Clinical significance of the prostate-specific antigen doubling time prior to and following radical prostatectomy to predict the outcome of prostate cancer

Commentary: On measurement error, PSA doubling time, and prostate cancer

Exposure measurement error is a pervasive problem for epidemiology research projects designed to provide valid and precise statistical evidence supporting postulated exposure-disease relationships of interest. The purpose of this commentary is to highlight an important real-life example of this exposure measurement error problem and to provide a simple and useful diagnostic tool for physicians and their patients that corrects for the exposure measurement error. More specifically, prostate-specific antigen doubling time (PSADT) is a widely used measure for guiding future treatment options for patients with biochemically recurrent prostate cancer. Numerous papers have been published claiming that a low calculated PSADT value (denoted PSADT ^ ) is predictive of metastasis and premature death from prostate cancer. Unfortunately, none of these papers have adjusted for the measurement error in PSADT ^ , an estimator that is typically computed using the popular Memorial Sloan Kettering website very often visited by both physicians and their patients. For this website, the estimator PSADT ^ of the true (but unknown) PSADT for a patient (denoted PSADT∗) is computed as the natural log of 2 (i.e., 0.6931) divided by the estimated slope of the straight-line regression of the natural log of PSA (in ng/mL) on time. We utilize PSADT ^ to derive an expression for the probability that the unknown PSADT∗ for a patient is below a specified value C (> 0 ) of concern to both the physician and the patient. This probability is easy to interpret and takes into account the fact that PSADT ^ is a statistical estimator with variability. This variability introduces measurement error, namely, the difference between a computed value PSADT ^ and the true, but unknown, value PSADT∗. We have developed an Excel calculator that, once the [time, ln(PSA)] values are entered, outputs both the value of PSADT ^ and the desired probability. In addition, we discuss problematic statistical issues attendant with PSADT∗ estimation typically based on at most three or four PSA values. We strongly recommend the use of this probability when physicians are discussing PSADT ^ values and associated treatment options with their patients. And, we stress that future epidemiology research projects involving PSA doubling time should take into account the measurement error problem highlighted in this Commentary.

Clinical efficiency of combination therapy using testosterone replacement therapy, phosphodiesterase 5 inhibitors and Kampo herbal medicine for eugonadal patients with late-onset hypogonadism syndrome

In the present study, the initial treatment efficiency of combination therapy using testosterone replacement therapy (TRT), herbal medicine and phosphodiesterase 5 inhibitors (PDE5i) in male patients with late-onset hypogonadism (LOH) were assessed. A total of 21 patients were enrolled and after 12 weeks, the clinical efficacy was evaluated based on improvement of LOH symptoms via laboratory parameters and several questionnaires, including the Ageing Males' Symptoms (AMS) scale. The overall AMS scores, as well as the psychological, physical and sexual AMS factors prior to and after treatment in the TRT, testosterone enanthate (T enanthate) monotherapy and T enanthate + PDE5i treatment groups were significantly improved. In the herbal medicine group, only the AMS physiological factors were significantly improved after treatment compared with the baseline. The improvement of the overall AMS scores, as well as the physiological and sexual AMS factors, were significantly negatively correlated with the free testosterone (FT) value prior to treatment. In conclusion, treatment with combination therapy using TRT, herbal medicine and PDE5i improved AMS scores in patients with LOH syndrome. Particularly in patients with LOH syndrome and low FT, the symptoms were significantly improved following combination therapy.

Tissue- and Liquid-Based Biomarkers in Prostate Cancer Precision Medicine

Worldwide, prostate cancer (PC) is the second-most-frequently diagnosed male cancer and the fifth-most-common cause of all cancer-related deaths. Suspicion of PC in a patient is largely based upon clinical signs and the use of prostate-specific antigen (PSA) levels. Although PSA levels have been criticised for a lack of specificity, leading to PC over-diagnosis, it is still the most commonly used biomarker in PC management. Unfortunately, PC is extremely heterogeneous, and it can be difficult to stratify patients whose tumours are unlikely to progress from those that are aggressive and require treatment intensification. Although PC-specific biomarker research has previously focused on disease diagnosis, there is an unmet clinical need for novel prognostic, predictive and treatment response biomarkers that can be used to provide a precision medicine approach to PC management. In particular, the identification of biomarkers at the time of screening/diagnosis that can provide an indication of disease aggressiveness is perhaps the greatest current unmet clinical need in PC management. Largely through advances in genomic and proteomic techniques, exciting pre-clinical and clinical research is continuing to identify potential tissue, blood and urine-based PC-specific biomarkers that may in the future supplement or replace current standard practices. In this review, we describe how PC-specific biomarker research is progressing, including the evolution of PSA-based tests and those novel assays that have gained clinical approval. We also describe alternative diagnostic biomarkers to PSA, in addition to biomarkers that can predict PC aggressiveness and biomarkers that can predict response to certain therapies. We believe that novel biomarker research has the potential to make significant improvements to the clinical management of this disease in the near future.

Parameters predicting [18F]PSMA-1007 scan positivity and type and number of detected lesions in patients with biochemical recurrence of prostate cancer

BACKGROUND

Detection of the site of recurrence using PSMA-PET/CT is important to guide treatment in patients with biochemical recurrence of prostate cancer (PCa). The aim of this study was to evaluate the positivity rate of [¹⁸F]PSMA-1007-PET/CT in patients with biochemically recurrent PCa and identify parameters that predict scan positivity as well as the type and number of detected lesions. This monocentric retrospective study included 137 PCa patients with biochemical recurrence who underwent one or more [¹⁸F]PSMA-1007-PET/CT scans between August 2018 and June 2019. PET-positive malignant lesions were classified as local recurrence, lymph node (LN), bone or soft tissue lesions. The association between biochemical/paraclinical parameters, as PSA value, PSA doubling time, PSA velocity, Gleason score (GS) and androgen deprivation therapy (ADT), and scan positivity as well as type and number of detected lesions was evaluated using logistic regression analysis (binary outcomes) and Poisson models (count-type outcomes).

RESULTS

We included 175 [¹⁸F]PSMA-1007-PET/CT scans after radical prostatectomy (78%), external beam radiation therapy (8.8%), ADT (7.3%), brachytherapy (5.1%) and high intensity focused ultrasound (0.7%) as primary treatment (median PSA value 1.6 ng/ml). Positivity rate was 80%. PSA value and PSA velocity were significant predictors of scan positivity as well as of the presence of bone and soft tissue lesions and number of bone, LN and soft tissue lesions, both in uni- and/or multivariable analysis. Multivariable analysis also showed prior ADT as predictor of bone and soft tissue lesions, GS as predictor of the number of bone lesions and ongoing ADT as predictor of the number of LN lesions.

CONCLUSION

[¹⁸F]PSMA-1007-PET/CT showed a high positivity rate in patients with biochemically recurrent PCa. PSA value and PSA velocity were significant predictors of scan positivity as well as of the presence and number of bone and soft tissue lesions and the number of LN lesions. Our findings can guide clinicians in optimal patient selection for [¹⁸F]PSMA-1007-PET/CT and support further research leading to the development of a prediction nomogram.

Long non-coding RNA SNHG17 enhances the aggressiveness of C4-2 human prostate cancer cells in association with β-catenin signaling

Long non-coding (lnc) RNAs have emerged as important regulators of cancer development and progression. Several lncRNAs have been reported to be associated with prostate cancer (PCa); however, the involvement of lncRNA SNHG17 in PCa remains unclear. In the present study, the mRNA expression level of SNHG17 in 58 pairs of PCa tumor samples and adjacent non-tumor tissues, as well as in PCa tumor cell lines was analyzed. The regulatory effect of SNHG17 on the oncogenic phenotypes of the C4-2 tumor cell line was also investigated. The clinicopathological analysis revealed that SNHG17 mRNA expression level was increased in the PCa tumor samples, and its high expression levels were associated with poor patient outcomes, indicating that SNHG17 may act as a biomarker for the prognosis of PCa. SNHG17 mRNA expression level was also increased in different PCa tumor cell lines. Functionally, SNHG17 increased C4-2 tumor cell growth and aggressiveness by stimulating tumor cell proliferation, survival, invasion and resistance to chemotherapy. Furthermore, SNHG17 promoted in vivo tumor growth in a xenograft mouse model. Notably, the SNHG17-induced in vitro and in vivo oncogenic effects were associated with activation of the β-catenin pathway. The results from the present study revealed that lncRNA SNHG17 could be an important regulator in the oncogenic properties of human PCa and may; therefore, represent a potential PCa therapeutic target.

Metastatic Spread in Prostate Cancer Patients Influencing Radiotherapy Response

Radiotherapy and surgery are curative treatment options for localized prostate cancer (PCa) with a 5-year survival rate of nearly 100%. Once PCa cells spread into distant organs, such as bone, the overall survival rate of patients drops dramatically. The metastatic cascade and organotropism of PCa cells are regulated by different cellular subtypes, organ microenvironment, and their interactions. This cross-talk leads to pre-metastatic niche formation that releases chemo-attractive factors enforcing the formation of distant metastasis. Biological characteristics of PCa metastasis impacting on metastatic sites, burden, and latency is of clinical relevance. Therefore, the implementation of modern hybrid imaging technologies into clinical routine increased the sensitivity to detect metastases at earlier stages. This enlarged the number of PCa patients diagnosed with a limited number of metastases, summarized as oligometastatic disease. These patients can be treated with androgen deprivation in combination with local-ablative radiotherapy or radiopharmaceuticals directed to metastatic sites. Unfortunately, the number of patients with disease recurrence is high due to the enormous heterogeneity within the oligometastatic patient population and the lack of available biomarkers with predictive potential for metastasis-directed radiotherapy. Another, so far unmet clinical need is the diagnosis of minimal residual disease before onset of clinical manifestation and/or early relapse after initial therapy. Here, monitoring of circulating and disseminating tumor cells in PCa patients during the course of radiotherapy may give us novel insight into how metastatic spread is influenced by radiotherapy and vice versa. In summary, this review critically compares current clinical concepts for metastatic PCa patients and discuss the implementation of recent preclinical findings improving our understanding of metastatic dissemination and radiotherapy resistance into standard of care.

Decreased biochemical progression in patients with castration-resistant prostate cancer using a novel mefenamic acid anti-inflammatory therapy: A randomized controlled trial

Prostate cancer (PCa) is the second most common non-dermatological cancer in men and is a growing public health problem. Castration-resistant disease (CRD) is the most advanced stage of the disease and is difficult to control. Patients with CRD may no longer accept conventional therapies as they are not in appropriate clinical conditions or they refuse to receive it. Given that inflammation is an essential component of CRD origin and progression, anti-inflammatory agents could be a therapeutic option with fenamates as one of the proposed choices. A prospective, randomized, double-blinded, 2-arm, parallel group, phase II-III clinical trial was performed involving 20 patients with CRD-PCa (with a prostate specific antigen level <100 ng/ml) that were undergoing androgen deprivation therapy (ADT) and did not accept any established treatment for that disease stage. In addition to ADT, 10 patients received placebo and 10 received mefenamic acid (500 mg orally every 12 h) for 6 months. The primary endpoint was the change in serum prostate-specific antigen (PSA) at 6 months. The PSA levels decreased significantly with mefenamic acid (an average 42% decrease), whereas there was an average 55% increase in the placebo group (P=0.024). In the patients treated with the placebo, 70% had biochemical disease progression (an increase of ≥25% in PSA levels), which did not occur in any of the patients treated with mefenamic acid (relative risk=0.12; 95% confidence interval, 0.01-0.85; P=0.033). There was a significant increase in quality of life (EQ-5D-5L score) and body mass index (BMI) with the experimental treatment. In conclusion, mefenamic acid administration decreased biochemical progression in patients with castration resistant PCa, improved their quality of life and increased their BMI. Future studies are required in order to strengthen the findings of the present clinical trial. Trial registration, Cuban Public Registry of Clinical Trials Database RPCEC00000248, August 2017.

Prognostic significance of a novel indicator (PSApostd3/PSApre) for PSA recurrence in patients after radical prostatectomy

Purpose

Radical prostatectomy (RP) is a common treatment for prostate cancer, but a fraction of patients may experience PSA recurrence after surgery, manifesting as an elevation in prostate specific antigen (PSA). Vast literature has reported different prognostic factors for PSA recurrence without reaching a consensus. This retrospective study investigated the efficacy of a new indicator in predicting PSA recurrence in patients after RP.

Patients and methods

From October 2000 to December 2015, 102 PCa patients who underwent laparoscopic prostatectomy in the Urology Department of Peking Union Medical College Hospital were analyzed. We calculated PSA_postd3/PSA_pre, defined as the ratio of the PSA on day 3 postop as the numerator and the pre-operative PSA as the denominator, in these patients to represent PSA decrement after surgery, and investigated its relationship with PSA recurrence during follow-up.

Results

The receiver operating characteristic (ROC) curve of PSA_postd3/PSA_pre derived a cut-off at 0.453 (sensitivity=0.704, specificity=0.853, P<0.0001), suggesting an increased risk of PSA recurrence in patients whose PSA on day 3 postop did not decrease to approximately half of their preoperative levels. Among several factors, PSA_postd3/PSA_pre (P<0.0001), pathological T stage (P=0.042) and Gleason Grade (P=0.021) were determined to be significantly associated with PSA recurrence by Fisher’s exact test, while only PSA_postd3/PSA_pre (P<0.001) was significantly related to PSA recurrence-free survival (PRFS) by multivariate logistic regression analysis.

Conclusion

These results imply that PSA_postd3/PSA_pre could provide substantial information for PSA recurrence prediction in patients after RP.

The Prognostic Factors of Biochemical Recurrence-Free Survival Following Radical Prostatectomy

Objective: To evaluate outcomes, biochemical recurrence-free survival (BCRFS) and to identify parameters influencing BCRFS of radical prostatectomy (RP) and bilateral pelvic lymph node dissection in a single-institution. Methods: A retrospective review of prostate cancer (PC) patients received RP was identified from the medical records. Data was collected from 2007 to 2016. 178 patients received RP were enrolled in a study. These patients were evaluated on efficacy of RP by using prostate-specific antigen (PSA) to analyze BCRFS and compared with Gleason score, pathologic staging, margin status and lymph node status with BCRFS. Results: The median follow up was 32.5 months (n = 178). Sixty-nine patients had extracapsular extension on pathologic results whereas 93 patients were classified as a high risk group. The median time for biochemical recurrence (BCR) was 22.3 months. The 3-year BCRFS in patients with a Gleason score 6, 3+4, 4+3, 8 and 9-10 were 85.8%, 84.6%, 78.7%, 53.3% and 35.8% . Multivariate analysis showed that extracapsular extension was independently associated with BCRFS. Conclusions: New group grading system indicates impact on BCRFS on univariate analysis but show negative impact on a multivariate Cox regression, only pathologic staging was independently associated with the cancer control outcome.