Prediction of pathological outcomes for a single microfocal (≤3 mm) Gleason 6 prostate cancer detected via contemporary multicore (≥12) biopsy in men with prostate‐specific antigen ≤10 ng/mL
Authors: Hong Sung Kyu , Na Woong , Park Jung Min , Byun Seok‐Soo , Oh Jong Jin , Nam Jung Soo , Jeong Chang Wook , Choe Gheeyoung , Lee Hak Jong , Hwang Sung Il , Lee Sang Eun 
Published: December 2010

Study Type – Diagnostic (exploratory cohort)

Level of Evidence 2b

What’s known on the subject? and What does the study add?

It has been reported that patients with Gleason 6 prostate cancer detected in a single microfocal positive core may actually harbour more aggressive disease. Meanwhile, several studies analyzing cases of single microfocal prostate cancer included a significant number of patients with serum PSA ≥ 10 ng/mL. Also, significant proportions of currently available published data on actual pathological characteristics of prostate cancer with favourable biopsy features were obtained from patients who underwent prostate biopsies performed in non‐systematic fashion at different institutions and/or via non‐contemporary scheme, such as sextant biopsy.

Although PSA density can be considered an independent predictor of pathologically insignificant tumour among the patients with PSA ≤ 10 ng/mL and only a single microfocal tumour detected via multi (≥12)‐core biopsy, clinical and biopsy‐related parameters currently available have limited value in predicting pathologically insignificant or unfavourable prostate cancer in such patients.

OBJECTIVE

• To examine potential predictors of pathological outcomes for a single microfocal (≤3 mm) positive prostate cancer detected via contemporary biopsy scheme in patients presenting with prostate‐specific antigen (PSA) ≤10 ng/mL.

PATIENTS AND METHODS

• We reviewed the data of 119 patients who had prebiopsy PSA ≤ 10 ng/mL and a single microfocal (≤3 mm) Gleason ≤6 prostate cancer identified via multicore (≥12) biopsy and who subsequently underwent radical prostatectomy (RP).

• We assessed the rates of insignificant prostate cancer (organ‐confined and pathological Gleason ≤6 with tumour volume <0.5 mL) and unfavourable prostate cancer (upstaging and/or upgrading) by analysing pathological findings.

• Potential preoperative predictors of insignificant or unfavourable prostate cancer were analysed. Multivariable models for predicting insignificant and unfavourable tumours were devised and evaluated.

RESULTS

• Overall rates of insignificant and unfavourable prostate cancer were 44.5% and 24.4%, respectively. In multivariate analysis, only PSA density was an independent predictor of insignificant prostate cancer.

• Predictive accuracies of multivariable models for predicting insignificant prostate cancer did not exceed 68.2%. No significant predictor for pathologically unfavourable tumour was found in multivariate analysis.

• All versions of the multivariable model devised for prediction of unfavourable tumour showed predictive accuracies ≤66.9%.

CONCLUSION

• Although PSA density can be considered an independent predictor of pathologically insignificant tumour among patients with PSA ≤10 ng/mL and only a single microfocal tumour detected via multicore (≥12) biopsy, the clinical and biopsy‐related parameters that are currently available have limited value in predicting pathologically insignificant or unfavourable prostate cancer in such patients.