Systematic lateral prostate biopsy--are the benefits worth the costs?

We quantified the additional benefit of routinely adding 4 lateral biopsies to the initial sextant and transrectal ultrasound lesion targeted biopsy pattern in terms of cancer detection. We related this to costs.

Prospective data were accrued on 1,010 consecutive patients referred for initial transrectal ultrasound directed prostate biopsy between June 16, 2000 and September 1, 2005. Costs were estimated for the pathology and clinical departments in terms of staff time.

Of 1,010 patients 494 (48.9%) were diagnosed with prostate adenocarcinoma. In these cases 411 cancers (83%) were found in medial samples, including 107 (22%) isolated to medial cores alone and 304 (62%) in medial and lateral cores. Only 55 patients (5.4%) had cancer isolated to systematic lateral cores. Of these cancers 30 (3%) were defined as clinically significant based on Gleason grade 7 or greater, or Gleason grade 6 involving more than 5% of any core. There was a 24% increase in biopsy related costs and a 36% increase in pathology costs associated with the 4 additional lateral biopsies.

Medial sextant and targeted biopsy directed at transrectal ultrasound identified lesions detects 94.6% of the prostate cancer that is detected with a 10 core biopsy protocol. The latter detects an extra 3% of clinically significant prostate cancer, while increasing costs by 30%. It is important to consider the absolute benefits of systematic lateral prostate biopsy in light of this additional expense when selecting an appropriate transrectal ultrasound biopsy regimen for a patient suspected of harboring prostate cancer.