The Percentage of Core Involved by Cancer Is the Best Predictor of Insignificant Prostate Cancer, According to an Updated Definition (Tumor Volume up to 2.5 cm3): Analysis of a Cohort of 210 Consecutive Patients With Low-risk Disease

High-volume prostate biopsy core involvement is not associated with an increased risk of cancer recurrence following 5-fraction stereotactic body radiation therapy monotherapy

PURPOSE

Percentage of positive cores involved on a systemic prostate biopsy has been established as a risk factor for adverse oncologic outcomes and is a National Comprehensive Cancer Network (NCCN) independent parameter for unfavorable intermediate-risk disease. Most data from a radiation standpoint was published in an era of conventional fractionation. We explore whether the higher biological dose delivered with SBRT can mitigate this risk factor.

METHODS

A large single institutional database was interrogated to identify all patients diagnosed with localized prostate cancer (PCa) treated with 5-fraction SBRT without ADT. Pathology results were reviewed to determine detailed core involvement as well as Gleason score (GS). High-volume biopsy core involvement was defined as ≥ 50%. Weighted Gleason core involvement was reviewed, giving higher weight to higher-grade cancer. The PSA kinetics and oncologic outcomes were analyzed for association with core involvement.

RESULTS

From 2009 to 2018, 1590 patients were identified who underwent SBRT for localized PCa. High-volume core involvement was a relatively rare event observed in 19% of our cohort, which was observed more in patients with small prostates (p < 0.0001) and/or intermediate-risk disease (p = 0.005). Higher PSA nadir was observed in those patients with low-volume core involvement within the intermediate-risk cohort (p = 0.004), which was confirmed when core involvement was analyzed as a continuous variable weighted by Gleason score (p = 0.049). High-volume core involvement was not associated with biochemical progression (p = 0.234).

CONCLUSIONS

With a median follow-up of over 4 years, biochemical progression was not associated with pretreatment high-volume core involvement for patients treated with 5-fraction SBRT alone. In the era of prostate SBRT and MRI-directed prostate biopsies, the use of high-volume core involvement as an independent predictor of unfavorable intermediate risk disease should be revisited.

Development and internal validation of a novel nomogram for predicting lymph node invasion for prostate cancer patients undergoing extended pelvic lymph node dissection

Background

Few studies have focused on the performance of Briganti 2012, Briganti 2017 and MSKCC nomograms in the Chinese population in assessing the risk of lymph node invasion(LNI) in prostate cancer(PCa) patients and identifying patients suitable for extended pelvic lymph node dissection(ePLND). We aimed to develop and validate a novel nomogram based on Chinese PCa patients treated with radical prostatectomy(RP) and ePLND for predicting LNI.

Methods

We retrospectively retrieved clinical data of 631 patients with localized PCa receiving RP and ePLND at a Chinese single tertiary referral center. All patients had detailed biopsy information from experienced uropathologist. Multivariate logistic-regression analyses were performed to identify independent factors associated with LNI. The discrimination accuracy and net-benefit of models were quantified using the area under curve(AUC) and Decision curve analysis(DCA).The nonparametric bootstrapping were used to internal validation.

Results

A total of 194(30.7%) patients had LNI. The median number of removed lymph nodes was 13(range, 11-18). In univariable analysis, preoperative prostate-specific antigen(PSA), clinical stage, biopsy Gleason grade group, maximum percentage of single core involvement with highest-grade PCa, percentage of positive cores, percentage of positive cores with highest-grade PCa and percentage of cores with clinically significant cancer on systematic biopsy differed significantly. The multivariable model that included preoperative PSA, clinical stage, biopsy Gleason grade group, maximum percentage of single core involvement with highest-grade PCa and percentage of cores with clinically significant cancer on systematic biopsy represented the basis for the novel nomogram. Based on a 12% cutoff, our results showed that 189(30%) patients could have avoided ePLND while only 9(4.8%) had LNI missing ePLND. Our proposed model achieved the highest AUC (proposed model vs Briganti 2012 vs Briganti 2017 vs MSKCC model: 0.83 vs 0.8 vs 0.8 vs 0.8, respectively) and highest net-benefit via DCA in the Chinese cohort compared with previous nomograms. In internal validation of proposed nomogram, all variables had a percent inclusion greater than 50%.

Conclusion

We developed and validated a nomogram predicting the risk of LNI based on Chinese PCa patients, which demonstrated superior performance compared with previous nomograms.

Preoperative endogenous total testosterone predicts prostate cancer progression: results in 580 consecutive patients treated with robot assisted radical prostatectomy for clinically localized disease

PURPOSE

To test the role of endogenous total testosterone (ETT) as a predictor of prostate cancer (PCa) progression in patients treated with robot assisted radical prostatectomy for clinically localized disease.

METHODS

Between November 2014 and December 2019, 580 consecutive patients were evaluated. Preoperative ETT levels were classified as ≤ 350 ng/dL vs. > 350 ng/dL. The associations between ETT levels and the risk of PCa progression, defined as any event of biochemical recurrence and/or local recurrence and/or distant metastases, or other clinical and pathological factors were evaluated by regression analyses.

RESULTS

Preoperative ETT levels resulted ≤ 350 ng/dL in 173 (29.8%) patients. Disease progression occurred in 101 (17.1%) cases. Progressing patients were more likely to present with PSA levels > 10 ng/mL, as well as with unfavorable tumor grade (ISUP 4-5) and stage (pT3b) at final pathology, but less likely to have ETT levels ≤ 350 ng/mL. On clinical multivariable Cox regression models, ETT ≤ 350 ng/mL exhibited a statistically significant protective effect on tumor progression (hazard ratio: 0.57, p = 0.013). Subjects presenting with ETT levels ≤ 350 ng/mL were less likely to harbor ISUP 4-5 tumor grade either at biopsy (odds ratio [OR]: 0.46, p = 0.028) or final pathology (OR: 0.45, p = 0.032).

CONCLUSIONS

At PCa diagnosis, ETT, which associates with ISUP tumor grade, is an independent predictor of disease progression. Accordingly, as ETT decreases to levels ≤ 350 ng/dL, the risk of unfavorable tumor grade decreases, and a more favorable prognosis is expected. Preoperative ETT levels may allow further patient stratification along prognostic risk groups.

Preoperative endogenous testosterone density predicts disease progression from localized impalpable prostate cancer presenting with PSA levels elevated up to 10 ng/mL

OBJECTIVE

To investigate endogenous testosterone density (ETD) predicting disease progression from clinically localized impalpable prostate cancer (PCa) presenting with prostate-specific antigen (PSA) levels elevated up to 10 ng/mL and treated with radical prostatectomy.

MATERIALS AND METHODS

In a period ranging from November 2014 to December 2019, 805 consecutive PCa patients who were not under androgen blockade had endogenous testosterone (ET, ng/dL) measured before surgery. ETD was evaluated as the ratio of ET on prostate volume (PV). Unfavorable disease was defined as including ISUP ≥ 3 and/or seminal vesicle invasion in the surgical specimen. The risk of disease progression was evaluated by statistical methods.

RESULTS

Overall, the study selected 433 patients, of whom 353 (81.5%) had available follow-up. Unfavorable disease occurred in 46.7% of cases and was predicted by tumor quantitation features that were positively associated with ETD. Disease progression, which occurred for 46 (13%) cases, was independently predicted only by ETD (hazard ratio, HR = 1.037; 95% CI 1.004-1.072; p = 0.030) after adjusting for unfavorable disease. According to a multivariate model, ETD above the third quartile was confirmed to be an independent predictor for PCa progression (HR = 2.479; 95% CI 1.355-4.534; p = 0.003) after adjusting for unfavorable disease. The same ETD measurements, ET mean levels were significantly lower in progressing cancers.

CONCLUSIONS

In this particular subset of patients, increased ETD with low ET levels, indicating androgen independence, resulted in a more aggressive disease with poorer prognosis.

Tumor Location and a Tumor Volume over 2.8 cc Predict the Prognosis for Japanese Localized Prostate Cancer

(1) Objective: Our study investigated the prognostic value of tumor volume and location in prostate cancer patients who received radical prostatectomy (RP). (2) Methods: The prognostic significance of tumor volume and location, together with other clinical factors, was studied using 557 patients who received RP. (3) Results: The receiver operating characteristic (ROC) curve identified the optimal cutoff value of tumor volume as 2.8 cc for predicting biochemical recurrence (BCR). Cox regression analysis revealed that a tumor in the posterior area (p = 0.031), peripheral zone (p = 0.0472), and tumor volume ≥ 2.8 cc (p < 0.0001) were predictive factors in univariate analysis. After multivariate analysis, tumor volume ≥ 2.8 cc (p = 0.0225) was an independent predictive factor for BCR. Among them, a novel risk model was established using tumor volume and location in the posterior area and peripheral zone. The progression-free survival (PFS) of patients who met the three criteria (unfavorable group) was significantly worse than other groups (p ≤ 0.001). Furthermore, multivariate analysis showed that the unfavorable risk was an independent prognostic factor for BCR. The prognostic significance of our risk model was observed in low- to intermediate-risk patients, although it was not observed in high-risk patients. (4) Conclusion: Tumor volume (≥2.8 cc) and localization (posterior/peripheral zone) may be a novel prognostic factor in patients undergoing RP.

Endogenous testosterone density as ratio of endogenous testosterone levels on prostate volume predicts tumor upgrading in low-risk prostate cancer

OBJECTIVES

To evaluate preoperative endogenous testosterone (ET) density (ETD), defined as the ratio of ET on prostate volume, and tumor upgrading risk in low-risk prostate cancer (PCa).

MATERIALS AND METHODS

From November 2014 to December 2019, 172 low-risk patients had ET (nmol/L) measured. ETD, prostate-specific antigen density (PSAD) and the ratio of percentage of biopsy positive cores (BPC) to prostate volume (PV), defined as BPC density (BPCD), were evaluated. Associations with tumor upgrading in the surgical specimen were assessed by statistical methods.

RESULTS

Overall, 121 patients (70.3%) had tumor upgrading, which was predicted by BPCD (odds ratio, OR = 4.640; 95% CI 1.903-11.316; p = 0.001; overall accuracy: 70.3%). On multivariate analysis, tumor upgrading and clinical density factors related to each other for BPCD being predicted by ETD (regression coefficient, b = 0.032; 95% CI 0.021-0.043; p < 0.0001), PSAD (b = 1.962; 95% CI 1.067-2.586; p < 0.0001) and tumor upgrading (b = 0.259; 95% CI 0.112-0.406; p = 0.001). According to the model, as BPCD increased, ETD and PSAD increased, but the increase was higher for upgraded cases who showed either higher tumor load but significantly lower mean levels of either ET or PSA.

CONCLUSIONS

As ETD increased, higher tumor loads were assessed; however, in upgraded patients, lower ET was also detected. ETD might stratify low-risk disease for tumor upgrading features.

MRI-directed biopsy for primary detection of prostate cancer in a population of 223 men: MRI In-Bore vs MRI-transrectal ultrasound fusion-targeted techniques

Objectives:

To compare the detection rates of overall prostate cancer (PCa) and clinically significant PCa (csPCa) and the median percentage of cancer per biopsy core between MRI-guided In-bore and MRI-TRUS fusion-targeted biopsy (TBx).

Methods:

In this retrospective study, 223 patients who underwent prostate multiparametric MRI (mpMRI) and subsequent MR-directed biopsy were included. For PCa and csPCa detection rate (DR), contingency tables were tested via the Pearson’s chi-squared to explore the variance of the outcome distribution. The percentage of cancer per biopsy core was tested with a two-tailed Mann-Withney test.

Results:

One hundred and seventeen and 106 patients underwent MRI-TRUS fusion or MRI In-bore TBx, respectively. 402 MRI biopsy targets were identified, of which 206 (51.2%) were biopsied with the MRI-TRUS TBx and 196 (48.8%) with the MRI In-bore TBx technique. Per-patient PCa and csPCa detection rates were 140/223 (62.8%) and 97/223 (43.5%), respectively. PCa-DR was 73/117 (62.4%) and 67/106 (63.2%) for MRI-TRUS and MRI In-Bore TBx (p = 0.9), while csPCa detection rate reached 50/117 (42.7%) and 47/106 (44.3%), respectively (p = 0.81). The median per-patient percentage of malignant tissue within biopsy cores was 50% (IQR: 27–65%) for PCa and 60% (IQR: 35–68%) for csPCa, with a statistically significant difference between the techniques.

Conclusion

No statistically significant difference in the detection rate of MRI In-bore and MRI-TRUS fusion TBx was found. MRI In-bore TBx showed higher per-core percentage of malignant cells.

Advances in knowledge

MRI In-bore biopsy might impact risk stratification and patient management considering the higher per-core percentage of malignant cells, especially for patients eligible for active surveillance or focal therapy.

External validation of Cormio nomogram for predicting all prostate cancers and clinically significant prostate cancers

PURPOSE

Recently, the Cormio et al. nomogram has been developed to predict prostate cancer (PCa) and clinically significant PCa using benign prostatic obstruction parameters. The aim of the present study was to externally validate the nomogram in a multicentric cohort.

METHODS

Between 2013 and 2019, patients scheduled for ultrasound-guided prostate biopsy were prospectively enrolled at 11 Italian institutions. Demographic, clinical and histological data were collected and analysed. Discrimination and calibration of Cormio nomogram were assessed with the receiver operator characteristics (ROC) curve and calibration plots. The clinical net benefit of the nomogram was assessed with decision curve analysis. Clinically significant PCa was defined as ISUP grade group > 1.

RESULTS

After accounting for inclusion criteria, 1377 patients were analysed. 816/1377 (59%) had cancer at final pathology (574/816, 70%, clinically significant PCa). Multivariable analysis showed age, prostate volume, DRE and post-voided residual volume as independent predictors of any PCa. Discrimination of the nomogram for cancer was 0.70 on ROC analysis. Calibration of the nomogram was excellent (p = 0.94) and the nomogram presented a net benefit in the 40-80% range of probabilities. Multivariable analysis for predictors of clinically significant PCa found age, PSA, prostate volume and DRE as independent variables. Discrimination of the nomogram was 0.73. Calibration was poor (p = 0.001) and the nomogram presented a net benefit in the 25-75% range of probabilities.

CONCLUSION

We confirmed that the Cormio nomogram can be used to predict the risk of PCa in patients at increased risk. Implementation of the nomogram in clinical practice will better define its role in the patient's counselling before prostate biopsy.

Prostate volume and biopsy tumor length are significant predictors for classical and redefined insignificant cancer on prostatectomy specimens in Japanese men with favorable pathologic features on biopsy

Background

Gleason pattern 3 less often has molecular abnormalities and often behaves indolent. It is controversial whether low grade small foci of prostate cancer (PCa) on biopsy could avoid immediate treatment or not, because substantial cases harbor unfavorable pathologic results on prostatectomy specimens. This study was designed to identify clinical predictors for classical and redefined insignificant cancer on prostatectomy specimens in Japanese men with favorable pathologic features on biopsy.

Methods

Retrospective review of 1040 PCa Japanese patients underwent radical prostatectomy between 2006 and 2013. Of those, 170 patients (16.3%) met the inclusion criteria of clinical stage ≤ cT2a, Gleason score (GS) ≤ 6, up to two positive biopsies, and no more than 50% of cancer involvement in any core. The associations between preoperative data and unfavorable pathologic results of prostatectomy specimens, and oncological outcome were analyzed. The definition of insignificant cancer consisted of pathologic stage ≤ pT2, GS ≤ 6, and an index tumor volume < 0.5 mL (classical) or 1.3 mL (redefined).

Results

Pathologic stage ≥ pT3, upgraded GS, index tumor volume ≥ 0.5 mL, and ≥ 1.3 mL were detected in 25 (14.7%), 77 (45.3%), 83 (48.8%), and 53 patients (31.2%), respectively. Less than half of cases had classical (41.2%) and redefined (47.6%) insignificant cancer. The 5-year recurrence-free survival was 86.8%, and the insignificant cancers essentially did not relapse regardless of the surgical margin status. MRI-estimated prostate volume, tumor length on biopsy, prostate-specific antigen density (PSAD), and findings of magnetic resonance imaging were associated with the presence of classical and redefined insignificant cancer. Large prostate volume and short tumor length on biopsy remained as independent predictors in multivariate analysis.

Conclusions

Favorable features of biopsy often are followed by adverse pathologic findings on prostatectomy specimens despite fulfilling the established criteria. The finding that prostate volume is important does not simply mirror many other studies showing PSAD is important, and the clinical criteria for risk assessment before definitive therapy or active surveillance should incorporate these significant factors other than clinical T-staging or PSAD to minimize under-estimation of cancer in Japanese patients with low-risk PCa.