By counting the number of cancerous tumour cells in the blood, scientists could accurately predict survival and which patients would respond to treatments, according to an article in the journal Lancet Oncology.
The test could be used in combinations with current methods to help judge the efficacy of new drugs as they go through clinical trials.
Prostate cancer is the most common form of cancer in men in the UK with more than 34,000 new diagnoses each year. Over the last 30 years rates of prostate cancer have almost tripled and this is thought to be due to better detection of the disease although recent research has linked it to increased use of cannabis.
Professor Howard Scher, from the Memorial Sloan Kettering Cancer Centre, New York City, USA and colleagues assessed the association between circulating tumour cells number, before and after treatment, and subsequent survival in 164 patients.
The researchers found that, before treatment, high values of circulating tumour cells number and prostate-specific antigen, used at the current test, were associated with increased risk of death.
Changes in the levels of circulating tumour cells was more predictive of response to treatment than the level of prostate-specific antigen, the authors said.
