17 May 2009
ByAppeared in BioNews 508
Screening the genetic material present in patients' urine could distinguish between aggressive from dormant prostate cancers, suggests a study published this month in the British Journal of Cancer. The research paper reports pilot findings from 11 prostate cancer patients and may provide new hope for the 34,000 men who are diagnosed with the disease each year. Differentiating between aggressive and dormant forms of prostate cancer is important since treatment is invasive and can leave men with long-term side effects, including incontinence and impotence. Conversely, dormant forms can be left untreated as they often do not progress.
The main method for distinguishing aggressive tumours currently is based upon detecting levels of protein in the urine. However, this method leads to false positives (classifying aggressive cancer as present when it is not) because other prostate conditions can cause excretion of the same proteins.
The new approach, led by Dr Jonas Nilsson from Umea University, Sweden, takes a step further back along the process and looks at the RNA which produces these proteins in the first place. RNA is the molecule responsible for 'reading' the DNA code that makes up a gene, enabling the cell to make whichever proteins have been copied into RNA. The team showed that aggressive and dormant cancers showed differing RNA patterns, reflecting different gene activity. The results from this pilot study suggest that genetic information inside fatty deposits excreted in urine can be used for tumour detection and discovery of biomarkers of prostate cancer.
Dr Lesley Walker, director of cancer information at Cancer Research UK, said, 'This technique is a fresh view on an old problem and could really help scientists find that elusive biomarker. It's still unclear what the best treatment approach is for early prostate cancer, so it's important we find answers to this as soon as possible. Distinguishing the aggressive tumours that must be treated from those that don't need treatment will go a long way towards resolving this issue'.