Trends in Treatment for Prostate Cancer in China: Preliminary Patterns of Care Study in a Single Institution

MRI T2w Radiomics-Based Machine Learning Models in Imaging Simulated Biopsy Add Diagnostic Value to PI-RADS in Predicting Prostate Cancer: A Retrospective Diagnostic Study

BACKGROUND

Currently, prostate cancer (PCa) prebiopsy medical image diagnosis mainly relies on mpMRI and PI-RADS scores. However, PI-RADS has its limitations, such as inter- and intra-radiologist variability and the potential for imperceptible features. The primary objective of this study is to evaluate the effectiveness of a machine learning model based on radiomics analysis of MRI T2-weighted (T2w) images for predicting PCa in prebiopsy cases.

METHOD

A retrospective analysis was conducted using 820 lesions (363 cases, 457 controls) from The Cancer Imaging Archive (TCIA) Database for model development and validation. An additional 83 lesions (30 cases, 53 controls) from Hong Kong Queen Mary Hospital were used for independent external validation. The MRI T2w images were preprocessed, and radiomic features were extracted. Feature selection was performed using Cross Validation Least Angle Regression (CV-LARS). Using three different machine learning algorithms, a total of 18 prediction models and 3 shape control models were developed. The performance of the models, including the area under the curve (AUC) and diagnostic values such as sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were compared to the PI-RADS scoring system for both internal and external validation.

RESULTS

All the models showed significant differences compared to the shape control model (all p < 0.001, except SVM model PI-RADS+2 Features p = 0.004, SVM model PI-RADS+3 Features p = 0.002). In internal validation, the best model, based on the LR algorithm, incorporated 3 radiomic features (AUC = 0.838, sensitivity = 76.85%, specificity = 77.36%). In external validation, the LR (3 features) model outperformed PI-RADS in predictive value with AUC 0.870 vs. 0.658, sensitivity 56.67% vs. 46.67%, specificity 92.45% vs. 84.91%, PPV 80.95% vs. 63.64%, and NPV 79.03% vs. 73.77%.

CONCLUSIONS

The machine learning model based on radiomics analysis of MRI T2w images, along with simulated biopsy, provides additional diagnostic value to the PI-RADS scoring system in predicting PCa.

PRIORITI: Phase 4 study of triptorelin or active surveillance in high-risk prostate cancer

AIM

To evaluate the efficacy and safety of triptorelin after radical prostatectomy (RP) in patients with negative lymph nodes.

METHODS

PRIORITI (NCT01753297) was a prospective, open-label, randomized, controlled, phase 4 study conducted in China and Russia. Patients with high-risk (Gleason score ≥ 8 and/or pre-RP prostate-specific antigen [PSA] ≥ 20 ng/mL and/or primary tumor stage 3a) prostate adenocarcinoma without evidence of lymph node or distant metastases were randomized to receive triptorelin 11.25 mg at baseline (≤ 8 weeks after RP) and at 3 and 6 months, or active surveillance. The primary endpoint was biochemical relapse-free survival (BRFS), defined as the time from randomization to biochemical relapse (BR; increased PSA > 0.2 ng/mL). Patients were monitored every 3 months for at least 36 months; the study ended when 61 BRs were observed.

RESULTS

The intention-to-treat population comprised 226 patients (mean [standard deviation] age, 65.3 [6.4] years), of whom 109 and 117 were randomized to triptorelin or surveillance, respectively. The median BRFS was not reached. The 25th percentile time to BRFS (95% confidence interval) was 39.1 (29.9-not estimated) months with triptorelin and 30.0 (18.6-42.1) months with surveillance (p = 0.16). There was evidence of a lower risk of BR with triptorelin versus surveillance but this was not statistically significant at the 5% level (p = 0.10). Chemical castration was maintained at month 9 in 93.9% of patients who had received triptorelin. Overall, triptorelin was well tolerated and had an acceptable safety profile.

CONCLUSION

BRFS was observed to be longer with triptorelin than surveillance, but the difference was not statistically significant.

Single-site multiport vs. conventional multiport robot-assisted radical prostatectomy: A propensity score matching comparative study

Objective

Robot-assisted radical prostatectomy (RARP) is a dynamically evolving technique with its new evolution of single-site RARP. Here we sought to describe our extraperitoneal technique, named the single-site multiport RARP (ssmpRARP) using the da Vinci Si® platform and compare it with the transperitoneal conventional multiport RARP (cmpRARP).

Materials and Methods

Data were retrospectively collected for patients who underwent RARP for localized prostate cancer from June 2020 to January 2022 in a single center. Propensity score matching was performed based on age, prostate size, body mass index, neoadjuvant hormonal therapy usage, prostate-specific antigen levels, and clinical T stage. The differences between the matched two groups were investigated.

Results

Of the patients, 20 underwent ssmpRARP and 42 underwent cmpRARP during the period. After matching, 18 patients from each group were selected. Median follow-up was 7.8 months (2–12 months) for the ssmpRARP group, and 15.0 months (3–26 months) for cmpRARP. The demographic features between the two groups were comparable. The median total operative time, estimated blood loss, pathologic data, early follow-up outcomes, and hospitalization stays and costs were similar between the two groups. The ssmpRARP group tended to return to their bowel activities earlier (44.78 ± 10.83 h vs. 54.89 ± 12.97 h, p = 0.016). There were no significant differences in complication rates.

Conclusions

We demonstrated the feasibility and safety of performing extraperitoneal ssmpRARP using the da Vinci Si® robotic platform. Our technique showed comparable short-term outcomes with the transperitoneal cmpRARP. Prospective trials and long-term follow-up are necessary to confirm these results.

Prostate cancer treatment - China's perspective

Prostate cancer (PCa) incidence and mortality have rapidly increased in China. Notably, unique epidemiological characteristics of PCa are found in the Chinese PCa population, including a low but rising incidence and an inferior but improving disease prognosis. Consequently, the current treatment landscape of PCa in China demonstrates distinct features. Establishing a more thorough understanding of the characteristics of Chinese patients may help provide novel insights into potential treatment strategies for PCa patients. Herein, we review the epidemiological status and differences in treatment modalities of Chinese PCa patients. In addition, we discuss the underlying socioeconomic and biological factors that contribute to such diversity and further propose directions for future efforts in optimizing the PCa treatment in China.

PDZRN4 suppresses tumorigenesis and androgen therapy-resistance in prostate cancer

Background: PDZRN4 (PDZ domain-containing RING finger 4), a member of the LNX (ligand of numb protein-X) family that regulates the levels of NUMB, plays a critical role in suppressing the proliferation and invasion of hormone-related malignant tumours. There are few studies on the role of PDZRN4 in the pathogenesis of prostate cancer (PCa). We aimed to examine whether PDZRN4 regulates the growth and development of PCa.

Methods: Cell transduction and Western blotting were used to establish and confirm PDZRN4 knock down in PC cells. Using the MTT, wound healing, transwell migration, and animal experiments, we explored the biological function of PDZRN4 knockdown (PDZRN4-kd) cells. Via PCR and immunohistochemistry, the mRNA and protein expression of PDZRN4 was examined in PC cells and tissues.

Results: Hormone-dependent (LNCap) and hormone-independent (DU145, PC3, and C4-2) PC lines were transfected with lentivirus carrying PDZRN4 shRNA. The Western blotting results showed that the expression of PDZRN4 was stably downregulated in PDZRN4 knockdown (PDZRN4-kd) cells. The proliferation, invasion and migration of PDZRN4-kd cells were dramatically increased in vivo. To explore the expression of PDZRN4 in prostate cancer samples, we analysed TCGA data and found that PDZRN4 was negatively correlated with the development of PC. PDZRN4 levels were downregulated by androgen deprivation in hormone-sensitive cells. Moreover, PDZRN4 failed to induce proliferation in DU145 cells with androgen deprivation.

Conclusions: PDZRN4 is a functional suppressor of prostate cancer growth and development and is a potential target of biochemical therapy in hormone-resistant PC.

Use of miR‑145 and testicular nuclear receptor 4 inhibition to reduce chemoresistance to docetaxel in prostate cancer

The human testicular nuclear receptor 4 (TR4) is a critical regulatory gene for the progression of prostate cancer (PCa). Although it has been revealed that TR4 causes chemoresistance in PCa via the activation of octamer-binding transcription factor 4 (OCT4), the detailed mechanism remains unexplored. In the present study, it was revealed that inhibition of TR4 by shRNA in PCa enhanced the sensitivity to docetaxel in vitro and in vivo. TR4 induced the downregulation of miR-145 by directly binding it to the promoter of miR-145, which was confirmed by chromatin immunoprecipitation analysis and luciferase assay. The overexpression of miR-145 suppressed both the chemoresistance and the expression of OCT4 mRNA and protein. Additionally, the TR4 shRNA mediated re-sensitization to docetaxel, along with the downregulated expression of OCT4, were reversed by the concurrent inhibition of miR-145. The luciferase assay revealed that the activity of the wild-type OCT4 3′ untranslated region reporter was suppressed. This suppression diminished when the miR-145 response element mutated. These findings suggest an undescribed regulatory pathway in PCa, by which TR4 directly suppressed the expression of miR-145, thereby inhibiting its direct target OCT4, leading to the promotion of chemoresistance in PCa.

Cost-Effectiveness Analysis of Prostate Health Index in Decision Making for Initial Prostate Biopsy

Background

Clinical studies have suggested that prostate health index (phi) outperforms prostate-specific antigen (PSA) tests in prostate cancer detection. The cost-effectiveness of phi with different cutoffs is poorly understood in the context of decision making for prostate biopsy.

Methods

In a multicenter cohort, 3,348 men with elevated total PSA (tPSA) underwent initial prostate biopsy from August 2013 to May 2019. We constructed a decision model to evaluate the incremental cost-effectiveness ratios of different phi cutoffs. Total costs and reimbursement payments were based on the fee schedule of Shanghai Basic Medical Insurance and converted into United States dollars ($). Two willingness-to-pay thresholds were estimated as one or three times the average gross domestic product per capita of China ($7,760 or $23,279, respectively).

Results

The total costs of prostate biopsy and PSA tests were estimated at $315 and $19, respectively. The cost of phi test varied between $72 to $130 in different medical centers. Under different phi cutoffs (from 23 to 35), phi test predicted reductions of 420 (21.7%) to 972 (50.2%) in unnecessary biopsies, with a total gain of 23.77-57.58 quality adjusted life-years compared to PSA tests. All the cutoffs would be cost-effective for patients with tPSA levels of 2-10 ng/ml. Applying 27 as the cutoff was cost-effective for each tPSA range, with missing positive cases ranging from 11 (3.4%) to 33 (11.5%).

Conclusions

Using phi test was cost-effective in the decision-making process for initial prostate biopsy, especially for patients with tPSA values between 2-10 ng/ml. The phi cutoff of 27 was cost-effective regardless of tPSA ranges and should be recommended from a health-economic perspective.

Radium-223 in Asian patients with castration-resistant prostate cancer with symptomatic bone metastases: A single-arm phase 3 study

Aim

Radium‐223, a targeted alpha therapy, is approved widely for the treatment of patients with metastatic castrate‐resistant prostate cancer, based on a pivotal phase 3 study in predominantly white patients. We investigated the efficacy and safety of radium‐223 in Asian patients with castrate‐resistant prostate cancer and metastatic bone disease.

Methods

This multicenter, prospective, single‐arm, open‐label phase 3 trial evaluated the efficacy and safety of the standard radium‐223 regimen (55 kBq/kg every 4 weeks for six cycles) in patients from Asian countries. The primary endpoints were the safety and overall survival.

Results

A total of 226 patients were enrolled and received at least one dose of radium‐223. Median overall survival was 14.0 months (95% confidence interval [CI], 11.2–17.4). Median time to total alkaline phosphatase and prostate‐specific antigen progression were 7.5 (95% CI, 6.8–7.7) and 3.6 (95% CI, 3.1–3.7) months, respectively. Median skeletal‐related event‐free survival was 26.0 months (95% CI, 12.6–not reached). Grade ≥3 treatment‐emergent adverse events were reported in 103 (46%) of 226 patients, with anemia being the most common event (34 [15%] patients). Grade ≥3 drug‐related treatment‐emergent adverse events occurred in 39 (17%) of 226 patients. Serious treatment‐emergent adverse events were reported in 65 (29%) of 226 patients. Seven (3%) patients had an adverse event leading to death; none were considered to be related to radium‐223.

Conclusion

The results of this study support the use of the standard radium‐223 regimen for the treatment of Asian patients with castrate‐resistant prostate cancer and symptomatic bone metastases.

Association of long-chain non-coding RNA GAS5 gene polymorphisms with prostate cancer risk and prognosis in Chinese Han population

BACKGROUND

To investigate the correlation between growth arrest-specific transcript 5 (GAS5) gene polymorphism and the risk and prognosis of prostate cancer in Chinese Han population.

METHODS

Sanger sequencing was used to analyze genotypes at the rs17359906 and rs1951625 loci of the GAS5 gene in 218 prostate cancer patients and 220 healthy controls. The follow-up period was from August 2016 to August 2019, and the relationships between GAS5 gene polymorphisms at the rs17359906 and rs1951625 loci and the recurrence-free survival rate of prostate cancer patients were analyzed.

RESULTS

GAS5 A-allele carriers at the rs17359906 locus were 3.44 times more likely to develop prostate cancer than G-allele carriers (95% confidence interval (CI): 2.38-4.96, P < .001). Carriers of the GAS5 A allele at the rs1951625 locus had a 1.40-fold higher risk of prostate cancer than carriers of the G allele (95% CI: 1.05-1.86, P = .027). Plasma prostate-specific antigen (PSA), body mass index (BMI), and rs17359906 and rs1951625 loci were independent risk factors for prostate cancer. GAS5 AA genotype and A-allele carriers (GA + AA) at the rs1951625 locus were significantly correlated with Gleason scores ≤7 (P < .05). GAS5 genes rs17359906 G > A and rs1951625 G > A were associated with high plasma PSA levels. The recurrence-free survival rate of patients with prostate cancer with AA genotype at the rs17359906 locus of GAS5 (66.67%) was significantly lower than that of the GA genotype (76.47%), whereas the GG genotype was the highest (91.96%), and the difference was statistically significant (P = .002). The recurrence-free survival rate of patients with prostate cancer with the AA genotype at the rs1951625 locus of GAS5 (75.00%) was significantly lower than that of the GA genotype (81.82%), whereas the GG genotype was the highest (87.76%) with a statistically significant difference (P = .025).

CONCLUSION

GAS5 rs17359906 G > A and rs1951625 G > A are significantly associated with an increased risk of prostate cancer and a reduction in three-year relapse-free survival.

Long non-coding RNA NORAD induces cell proliferation and migration in prostate cancer

Objectives

Prostate cancer (PCA) is the deadliest urological disease affecting men worldwide. Long noncoding RNA activated by DNA damage (NORAD) levels are increased in many cancer types, and induce cancer cell progression. However, little is known about the biological functions of NORAD in PCA.

Methods

In this work, the roles of NORAD in cell proliferation, migration, and apoptosis were examined by Cell Counting Kit-8, scratch wound, and annexin V-fluorescein isothiocyanate/propidium iodide staining assays, respectively, in PCA cell lines. Knockdown of NORAD was achieved by small interfering (si)RNA in PCA cell lines, and quantitative real-time PCR was used to detect the expression of NORAD.

Results

Cell proliferation and migration rates were significantly lower in the siNORAD group than in the wild-type group, while the apoptosis level was significantly higher in the siNORAD group compared with the wild-type group.

Conclusions

These results suggest that NORAD promotes the proliferation and migration of PCA cells and inhibits their apoptosis.

Current Treatment for Low-Risk Prostate Cancer in China: A National Network Survey

Objective: To analyze the current treatment for low-risk prostate cancer (LRPC) in China.

Methods: A national questionnaire survey titled “A survey of current treatment of LRPC” was designed and released nationally through the network from July 16 to August 3, 2017.

Results: A total of 1,116 valid questionnaires were recovered. The percentages of preferred treatment by active surveillance (AS) or radical prostatectomy (RP) were 29.21% and 45.61%, respectively. A correspondence analysis showed that the physician in charge was more inclined to choose AS than RP. Respondents from different institution types, hospitals with different annual numbers of newly admitted patients with prostate cancer, and with different familiarity with the LRPC definition presented a significant difference in the preferred treatments (p < 0.05). Urologists chose AS or not for the following reasons: tumor progression (52.51%), potential medical disputes (42.56%) (i.e., medical disputes from patients or their relatives when urologists choose AS to treat patients with LRPC and the patient has a poor outcome), fear of cancer (41.94%), and surgical risk (39.07%). These reasons were ubiquitous, and there was no significant difference among urologists for these concerns (p > 0.05). Personal skills, surgical risk, and tumor progression were the most common factors that influenced whether AS or RP was preferred (p < 0.05). Concern about the medical disputes brought about by AS was a key factor for not choosing AS (p < 0.05).

Conclusions: LRPC is still dominated by RP in China, followed by AS. Personal skills, surgical risk, and concern about tumor progression were the common factors influencing whether AS or RP was preferred. In addition, medical disputes brought by AS are another key factor for not choosing AS. There will be more Chinese data in the future to guide treatment of LRPC.

Infectious Complications of Conventional Laparoscopic vs Robotic Laparoscopic Prostatectomy: A Systematic Literature Review and Meta-Analysis

BACKGROUND

Recent studies have shown that using minimally invasive surgical techniques (conventional laparoscopy or robotic) for prostatectomy is associated with lower perioperative complication rates compared with open radical retropubic prostatectomy. However, differences in infectious complications between these minimally invasive approaches are not well characterized. To study this further, we performed a systematic review of the literature and meta-analysis of the infectious complications of prostatectomy, comparing robotic prostatectomy (RP) with conventional laparoscopic prostatectomy (LP).

METHODS

We searched PubMed, CINAHL, CDSR, and EMBASE through September 2018 for studies evaluating minimally invasive prostatectomy and infectious complications. We employed random-effect models to obtain pooled odds ratio (pOR) estimates. Heterogeneity was evaluated with I² estimation and the Cochran Q statistic. pORs were calculated separately based on the indication for prostatectomy.

RESULTS

Fifteen studies were included in the final review for the meta-analysis with 14,121 patients undergoing minimally invasive prostatectomy. There was no statistically significant difference in the number of infectious complication events between RP and LP (pOR 0.94; 95% CI 0.50, 1.76). When we performed a stratified analysis, similar results were found with no statistically significant difference in infectious complications comparing RP with LP among patients with prostate cancer (pOR 0.73; 95% CI 0.43, 1.24). We observed that infectious complications were nearly threefold higher with the robotic approach in earlier studies (published between 2007 and 2012, pOR 2.81; 95% CI 1.07, 7.39), but no significant difference was found in later studies (between 2013 and 2018, pOR 0.80, 95% CI 0.40, 1.57).

CONCLUSIONS

The rate of infectious complications associated with RP was no different than that associated with conventional LP.