Radical Prostatectomy as Primary Treatment of High-risk Prostate Cancer

Radical Prostatectomy and Pelvic Lymph Node Dissection in Kaiser Permanente Southern California: 15-Year Experience

INTRODUCTION

Radical prostatectomy (RP) with pelvic lymph node dissection (PLND) is the standard treatment of high-risk prostate cancer. High-risk patients and those with lymph node metastasis (LNM) require further treatment. We review outcomes of RP+PLND in Kaiser Permanente Southern California (KPSC).

METHODS

Patients who underwent RP+PLND in KPSC from January 1, 2001, to July 1, 2015 were included. Patient charts were retrospectively reviewed for demographic information and clinicopathologic data which were used to calculate positive surgical margin rate, LNM, adjuvant treatment, 5-year biochemical recurrence, and overall survival. Univariate and multivariate logistic regression analyses were used to identify factors associated with margin positivity.

RESULTS

Patients (N = 1829) underwent RP+PLND (241 high-risk, 943 intermediate-risk, 645 low-risk). Positive margin rates were 17.8%, 14.8%, and 11.9% in the high, intermediate- and low-risk groups. Biochemical recurrence rates were 22% in high-risk and 12.1% in the low-risk category. Androgen deprivation use was 4.1% in the high-risk group and 0.9% in the low-risk group. Five-year overall survival was 92.5% in lymph node-positive patients and 94.9% in lymph node-negative patients (p = 0.8). On multivariate analysis, age (odds ratio [OR] = 1.02, p = 0.02), prebiopsy prostate-specific antigen (OR = 1.02, p < 0.001), and clinical T stage (OR = 1.49, p = 0.01) were associated with margin positivity.

CONCLUSION

In KPSC, RP+PLND was performed in patients with low-, intermediate-, and high-risk prostate cancer. Age, prebiopsy prostate-specific antigen, and clinical stage were associated with positive surgical margins in patients with LNM. Recipients of RP+PLND with LNM and positive surgical margins required adjuvant treatment.

Comparative effectiveness of treatments for high-risk prostate cancer patients

BACKGROUND

To determine the comparative effectiveness of primary radical prostatectomy (RP) compared to external bean radiation therapy (EBRT) with androgen deprivation therapy (ADT), or EBRT plus brachytherapy (BT) with or without ADT among Medicare fee-for-service beneficiaries with high-risk prostate cancer, for 10-year, mortality (overall and prostate cancer-specific), complications, health service use, and cost.

METHODS

This population-based cohort study used Surveillance, Epidemiology, and End Results - Medicare data. Eligible patients were men aged 66 or older and diagnosed with high-risk prostate cancer between 1996 and 2003. Outcomes evaluated were 10-year overall mortality and prostate cancer-specific mortality, complications, health service use, and cost. We used Cox regression, Poisson regression, and Generalized Linear Model (GLM) log-link models to assess the outcomes.

MAIN FINDINGS

The 10-year overall mortality of EBRT + ADT was comparable to that of the RP group (hazard ratio [HR] = 1.09, confidence interval [CI] = 0.72-1.66). The EBRT + BT ± ADT group had overall survival advantage compared to RP (HR = 0.47, CI = 0.31-0.73). Compared to the RP group, EBRT + ADT group had higher 10-year prostate cancer-specific mortality (HR = 2.19, CI = 1.92-5.21). Both EBRT + ADT and EBRT + BT ± ADT were associated with higher 10-year cost (odds ratio = 1.72, CI = 1.35-2.20; and odds ratio = 1.63, CI = 1.29-2.04), compared to RP group. Complications and health service use varied across 3 treatment groups and across phases of care.

PRINCIPAL CONCLUSIONS

Our results also demonstrate long-term overall survival benefits for EBRT + BT ± ADT, and greater bowel and bladder side effects over a decade, compared to RP. The RP group had advantage for long-term prostate-cancer specific mortality, compared to EBRT + ADT group. Thus, RP can provide superior cancer control with clear cost advantage for older men with high-risk disease. In terms of value proposition, our results support RP as preferred treatment option, compared to EBRT + ADT and EBRT + BT ± ADT for high-risk prostate cancer patients.

Cytoreductive prostatectomy: evidence in support of a new surgical paradigm (Review)

Prostate cancer (PCa) remains the second ranked cause of cancer deaths in the United States. The current standard of care for metastatic prostate cancer (mPCa) includes systemic therapies with no option for surgery. In contrast, in other malignancies such as breast and kidney cancer, cyto-reduction plays an integral role in the treatment of metastatic disease. In this framework, there are emerging data that suggest a potential oncologic benefit to cytoreduction in mPCa. The majority of the data are retrospective in nature suggesting that patients with mPCa who had prior radical prostatectomy (RP) had a better survival, as well as improved response to systemic therapy. Similarly, patients who presented with metastatic disease and received definitive local therapy (RP or radiation) had greater survival than patients who received no treatment. In order to confer maximum potential benefit, operating in the setting of mPCa must be technically feasible with acceptable morbidity. It has been demonstrated in many studies that operating on locally advanced disease (T3a/b) does have similar morbidity as lower stage cancer. This may be applicable in the metastatic setting, because although PCa may have metastasized, it may remain locally advanced. On the molecular level there are a number of explanations concerning the potential benefit of cytoreduction. However, these ideas remain speculative with no concrete evidence to date.

Is robot-assisted radical prostatectomy safe in men with high-risk prostate cancer? Assessment of perioperative outcomes, positive surgical margins, and use of additional cancer treatments

INTRODUCTION

Despite a rapid dissemination of robot-assisted radical prostatectomy (RARP) over open radical prostatectomy (ORP), to date no study has compared perioperative outcomes between the two approaches in patients with high-risk prostate cancer (PCa). The aim of our study was to evaluate the safety and feasibility of RARP in this setting.

PATIENTS AND METHODS

Overall, 1,512 patients with high-risk PCa within the Surveillance, Epidemiology, and End RESULTS (SEER) Medicare-linked database diagnosed between 2008 and 2009 were abstracted. Patients were treated with RARP or ORP. Postoperative complications, blood transfusions, prolonged length of stay (pLOS), positive surgical margins, and additional cancer therapy rates were compared. Propensity-score matched analyses and logistic regression models fitted with generalized estimating equations for clustering among hospitals were performed.

RESULTS

Overall, 706 (46.7%) and 806 (53.3%) patients underwent ORP and RARP, respectively. Following propensity-matched analyses, 706 patients remained. No differences were observed in complications (P=0.6), positive surgical margins (P=0.4), or additional therapy after surgery (P=0.2) between patients treated with RARP and ORP; however, RARP was associated with lower rates of transfusions and shorter hospitalization (all P<0.001). In multivariable analyses, patients undergoing RARP were less likely to receive a blood transfusion (P=0.002) or to experience pLOS (P<0.001) compared with men treated with ORP.

CONCLUSIONS

RARP and ORP have comparable complications, positive surgical margins, and additional cancer therapy rates in high-risk PCa. RARP is associated with lower rates of blood transfusions and shorter hospital stays. These findings suggest that RARP is safe and feasible even in this clinical scenario.

The role of radical prostatectomy in high-risk prostate cancer

Because of the increase in prostate cancer patients, urologists can detect more clinically localized prostate cancer in patients before the disease has progressed to advanced stages. Nevertheless, some patients are still diagnosed with high-risk prostate cancer. Even though several treatment options are available for high-risk prostate cancer patients, including radical prostatectomy, radiotherapy, and hormone therapy, used alone or in combination, the recurrence rate is high regardless of the type of treatment. Nevertheless, in the experience of many urologists, a substantial proportion of high-risk prostate cancer patients are cured by local definite therapy or multimodality treatment. Thus, several treatment combinations have been attempted as treatments in these patients. Among them, radical prostatectomy is regarded as the first step in high-risk prostate cancer patients, on a selective basis. In some high-risk prostate cancer patients, surgery is a one-step modality in treatment and has an excellent oncological prognosis. However, because of the lack of evidence and well-controlled comparative prospective studies, the best course of treatment can be unclear, and oncological outcomes often appear heterogeneous. We therefore review the current literature on clinical outcomes in high-risk prostate cancer.

Patient-derived tissue slice grafts accurately depict response of high-risk primary prostate cancer to androgen deprivation therapy

Background

Effective eradication of high-risk primary prostate cancer (HRPCa) could significantly decrease mortality from prostate cancer. However, the discovery of curative therapies for HRPCa is hampered by the lack of authentic preclinical models.

Methods

We improved upon tumorgraft models that have been shown to predict drug response in other cancer types by implanting thin, precision-cut slices of HRPCa under the renal capsule of immunodeficient mice. Tissue slice grafts (TSGs) from 6 cases of HRPCa were established in mice. Following androgen deprivation by castration, TSGs were recovered and the presence and phenotype of cancer cells were evaluated.

Results

High-grade cancer in TSGs generated from HRPCa displayed characteristic Gleason patterns and biomarker expression. Response to androgen deprivation therapy (ADT) was as in humans, with some cases exhibiting complete pathologic regression and others showing resistance to castration. As in humans, ADT decreased cell proliferation and prostate-specific antigen expression in TSGs. Adverse pathological features of parent HRPCa were associated with lack of regression of cancer in corresponding TSGs after ADT. Castration-resistant cancer cells remaining in TSGs showed upregulated expression of androgen receptor target genes, as occurs in castration-resistant prostate cancer (CRPC) in humans. Finally, a rare subset of castration-resistant cancer cells in TSGs underwent epithelial-mesenchymal transition, a process also observed in CRPC in humans.

Conclusions

Our study demonstrates the feasibility of generating TSGs from multiple patients and of generating a relatively large number of TSGs from the same HRPCa specimen with similar cell composition and histology among control and experimental samples in an in vivo setting. The authentic response of TSGs to ADT, which has been extensively characterized in humans, suggests that TSGs can serve as a surrogate model for clinical trials to achieve rapid and less expensive screening of therapeutics for HRPCa and primary CRPC.