Evaluating PSA Density as a Predictor of Biochemical Failure after Radical Prostatectomy: Results of a Prospective Study after a Median Follow-Up of 36 Months

High monoamine oxidase a expression predicts poor prognosis for prostate cancer patients

BACKGROUND

Monoamine oxidase A (MAOA) is a mitochondrial enzyme that is involved in prostate tumorigenesis and cancer metastasis. The predictive power of the preoperative clinical and pathological indicators for prostate cancer(PC) remains to be improved. To enrich evidence regarding the value of MAOA as a prognostic biomarker in clinical practice, this study explored the significance of MAOA expression as a prognostic marker for patients with PC after radical prostatectomy-pelvic lymph node dissection (RP-PLND).

METHODS

MAOA expression was analyzed in 50 benign prostate tissues and 115 low-intermediate risk and 163 high-risk PC tissues using tissue immunohistochemistry (IHC). Propensity score matching, survival analysis and COX regression analysis were conducted to investigate the correlation between high MAOA expression and progression free survival (PFS) in PC patients.

RESULTS

MAOA expression was increased in PC patients, especially in those with high risk PC and pathological lymph node (pLN) metastasis. High MAOA expression was significantly associated with PSA recurrence for both low-intermediate risk PC patients (log-rank test: P = 0.02) and high risk PC patients (log-rank test: P = 0.03). Cox regression analysis revealed that high MAOA expression was an adverse prognostic factor for both low-intermediate risk PC patients (hazard ratio [HR] 2.74, 95% confidence interval [CI] 1.26-5.92; P = 0.011) and high risk PC patients (HR 1.73, 95% CI 1.11-2.71; P = 0.016). High MAOA expression was also significantly associated with PSA recurrence in high risk PC patients developed into castration-resistant prostate cancer (CRPC) and were receiving abiraterone therapy (log-rank: P = 0.01).

CONCLUSIONS

MAOA expression correlates with the malignant progression of PC. High MAOA expression may be a poor prognostic marker for patients with PC after RP-PLND. More careful follow up or potential of adjuvant hormonal therapy may be addressed for patients with high MAOA expression.

Re-evaluating the diagnostic efficacy of PSA as a referral test to detect clinically significant prostate cancer in contemporary MRI-based image-guided biopsy pathways

Introduction

Modern image-guided biopsy pathways at diagnostic centres have greatly refined the investigations of men referred with suspected prostate cancer. However, the referral criteria from primary care are still based on historical prostate-specific antigen (PSA) cut-offs and age-referenced thresholds. Here, we tested whether better contemporary pathways and biopsy methods had improved the predictive utility value of PSA referral thresholds.

Methods

PSA referral thresholds, age-referenced ranges and PSA density (PSAd) were assessed for positive predictive value (PPV) in detection of clinically significant prostate cancer (csPCa - histological ⩾ Grade Group 2). Data were analysed from men referred to three diagnostics centres who used multi-parametric magnetic resonance imaging (mpMRI)-guided prostate biopsies for disease characterisation. Findings were validated in a separate multicentre cohort. Results: Data from 2767 men were included in this study. The median age, PSA and PSAd were 66.4 years, 7.3 ng/mL and 0.1 ng/mL2, respectively. Biopsy detected csPCa was found in 38.7%. The overall area under the curve (AUC) for PSA was 0.68 which is similar to historical performance. A PSA threshold of ⩾ 3 ng/mL had a PPV of 40.3%, but this was age dependent (PPV: 24.8%, 32.7% and 56.8% in men 50-59 years, 60-69 years and ⩾ 70 years, respectively). Different PSA cut-offs and age-reference ranges failed to demonstrate better performance. PSAd demonstrated improved AUC (0.78 vs 0.68, p < 0.0001) and improved PPV compared to PSA. A PSAd of ⩾ 0.10 had a PPV of 48.2% and similar negative predictive value (NPV) to PSA ⩾ 3 ng/mL and out-performed PSA age-reference ranges. This improved performance was recapitulated in a separate multi-centre cohort (n = 541).

Conclusion

The introduction of MRI-based image-guided biopsy pathways does not appear to have altered PSA diagnostic test characteristics to positively detect csPCa. We find no added value to PSA age-referenced ranges, while PSAd offers better PPV and the potential for a single clinically useful threshold (⩾0.10) for all age groups.

Level of evidence

IV.

Prostate-Specific Antigen Density: A Measurement to Differentiate Benign Hypertrophy of Prostate from Prostate Carcinoma

Background  Determination of isolated prostate-specific antigen (PSA) in asymptomatic individuals has not demonstrated sufficient sensitivity and specificity to be useful in the routine evaluation of prostate disease. To enhance the accuracy of serum PSA we have used a proportion of serum PSA and prostate volume, which we refer to as prostate-specific antigen density (PSAD). Prostate volume in this study was calculated using transrectal ultrasonography (TRUS). Materials and Methods  A total of 106 patients with prostatic disease clinically confined to the prostate glands were evaluated. Results and Observation  The mean PSAD for prostate cancer was 0.15 ± 0.01 while that for benign hypertrophy of the prostate (BPH) was 0.11 ± 0.02 ( p < 0.05). Significant difference ( p < 0.05) was noted in the prostate volume in these two groups with the mean prostate volume measured by TRUS in the BPH to be 53.85 ± 9.71 mL compared with 58.14 ± 7.48 mL in the carcinoma. PSA density of 0.13 ng/mL can be used as a cutoff for the individual in our set-up who should go for prostate biopsy with sensitivity and specificity of over 90%. Conclusion  These results suggest that PSAD may be useful in distinguishing BPH and prostate cancer.