The effect of cisplatin-based neoadjuvant chemotherapy on the renal function of patients undergoing radical cystectomy

INTRODUCTION

Cisplatin-based neoadjuvant chemotherapy (NAC) is the standard of care for patients with muscle-invasive bladder cancer (MIBC) undergoing radical cystectomy (RC). Cisplatin, however, can induce renal toxicity. Furthermore, RC is an independent risk factor for renal injury, with decreases in estimated glomerular filtration rate (eGFR) of up to 6 mL/min/1.73 m2 reported at one year postoperatively. Our objective was to evaluate the effect of cisplatin-based NAC and RC on the renal function of patients undergoing both.

METHODS

We analyzed a multicenter database of patients with MIBC, all of whom received cisplatin-based NAC prior to RC. eGFR values were collected at time points T1 (before NAC), T2 (after NAC but before RC), and T3 (one year post-RC). eGFR and proportion of patients with eGFR <60 ml/min/1.73m2 (chronic kidney disease [CKD] stage ≥3) were compared between these time points. As all patients in this dataset had received NAC, we identified a retrospective cohort of patients from one institution who had undergone RC during the same time period without NAC for context.

RESULTS

We identified 234 patients with available renal function data. From T1 to T3, there was a mean decline in eGFR of 17% (13 mL/min/1.73 m2) in the NAC cohort and an increase in proportion of patients with stage ≥3 CKD from 27% to 50%. The parallel cohort of patients who did not receive NAC was comprised of 236 patients. The mean baseline eGFR in this cohort was lower than in the NAC cohort (66 vs. 75 mL/min/1.73 m2). The mean eGFR decline in this non-NAC cohort from T1 to T3 was 6% (4 mL/min/1.73 m2), and the proportion of those with stage ≥3 CKD increased from 37% to 51%.

CONCLUSIONS

Administration of NAC prior to RC was associated with a 17% decline in eGFR and a nearly doubled incidence of stage ≥3 CKD at one year after RC. Patients who underwent RC without NAC had a higher rate of stage ≥3 CKD at baseline but appeared to have less renal function loss at one year.

Multicenter evaluation of neoadjuvant and induction gemcitabine-carboplatin versus gemcitabine-cisplatin followed by radical cystectomy for muscle-invasive bladder cancer

PURPOSE

Cisplatin-based chemotherapy followed by radical cystectomy (RC) is recommended in patients with muscle-invasive bladder cancer (MIBC). However, up to 50% of patients are cisplatin ineligible. The aim of this study was to compare clinical outcomes after ≥ 3 cycles of preoperative gemcitabine-carboplatin (gem-carbo) versus gemcitabine-cisplatin (gem-cis).

METHODS

We identified 1865 patients treated at 19 centers between 2000 and 2013. Patients were included if they had received ≥ 3 cycles of neoadjuvant (cT2-4aN0M0) or induction (cTanyN + M0) gem-carbo or gem-cis followed by RC.

RESULTS

We included 747 patients treated with gem-carbo (n = 147) or gem-cis (n = 600). Patients treated with gem-carbo had a higher Charlson Comorbidity Index (p = 0.016) and more clinically node-positive disease (32% versus 20%; p = 0.013). The complete pathological response (pCR; ypT0N0) rate did not significantly differ between gem-carbo and gem-cis (20.7% versus 22.1%; p = 0.73). Chemotherapeutic regimen was not significantly associated with pCR (OR 0.99 [95%CI 0.61-1.59]; p = 0.96), overall survival (OS) (HR 1.20 [95%CI 0.85-1.67]; p = 0.31), or cancer-specific survival (CSS) (HR 1.35 [95%CI 0.93-1.96]; p = 0.11). Median OS of patients treated with gem-carbo and gem-cis was 28.6 months (95%CI 18.1-39.1) and 45.1 months (95%CI 32.7-57.6) (p = 0.18), respectively. Median CSS of patients treated with gem-carbo and gem-cis was 28.8 months (95%CI 9.8-47.8) and 71.0 months (95%CI median not reached) (p = 0.02), respectively. Subanalyses of the neoadjuvant and induction setting did not show significant survival differences.

CONCLUSION

Our results show that a subset of cisplatin-ineligible patients with MIBC achieve pCR on gem-carbo and that survival outcomes seem comparable to gem-cis provided patients are able to receive ≥ 3 cycles and undergo RC.

Neoadjuvant chemotherapy plus radical cystectomy versus radical cystectomy alone in clinical T2 bladder cancer without hydronephrosis

OBJECTIVES

To assess the efficacy of neoadjuvant chemotherapy (NAC) before radical cystectomy (RC) in a retrospective multicentre cohort of patients with cT2N0M0 bladder cancer (BCa) without preoperative hydronephrosis.

PATIENTS AND METHODS

This was a propensity-based analysis of 619 patients. Of these, 316 were treated with NAC followed by RC and 303 with upfront RC. After multiple imputations, inverse probability of treatment weighting (IPTW) was used to account for potential selection bias. Multivariable logistic regression analysis was performed to evaluate the impact of NAC on pathological complete response and downstaging at RC, while IPTW-adjusted Kaplan-Meier curves and Cox regression models were built to evaluate the impact of NAC on overall survival (OS).

RESULTS

After IPTW-adjusted analysis, standardised differences between groups were <15%. A complete response (pT0N0) at final pathology was achieved in 94 (30%) patients receiving NAC and nine (3%) undergoing upfront RC. Downstaging to non-muscle-invasive disease (<pT2N0M0) was observed in 174 (55%) patients after NAC and in 72 (24%) without NAC. On multivariable analysis, NAC was found to be an independent predictor of both pathological complete response and downstaging. No significant difference with respect to OS was observed between groups with a median follow-up of 18 months.

CONCLUSIONS

In patients with cT2N0 BCa and no preoperative hydronephrosis, NAC increased the rate of pathological complete response and downstaging.

Comparative effectiveness of neoadjuvant chemotherapy in bladder and upper urinary tract urothelial carcinoma

Objective

To assess the differential response to neoadjuvant chemotherapy (NAC) in patients with urothelial carcinoma of the bladder (UCB) compared to upper tract urothelial carcioma (UTUC) treated with radical surgery.

Patients and Methods

Data from 1299 patients with UCB and 276 with UTUC were obtained from multicentric collaborations. The association of disease location (UCB vs UTUC) with pathological complete response (pCR, defined as a post‐treatment pathological stage ypT0N0) and pathological objective response (pOR, defined as ypT0‐Ta‐Tis‐T1N0) after NAC was evaluated using logistic regression analyses. The association with overall (OS) and cancer‐specific survival (CSS) was evaluated using Cox regression analyses.

Results

A pCR was found in 250 (19.2%) patients with UCB and in 23 (8.3%) with UTUC (P < 0.01). A pOR was found in 523 (40.3%) patients with UCB and in 133 (48.2%) with UTUC (P = 0.02). On multivariable logistic regression analysis, patients with UTUC were less likely to have a pCR (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.27–0.70; P < 0.01) and more likely to have a pOR (OR 1.57, 95% CI 1.89–2.08; P < 0.01). On univariable Cox regression analyses, UTUC was associated with better OS (hazard ratio [HR] 0.80, 95% CI 0.64–0.99, P = 0.04) and CSS (HR 0.63, 95% CI 0.49–0.83; P < 0.01). On multivariable Cox regression analyses, UTUC remained associated with CSS (HR 0.61, 95% CI 0.45–0.82; P < 0.01), but not with OS.

Conclusions

Our present findings suggest that the benefit of NAC in UTUC is similar to that found in UCB. These data can be used as a benchmark to contextualise survival outcomes and plan future trial design with NAC in urothelial cancer.

Nomogram Predicting Bladder Cancer-specific Mortality After Neoadjuvant Chemotherapy and Radical Cystectomy for Muscle-invasive Bladder Cancer: Results of an International Consortium

BACKGROUND

Cisplatin-based neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) is associated with improved overall and cancer-specific survival. The post-NAC pathological stage has previously been reported to be a major determinant of outcome.

OBJECTIVE

To develop a postoperative nomogram for survival based on pathological and clinical parameters from an international consortium.

DESIGN, SETTING, AND PARTICIPANTS

Between 2000 and 2015, 1866 patients with MIBC were treated at 19 institutions in the USA, Canada, and Europe. Analysis was limited to 640 patients with adequate follow-up who had received three or more cycles of NAC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

A nomogram for bladder cancer-specific mortality (BCSM) was developed by multivariable Cox regression analysis. Decision curve analysis was used to assess the model's clinical utility.

RESULTS AND LIMITATIONS

A total of 640 patients were identified. Downstaging to non-MIBC (ypT1, ypTa, and ypTis) occurred in 271 patients (42 %), and 113 (17 %) achieved a complete response (ypT0N0). The 5-yr BCSM was 47.2 % (95 % confidence interval [CI]: 41.2-52.6 %). On multivariable analysis, covariates with a statistically significant association with BCSM were lymph node metastasis (hazard ratio [HR] 1.90 [95% CI: 1.4-2.6]; p < 0.001), positive surgical margins (HR 2.01 [95 % CI: 1.3-2.9]; p < 0.001), and pathological stage (with ypT0/Tis/Ta/T1 as reference: ypT2 [HR 2.77 {95 % CI: 1.7-4.6}; p < 0.001] and ypT3-4 [HR 5.9 {95 % CI: 3.8-9.3}; p < 0.001]). The area under the curve of the model predicting 5-yr BCSM after cross validation with 300 bootstraps was 75.4 % (95 % CI: 68.1-82.6 %). Decision curve analyses showed a modest net benefit for the use of the BCSM nomogram in the current cohort compared with the use of American Joint Committee on Cancer staging alone. Limitations include the retrospective study design and the lack of central pathology.

CONCLUSIONS

We have developed and internally validated a nomogram predicting BCSM after NAC and radical cystectomy for MIBC. The nomogram will be useful for patient counseling and in the identification of patients at high risk for BCSM suitable for enrollment in clinical trials of adjuvant therapy.

PATIENT SUMMARY

In this report, we looked at the outcomes of patients with muscle-invasive bladder cancer in a large multi-institutional population. We found that we can accurately predict death after radical surgical treatment in patients treated with chemotherapy before surgery. We conclude that the pathological report provides key factors for determining survival probability.

Outcomes of men with ductal prostate cancer undergoing definitive therapy for localized disease

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Background: Ductal prostate adenocarcinoma (DAC) is an aggressive variant of prostate cancer (PC). We aimed to assess the outcomes of men with localized DAC undergoing radical prostatectomy (RP) or external beam radiotherapy (RTx) compared to acinar adenocarcinoma of the prostate (PAC) and investigate any difference between these treatment modalities. Methods: All patients presenting to our institution with localized DAC from January 2005 - November 2018 were compared to a pooled cohort of patients from 3 tertiary referral centers who underwent RP for Gleason 8 PC and a cohort of high risk PC patients who underwent RTx for PAC. Patient, tumor characteristics and outcome data were analyzed. Results: 257 men with DAC were identified and compared to 803 with PAC. 203 men with DAC and 729 men with PAC underwent RP while 54 men with DAC and 74 men with PAC underwent RTx. Men with DAC were older (65 vs 63 years and 70.5 vs 66 years) and had higher cT3/T4 stage (43% vs 2.8% and 44.5% vs 31.1%) in both groups, respectively (all p <0.05). The median follow-up for men undergoing RP was 34 (range 0.9 to 177) months and 73.4 (range 0.6 – 224.2) months for men having RTx. Presence of DAC was an independent risk factor for metastases (HR 2.5 (95% CI 1.4- 4.8); p<0.01) and death (HR 2.3 (95% CI 1.1 – 4.7); p=0.02) following RP. The 3- year overall survival (OS) rates for DAC and PAC in men undergoing RP were 93.3% vs 99.3% (p<0.01). On adjusting for Gleason score, clinical T stage, PSA and age, DAC was also an independent risk factor for death (HR 6.1 (95% CI 1.7-22.2); p<0.01) in men undergoing RTx with 5-year OS rates of 100% and 81.6% for DAC and PAC, respectively. There was no difference in the OS of men with DAC between RP and RTx. Conclusions: Men undergoing RP or RTx for localized DAC had worse outcomes compared to PAC, but no survival difference was seen between these treatment modalities. DAC behaves clinically differently than PAC. Further evaluation of the underlying biology and potential for specific targeted multimodality therapies in DAC is needed.

Association of Baseline Prostate-Specific Antigen Level With Long-term Diagnosis of Clinically Significant Prostate Cancer Among Patients Aged 55 to 60 Years: A Secondary Analysis of a Cohort in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial

IMPORTANCE

The use of prostate-specific antigen (PSA) screening for prostate cancer is controversial because of the risk of overdiagnosis and overtreatment of indolent cancers. Optimal screening strategies are highly sought.

OBJECTIVE

To estimate the long-term risk of any prostate cancer and clinically significant prostate cancer based on baseline PSA levels among men aged 55 to 60 years.

DESIGN, SETTING, AND PARTICIPANTS

This secondary analysis of a cohort in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial uses actuarial analysis to analyze the association of baseline PSA levels with long-term risk of any prostate cancer and of clinically significant prostate cancer among men aged 55 to 60 years enrolled in the screening group of the trial between 1993 and 2001.

EXPOSURE

Single PSA measurement at study entry.

MAIN OUTCOMES AND MEASURES

Long-term risk of any prostate cancer and clinically significant prostate cancer diagnoses.

RESULTS

There were 10 968 men aged 55 to 60 years (median [interquartile range] age, 57 [55-58] years) at study enrollment in the screening group of the PLCO Cancer Screening Trial who had long-term follow-up. Actuarial 13-year incidences of clinically significant prostate cancer diagnosis among participants with a baseline PSA of 0.49 ng/mL or less was 0.4% (95% CI, 0%-0.8%); 0.50-0.99 ng/mL, 1.5% (95% CI, 1.1%-1.9%); 1.00-1.99 ng/mL, 5.4% (95% CI, 4.4%-6.4%); 2.00-2.99 ng/mL, 10.6% (95% CI, 8.3%-12.9%); 3.00-3.99 ng/mL, 15.3% (95% CI, 11.4%-19.2%); and 4.00 ng/mL and greater, 29.5% (95% CI, 24.2%-34.8%) (all pairwise log-rank P ≤ .004). Only 15 prostate cancer-specific deaths occurred during 13 years of follow-up, and 9 (60.0%) were among men with a baseline PSA level of 2.00 ng/mL or higher.

CONCLUSIONS AND RELEVANCE

In this secondary analysis of a cohort from the PLCO Cancer Screening Trial, baseline PSA levels among men aged 55 to 60 years were associated with long-term risk of clinically significant prostate cancer. These findings suggest that repeated screening can be less frequent among men aged 55 to 60 years with a low baseline PSA level (ie, <2.00 ng/mL) and possibly discontinued among those with baseline PSA levels of less than 1.00 ng/mL.

The prognostic value of the neutrophil-to-lymphocyte ratio in patients with muscle-invasive bladder cancer treated with neoadjuvant chemotherapy and radical cystectomy

INTRODUCTION

The neutrophil-to-lymphocyte ratio (NLR) is an attractive marker because it is derived from routine bloodwork. NLR has shown promise as a prognostic factor in muscle invasive bladder cancer (MIBC) but its value in patients receiving neoadjuvant chemotherapy (NAC) before radical cystectomy (RC) is not yet established. Since NLR is related to an oncogenic environment and poor antitumor host response, we hypothesized that a high NLR would be associated with a poor response to NAC and would remain a poor prognostic indicator in patients receiving NAC.

METHODS

A retrospective analysis was performed on patients with nonmetastatic MIBC (cT2-4aN0M0) who received NAC prior to RC between 2000 and 2013 at 1 of 19 centers across Europe and North America. The pre-NAC NLR was used to split patients into a low (NLR ≤ 3) and high (NLR > 3) group. Demographic and clinical parameters were compared between the groups using Student's t test, chi-squared, or Fisher's exact test. Putative risk factors for disease-specific and overall survival were analyzed using Cox regression, while predictors of response to NAC (defined as absence of MIBC in RC specimen) were investigated using logistic regression.

RESULTS

Data were available for 340 patients (199 NLR ≤ 3, 141 NLR > 3). Other than age and rate of lymphovascular invasion, demographic and pretreatment characteristics did not differ significantly. More patients in the NLR > 3 group had residual MIBC after NAC than the NLR ≤ 3 group (70.8% vs. 58.3%, P = 0.049). NLR was the only significant predictor of response (odds ratio: 0.36, P = 0.003) in logistic regression. NLR was a significant risk factor for both disease-specific (hazard ratio (HR): 2.4, P = 0.006) and overall survival (HR:1.8, P = 0.02).

CONCLUSION

NLR > 3 was associated with a decreased response to NAC and shorter disease-specific and overall survival. This suggests that NLR is a simple tool that can aid in MIBC risk stratification in clinical practice.

Phase II trial of continuous treatment with sunitinib in patients with high-risk (BCG-refractory) non-muscle invasive bladder cancer

Purpose Sunitinib is a vascular endothelial growth factor receptor (VEGFR) inhibitor with antitumor activity against bladder cancer. We hypothesized that treatment with sunitinib may decrease progression or recurrence in non-muscle invasive bladder cancer (NMIBC) refractory to intra-vesical BCG. Patients and Methods This is a single-arm phase II study of sunitinib in patients (pts) with NMIBC who progressed after BCG. Treatment included sunitinib 37.5 g daily for 12 weeks followed by 12± 2-week cystoscopy and surveillance for one year. The primary endpoint was the complete response rate at 12 months. Secondary endpoints included recurrence free survival (RFS), progression free survival (PFS), overall survival (OS), and safety of sunitinib. Correlative studies on effects of sunitinib on myeloid derived suppressor cells (MDSC) and humoral immune responses were also performed. This trial was registered on ClinicalTrials.gov, number NCT01118351. Results Between June 2011 and September 2011, 15/19 pts. completed 12 weeks of therapy. The remaining 4 pts. had treatment related adverse events leading to discontinuation of sunitinib with one patient withdrawing consent. On the 12-week cystoscopy, 44% (8/18) of the pts. showed remission, 50% (9/18) progression and 1/18 recurrence. Overall, 22% (4/18) of pts. remained free of progression for >12 months. Grade (G) 4 toxicities were noted in 2 pts. (anemia and thrombocytopenia) while G3 were noted in 58%. Sunitinib resulted in reversal of MDSC mediated immunosuppression. Conclusions In NMIBC refractory to BCG, treatment with sunitinib was safe but not associated with improved clinical outcomes. The immune effects of sunitinib deserve further investigation.

Older Age at Diagnosis and Initial Disease Volume Predict Grade Reclassification Risk on Confirmatory Biopsy in Patients Considered for Active Surveillance

OBJECTIVE

To identify which active surveillance candidates benefit most from confirmatory biopsies to exclude grade underclassification.

MATERIALS AND METHODS

This observational study includes 556 men diagnosed between 2002 and 2015 with Gleason 3 + 3 (GG1) disease on initial diagnostic biopsy, of whom 406 received a confirmatory biopsy within 12 months for active surveillance. Multivariable logistic regression analysis was performed to determine clinicopathologic features associated with Gleason 7 or higher (GG2+) on a confirmatory biopsy. Regression tree analysis was employed to stratify patients into select risk groups.

RESULTS

Eighty-five of 406 patients (20.9%) with initially GG1 disease were reclassified to GG2+ on a confirmatory biopsy. On multivariable analysis, increasing age (per year odds ratio 1.07; 95% confidence interval 1.02-1.12; P <.01) and more positive cores at diagnosis (per core, odds ratio 1.37, 95% confidence interval 1.09-1.72; P <.01) were significantly associated with reclassification, independent of prostate volume, clinical stage, initial PSA, or confirmatory biopsy type (including magnetic resonance imaging-targeted approaches or transrectal saturation random sampling). Recursive partitioning demonstrated that age over 73 and 5 or more positive cores were factors associated with the greatest reclassification risk.

CONCLUSION

In our cohort, both advancing age and additional positive cores were associated with increased odds of reclassification to GG2+ on confirmatory biopsy. In men over age 73 or with 5 or more positive cores, a repeat biopsy within 12 months may be particularly beneficial to minimize tumor grade underclassification.

Randomized phase II trial of neoadjuvant everolimus in patients with high-risk localized prostate cancer

Background Despite definitive local therapy, patients with high-risk prostate cancer have a significant risk for local and distant failure. To date, no systemic therapy given prior to surgery has been shown to improve outcomes. The phosphatidilinositol 3-kinase/AKT/mTOR pathway is commonly dysregulated in men with prostate cancer. We sought to determine the clinical efficacy and safety of the mTOR/TORC1 inhibitor everolimus in men with high-risk prostate cancer undergoing radical prostatectomy. Methods This is a randomized phase II study of everolimus at two different doses (5 and 10 mg daily) given orally for 8 weeks before radical prostatectomy in men with high-risk prostate cancer. The primary endpoint was the pathologic response (histologic P0, margin status, extraprostatic extension) and surgical outcomes. Secondary endpoints included changes in serum PSA level and treatment effects on levels of expression of mTOR, p4EBP1, pS6 and pAKT. Results Seventeen patients were enrolled: nine at 10 mg dose and eight at 5 mg dose. No pathologic complete responses were observed and the majority of patients (88%) had an increase in their PSA values leading to this study being terminated early due to lack of clinical efficacy. Treatment-related adverse events were similar to those previously reported with the use of everolimus in other solid tumors and no additional surgical complications were observed. A significant decrease in the expression of p4EBP1 was noted in prostatectomy samples following treatment. Conclusions Neoadjuvant everolimus given at 5 mg or 10 mg daily for 8 weeks prior to radical prostatectomy did not impact pathologic responses and surgical outcomes of patients with high-risk prostate cancer. Trial registration NCT00526591 .

Blood myeloid derived suppressor cells (MDSC) in metastatic urothelial carcinoma (mUC) are correlated with neutrophil-to-lymphocyte ratio (NLR) and overall survival (OS)

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Background: MDSC have been linked to the chronic inflammatory microenvironment of tumor cells and pathologic outcomes in UC patients (pts) undergoing cystectomy. NLR is an established inflammatory biomarker with prognostic properties in mUC. We hypothesized that MDSCs correlate with NLR and OS in mUC. Methods: MDSCs were measured in blood samples from mUC patients by fresh unfractionated whole blood (WB) and peripheral blood mononuclear cells (PBMC). MDSCs were identified by flow cytometry in WB and defined as LinloCD33+/HLADR- (Total MDSC). MDSC subsets were defined as polymorphonuclear (PMN-MDSC: CD15+/CD14-), monocytic (M-MDSC: CD15-/CD14+), and uncommitted (UC-MDSC: CD15-/CD14-). MDSC populations were presented as % of live nucleated blood cells from PB and absolute numbers from WB. Spearman’s correlation assessed correlations between MDSC & NLR. Kaplan Meier curves and log rank test estimated OS from the time of MDSC collection to last follow up or date of death. Results: Of 79 pts, 77% were men and 42% were never smokers with a median age of 69 (31-83). Overall, 71% had pure UC and 81% had lower tract UC. Prior therapies include intravesical therapy (22%), neoadjuvant chemotherapy (31%), and cystectomy/nephroureterectomy (61%). Median follow up was 12 months (range: 0.6-36.5). PMN-MDSC was the predominant subset in WB and PBMC. There was significant correlation between individual MDSC subsets in WB and PBMC (p≤0.001). Negative correlation was noted between NLR and WB UC-MDSC:PMN-MDSC ratios (rho = -0.27, p = 0.03), as well as NLR and PB UC-MDSC:PMN-MDSC (rho = -0.28, p = 0.02). Median survival was 17.7 months (95% CI: 11.0-NA months). Overall 1-yr and 3-yr survival were 0.60 (95% CI: 0.49-0.73) and 0.15 (95% CI: 0.03-0.67), respectively. Higher WB UC-MDSC levels were associated with shorter OS (HR 2.85, 95% CI: 1.43-5.65, p = 0.003). Conclusions: Specific MDSC subsets correlate with NLR. Higher WB UC-MDSC levels have negative prognostic roles for OS. Given the feasibility of serial blood draws, dynamic assessment of MDSC over time and further validation with longer follow up are needed.

Moderately hypofractionated radiotherapy for localized prostate cancer: Long-term outcomes for 854 consecutive patients treated over 10 years (70 Gy in 2.5 Gy/fraction)

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Background: Moderately hypofractionated radiotherapy has been increasingly adopted in the management of localized prostate cancer (PCa). We report 10-year outcomes for patients treated with intensity modulation radiation therapy (IMRT) for localized PCa with 70 Gy in 28 fractions at 2.5 Gy/fraction. Methods: This retrospective study included 854 consecutive patients with localized PCa treated with image-guided moderately hypofractionated IMRT at a single institution between 1998 and 2012. Patients with a single intermediate-risk factor were considered to have favorable intermediate-risk (FIR) disease; multiple intermediate-risk factors were considered unfavorable (UIR). Biochemical relapse free survival (bRFS), clinical relapse free survival (cRFS), overall survival (OS) and PCa specific mortality (PCSM) were analyzed used Kaplan-Meier analysis. Grade ≥3 genitourinary (GU) and gastrointestinal (GI) toxicities were recorded (CTCAE v4.03). Results: The median follow-up was 11.3 years (Max. 19 years). For patients with low-risk (LR, 31%), FIR (28%), UIR (12.5%), and high-risk (HR, 28.5%) disease the 10 year bRFS rates were 88%, 78%, 71% and 42%, respectively (p < 0.0001). The number of patients receiving no ADT, 1-6 months, or > 6 months of ADT were 39%, 50%, and 11%, respectively, reflecting practice patterns during this treatment period. The 10-year cRFS were 95%, 91%, 85% and 72% for patients with LR, FIR, UIR, and HR, respectively (p < 0.0001). The 10-year actuarial OS rate was 69% (95% CI 66-73%) and the 10-year PCSM was 6.8% (95% CI 5.1-8.6%) overall. For patients with LR, FIR, UIR and HR disease, the 10 year PCSM rates were 2%, 5%, 5% and 15%. 10-year cumulative incidence of grade ≥3 GU and GI toxicity was 2% and 1%, respectively. Multivariate analysis identified associations between clinical variables (ADT use, PSA nadir < 0.5ng/ml, and ISUP Grade Group) and bRFS, cRFS, and PCSM. Conclusions: Moderately hypofractionated IMRT with daily image guidance for localized PCa demonstrates favorable 10-year oncologic outcomes with a low incidence of toxicity for patients across all risk groups.

The effect of the timing of biochemical failure after external beam radiotherapy or low-dose-rate brachytherapy for definitive prostate cancer treatment

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Background: To assess the effect of the timing of biochemical failure (bF) after definitive radiotherapy with external beam (EBRT) or low dose-rate brachytherapy (LDR) on clinical failure (cF) and prostate cancer-specific mortality (PCSM). Methods: From 1996 to 2009, 4478 patients were treated and by 2010, 456 patients were noted to have a bF. They were categorized as early (< 5 years post-therapy) or late (≥ 5 years post-therapy) failures. Factors thought to influence cF and PCSM were scored. Cox regression was used to assess the timing of bF on cF and Fine and Gray regression was used to assess the timing of bF on PCSM. Results: There were 330 (72.4 %) patients categorized as early and 126 (27.6 %) as late failures. The median PSA follow-up post-radiotherapy for the early bF group is 82 months vs. 155 months for the late bF group, and the median PSA follow-up post-bF is 54 months for the early bF group vs. 69 months for the late bF group. The early failures were more likely to be high-risk (p = 0.0080), have a higher Gleason score (p = 0.0008), and use ADT (p = 0.0325). The five-year rate of cF post early bF is 61% vs 43% post late bF (p <0.0001). The five-year rate of PCSM post early bF is 27% vs 9% post late bF (p <0.0001). The multivariable analyses assessing the cF and PCSM are shown in Table. Conclusions: Early bF is associated with higher rates of cF and PCSM. Patients treated with LDR have a lower risk of PCSM. [Table: see text]

Outcomes of active surveillance for African-American men with prostate cancer: Results of a matched analysis

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Background: Prior work has questioned the safety of active surveillance (AS) for African-American (AA) men with prostate cancer. However, studies of AA men on AS are rare, and some show contradictory results as more AA men may undergo definitive therapy leaving a well-selected AS population. To overcome these limitations we performed a retrospective matched cohort study of AA men on AS. Methods: We queried our AS database (2000-2016) for all AA patients. AA men were matched to non-AA men using a 1:1 algorithm based on National Comprehensive Cancer Network (NCCN) risk, age at diagnosis, and year of diagnosis. Cohorts were compared on outcomes of NCCN risk reclassification, receipt of treatment, post-treatment recurrence, development of metastases, and prostate cancer specific mortality. Results: Fifty-nine AA patients were identified and matched, including 18 very low risk (31%), 24 low risk (41%), and 17 intermediate risk patients (29%). Groups were equally matched by NCCN risk and year of diagnosis, and had similar ages at diagnosis (65.6 years AA, 65.9 years non-AA, p=0.97). Initial PSA values were similar between groups (5.2 AA versus 5.1 non-AA, p=0.77). Rates of risk reclassification during AS were higher among AA patients (54% versus 39% p=0.09), though treatment (46% vs 44%) and post-treatment recurrence (11% vs 19%) rates were similar. While AA patients were more often reclassified, many were due to PSA rise (40% AA, 8% non-AA upgraded by PSA alone) rather than pathologic upgrading. AA patients had a longer time to reclassification and treatment than non-AA patients (2.9 and 2.8 years vs 0.9 and 1.0 years, p=0.14). Similar follow-up time was noted (AA 6.0 years versus non-AA 6.4 years, p=0.91). One patient in each group developed metastases. No cancer specific mortalities occurred. Conclusions: In a matched analysis of AA versus non-AA patients on AS, rates of risk reclassification were higher among AA patients, though receipt of treatment and treatment outcomes were similar between groups. Metastatic progression and prostate cancer mortality were rare in both groups. AS appears to be a reasonable option for AA patients with long treatment free periods and reasonable post-treatment outcomes.

Prospective evaluation of a new patient decision aid to enhance prostate cancer screening decision-making

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Background: We previously developed screening nomograms to predict 15-year risk of all-cause mortality, prostate cancer diagnosis, and prostate cancer mortality, and incorporated them into a graphical patient decision aid (PtDA). Our objective was to prospectively recruit primary care patients interested in shared-decision making regarding prostate specific antigen (PSA) screening and assess the impact of individualized counseling using our new PtDA. Methods: 50 patients from one internal medicine practice were enrolled in a single-arm sequential trial design, with face-to-face clinician counseling and questionnaires. Eligibility criteria included men age 50-69 years old and life expectancy > 10 years. Patients were excluded for a personal history of prostate cancer or PSA screening within the prior year. Participants completed baseline questionnaires regarding prior PSA testing, demographic information, health literacy, and the Control Preferences Scale (CPS). They then received standardized counseling (based on large trial and epidemiologic data) regarding PSA screening, followed by individualized counseling using our new PtDA. Participants then made a screening decision, and completed a post decision questionnaire including a Decisional Conflict Scale. Results: The median age was 60 (IQR 54; 65). 41 (82%) had a prior PSA test, while 9 (18%) had not. 42 (84%) of participants received some education beyond high school, 41 (82%) demonstrated high health literacy, and 45 (90%) desired to have an active role in decision-making based on the CPS. After undergoing counseling, 34 (68%) participants chose to undergo initial or repeat PSA screening, 8 (16%) chose against future screening, and 8 (16%) remained uncertain. 45 (90%) participants found individualized counseling using the PtDA more useful than standardized counseling. Finally, patients reported reduced decisional conflict compared to historical controls (P < 0.001). Conclusions: Our process of standardized counseling followed by individualized counseling using our new PtDA was effective in reducing decisional conflict. The majority of participants found the PtDA more useful for decision making than standardized counseling. Clinical trial information: NCT03387527.

Identification of gene expression determinants of radiosensitivity in bladder cancer (BCa) cell lines

470

Background: Trimodality therapy with TURBT followed by concurrent chemoradiation is an alternative to cystectomy in selected patients with muscle invasive BCa. Identifying genetic determinants of radiation response may help select patient for organ-sparing treatments with curative intent. Methods: Molecular characterization of 20 cell lines was previously performed, including mutation analysis, CNA (high density SNP arrays) and gene expression (RNAseq). Cell line identity was authenticated by genomic fingerprinting. We performed colony forming assays (CFA) and cumulative survival was quantified using the area under the cell survival curve (AUC, range 0-8Gy) to create a radiosensitivity index. Pre and post-radiation proliferative capacity was determined by cell titer glo (CTG) assay. Gene (R v3.5.1) and network (Ingenuity Pathyway Analysis) level expression differences were determined as a function of AUC to identify biologically relevant associations with radiation response. Results: Of 20 cell lines (7 basal, 13 luminal subtype), both CFA and CTG data was successfully obtained for 13 cell lines (6 basal, 7 luminal) treated with high dose rate (HDR) radiation. AUCs for the colony forming assay (CFA) survival curves ranged 1.79-3.27. RNAseq identified 18,634 unique transcripts mapping to distinct loci and 196 genes were identified with AUC correlation p values <0.01 (FDR <0.5, mean FPKM>0.5). These genes were strongly enriched for membership in the peroxisome proliferator (PPAR) pathway (IPA, p = 9.40E-03) and STAT3 pathway (IPA, p = 1.56E-3). Validation studies confirmed PPARγ, ICAM2, JAK3, IL1B, OAS1 and OAS2 genes to be associated with differential response to radiation, with expression upregulated in radio-resistant cells. A basal subtype was strongly associated with a radiosensitive phenotype (Chi-Squared χ2 p=0.0083). Conclusions: BCa radio-sensitivity was associated with baseline gene expression differences in vitro. The basal subtype and repression of either the PPAR or STAT3 pathways predicted increased radiosensitivity. This study nominates candidate biomarkers for mechanistic studies and clinical validation in BCa.

Correlation of myeloid-derived suppressor cells (MDSC) with pathologic complete response (pCR), recurrence free survival (RFS), and overall survival (OS) in patients with urothelial carcinoma (UC) undergoing cystectomy

437

Background: MDSCs play an important role in maintaining a tumor immunosuppressive microenvironment. The association of circulating levels of MDSCs with pCR (pT0N0) and outcomes was investigated in patients (pts) with non-metastatic UC undergoing cystectomy. Methods: Peripheral blood samples from pts with non-metastatic UC was collected. MDSCs were measured in freshly purified peripheral blood mononuclear cells, using flow cytometry. Total (T) MDSC was defined as CD33+/HLADR-. T-MDSC subtypes were polymorphonuclear (PMN-MDSC: CD15+/CD14-), monocytic (M-MDSC: CD15-/CD14+], and uncommitted (UC-MDSC: CD15-/CD14-]. MDSC populations were presented as % of live nucleated blood cells. Wilcoxon rank sum test was used to compare MDSCs between pCR groups. Kaplan-Meier and log-rank test were used to analyze RFS and OS. Results: MDSC data were available for 124 pts (106 male, 18 female), median age 68, 28 (23%) never smokers, 93 (75%) pure UC. Thirty four pts (27%) received intravesical BCG; 49 (39%) received neoadjuvant chemotherapy (NAC); 22 (19%) had pCR (pT0N0) following surgery. PMN-MDSC was the dominant subtype (42%) and frequency of UC-MDSC and M-MDSC was 40% and 17%, respectively. Circulating levels of T-MDSC and PMN-MDSC were significantly lower in pCR patients than those in non-pCR patients (Table). Sixteen deaths were observed and 21 pts recurred after surgery. The median follow-up time of patients alive was 18.7 months (range 0.3-42.4). The median OS or RFS of all patients was not reached. One-year and two-year OS rates were 94% and 83%, respectively. One-year and two-year RFS rates were 82% and 69%, respectively. There was no association between MDSC subtypes with OS or RFS. Conclusions: Total- and PMN-MDSC subtypes in blood were significantly correlated with pCR in pts with non-metastatic UC who undergo cystectomy. The relatively short follow-up may impact the association with RFS and OS; additional follow-up is needed. [Table: see text]

Does time from diagnosis to treatment of high- or very-high-risk prostate cancer affect outcome?

OBJECTIVE

To determine whether time from diagnosis to treatment impacted outcomes in a multicentre cohort of high- and very-high-risk (VHR) patients with prostate cancer undergoing radical prostatectomy (RP).

PATIENTS AND METHODS

In all, 1392 patients from three tertiary centres who underwent RP for either high-risk or VHR disease, from 2005 to 2015, were identified. The cohort was divided into tertiles based on time from diagnostic biopsy to RP. Cumulative incidence of biochemical recurrence (BCR), metastasis, and prostate cancer-specific mortality (PCSM) were calculated for each tertile. The Kaplan-Meier method was used to evaluate for differences in all-cause mortality (ACM) amongst tertiles. Competing risks regression models, as well as Cox proportional hazards regression models, were fitted to assess the association between time-to-event outcomes and patient characteristics.

RESULTS

The median (interquartile range [IQR]) time from biopsy to RP was 68 (50-94) days. The median (IQR) follow-up was 31 (12.1-55.7) months. The cumulative incidence of BCR (P = 0.14), metastasis (P = 0.15), and PCSM (P = 0.69) did not differ amongst time-to-treatment tertiles of VHR patients. Also, Kaplan-Meier estimates of ACM (P = 0.53) did not differ amongst time-to-treatment tertiles. Similarly, BCR, metastasis, PCSM, and ACM did not significantly differ amongst time-to-treatment tertiles in multivariable modelling.

CONCLUSION

In this pooled meta-dataset of patients with high-risk or VHR prostate cancer, time from diagnosis to RP did not appear to significantly contribute to differences in clinical outcomes. This finding supports the safety of enrollment of such patients into neoadjuvant clinical trials.

Outcomes of very high-risk prostate cancer after radical prostatectomy: Validation study from 3 centers

BACKGROUND

Among men with localized high-risk prostate cancer (PCa), patients who meet very high-risk (VHR) criteria have been shown to experience worse outcomes after radical prostatectomy (RP) in a previous study. Variations of VHR criteria have been suggested to be prognostic in other single-center cohorts, but multicenter outcomes validating VHR criteria have not been described. This study was designed to validate VHR criteria for identifying which PCa patients are at greatest risk for cancer progression.

METHODS

Patients with high-risk PCa undergoing RP (2005-2015) at 3 tertiary centers were pooled. The outcomes of men with VHR PCa were compared with the outcomes of those who did not meet VHR criteria. The high-risk criteria were a clinical stage of T3 to T4, a prostate-specific antigen level > 20 ng/mL, or a biopsy Gleason grade sum of 8 to 10. The VHR criteria were multiple high-risk features, >4 biopsy cores with a Gleason grade sum of 8 to 10, or primary Gleason grade pattern 5. Biochemical recurrence, metastasis (METS), and cancer-specific mortality (CSM) were assessed with competing risks regressions. Overall mortality was assessed with Cox survival models.

RESULTS

Among 1981 patients with high-risk PCa, men with VHR PCa (n = 602) had adverse pathologic outcomes: 37% versus 25% for positive margins and 37% versus 15% for positive lymph nodes (P <  .001 for both comparisons). Patients with VHR PCa also had higher adjusted hazard ratios for METS (2.78; 95% confidence interval [CI], 2.08-3.72), CSM (6.77; 95% CI, 2.91-15.7), and overall mortality (2.44; 95% CI, 1.56-3.80; P <  .001 for all comparisons).

CONCLUSIONS

In a validation study of patients who underwent treatment for high-risk PCa, VHR criteria were strongly associated with adverse pathologic and oncologic outcomes.

Transcriptomic and Protein Analysis of Small-cell Bladder Cancer (SCBC) Identifies Prognostic Biomarkers and DLL3 as a Relevant Therapeutic Target

PURPOSE

Transcriptomic profiling can shed light on the biology of small-cell bladder cancer (SCBC), nominating biomarkers, and novel therapeutic targets.

EXPERIMENTAL DESIGN

Sixty-three patients with SCBC had small-cell histology confirmed and quantified by a genitourinary pathologist. Gene expression profiling was performed for 39 primary tumor samples, 1 metastatic sample, and 6 adjacent normal urothelium samples (46 total) from the same cohort. Protein levels of differentially expressed therapeutic targets, DLL3 and PDL1, and also CD56 and ASCL1, were confirmed by IHC. A SCBC PDX model was utilized to assess in vivo efficacy of DLL3-targeting antibody-drug conjugate (ADC).

RESULTS

Unsupervised hierarchical clustering of 46 samples produced 4 clusters that correlated with clinical phenotypes. Patients whose tumors had the most "normal-like" pattern of gene expression had longer overall survival (OS) compared with the other 3 clusters while patients with the most "metastasis-like" pattern had the shortest OS (P = 0.047). Expression of DLL3, PDL1, ASCL1, and CD56 was confirmed by IHC in 68%, 30%, 52%, and 81% of tissue samples, respectively. In a multivariate analysis, DLL3 protein expression on >10% and CD56 expression on >30% of tumor cells were both prognostic of shorter OS (P = 0.03 each). A DLL3-targeting ADC showed durable antitumor efficacy in a SCBC PDX model.

CONCLUSIONS

Gene expression patterns in SCBC are associated with distinct clinical phenotypes ranging from more indolent to aggressive disease. Overexpression of DLL3 mRNA and protein is common in SCBC and correlates with shorter OS. A DLL3-targeted ADC demonstrated in vivo efficacy superior to chemotherapy in a PDX model of SCBC.

Testing of a Tool for Prostate Cancer Screening Discussions in Primary Care

Background

As prostate cancer (PCa) screening decisions often occur in outpatient primary care, a brief tool to help the PCa screening conversation in busy clinic settings is needed.

Methods

A previously created 9-item tool to aid PCa screening discussions was tested in five diverse primary care clinics. Fifteen providers were recruited to use the tool for 4 weeks, and the tool was revised based upon feedback. The providers then used the tool with a convenience sample of patients during routine clinic visits. Pre- and post-visit surveys were administered to assess patients’ knowledge of the option to be screened for PCa and of specific factors to consider in the decision. McNemar’s and Stuart–Maxwell tests were used to compare pre-and post-survey responses.

Results

14 of 15 providers completed feedback surveys and had positive responses to the tool. All 15 providers then tested the tool on 95 men aged 40–69 at the five clinics with 2–10 patients each. The proportion of patients who strongly agreed that they had the option to choose to screen for PCa increased from 57 to 72% (p = 0.018) from the pre- to post-survey, that there are factors in the personal or family history that may affect PCa risk from 34 to 47% (p = 0.012), and that their opinions about possible side effects of treatment for PCa should be considered in the decision from 47 to 61% (p = 0.009).

Conclusion

A brief conversation tool for the PCa screening discussion was well received in busy primary-care settings and improved patients’ knowledge about the screening decision.

Effects of pathological upstaging or upgrading on metastasis and cancer-specific mortality in men with clinical low-risk prostate cancer

OBJECTIVES

To determine if the presence of adverse pathological features in patients eligible for active surveillance (AS) are prognostic of poor oncological outcomes, independent of pretreatment risk.

PATIENTS AND METHODS

A retrospective analysis was performed on patients who underwent radical prostatectomy (RP) at two institutions (Cleveland Clinic Foundation and Memorial Sloan Kettering Cancer Center) between 1987 and 2008, and who had subsequent follow-up. Rates of biochemical recurrence, metastasis and death from prostate cancer were compared amongst patients with adverse pathological features (Gleason score ≥7, ≥pT3, or lymph node invasion) based on D'Amico clinical risk (low vs intermediate/high). We also compared survival outcomes between patients with and without pathological upgrading/upstaging amongst D'Amico low-risk patients. Univariate and multivariable Cox regression models were used to assess the association between clinical risk, pathological reclassification, and oncological outcomes.

RESULTS

We identified 16 341 patients who underwent RP, of whom 6 371 were clinically low-risk. Adverse outcomes in men with adverse pathological features were significantly lower in those with low clinical risk, with an ~50% and ~70% reduction in the risk of metastasis and death, respectively. Only pathological upgrading/upstaging to Gleason score ≥8, seminal vesicle invasion, and lymph node invasion from clinical low-risk disease, were associated with adverse outcomes. However, these types of reclassification were rare.

CONCLUSION

Clinical low-risk patients with pathological upgrading/upstaging have substantially lower rates of important oncological outcomes compared to those with higher pretreatment risk and not substantially different than low-risk patients without pathological upgrading/upstaging. These results call into question the use of this endpoint to counsel patients about the merits and risks of AS.

Optimizing the Timing of Salvage Postprostatectomy Radiotherapy and the Use of Concurrent Hormonal Therapy for Prostate Cancer

CONTEXT

Currently, salvage radiotherapy (SRT) is the only known curative intervention for men with recurrent disease following prostatectomy. Critical issues in the optimal selection and management of men being considered for SRT include the threshold prostate-specific antigen (PSA) value at which to initiate treatment (ie, pre-SRT PSA) and the role of concurrent hormonal therapy (HT).

OBJECTIVE

To review the published evidence pertaining to the optimal timing for SRT and the role of concurrent HT.

EVIDENCE ACQUISITION

MEDLINE (via PubMed), EMBASE, the Cochrane Central Register of Controlled Trials, and guideline statements from professional organizations were queried from January 1, 2000 through January 10, 2018.

EVIDENCE SYNTHESIS

Thirty-three independent reports, including two randomized trials evaluating HT with SRT, were identified. Retrospective data suggest that SRT initiation at lower pre-SRT PSA levels is associated with better clinical outcomes. Prospective data suggest an overall survival benefit with concurrent HT that manifests during long-term follow-up, with the caveat that hypothesis-generating subgroup analyses suggest that this benefit may be limited to patients with higher pre-SRT PSA levels. Patients with adverse risk factors, such as Gleason grade group 4-5 disease, are likely to benefit the most from earlier SRT initiation and/or the use of HT.

CONCLUSIONS

Given the limitations of the available data, it is imperative that physicians participate in shared decision-making, with the recommendation tailored for each man's desire to maximize oncologic benefit (with a risk of overtreatment) versus potential quality-of-life optimization (with a risk of undertreatment). Within that framework, a significant body of retrospective data supports initiation of SRT at low pre-SRT PSA values, without an arbitrary absolute threshold. Prospective data suggest a benefit of HT, but this benefit may be greatest in patients with a pre-SRT PSA that is higher than the typical level in most patients receiving "early" SRT. Further research is necessary before absolute recommendations can be made.

PATIENT SUMMARY

Two ways to potentially improve outcomes following salvage radiotherapy for prostate cancer that recurs after prostatectomy are to start treatment at a lower prostate-specific antigen level and to use concurrent hormonal therapy. Our review suggests that the available evidence is imperfect, but highlights that both measures are likely to improve clinical outcomes in general, but perhaps not uniformly and/or consistently for all patients. Physician-patient shared decision-making and further research are critical.

Comparison Between Adjuvant and Early-Salvage Postprostatectomy Radiotherapy for Prostate Cancer With Adverse Pathological Features

Importance

Prostate cancer with adverse pathological features (ie, pT3 and/or positive margins) after prostatectomy may be managed with adjuvant radiotherapy (ART) or surveillance followed by early-salvage radiotherapy (ESRT) for biochemical recurrence. The optimal timing of postoperative radiotherapy is unclear.

Objective

To compare the clinical outcomes of postoperative ART and ESRT administered to patients with prostate cancer with adverse pathological features.

Design, Setting, and Participants

This multi-institutional, propensity score-matched cohort study involved 1566 consecutive patients who underwent postprostatectomy ART or ESRT at 10 US academic medical centers between January 1, 1987, and December 31, 2013. Propensity score 1-to-1 matching was used to account for covariates potentially associated with treatment selection. Data were collected from January 1 to September 30, 2016. Data analysis was conducted from October 1, 2016, to October 21, 2017.

Main Outcomes and Measures

Freedom from postirradiation biochemical failure, freedom from distant metastases, and overall survival. All outcomes were measured from date of surgery to address lead-time bias.

Results

Of 1566 patients, 1195 with prostate-specific antigen levels of 0.1 to 0.5 ng/mL received ESRT and 371 patients with prostate-specific antigen levels lower than 0.1 ng/mL received ART. The median age (interquartile range) was 60 (55-65) years. After propensity score matching, the median (interquartile range) follow-up after surgery was similar between the ESRT and ART groups (73.3 [44.9-106.6] months vs 65.8 [40-107] months; P = .22). Adjuvant RT, compared with ESRT, was associated with higher freedom from biochemical failure (12-year actuarial rates: 69% [95% CI, 60%-76%] vs 43% [95% CI, 35%-51%]; effect size, 26%), freedom from distant metastases (95% [95% CI, 90%-97%] vs 85% [95% CI, 76%-90%]; effect size, 10%), and overall survival (91% [95% CI, 84%-95%] vs 79% [95% CI, 69%-86%]; effect size, 12%). Adjuvant RT, lower Gleason score and T stage, nodal irradiation, and postoperative androgen deprivation therapy were favorable prognostic features on multivariate analysis for biochemical failure. Sensitivity analysis demonstrated that the decreased risk of biochemical failure associated with ART remained significant unless more than 56% of patients in the ART group were cured by surgery alone. This threshold is greater than the estimated 12-year freedom from biochemical failure rate of 33% to 52% after radical prostatectomy alone, as determined by a contemporary dynamic nomogram.

Conclusions and Relevance

Adjuvant RT, compared with ESRT, was associated with reduced biochemical recurrence, distant metastases, and death for high-risk patients, pending prospective validation. These findings suggest that a greater proportion of patients with prostate cancer who have adverse pathological features may benefit from postprostatectomy ART rather than surveillance followed by ESRT.

Radical Prostatectomy, External Beam Radiotherapy, or External Beam Radiotherapy With Brachytherapy Boost and Disease Progression and Mortality in Patients With Gleason Score 9-10 Prostate Cancer

IMPORTANCE

The optimal treatment for Gleason score 9-10 prostate cancer is unknown.

OBJECTIVE

To compare clinical outcomes of patients with Gleason score 9-10 prostate cancer after definitive treatment.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study in 12 tertiary centers (11 in the United States, 1 in Norway), with 1809 patients treated between 2000 and 2013.

EXPOSURES

Radical prostatectomy (RP), external beam radiotherapy (EBRT) with androgen deprivation therapy, or EBRT plus brachytherapy boost (EBRT+BT) with androgen deprivation therapy.

MAIN OUTCOMES AND MEASURES

The primary outcome was prostate cancer-specific mortality; distant metastasis-free survival and overall survival were secondary outcomes.

RESULTS

Of 1809 men, 639 underwent RP, 734 EBRT, and 436 EBRT+BT. Median ages were 61, 67.7, and 67.5 years; median follow-up was 4.2, 5.1, and 6.3 years, respectively. By 10 years, 91 RP, 186 EBRT, and 90 EBRT+BT patients had died. Adjusted 5-year prostate cancer-specific mortality rates were RP, 12% (95% CI, 8%-17%); EBRT, 13% (95% CI, 8%-19%); and EBRT+BT, 3% (95% CI, 1%-5%). EBRT+BT was associated with significantly lower prostate cancer-specific mortality than either RP or EBRT (cause-specific HRs of 0.38 [95% CI, 0.21-0.68] and 0.41 [95% CI, 0.24-0.71]). Adjusted 5-year incidence rates of distant metastasis were RP, 24% (95% CI, 19%-30%); EBRT, 24% (95% CI, 20%-28%); and EBRT+BT, 8% (95% CI, 5%-11%). EBRT+BT was associated with a significantly lower rate of distant metastasis (propensity-score-adjusted cause-specific HRs of 0.27 [95% CI, 0.17-0.43] for RP and 0.30 [95% CI, 0.19-0.47] for EBRT). Adjusted 7.5-year all-cause mortality rates were RP, 17% (95% CI, 11%-23%); EBRT, 18% (95% CI, 14%-24%); and EBRT+BT, 10% (95% CI, 7%-13%). Within the first 7.5 years of follow-up, EBRT+BT was associated with significantly lower all-cause mortality (cause-specific HRs of 0.66 [95% CI, 0.46-0.96] for RP and 0.61 [95% CI, 0.45-0.84] for EBRT). After the first 7.5 years, the corresponding HRs were 1.16 (95% CI, 0.70-1.92) and 0.87 (95% CI, 0.57-1.32). No significant differences in prostate cancer-specific mortality, distant metastasis, or all-cause mortality (≤7.5 and >7.5 years) were found between men treated with EBRT or RP (cause-specific HRs of 0.92 [95% CI, 0.67-1.26], 0.90 [95% CI, 0.70-1.14], 1.07 [95% CI, 0.80-1.44], and 1.34 [95% CI, 0.85-2.11]).

CONCLUSIONS AND RELEVANCE

Among patients with Gleason score 9-10 prostate cancer, treatment with EBRT+BT with androgen deprivation therapy was associated with significantly better prostate cancer-specific mortality and longer time to distant metastasis compared with EBRT with androgen deprivation therapy or with RP.

The association between HSD3B1 genotype and steroid metabolism in normal and prostate cancer (PCa) tissue

TPS155

Background: The common germline variant HSD3B1(1245C) encodes for a gain-of-function in 3βHSD1 which is associated with a shorter duration of response to androgen deprivation therapy (ADT) and more rapid disease progression to castration resistant PCa (CRPC) as shown previously in 5 independent cohorts. Therefore, evaluating the effect of such genotype variation on the level of steroid metabolites and the intratumoral dihydrotestosterone (DHT) concentration in benign and tumor tissue of men on ADT is of significant importance. We hypothesize that patients with homozygous HSD3B1 (1245C) genotype (HZ) will have a sustained androgen synthesis from extragonadal precursor steroids and higher concentrations of DHT compared to patients with wild-type HSD3B1 (1245A) (WT) inheritance in the context of testosterone suppression. In addition, it is expected that heterozygous HSD3B1 (1245C) patients (HTZ) will have intermediate levels of DHT. We also hypothesize that treatment with androgen receptor (AR) antagonist (apalutamide) will reverse the effects of elevated DHT on AR signaling in benign and malignant prostate tissue. Methods: In this Phase II trial (NCT02770391), men with newly diagnosed intermediate or high-risk PCa (GS ≥ 4+3, ≥cT2b, or PSA ≥ 10) who are scheduled to undergo radical prostatectomy (RP) will be enrolled into 3 groups based on their HSD3B1 genotype. All pts will receive one dose of 7.5 mg leuprolide injection and apalutamide 240 mg/day orally for 28 ± 3 days prior to RP. DHT and 7 other androgens (including testosterone, Dehydroepiandrosterone, Androstenedione) will be evaluated in the normal and malignant prostate tissue as well as serum samples obtained at the time of RP. AR regulated genes expression (including PSA, FKBP5, TMPRSS2) will be compared across 3 genotypes. A sample size of 57 pts (WT = 30, HTZ = 15, HZ = 12) will allow a statistical power of > 80% (with two-sided α = 0.05) to detect a 4-fold trend in DHT concentrations in the resected prostate tissue (primary endpoint) as well as similar trend in other androgens (secondary endpoint). As of Oct 2017, 16 of planned 57 pts have been enrolled. Clinical trial information: NCT02770391.

Development of prostate-specific antigen (PSA) screening nomograms for 15-year prediction of prostate cancer diagnosis (PCDx), mortality (PCM), and all-cause mortality (ACM)

110

Background: Recommendations for PSA screening encourage shared decision making between patients and providers, rather than population-based screening. Nomograms provide individualized risk predictions potentially enhancing informed decisions to undergo screening. Our objective was to develop PSA screening nomograms using demographic and follow-up data from two large randomized screening trials: the Göteborg Screening Trial ( Lancet Oncol. 2010;11:725-32) and Prostate, Lung, Colon, and Ovarian (PLCO) Cancer Screening Trial ( N Engl J Med. 2009;360:1310-9). The endpoints of the models were PCDx, PCM, and ACM at 15 years. Methods: Patients with screening prior to trial entry were excluded, leaving 59,951 total subjects: 19,899 and 40,052 from Göteborg and PLCO, respectively. Demographic information including age, family history of PCDx, ethnicity, Charlson Comorbidity Index, marital status, education, and control vs. screening arm were used as predictive variables. If screened, baseline PSA was used as an additional continuous variable. Models for ACM were first developed, then models predicting PCDx and PCM using competing risk analysis. Predictive accuracy was assessed using the concordance index (c-index) and calibration plots. Results: On multivariable analysis, all variables were significant (P < 0.05) for predicting at least one outcome. Nomograms predicting PCDx, PCM, and ACM demonstrated reasonable discrimination: c-index 0.60, 0.65, 0.70, respectively. When a single baseline PSA was included, discriminative accuracy improved for PCDx and PCM, but remained the same for ACM: c-index 0.78, 0.74, 0.69, respectively. Estimates were well-calibrated for all endpoints. Conclusions: Using demographic information, we developed PSA screening nomograms, with good discrimination and calibration in predicting all three outcomes. A single baseline PSA improved nomogram discrimination substantially for PCDx and PCM. We will study the implementation of these nomograms into clinic practice to aid decisions for previously unscreened patients, or whether to continue PSA screening for patients with a known prior PSA.

The importance of the need for better systemic therapy in the definitive treatment of high-risk prostate cancer regardless of whether the initial treatment modality was external beam radiation, I-125 brachytherapy, or radical prostatectomy

65

Background: While androgen deprivation therapy (ADT) is a common form of systemic therapy for treating high-risk prostate cancer (HRCaP), distant metastases development remains the predominate form of failure. We present a description of the sites of failure after treatment of HRCaP with External Beam Radiation (EBRT), I-125 Brachytherapy (PB), or Radical Prostatectomy (RP). This is accompanied by an analysis of prostate cancer-specific mortality (PCSM) after clinical failure. Methods: The study includes 2186 patients with HRCaP according to NCCN guidelines (684 EBRT, 409 PB, and 1093 RP). The association of PCSM with clinical and pathologic variables was assessed with Fine and Gray regression with non-PCSM mortality treated as a competing event. Results: The median f/u is 52 months. Overall, there were 323 clinical failures (sites of first failures: 287 distant (DM), 34 local (LF), 2 DM + LF). The median time to the diagnosis of DM was 44 months. ADT was used in 93% of EBRT, 53% of PB and 19% of RP patients. Further details regarding the development of DM is shown in Table 1. The type of initial treatment was not associated with PCSM after DM (Table 1). The only factor significantly associated with PCSM was Gleason Score (p = 0.0372). Conclusions: DM is the primary mode of failure after definitive treatment of HRCaP. The type of initial definitive treatment did not affect PCSM after DM. The cure rates of all forms of definitive treatment of HRCaP would benefit from better systemic therapy. [Table: see text]

Clinicopathologic factors, treatment patterns, and outcomes in micropapillary urothelial carcinoma (UC)

439

Background: Micropapillary UC remains rare yet with an aggressive phenotype. Limited data exists regarding the optimal management of this variant in the contemporary era. Methods: A retrospective analysis was performed to identity patients (pts) with micropapillary UC at the Cleveland Clinic (1997-2017). Demographic, clinico-pathological, treatment regimens, and clinical outcomes, e.g. progression-free and overall survival (PFS and OS) data were collected. Results: A total of 102 pts with median age 70.5 (46-90) at diagnosis, 84%, men, 17% never smokers were identified. Stage at diagnosis for 68 pts with available data was T1 in 29, T2 in 36, T3 in 1, T4 in 2, N+ in 5, and M+ in 4 pts, respectively. Twelve pts were initially treated with intravesical therapy for NMIBC with 58% progressing to higher stage. Overall, 81% of pts had cystectomy; of those 19% had neoadjuvant chemotherapy (NAC; 81% cisplatin-based, median 3 cycles), 21 pts received adjuvant chemotherapy and 3 pts adjuvant radiation. Of 12 pts with available data, 4 had down-staging with NAC with 1 pCR. Pathologic stage was 0is, I, II, III, IV in 4%, 10%, 9%, 9%, and 67% respectively. Overall, 61 pts had recurrent or de-novo metastatic disease (most nodal/local-regional recurrence). For patients with recurrence post-surgery (n = 31), 35% received systemic chemotherapy, 16% had salvage surgery, 10% had salvage radiation, 19% had best supportive care, and the rest were lost to follow-up or refused treatment. The most common 1st-line regimen included platinum-doublet (46%), other combinations (23%), single-agent (23%) and immune checkpoint inhibitors (8%). Overall response (CR/PR) to 1st-line treatment was 38% and median PFS was 8 months (95%CI 0-16.4). Overall, 29 pts died with recurrent/metastatic disease with a median OS (from time of diagnosis) of 39.3 months (95%CI 28.4-50.2) Median OS (from time of diagnosis) for pts treated with cystectomy was 47.1 months (95%CI 23.9-50.2). Conclusions: Micropapillary UC was associated with advanced pathologic stage at cystectomy and limited use of NAC. Responses were noted with NAC and 1st line systemic treatment. Further validation can assist in prognostication and selection/stratification in future trials.

Prognostic value of CD56, ASCL1, and other biomarkers in small cell bladder cancer (SCBC)

452

Background: Increased DLL3 expression (exp) and small cell % (SC%) were found in prior analyses to predict worse outcomes in SCBC. Assessment of gene and protein exp of other Notch pathway and neuroendocrine (NE) markers, such as ASCL1 and CD56, can help with prognostication and treatment target identification in SCBC. Methods: Among 63 patients (pts) with biopsy-confirmed SCBC seen at Cleveland Clinic (1993-2015), 52 had tissue available for IHC analysis of tumor biomarkers: DLL3, PD-L1, ASCL1 and CD56. All pts had clinical and outcomes data, and had SC% quantified by central path review. A subset of 39 pts had gene exp analysis using HTG EdgeSeq OBP assay. Correlations among biomarkers, between biomarkers and pt characteristics as well as gene exp were assessed. Multivariate analyses (MVA) were used to identify predictors of overall (OS) and progression-free survival (PFS). Results: In the 52 pt cohort, median age was 71, 83% were men, 39% had LN+ disease, and 79% had SC% > 50%. Protein exp ( > 1% of tumor cells) of DLL3, PD-L1, ASCL1 and CD56 was noted in 68%, 30%, 52% and 81% of pts, respectively. ASCL1 protein exp correlated with protein exp of DLL3 (r = 0.73, p < .0001), CD56 (r = 0.35, p = .01), and SC% (r = 0.34, p = .01) and correlated with gene exp of several Notch genes and NE markers: DLL3, DLL4, Notch1, CHGA (p < .05 for all). CD56/NCAM1 protein exp correlated with DLL3 protein exp (r = 0.32, p = .02) and with SC% (r = 0.26, p = .06) and with gene exp of DLL4, Notch1, SYP and NCAM1 (p < .05 for all). In MVA, increased CD56 protein exp ( > 30%) was associated with shorter OS (HR: 2.23; 95%CI 1.06-4.70, p = .03) and PFS (HR: 2.07; 95%CI 1.02-4.20, p = .04). Pts with low protein exp of both CD56 (≤30%) and DLL3 (≤10%) had longer median OS (103.4 vs 18.4 months, p = .01) and PFS (92.2 vs 11.4 months, p = .02) relative to pts with high protein exp of either biomarker. Conclusions: Most SCBC tumors expressed CD56, and increased exp predicted shorter OS and PFS, findings similar to those reported for DLL3. Low concurrent exp of both CD56 and DLL3 proteins was associated with better outcomes. Strong correlation of CD56/NCAM1 gene and protein exp suggests that its regulation may be at the transcriptional level. Gene exp signature prognostic of outcomes is currently being pursued in SCBC.

Optimal timing of post-prostatectomy radiotherapy for prostate cancer with high-risk pathologic features: A multi-institutional analysis

24

Background: The use of radical prostatectomy (RP) as initial treatment of high-risk/locally-advanced prostate cancer is increasing but patients (pts) with adverse pathologic features such as positive surgical margins or T3 disease have up to 70% recurrence risk. These high-risk pts may be managed with adjuvant radiotherapy (ART) or early salvage radiotherapy (ESRT). The optimal timing of post-operative radiotherapy is unclear. Methods: Individual data from 1566 consecutive pts with pT2N0M0/R1 or pT3N0M0/R0-1 disease who underwent post-prostatectomy ART or ESRT (1987-2013) at 10 academic centers were pooled. Post-irradiation freedom from biochemical failure (FFBF), freedom from distant metastases (FFDM), prostate-cancer specific survival (PCSS), and overall survival (OS) were compared using Kaplan-Meier and multivariate competing-risks regression (MVA) analyses. Propensity score (PS) matching was used to account for covariates potentially associated with treatment allocation. All outcomes were measured from the date of surgery to address lead time bias. Results: After PS-matching, median follow-up after surgery was 66 vs. 73 months for the ART and ESRT groups, respectively, and baseline characteristics were well-matched. ART was associated with higher FFBF (12-yr: 69% vs. 43%; log-rank P < 0.0001), FFDM (12-yr: 95% vs. 85%; log-rank P = 0.03), PCSS (12-yr: 99% vs. 94%; log-rank P = 0.048), and OS (12-yr: 91% vs. 79%; log-rank P = 0.01). ART, lower Gleason score, lower T-stage, nodal irradiation, and postoperative androgen deprivation therapy were favorable prognostic features on MVA for BF. Sensitivity analysis demonstrated that the decreased risk of BF associated with ART remained significant unless more than 56% of ART pts were cured by surgery alone. This threshold is greater than the estimated 12-yr FFBF of 46% after RP alone as determined by a contemporary nomogram. Conclusions: To the best of our knowledge, this represents the largest multi-institutional study to date comparing ART to ESRT. ART was associated with reduced biochemical recurrence, distant metastases, and death compared to ESRT for high-risk pts, pending prospective validation.

Adjuvant enzalutamide (Enza) for men with non-metastatic high-risk prostate cancer (HRPCa) after radical prostatectomy (RP)

88

Background: Management of HRPCa is a clinical challenge. Novel AR inhibitors could potentially impact outcome in HRPCa men following RP. We conducted a phase II study evaluating the efficacy/safety of Enza in men with HRPCa following RP. Methods: HRPCa pts (≥pT3a, GS≥8, iPSA ≥20 ng/mL, +ve lymph nodes (LN), or ≥35% chance of biochemical recurrence (BCR) at 5 yrs based on MSKCC’s nomogram) with undetectable PSA within 3 months from RP were eligible. Enza 160mg PO daily was given in 28-day cycles until disease progression, intolerability, consent withdrawal, or study completion at 24 months. Accrual goal was N=40 to provide 80% power to detect a 75% decrease in the risk of BCR from historical 55% rate. BCR was defined as PSA ≥0.2ng/mL on 2 consecutive lab results or any PSA rise that resulted in subsequent therapy. Results: 42 men enrolled. Median age 59 (range 43-70), based on biopsy 45% were GS7; 36% GS8, 19% GS9. 76% men had cT1, 24% cT2, median iPSA was 8.2 (range 2-77). On prostatectomy pathology: 50% had pT3b; 52% +ve margins; 50% SVI; 24% had +LN. 37 (88%) pts completed 24 planned cycles. Of the 5 pts who did not complete all cycles, 3 withdrew consent for toxicity (2 had G3 fatigue, 1 had G3 fatigue and arthralgias/myalgias), 1 had rising PSA requiring subsequent therapy, and 1 had financial concerns. With median follow-up of 31 months (range 2.5-44.5), 37 (88%) pts remain free of BCR. Of the 5 pts who developed BCR, 4 completed all 24 months on therapy. Median time to BCR was 31 months (range 13-40). Most common adverse events (AE) are listed (Table). Conclusions: Adjuvant Enza in men with HRPCa following RP is safe and relatively well-tolerated. Long-term safety, efficacy, and genomic correlations (including tumor RNA expression) are ongoing. Clinical trial information: NCT01927627. [Table: see text]

Impact of neoadjuvant chemotherapy on pathologic outcomes in patients with upper tract urothelial carcinoma undergoing extirpative surgery

457

Background: Neoadjuvant chemotherapy (NAC) is infrequently administered to patients with upper tract urothelial carcinoma (UTUC) undergoing radical nephroureterectomy or segmental ureterectomy and its impact on pathologic outcomes unclear. We examine pathologic outcomes in patients with UTUC receiving NAC before extirpative surgery using a population-based cancer registry. Methods: Patients who underwent extirpative surgery for UTUC from 2006-2014 were identified from the National Cancer Database. Among patients with available clinicopathologic data, the incidence of pathologic down-staging, defined as a lesser pathologic compared to clinical stage, was compared between patients who did and did not receive NAC. A multivariable model was developed to identify predictors of pathologic down-staging. Results: 7,244 patients were identified with non-metastatic UTUC who underwent extirpative surgery in the study period. 260 patients (3.6%) received NAC, with the use of NAC increasing over time from 2.0% patients in 2006 to 7.1% of patients in 2014 (linear trend p < 0.001). Clinical and pathologic staging data were available for 119 and 2904 patients who did and did not receive NAC, respectively. Thirty patients (25.2%) who received NAC experienced pathologic down-staging, compared to 52 patients (1.8%) who did not receive NAC (p < 0.0001). On multivariable analysis, NAC was associated with a higher likelihood of pathologic down-staging (OR 10.2, 95% CI 5.4-19.3). Additional predictors of pathologic down-staging include a higher clinical T stage (p = 0.001) and African-American race (OR 2.7, 95% CI 1.1-6.6). Compared to renal pelvis UTUC, ureteral UTUC was associated with a similar likelihood of pathologic down-staging (OR 1.5, 95% CI 0.9-2.5). Conclusions: NAC is infrequently used among patients with UTUC undergoing extirpative surgery. A higher incidence of pathologic down-staging was observed among patients receiving NAC. These findings suggest clinical benefit of NAC with respect to pathologic outcomes in patients with UTUC and may help guide selection of patients for NAC prior to radical surgery until data from prospective studies becomes available.

Cisplatin-based neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) in patients (pts) with impaired renal function

446

Background: Cisplatin-based NAC followed by radical cystectomy is the standard of care in MIBC but many pts are cisplatin-unfit. Data in pts with low glomerular filtration rate (GFR) who receive cisplatin-based NAC is limited. Methods: A retrospective analysis of pts who received cisplatin-based NAC at Cleveland Clinic (2005-2016) was conducted. Pts with pre-NAC GFR < 60 ml/min by either CG or MDRD formula (low GFR; N = 30) were compared to pts with GFR ≥60 (normal GFR; N = 94) in terms of NAC tolerability and outcomes including pathologic complete (pCR, pT0N0) and partial response (pPR, < pT2N0). A secondary analysis compared 3 groups of pts: GFR < 50ml/min (N = 10), GFR 50-59 ml/min (N = 20), and GFR ≥60 (N = 94). Results: Low GFR pts were older (median age 71 vs 65, p < 0.001) and had higher rates of hydronephrosis (33% vs 15%, p = 0.03). ECOG PS, other demographic and TURBT features (stage, LVI, CIS) did not differ significantly. Low GFR pts were more likely to receive gemcitabine/cisplatin (83% vs 71%, p = 0.04) and get split-dose cisplatin (38% vs 16%, p = 0.02). Split-dose cisplatin use in low GFR pts did not impact NAC tolerability or outcomes. NAC cycles completed (median 3 per group) were comparable, and most low GFR pts (70%) completed intended NAC regimen. Low GFR pts were more likely to have early NAC discontinuation (30% vs 13%, p = 0.03) and NAC modification (delay, dose reduction, discontinuation) (66% vs 40%, p = 0.02). No differences were seen in cystectomy completion rate (93% per group), time to cystectomy, length of stay, surgical complications, and GFR change from baseline. Combined pCR/pPR was higher in normal GFR group (54% vs 25%, p = 0.01). Among pts with very low GFR ( < 50 ml/min), 60% completed intended NAC regimen and 70% had NAC modification. Rates of pCR and pPR were low: 0% and 12%, respectively. Conclusions: Low GFR pts were older, had more NAC discontinuations/modifications and lower pCR/pPR rate, but most completed planned NAC cycles. Relative to normal GFR pts, low GFR pts were not prevented or delayed in getting cystectomy, and had comparable impact of NAC on GFR. For carefully selected pts with GFR < 60 ml/min, cisplatin-based NAC is a treatment option, consistent with prior data.

Seminal vesicle schwannoma presenting as rectal pain: successful robotic-assisted excision

Schwannomas, not uncommon in the head and neck, rarely occur in the pelvis. Here we describe a seminal vesicle schwannoma, the first of its kind successfully excised via robotic surgery. An otherwise well 62 year−old male presented with a complaint of rectal pain. Colonoscopy identified a mass effect on the rectum, suggesting an external lesion. A computed tomography scan revealed a right seminal vesicle mass. Transrectal ultrasound guided biopsy returned a tissue diagnosis of schwannoma. To aid in operative planning, magnetic resonance imaging of the prostate and pelvis was obtained with and without contrast. This defined a 5 × 4 × 4 cm³ mass abutting the right seminal vesicle without evidence of invasion into adjacent structures. The patient underwent an elective robotic−assisted laparoscopic resection of the mass. Final pathology demonstrated a completely excised schwannoma arising from the soft tissue adherent to the right seminal vesicle.

Post-prostatectomy radiation therapy for locally recurrent prostate cancer

INTRODUCTION

Approximately 15-30% of men with localized prostate cancer will experience biochemical recurrence (BCR) after radical prostatectomy. Postoperative radiation therapy is used in men with adverse pathological features to reduce the risk of BCR or with curative intent in men with known BCR. In this study, we review the evidence for the adjuvant and salvage radiation therapy after radical prostatectomy. Areas covered: A literature review of the Medline and Embase databases was performed. The search strategy included the following terms: prostate cancer, adjuvant radiotherapy, salvage radiotherapy, radical prostatectomy, biochemical recurrence, and prostate cancer recurrence. Prospective randomized trials for the adjuvant radiotherapy and observational studies supporting salvage radiotherapy were included for discussion. Expert commentary: As postoperative radiotherapy is associated with non-trivial risks of acute and long-term toxicity and given the absence of compelling data supporting adjuvant over early salvage radiotherapy, the authors advocate, with rare exceptions, close observation and timely (early) salvage radiotherapy for patients with BCR and long life expectancy. Adjuvant radiotherapy may be considered in patients at high-risk for recurrence. Observation is appropriate in patients with limited life expectancy and/or absence of adverse features.

Testicular seminoma: oncologic rationale and role of surgery in treatment

Seminomas account for approximately 50% of all cases of testicular cancer. Testicular cancer is a highly curable disease that can be broadly classified as either seminomatous or nonseminomatous; the management and treatment of the 2 forms vary widely. Although surgery plays a large role in the management of nonseminoma, its role in the management of seminoma is much more limited. Most clinicians in the United States choose orchiectomy followed by surveillance for patients with stage I seminomatous disease, and chemotherapy or radiation-followed by surgery for the management of residual masses-for patients with disease that is stage II and higher. Recently, clinicians have proposed a larger role for surgery in stage II seminoma to avoid the long-term toxic effects of chemotherapy and radiation therapy. In this review, we discuss the oncologic rationale for the treatment of seminoma, the role of surgery, and the use of minimally invasive operative techniques for retroperitoneal lymph node dissection.

Direct Metabolic Interrogation of Dihydrotestosterone Biosynthesis from Adrenal Precursors in Primary Prostatectomy Tissues

Purpose: A major mechanism of castration-resistant prostate cancer (CRPC) involves intratumoral biosynthesis of dihydrotestosterone (DHT) from adrenal precursors. We have previously shown that adrenal-derived androstenedione (AD) is the preferred substrate over testosterone (T) for 5α-reductase expressed in metastatic CRPC, bypassing T as an obligate precursor to DHT. However, the metabolic pathway of adrenal-derived DHT biosynthesis has not been rigorously investigated in the setting of primary disease in the prostate.Experimental Design: Seventeen patients with clinically localized prostate cancer were consented for fresh tissues after radical prostatectomy. Prostate tissues were cultured ex vivo in media spiked with an equimolar mixture of AD and T, and stable isotopic tracing was employed to simultaneously follow the enzymatic conversion of both precursor steroids into nascent metabolites, detected by liquid chromatography-tandem mass spectrometry. CRPC cell line models and xenograft tissues were similarly assayed for comparative analysis. A tritium-labeled steroid radiotracing approach was used to validate our findings.Results: Prostatectomy tissues readily 5α-reduced both T and AD. Furthermore, 5α-reduction of AD was the major directionality of metabolic flux to DHT. However, AD and T were comparably metabolized by 5α-reductase in primary prostate tissues, contrasting the preference exhibited by CRPC in which AD was favored over T. 5α-reductase inhibitors effectively blocked the conversion of AD to DHT.Conclusions: Both AD and T are substrates of 5α-reductase in prostatectomy tissues, resulting in two distinctly nonredundant metabolic pathways to DHT. Furthermore, the transition to CRPC may coincide with a metabolic switch toward AD as the favored substrate. Clin Cancer Res; 23(20); 6351-62. ©2017 AACR.