It is a fact that the current standard-practice TRUS biopsy can be negative in up to one third of men who actually have cancer. This is because it misses large areas of the prostate such as the ends of the prostate as well as areas high up in the prostate (known as ‘under sampling’). Over half of men have more areas of cancer than detected by TRUS biopsy.
TRUS biopsy can give incorrect information about how aggressive the prostate cancer is. 1 in 4 men actually have a more aggressive cancer than originally detected on TRUS biopsy. This is because they can miss cancers or not sample the tumour properly (at its centre) but only just skim the edge of it. Higher risk areas in the tumour can be missed and the size of the tumour can be underestimated. Template biopsies have been shown to be accurate at finding important cancer with an accuracy of 95%. This is because the whole gland is sampled in a systematic and careful way.