Percentage of tumour-positive biopsy cores: an independent predictor of extraprostatic disease

Clinical and pathological parameters predicting extracapsular disease in patients undergoing a radical prostatectomy for clinically localized prostate cancer

To determine the epidemiological, clinical and pathological factors that can potentially predict extracapsular extension of prostate cancer in patients undergoing radical prostatectomy for clinically localized disease. We retrospectively analyzed the medical records of patients who undergone radical prostatectomy from January 2001 until November 2010. Patients age, prostate volume, PSA, PSA density, percent of cancer in prostate biopsy material, presence of cancer in biopsy cores of the right lobe or the left lobe or both lobes, Gleason summary, 1st Gleason pattern and 2nd Gleason pattern were analyzed for their predictive ability. From 187 studied patients, 44 of them (23.5%) had extracapsular disease. Multivariate analyses revealed that smaller prostate volumes and the presence of malignancy in both lobes after prostate biopsy were significant predictors for non-organ confined disease in the total population and in patients with Gleason score ≥ 7. Presence of malignancy in both lobes was the only significant predictive factor in patients with PSA ≤ 10 and in those with Gleason score ≤ 6. Prostate volume and positive cores for malignancy from both lobes after prostate biopsy are preoperative data that can be used for prediction of extracapsular disease. This information can be valuable in cases a nerve sparing radical prostatectomy is planned.

Preoperative characteristics of men with unfavorable high-Gleason prostate cancer at radical prostatectomy

INTRODUCTION

Some men with Gleason sum 8-10 prostate cancer (PC) at RP have favorable outcomes: Biochemical recurrence free (BFS) and prostate cancer-specific survival (CSS) are improved for such men with pT2 or pT3a disease compared with pT3b or N1 disease at radical prostatectomy (RP). We examine biopsy characteristics of men with high-grade PC at RP to better select those who may benefit from surgery.

MATERIALS AND METHODS

A total of 1,174 men from our Institutional Database (1982-2010) had Gleason 8-10 cancer at RP. Their demographic and prostate biopsy characteristics were compared among those with disease defined as favorable (pT2 or pT3a) vs. unfavorable (pT3b or N1). Logistic regression was used to determine predictors of unfavorable disease. Kaplan-Meier analysis was used to determine survival outcomes.

RESULTS

Biopsy data were available for 1,157 men (median cores 12 [2-20]); 779 (66.4%) favorable, 394 (33.6%) unfavorable; 102 (8.7%), 515 (44.1%), and 552 (47.2%) were low, intermediate, and high-risk. For favorable and unfavorable cases, 10-year BFS was 40.0% and 5.7% (P < 0.001) and CSS was 84.9% and 60.3% (P < 0.001). Multivariate logistic regression revealed that PSA ≥ 20 and perineural invasion (PNI) at biopsy increased the likelihood of unfavorable, high-grade disease. Considering PSA ≥ 20 and PNI as adverse features, 23.7%, 40.1%, and 71.4% of patients with none, 1, or 2 adverse features had unfavorable, high-Gleason PC (P < 0.001).

CONCLUSIONS

High-Gleason PC was not uniformly associated with poor outcomes after RP, though men with unfavorable (pT3b/N1) disease fared poorly. Preoperative predictors of high-Gleason, unfavorable disease in a cohort of predominantly intermediate and high-risk patients were PSA ≥ 20 and PNI.

Measurements of cancer extent in a conservatively treated prostate cancer biopsy cohort

The optimal method for measuring cancer extent in prostate biopsy specimens is unknown. Seven hundred forty-four patients diagnosed between 1990 and 1996 with prostate cancer and managed conservatively were identified. The clinical end point was death from prostate cancer. The extent of cancer was measured in terms of number of cancer cores (NCC), percentage of cores with cancer (PCC), total length of cancer (LCC) and percentage length of cancer in the cores (PLC). These were correlated with prostate cancer mortality, in univariate and multivariate analysis including Gleason score and prostate-specific antigen (PSA). All extent of cancer variables were significant predictors of prostate cancer death on univariate analysis: NCC, hazard ration (HR) = 1.15, 95% confidence interval (CI) = 1.04-1.28, P = 0.011; PPC, HR = 1.01, 95% CI = 1.01-1.02, P < 0.0001; LCC, HR = 1.02, 95% CI = 1.01-1.03, P = 0.002; PLC, HR = 1.01, 95% CI = 1.01-1.02, P = 0.0001. In multivariate analysis including Gleason score and baseline PSA, PCC and PLC were both independently significant P = 0.004 and P = 0.012, respectively, and added further information to that provided by PSA and Gleason score, whereas NNC and LCC were no longer significant (P = 0.5 and P = 0.3 respectively). In a final model, including both extent of cancer variables, PCC was the stronger, adding more value than PLC (χ² (1df) = 7.8, P = 0.005, χ² (1df) = 0.5, P = 0.48 respectively). Measurements of disease burden in needle biopsy specimens are significant predictors of prostate-cancer-related death. The percentage of positive cores appeared the strongest predictor and was stronger than percentage length of cancer in the cores.