Surgical management of prostate cancer

Distribution of neurovascular structures within the prostate gland and their relationship to complications after radical prostatectomy

BACKGROUND

Radical prostatectomy remains the main choice of treatment for prostate cancer. However, despite improvements in surgical techniques and neurovascular sparing procedures, rates of erectile dysfunction, and urinary incontinence remain variable. This is due, at least in part, to an incomplete understanding of neurovascular structures associated with the prostate. The objective of this study was to provide a comprehensive, detailed histological overview of the distribution of nerves and blood vessels within the prostate, facilitating subsequent correlation of prostatic neurovascular structures with patients' clinical outcomes after radical prostatectomy.

METHODS

Neurovascular structures within the prostate were investigated in a total of 309 slides obtained from 15 patients who underwent non-nerve-sparing radical prostatectomy. Immunohistochemical staining was performed to identify and distinguish between parasympathetic and sympathetic nerves, whereas hematoxylin and eosin staining was used to identify blood vessels. The total number, density, and relative position of nerves and blood vessels were established using quantitative morphometry and illustrated using visualization approaches. Patient-specific outcome data were then used to establish whether the internal distribution of nerves and blood vessels within the prostate correlated with the nature and extent of complications after surgery. One-way analysis of variance tests and unpaired t tests were applied to establish statistically significant differences across the measured variables.

RESULTS

Nerves and blood vessels were present across all prostatic levels and regions. However, their number and density varied considerably between regions. Assessment of the precise positioning of neurovascular structures revealed that the majority of nerve fibers were located within the dorsal and peripheral aspects of the gland. In contrast, blood vessels were predominantly located within ventral and dorsal midline regions. The number of intraprostatic nerves was found to be significantly lower in patients who recovered their continence within 12 months of surgery, compared to those whose recovery took 12 months or longer.

CONCLUSION

We report an unexpected disconnect between the localization and positioning of nerve fibers and blood vessels within the prostate. Moreover, individual variability in the density of intraprostatic neurovascular structures appears to correlate with the successful recovery of urinary continence after radical prostatectomy, suggesting that differences in intrinsic neurovascular arrangements of the prostate influence postoperative outcomes.

PRPF19 promotes the proliferation, migration, and inhibits autophagy in prostate cancer by suppressing SLC40A1

Prostate cancer (PCa) is a common cancer and the leading cause of cancer-related death in men. To investigate the role of pre-mRNA processing factor 19 (PRPF19) in proliferation, migration of PCa, and evaluate the potential ability of PRPF19 as a therapeutic target. PRPF19 expression was analyzed from The Cancer Genome Atlas and GEPIA databank. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to evaluate the transcription of PRPF9 and solute carrier family 40 member 1 (SLC40A1). Immunohistochemistry (IHC) was used to test PRPF9 expression in PCa tissues. The cell viability and 5-ethynyl-2'-deoxyuridine incorporation analysis were performed to assess cell proliferation. Transwell assay was performed to investigate the migration and invasion of cancer cells. Western blot was used to measure the expression level of PRPF9, E-cadherin, Vimentin and α-smooth muscle actin (α-SMA), SLC40A1, LC3, Beclin-1 and ATG7. Immunofluorescence assay was performed to measure LC3 expression in PCa cells. The bioinformatic analysis revealed PRPF19 was highly expressed in PCa which was certified by qRT-PCR, western blot and IHC detection in PCa tissues. The proliferation of PCa cells could be promoted by PRPF19 overexpression and suppressed by PRPF19 knockdown. Moreover, the migration and invasion of PCa cells could be positively regulated by PRPF19 which promoted the expression of E-cadherin, Vimentin, and α-SMA. Furthermore, the expression of LC3, Beclin-1, and ATG7 was negatively regulated by PRPF19, indicating that PRPF19 inhibited autophagy in PCa cells. In the double knockdown of PRPF19 and SLC40A1, PRPF19 repressed the mRNA and reduced protein level of SLC40A1, and SLC40A1 antagonized effects of PRPF19 on proliferation, migration and autophagy of PCa cells. PRPF19 promoted proliferation and migration, and inhibited autophagy in PCa by attenuating SLC40A1 expression, indicating PRPF19 was a potential therapeutic target for PCa treatment.

Hsa_circRNA_100146 Promotes Prostate Cancer Progression by Upregulating TRIP13 via Sponging miR-615-5p

Objective: This study was conducted for investigating the functions of circular RNA circRNA_100146 (circRNA_100146) in the development of prostate cancer (PCa) and identifying the underlying mechanisms of the circRNA_100146/miR-615-5p/TRIP13 axis. Materials and Methods: Under the support of RT-PCR, the expression of circRNA_100146 in PCa cells was examined. Cell Counting Kit-8 (CCK-8) assays and clone formation assays were applied to the assessment of cell proliferation. We then determined cell invasion and migration through transwell assays and wound healing assays. RNA pull-down assays and luciferase reporter assays were performed for the exploration of the regulatory effects of potential molecules on the expressions of the targeting genes. In addition, a nude mouse xenograft model was applied to demonstrate the oncogenic roles of circRNA_100146 in PCa. Results: CircRNA_100146 expression was distinctly upregulated in PCa cells. Silencing of circRNA_100146 suppressed PCa cells' invasion, migration, and proliferation. CircRNA_100146 sponged miR-615-5p to suppress its expressions, while miR-615-5p targeted the 3'-UTR of TRIP13 to repress the expression of TRIP13. In addition, we observed that knockdown of miR-615-5p reversed the suppression of circRNA_100146 silence on the proliferation and invasion of PCa cells. In addition, the tumor growth was also suppressed by silencing circRNA_100146 in vivo. Conclusion: CircRNA_100146 is a tumor promoter in PCa, which promoted progression by mediating the miR-615-5p/TRIP13. CircRNA_100146 can be a potential candidate for targeted therapy of PCa.

Extracapsular extension on multiparametric magnetic resonance imaging better predicts pT3 disease at radical prostatectomy compared to perineural invasion on biopsy

INTRODUCTION

Risk assessment for non-organ-confined prostate cancer (PCa) is important in the surgical planning for radical prostatectomy (RP). Perineural invasion (PNI) on prostate biopsy has been associated with adverse pathological outcomes at prostatectomy. Similarly, the identification of suspected extracapsular extension (ECE) on multiparametric magnetic resonance imaging (mpMRI) has been shown to predict non-organ-confined disease. However, no prior study has compared these factors in predicting adverse pathology at prostatectomy. We evaluated mpMRI ECE and prostate biopsy PNI on multivariable analysis to determine their ability to predict pathological stage at time of RP.

METHODS

We retrospectively investigated the prostatectomy database at our institution to identify men who underwent prostate biopsy with pre-biopsy mpMRI and subsequent RP from 2013-2017. Multivariable regression analysis was performed to compare the association of mpMRI ECE (mECE) and PNI on prostate biopsy on the likelihood of finding pT3 disease on pathology post-prostatectomy.

RESULTS

Of a total 454 RP between 2013 and 2017, 191 patients met our inclusion criteria. Stage pT2 and pT3+ were found in 120 (62.8%) and 71 (37.2%) patients, respectively. Patients with mECE had 4.84 cumulative odds of worse pathological stage on RP (p=0.045) compared to PNI on biopsy, which showed cumulative odds of 2.25 (p=0.048). When controlling only for those patients without PNI, mECE was still found to be a significant predictor of pT3 disease at RP (p=0.030); however, in patients without mECE, PNI was not significant (p=0.062).

CONCLUSIONS

While mECE and biopsy PNI were both associated with worse pathological stage on RP, mECE had significantly higher cumulative odds compared to PNI. The significant predictive ability of mECE adds further clinical value to the use of mpMRI in PCa management. While validation in a larger cohort is required, these factors have important clinical implications with regards to early diagnosis of advanced disease and surgical planning.

Lymphadenectomy in Gleason 7 prostate cancer: Adherence to guidelines and effect on clinical outcomes

BACKGROUND

To examine usage trends, guideline adherence, and survival data for patients undergoing lymphadenectomy (LND) at the time of radical prostatectomy (RP) for Gleason 7 prostate cancer (PCa).

METHODS

The SEER database was queried for all patients with nonmetastatic biopsy Gleason 7 PCa from 2004 to 2013. Distribution and trends of LND were analyzed. The Memorial-Sloan Kettering Cancer Center nomogram was applied to stratify patients based on risk of nodal disease at time of RP (<5% risk or ≥5% risk). Analyses were performed to determine covariates associated with LND receipt at time of RP and cancer-specific mortality (CSM).

RESULTS

A total of 78,641 patients with either G34 or G43 PCa underwent RP (59,194 and 19,447, respectively). Of these patients, 61.2% of G34 and 73.5% of G43 patients underwent LND. During this 10-year period, the proportion of G43 patients undergoing LND remained relatively stable, whereas the proportion of G34 patients undergoing LND ranged between 55.9% and 67.9%. Regional differences were a predictor of LND receipt regardless of risk stratification, but did not translate to higher risk of CSM. Receipt of LND was not predictive of improved CSM in any of the cohorts analyzed.

CONCLUSIONS

The role of LND for Gleason 7 prostate adenocarcinoma is not yet standardized, as indicated by the variability of LND dissection rates. Receipt of LND did not improve CSM, and in G43 patients, it predicted higher CSM. As the effect of LND on CSM is uncertain, further evaluation of oncologic benefit in this patient population is warranted.

[Comparative oncologic and functional outcomes of prostate cancer surgery with other curative treatments]

OBJECTIVE

Review of the comparative results of different treatment strategies (surgery, radiotherapy, ultrasound, surveillance) of prostate cancer, in which the main goal is the local control and the second target is the tolerance of the side effects of those treatments.

MATERIALS AND METHODS

Review of literature using Medline databases selected based on scientific relevance. Clinical keys centered on the oncological and functional outcomes of comparative series between different curative treatments.

RESULTS

The numerous comparative series between surgery and other therapeutic modalities are essentially retrospective with significant methodological bias that is difficult to overcome in order to formulate the optimal thesis. However, there is a clear tendency toward surgery usually with young patients who have intermediate risk tumors without important comorbidity.

CONCLUSION

In the absence of randomized comparative series with significant power, the oncological and functional results of the radical prostatectomy with or without adjuvant treatment seem at least the same, in a selected population of patients, compared with the combination of radiotherapy-hormonotherapy in terms of survival, without biochemical recurrence, disease-specific survival and overall survival, for the aggressive tumors necessitating curative local treatments.

[Oncological outcomes of prostate cancer surgery]

OBJECTIVE

Review of the oncological results of the radical prostatectomy as initial treatment of prostate cancer, according to the surgical approach and the risk stratification using D'Amico risk groups.

MATERIALS AND METHODS

Review of literature using Medline databases and MedScience based on scientific relevance. Research focused on the oncological results of the radical prostatectomy in series and meta-analysis published since 10 years, taking into consideration the surgical approach if mentioned.

RESULTS

The characteristics of the operated tumor highly impact the local control authenticated by the pathologic stage and the rates of positive surgical margins (PSM), in addition to the survival and the biochemical recurrence. Surgical technique adapted according to the tumor treated, was a constant challenge to the urologist, who counter balance between the oncological control and the conservation of urinary and sexual function by conditioning the type of radical prostatectomy. Results of radical prostatectomy acceptable in terms of PSM and survival are not influenced by the surgical approach but by the degree of surgical experience.

CONCLUSION

Results of radical prostatectomy show the efficient local control of prostate cancer, taking into consideration the oncological rules and indications validated by multidisciplinary meetings, based on the national (CCAFU) and European oncological guidelines. Tendency is going toward considering radical prostatectomy indicated for patients with higher risk of disease progression, so integrating surgery in a multidisciplinary personalized approach.