What is the adequacy of biopsies for prostate sampling?

To investigate the adequacy of the samples obtained by prostate biopsies and the factors those could affect this adequacy.

Three hundred seventy-eight patients who underwent transrectal ultrasound guided biopsy have been included into the study. The biopsy samples have been retrospectively reviewed in terms of presence of prostatic glandular elements and prostatic tissue. Factors which may affect the presence of glandular elements have been investigated.

The mean age, PSA level, and prostate volume were 65 ± 8.1 years, 13.6 ± 17.8 ng/ml, and 52.5 ± 29.8 ml, respectively. Overall cancer detection rate was 25.3%. The highest incidence of absence of prostatic glandular elements was detected at apical (21.8%) and far lateral (21.5%) biopsy samples. The overall rate of absence of glandular elements was 0.16. Absence of glandular elements in at least 1 sample of the biopsy set was detected in 50% of patients. This figure was 27.8% and 16.1% for the absence of glands in at least 3 and 5 samples of the biopsy set, respectively. These results have also been found to be operator-dependent. For patients with PSA between 4 and 10 ng/ml, we found that cancer detection rate was lower in patients with absence of glandular elements. When the possible factors were analyzed, age, PSA, prostate volume, findings of prostate examination, and presence of cancer were not found to be effective on these parameters, whereas the most important factor was the biopsy localization.

Our study showed that prostatic glandular elements, which are keys for histological diagnosis, were absent in a significant number of prostatic biopsy samples and patients. This inadequacy was most prominent in apical and far lateral biopsy specimens and found to be operator-dependent.