Association Between Erectile Dysfunction and Subsequent Prostate Cancer Development: A Population-Based Cohort Study With Double Concurrent Comparison Groups

Phosphodiesterase-5 Inhibitor Use in Robot Assisted Radical Prostatectomy Patients Is Associated with Reduced Risk of Death: A Propensity Score Matched Analysis of 1,058 Patients

PURPOSE

We investigated whether the use of a phosphodiesterase-5 inhibitor (PDE5i) after robot assited radical prostatectomy has a survival benefit over non-use patients because there are controversial results on the association between PDE5i use and survival outcomes for prostate cancer patients in literature.

MATERIALS AND METHODS

We designed a retrospective, matched, large-sample cohort study of 5,545 patients who underwent robot assisted radical prostatectomy (RARP) during 2013-2021 in a single institute. The exclusion criteria was patients who were aged >70 years at surgery, American Society of Anesthesiologists (ASA) physical status classification grade 4 or 5, history of other malignancies, patients who started PDE5i 6 months after survery and patients with follow up period less than 24 months after surgery. Among the 1,843 included patients, 1,298 were PDE5i users, and 545 were PDE5i non-users. We performed propensity score matching (PSM) of PDE5i users (n=529) with non-users (n=529) by adjusting for the variables of age, Gleason grade group, pathological T stage, preoperative ASA physical status grade, and International Index of Erectile Function score.

RESULTS

There were no significant difference in patient characteristics according to PSM. Kaplan-Meier curve revealed the difference of overall survival for PDE5i users and non-users (clustered log-rank test p<0.05). In a stratified Cox regression analysis, PDE5i use after RARP was associated with improved overall survival and reduced risk of death (hazard ratio 0.43; confidence interval 0.24-0.79; p=0.007). The limitation of this study was that the indication for the prescription of PDE5i was not given.

CONCLUSIONS

PDE5i administration after RARP were associated with overall survival of patients with prostate cancer. A further randomized control trial may reveal whether routine use of PDE5i after prostatectomy can improve survival of prostate cancer patient.

The association between sexual dysfunction and prostate cancer: a systematic review and meta-analysis

BACKGROUND

Whether there is a connection between sexual dysfunction (SD) and prostate cancer (PCa) is controversial.

AIM

We sought to review the interrelationship between SD and PCa and to determine whether there is a definitive risk of men developing PCa after suffering from SD.

METHODS

A complete search of the PubMed, Web of Science, Ovid MEDLINE, Embase, and Cochrane Library databases was performed to search for eligible studies published up to October 2022. The protocol for this meta-analysis is available from PROSPERO (ID: CRD42022342381).

OUTCOMES

The associations between SD and the risk of PCa were assessed by calculating pooled ORs with 95% CIs, and the standard mean difference (SMD) and its 95% CI were used to assess the relationship between SD and prostate-specific antigen (PSA) levels or prostate volume (PV). Random-effects models were used to account for potential heterogeneity, and the Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the included studies.

RESULTS

Twenty studies involving 215,626 individuals were included in our meta-analysis. Compared with controls, subjects with SD had a 1.62-fold increased risk of PCa (OR = 1.62, 95% CI, 1.77-2.23, P = .003; heterogeneity: I2 = 97.8%, P < .001). Patients with SD had higher PSA levels than controls (SMD =0.07, 95% CI, 0.00 to 0.13, P = .041; heterogeneity: I2 = 55.6%, P = .027). However, there was no association between SD and PV (SMD = 0.03, 95% CI, -0.05 to 0.11, P = .122; heterogeneity: I2 = 48.5%, P = .100).

CLINICAL IMPLICATIONS

Current evidence confirms a potential link between SD and the risk of PCa and that SD in PCa patients should be of concern to clinicians.

STRENGTHS AND LIMITATIONS

The strength of this study is that it is to our knowledge the first meta-analysis of studies on the risk of PCa in men with SD. A limitation is that most of the studies included in this meta-analysis focused on ED.

CONCLUSION

Our systematic review and meta-analysis results suggest that men with SD have a higher risk of PCa and higher PSA levels than men without SD. However, this is merely inferential, and causality cannot be determined based on the current data. Further longitudinal studies should be performed to validate our preliminary findings.

Long-term administration of resveratrol and MitoQ stimulates cavernosum antioxidant gene expression in a mouse castration model of erectile dysfunction

AIMS

Erectile dysfunction is a common complication within many pathological conditions associated with low testosterone. Testosterone deficiency increases oxidative stress in the penile tissue that contributes to endothelial dysfunction and subsequent erectile dysfunction. Current therapies do not ameliorate oxidative stress so targeting oxidative stress may improve erectile dysfunction. Resveratrol and MitoQ are two prospective drugs that have antioxidant-like properties and may be useful to improve erectile dysfunction induced by androgen deprivation.

MATERIALS AND METHODS

We castrated 12-week-old male C57BL/6 mice and performed an eight-week intervention with oral delivery of resveratrol or MitoQ at low and high doses. We assessed vascular reactivity of the corpus cavernosum and internal pudendal arteries (IPA) through dose-dependent responses to vasodilatory, vasocontractile, and neurogenic stimuli in a myograph system. We performed qRT-PCR to measure expression changes of 18 antioxidant genes in the corpus cavernosum.

KEY FINDINGS

Castration significantly impaired erectile function via impaired endothelial-dependent and-independent relaxation, and increased constriction of the corpus cavernosum, and induced severe endothelial dysfunction of the IPA. Castration decreased expression of 8 of the antioxidant genes investigated. Resveratrol and MitoQ were ineffective in reversing the effects of androgen deprivation on vascular reactivity, however high-dose resveratrol treatment upregulated several key antioxidant genes, including Cat, Sod1, Gstm1, and Prdx3.

SIGNIFICANCE

Our findings suggest that oral resveratrol and MitoQ treatment may provide protection to the corpus cavernosum under androgen deprived conditions by stimulating endogenous antioxidant systems. However, they may need to be paired with vasoactive drugs to reverse erectile dysfunction under androgen deprived conditions.

High altitude exposure affects male reproductive parameters: Could it also affect the prostate?†

Living at high altitudes and living with prostatic illness are two different conditions closely related to a hypoxic environment. People at high altitudes exposed to acute, chronic, or intermittent hypobaric hypoxia turn on several mechanisms at the system, cellular and molecular level to cope with oxygen atmosphere scarcity maintaining the oxygen homeostasis. This exposure affects the whole organism and function of many systems, such as cardiovascular, respiratory, and reproductive. On the other hand, malignant prostate is related to the scarcity of oxygen in the tissue microenvironment due to its low availability and high consumption due to the swift cell proliferation rates. Based on the literature, this similarity in the oxygen scarcity suggests that hypobaric hypoxia, and other common factors between these two conditions, could be involved in the aggravation of the pathological prostatic status. However, there is still a lack of evidence in the association of this disease in males at high altitudes. This review aims to examine the possible mechanisms that hypobaric hypoxia might negatively add to the pathological prostate function in males who live and work at high altitudes. More profound investigations of hypobaric hypoxia's direct action on the prostate could help understand this exposure's effect and prevent worse prostate illness impact in males at high altitudes.

The Etiology and Pathophysiology Genesis of Benign Prostatic Hyperplasia and Prostate Cancer: A New Perspective

Background: The etiology of benign prostatic hyperplasia and prostate cancer are unknown, with ageing being the greatness risk factor. Methods: This new perspective evaluates the available interdisciplinary evidence regarding prostate ageing in terms of the cell biology of regulation and homeostasis, which could explain the timeline of evolutionary cancer biology as degenerative, inflammatory and neoplasm progressions in these multifactorial and heterogeneous prostatic diseases. Results: This prostate ageing degeneration hypothesis encompasses the testosterone-vascular-inflamm-ageing triad, along with the cell biology regulation of amyloidosis and autophagy within an evolutionary tumorigenesis microenvironment. Conclusions: An understanding of these biological processes of prostate ageing can provide potential strategies for early prevention and could contribute to maintaining quality of life for the ageing individual along with substantial medical cost savings.

Metformin reduces prostate cancer risk among men with benign prostatic hyperplasia: A nationwide population-based cohort study

Benign Prostate Hyperplasia (BPH) has been associated with prostate cancer prevalent among men after 50 years of age, however, it is unclear whether the antidiabetic drug, metformin, can reduce prostate cancer for men with BPH. The insurance claims data of men aged 50 years or older, with both type 2 diabetes mellitus (T2DM) and BPH diagnosed from 1997 to 2007 were analyzed. Individuals were followed up for at least 5 years. We identified 2906 and 2906 patients as the metformin cohort and nonmetformin cohort, respectively. The Cox method analysis showed that the metformin cohort had an adjusted hazard ratio (aHR) of 0.69 (95% confidence interval [CI] = 0.49‐0.96, P = 0.0298) for prostate cancer, compared to the nonmetformin cohort after controlling for age, traditional Chinese medicine (TCM) use, prostate specific antigen, and Charlson comorbidity index. Patients using TCM for BPH (per 6 months) also had an aHR of 0.41 (95% CI = 0.24‐0.69; P = 0.0009). In conclusion, both metformin medication and TCM use could be associated with reduced risk of prostate cancer for men with BPH and diabetes.

Free testosterone value before radical prostatectomy is related to oncologic outcomes and post-operative erectile function

PURPOSE

To investigate whether free testosterone (FT) prior to radical prostatectomy was related to post-operative oncologic outcomes, erectile function and continence.

METHODS

The data of 586 patients with available information underwent treatment in our center was retrospectively reviewed. Total testosterone (TT) was tested by chemiluminescence immunoassay, and FT value was calculated using Vermeulen's formula. Post-operative continence and erectile function were evaluated by the requirement of pad and the IIEF-5 score at 12 months.

RESULTS

The median TT and FT value was 344 ng/dL (interquartile, IQR 314-374) and 6.9 ng/dL (IQR 6.4-7.3), and 106 patients (18.1%) and 152 patients (25.9%) were evaluated as having low TT and low FT based on current guidelines. Low TT and FT value were both related to older age (both p < 0.001), concomitant diabetes (p = 0.018 & 0.049), higher possibility of pre-operative erectile dysfunction (ED, both p < 0.001), higher pre-operative PSA value (both p < 0.001), higher clinical stage (both p < 0.001) and higher Gleason score in biopsy (both p < 0.001). Low FT was related to higher risk for pT3 (p = 0.020) and high Gleason score (p = 0.011) in logistic regression. The median follow-up duration was 52 moths (IQR 29-67) and FT was found to be an independent risk factor for biochemical recurrence (p = 0.005). In logistic regression TT was related to pre-operative ED (p = 0.010) and FT was related to post-operative ED (p = 0.001).

CONCLUSION

Low FT value before radical prostatectomy was related to adverse pathological outcomes, biochemical recurrence and post-operative ED.