressing hair loss for many months, making every day a challenge.
"However, there remains a long road from this study on mice to any potential changes in clinical practice," she said.
"And we want to reassure anyone concerned, the treatment currently out there has been successfully trialled on thousands of patients." (© Daily Telegraph London)