May 2 2006
In the era before extended biopsy schemes, patients with prostate biopsy results showing high grade prostatic intraepithelial neoplasia were recommended for re-biopsy in 3 to 6 months.
Data from contemporary series performing more than 6 transrectal biopsies have suggested that immediate re-biopsy may not be necessary in patients with HGPIN due to its increased sensitivity.
In the March issue of the Journal of Urology, Epstein and Herawi from Johns Hopkins present a review of the available literature on the subsequent risk of prostate cancer in patients with HGPIN or atypical foci suspicious for cancer. The authors make the following statements and recommendations regarding HGPIN:
- Low grade PIN should not appear on pathology reports due to the significant interobserver variability in its diagnosis.
- The incidence of HGPIN on a biopsy ranges between 5 and 8%,
- In a patient diagnosed with HGPIN using an extended biopsy scheme, the risk of a subsequent positive biopsy is approximately 24%, not significantly higher than other patients without HGPIN who undergo re-biopsy.
- No clinical or pathological characteristics reliably predict a subsequent positive biopsy in patients with HGGPIN.
- Based on these data, re-biopsy of all patients with HGPIN in the first year after the diagnosis is not warranted. The indication and timing of a repeat biopsy after the first year of a HGPIN diagnosis remains controversial.
Based on their review of the literature, however, recommendations were different for patients with a diagnosis of atypical gland suspicious for carcinoma:
- This finding is diagnosed in approximately 5% of patients who undergo prostate biopsy, with the risk of a subsequent positive biopsy approaching 40%.
- Differentiating atypical glands from carcinoma may be challenging even if staining tools such as basal cell markers or AMACR (alpha-methyl-acyl-coenzyme A racemase) are used. Contrary to patients with HGPIN, biopsies read as atypical-suspicious have the highest likelihood of being changed upon expert review. Urologists should consider consultation with a urologic pathologist in such cases.
- Site-specific labeling of prostate biopsies proves useful to obtain additional cores at the site of the atypical diagnosis at the time of re-biopsy.
- Patients with an atypical diagnosis should undergo repeat biopsies 3-6 months after the initial diagnosis.
Dr. Epstein should be congratulated for providing an expert, distilled summary of such a common problem in urologic oncology.
Reference:
J Urol. 2006 Mar;175(3 Pt 1):820-34.
http://www.ncbi.nlm.nih.gov/entrez/
Epstein JI,
Herawi M.
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