Usefulness of postoperative nadir prostate-specific antigen value by ultrasensitive assay as a predictor of prostate-specific antigen relapse for pathological T3 or positive surgical margins after radical prostatectomy for prostate cancer

Prostate-Specific Antigen as an Ultrasensitive Biomarker for Patients with Early Recurrent Prostate Cancer: How Low Shall We Go? A Systematic Review

Serum prostate-specific antigen (PSA) needs to be monitored with ultrasensitive PSA assays (uPSAs) for oncologists to be able to start salvage radiotherapy (SRT) while PSA is <0.5 µg/L for patients with prostate cancer (PCa) relapsing after a radical prostatectomy (RP). Our systematic review (SR) aimed to summarize uPSAs for patients with localized PCa. The SR was registered as InPLASY2023110084. We searched for studies on Google Scholar, PUBMED and reference lists of reviews and studies. We only included studies on uPSAs published in English and excluded studies of women, animals, sarcoidosis and reviews. Of the 115 included studies, 39 reported PSA assay methods and 76 reported clinical findings. Of 67,479 patients, 14,965 developed PSA recurrence (PSAR) and 2663 died. Extremely low PSA nadir and early developments of PSA separated PSAR-prone from non-PSAR-prone patients (cumulative p value 3.7 × 1012). RP patients with the lowest post-surgery PSA nadir and patients who had the lowest PSA at SRT had the fewest deaths. In conclusion, PSA for patients with localized PCa in the pre-PSAR phase of PCa is strongly associated with later PSAR and survival. A rising but still exceedingly low PSA at SRT predicts a good 5-year overall survival.

Oncological Outcome of Combining Cytoreductive Prostatectomy and Metastasis-Directed Radiotherapy in Patients with Prostate Cancer and Bone Oligometastases: A Retrospective Cohort Study

Background

The current standard of care for metastatic prostate cancer (mPCa) is androgen deprivation therapy (ADT) with or without anti-androgen and chemotherapy. The aim of this study was to evaluate the efficacy and safety of a multimodal approach including local primary tumor therapy, metastasis-directed therapy (MDT), and hormonal therapy in patients with oligometastatic prostate cancer (PCa).

Methods

We reviewed data of patients with PCa and bone oligometastases at diagnosis treated in three institutions with ADT followed by cytoreductive surgery with or without metastases-directed radiotherapy. Oligometastases were defined as the presence of five or fewer metastatic lesions with the absence of visceral metastases. In this retrospective cohort study, 58 patients underwent cytoreductive radical prostatectomy and ADT. Of these, 26 patients (45%) received stereotactic body radiation therapy (SBRT) to all metastatic sites as a MDT. Oncological outcomes were analyzed using the Kaplan–Meier method.

Results

The median follow-up period was 46.2 months. Of the 58 patients, the 3-year castration-resistant prostate cancer (CRPC)-free survival and cancer-specific survival was 75.9% and 91.4%, respectively. Pre- or post-treatment predictive factors for progression to CRPC, including prostate-specific antigen (PSA) level at diagnosis ≥20 ng/mL, Gleason grade groups 5, clinical T stage cT3b-4, PSA nadir level of ≥0.05 ng/mL, and no MDT with SBRT, were significantly associated with progression to CRPC. Subgroup analysis showed that the MDT group had significantly better CRPC-free survival than the non-MDT group with Gleason grade groups 1–4 (HR=0.228; 95% CI= 0.056–0.926). A total of 3.4% of the patients had grade 2 acute genitourinary toxicities and 5.2% had grade 2 acute gastrointestinal toxicities. No late grade >2 adverse events were observed.

Conclusion

This multi-center, retrospective cohort study revealed the feasibility of combining cytoreductive prostatectomy and metastasis-directed radiotherapy for newly-diagnosed oligometastatic PCa. This treatment strategy has the potential to delay the progression to CRPC.

The significance of reporting to the thousandths place: Figuring out the laboratory limitations

OBJECTIVES

A request to report laboratory values to a specific number of decimal places represents a delicate balance between clinical interpretation of a true analytical change versus laboratory understanding of analytical imprecision and significant figures. Prostate specific antigen (PSA) was used as an example to determine if an immunoassay routinely reported to the hundredths decimal place based on significant figure assessment in our laboratory was capable of providing analytically meaningful results when reported to the thousandths places when requested by clinicians.

DESIGN AND METHODS

Results of imprecision studies of a representative PSA assay (Roche MODULAR E170) employing two methods of statistical analysis are reported. Sample pools were generated with target values of 0.01 and 0.20 μg/L PSA as determined by the E170. Intra-assay imprecision studies were conducted and the resultant data were analyzed using two independent statistical methods to evaluate reporting limits.

RESULTS

These statistical methods indicated reporting results to the thousandths place at the two assessed concentrations was an appropriate reflection of the measurement imprecision for the representative assay. This approach used two independent statistical tests to determine the ability of an analytical system to support a desired reporting level. Importantly, data were generated during a routine intra-assay imprecision study, thus this approach does not require extra data collection by the laboratory.

CONCLUSIONS

Independent statistical analysis must be used to determine appropriate significant figure limitations for clinically relevant analytes. Establishing these limits is the responsibility of the laboratory and should be determined prior to providing clinical results.

Determining When to Stop Prostate Specific Antigen Monitoring after Radical Prostatectomy: the Role of Ultrasensitive Prostate Specific Antigen

PURPOSE

We analyzed long-term followup data after radical prostatectomy to determine how long we should follow patients in whom the serum prostate specific antigen level measured by an ultrasensitive assay was consistently low.

MATERIALS AND METHODS

We retrospectively reviewed clinicopathological data for 582 consecutive patients who underwent open or laparoscopic radical prostatectomy between 1995 and 2004, excluding 4 patients who received adjuvant therapy. We stratified the patients according to prostate specific antigen at 3 and 5 years after surgery, and examined subsequent biochemical recurrence (elevation of prostate specific antigen to greater than 0.2 ng/ml) during followup. Mean followup was 9.7 years.

RESULTS

At 3 years after surgery prostate specific antigen levels were measured by an ultrasensitive assay in 323 patients who had not experienced biochemical recurrence. In 187 patients with undetectable prostate specific antigen levels (less than 0.01 ng/ml) the 10 and 15-year biochemical recurrence-free survival rates were 99% and 96%, respectively. At 5 years after surgery prostate specific antigen was measured in 315 patients by the ultrasensitive assay. In 162 patients with undetectable prostate specific antigen levels the 10 and 15-year biochemical recurrence-free survival rates were both 100%. In this group the prostate specific antigen level at last followup was less than 0.01 ng/ml in 132 patients, 0.01 to 0.03 ng/ml in 27 patients, and 0.06 ng/ml, 0.07 ng/ml and 0.11 ng/ml in 1 patient each.

CONCLUSIONS

This long-term review indicates that if patients have continuously undetectable prostate specific antigen levels by an ultrasensitive assay for 5 years, prostate specific antigen monitoring can be stopped with an extremely low risk of subsequent biochemical recurrence.

[RETROSPECTIVE ANALYSIS OF POSITIVE SURGICAL MARGIN AT RADICAL PROSTATECTOMY]

We retrospectively reviewed 182 patients who underwent radical prostatectomy in our hospital between April, 2009 to December, 2012, and who had not received any prior hormonal therapy. We also excluded the patients who couldn't followed up more than 6 months after surgery and pN1 patients. Positive surgical margins were observed in 65 cases. We determined what were the significant factors associated with the margin status. The another aim of present study is to evaluate the risk factor which might have significance for biochemical recurrence. BMI ≥ 25.0, prostate volume < 40 cm3, and biopsy positive core ≥ 25% were significant predictors of positive surgical margin. PSA nadir ≥ 0.02 ng/ml and pT3 were the significant factors which associated with biochemical recurrence of those patients with positive margin status.

Oncological outcomes of cryosurgery as primary treatment in T3 prostate cancer: experience of a single centre

OBJECTIVE

To assess the oncological outcomes and determine prognostic factors for overall survival (OS), cancer-specific survival (CSS), and biochemical progression-free survival (BPFS) after cryosurgery for clinical stage T3 prostate cancer.

PATIENTS AND METHODS

Between 2002 and 2007, 75 patients with clinical stage T3 prostate cancer received cryosurgery as primary treatment in our institution. No adjuvant treatment was provided until biochemical failure. After biochemical failure, hormone therapy was administered. Kaplan-Meier analysis was used to calculate the OS, CSS, and BPFS. Cox regression was used to identify factors predictive of survival.

RESULTS

Clinical stage T3a (cT3a) was detected in 60% (45/75) of patients and cT3b detected in 40% (30/75). The 5-year OS, CSS, and BPFS rates were 85.3%, 92.0%, and 48%, respectively. There was a significant difference when comparing the pT3a with the pT3b group for 5-year OS (88.9% vs 80%, P = 0.02) and BPFS (55.6% vs 36.7%, P = 0.01), but there was no difference in CSS (93.3% vs 90%, P = 0.63). Stage, Gleason score, and nadir prostate-specific antigen (PSA) were associated with BPFS, while Gleason score and nadir PSA were the most significant predictors for CSS.

CONCLUSIONS

Cryosurgery can offer good 5-year OS, CSS, and BPFS rates for cT3 prostate cancer, and there was no difference between T3a and T3b for CSS. Gleason score and nadir PSA were the most significant predictors of survival. Further clinical trials are warranted for evaluating the role of cryosurgery for cT3 prostate cancer.