Radium-223 Dichloride in Combination with Vascular Endothelial Growth Factor-Targeting Therapy in Advanced Renal Cell Carcinoma with Bone Metastases

Purpose: This study investigates the biologic activity of radium-223 with VEGF-targeted therapy in patients with advanced renal cell carcinoma (aRCC) and bone metastases.Patients and Methods: Fifteen treatment-naïve patients (n = 15) received pazopanib 800 mg orally once daily, and 15 previously treated patients received sorafenib 400 mg orally twice daily. Radium-223 55 kilobecquerel/kg was administered concurrently every 4 weeks for up to six infusions in both cohorts. The primary endpoint was decline in bone turnover markers (Procollagen I Intact N-Terminal, N-telopeptide, C-telopeptide, osteocalcin, and bone-specific alkaline phosphatase) compared with baseline. Secondary endpoints included safety, rate of symptomatic skeletal event (SSE) and time to first SSE, objective response rate, change in analgesic use, and quality of life. Exploratory analysis of tumor genomic alterations was performed.Results: Of the 30 patients enrolled, 83% had IMDC intermediate- or poor-risk disease, 33% had liver metastases, and 83% had a history of SSE prior to enrollment. No dose-limiting toxicity was observed. All bone turnover markers significantly declined from baseline at week 8 and 16. Forty percent of patients experienced treatment-related grade ≥3 adverse events. Response rates were 15% and 18% per RECIST v1.1 and bone response was 50% and 30% per MD Anderson criteria, in the pazopanib and sorafenib cohort, respectively. Median SSE-free interval was 5.8 months and not reached, respectively. Analgesic use remained stable over the study time.Conclusions: Radium-223 combined with VEGF-targeted therapy is biologically active and safe. Randomized-controlled trials are needed to define the role of radium-223 in aRCC with skeletal metastases. Clin Cancer Res; 24(17); 4081-8. ©2018 AACR.

A dose finding clinical trial of cabozantinib (XL184) administered in combination with abiraterone acetate in metastatic castration-resistant prostate cancer

BACKGROUND

Cabozantinib can enhance the effect of abiraterone in preclinical prostate cancer models. This study aimed to define the recommended phase 2 dose (RP2D) and preliminary efficacy of abiraterone + cabozantinib in mCRPC.

METHODS

Patients with progressive mCRPC with 0-2 prior chemotherapy regimens but no prior CYP17A1 or MET inhibitor received abiraterone acetate at 1000 mg daily with prednisone 5 mg BID in combination with cabozantinib at 20, 40, or 60 mg daily in a dose-escalation 3 + 3 open-label phase 1 design (Part A). After tolerable doses were defined, cohorts were expanded to better define toxicity and efficacy (Part B).

RESULTS

There were no dose-limiting toxicities (DLTs) in the first 4 weeks at any of the three dose levels in Part A. Two of the three patients at the 60 mg dose level required dose reductions beyond cycle 2 due to fatigue. In Part B, nine more patients were accrued to each of the 20 and 40 mg doses. Of the 12 patients treated at the 40 mg dose, only one DLT (grade 3 Lipase elevation) was observed in cycle 1. The median time to radiographic progression was 12.88 months (95% CI:5.42- not estimated [NE]) in the 20 mg cohort and 22.01 months (95% CI:15.44-NE) in the 40 mg cohort. Median overall survival was 23.29 months (95% CI:19.06-NE) in the 20 mg cohort and 39.08 months (95% CI:17.38-NE) in the 40 mg cohort.

CONCLUSIONS

Based on tolerability and preliminary efficacy, 40 mg cabozantinib plus 1000 mg abiraterone daily is the RP2D.

Contemporary Patterns of Multidisciplinary Care in Patients With Muscle-invasive Bladder Cancer

BACKGROUND

Multidisciplinary clinics integrate the expertise of several specialties to provide effective treatment to patients. This exposure is especially relevant in the management of muscle-invasive bladder cancer (MIBC), which requires critical input from urology, radiation oncology, and medical oncology, among other supportive specialties.

MATERIALS AND METHODS

In the present study, we sought to catalog the different styles of multidisciplinary care models used in the management of MIBC and to identify barriers to their implementation. We surveyed providers from academic and community practices regarding their currently implemented multidisciplinary care models, available resources, and perceived barriers using the Bladder Cancer Advocacy Network and the Genitourinary Medical Oncologists of Canada e-mail databases.

RESULTS

Of the 101 responding providers, most practiced at academic institutions in the United States (61%) or Canada (29%), and only 7% were from community practices. The most frequently used model was sequential visits on different days (57%), followed by sequential same-day (39%) and concurrent (1 visit with all providers; 22%) models. However, most practitioners preferred a multidisciplinary clinic involving sequential same-day (41%) or concurrent (26%) visits. The lack of clinic space (58%), funding (41%), staff (40%), and time (32%) were the most common barriers to implementing a multidisciplinary clinic.

CONCLUSION

Most surveyed practitioners at academic centers use some form of a multidisciplinary care model for patients with MIBC. The major barriers to more integrated multidisciplinary clinics were limited time and resources rather than a lack of provider enthusiasm. Future studies should incorporate patient preferences, further evaluate practice patterns in community settings, and assess their effects on patient outcomes.

The Clinical Activity of PD-1/PD-L1 Inhibitors in Metastatic Non-Clear Cell Renal Cell Carcinoma

Programmed death 1 (PD-1) and PD ligand 1 (PD-L1) inhibitors have shown activity in metastatic clear cell renal cell carcinoma (ccRCC). Data on the activity of these agents in patients with non-clear cell RCC (nccRCC) or patients with sarcomatoid/rhabdoid differentiation are limited. In this multicenter analysis, we explored the efficacy of PD-1/PD-L1 inhibitors in patients with nccRCC or sarcomatoid/rhabdoid differentiation. Baseline and follow-up demographic, clinical, treatment, and radiographic data were collected. The primary endpoint was objective response rate. Secondary endpoints include time-to-treatment failure (TTF), overall survival (OS), and biomarker correlates. Forty-three patients were included: papillary (n = 14; 33%), chromophobe (n = 10; 23%), unclassified (n = 9; 21%), translocation (n = 3; 7%), and ccRCC with sarcomatoid differentiation (n = 7, 16%). Of those 43 patients, 11 patients (26%) had sarcomatoid and/or rhabdoid differentiation (n = 7 with ccRCC; n = 4 nccRCC). Overall, 8 patients (19%) objectively responded, including 4 patients (13%) who received PD-1/PD-L1 monotherapy. Responses were observed in patients with ccRCC with sarcomatoid and/or rhabdoid differentiation (n = 3/7, 43%), translocation RCC (n = 1/3, 33%), and papillary RCC (n = 4/14, 29%). The median TTF was 4.0 months [95% confidence interval (CI), 2.8-5.5] and median OS was 12.9 months (95% CI, 7.4-not reached). No specific genomic alteration was associated with clinical benefit. Modest antitumor activity for PD-1/PD-L1-blocking agents was observed in some patients with nccRCC. Further prospective studies are warranted to investigate the efficacy of PD-1/PD-L1 blockade in this heterogeneous patient population. Cancer Immunol Res; 6(7); 758-65. ©2018 AACR.

The Clinical Activity of PD-1/PD-L1 Inhibitors in Metastatic Non-Clear Cell Renal Cell Carcinoma

Programmed death 1 (PD-1) and PD ligand 1 (PD-L1) inhibitors have shown activity in metastatic clear cell renal cell carcinoma (ccRCC). Data on the activity of these agents in patients with non-clear cell RCC (nccRCC) or patients with sarcomatoid/rhabdoid differentiation are limited. In this multicenter analysis, we explored the efficacy of PD-1/PD-L1 inhibitors in patients with nccRCC or sarcomatoid/rhabdoid differentiation. Baseline and follow-up demographic, clinical, treatment, and radiographic data were collected. The primary endpoint was objective response rate. Secondary endpoints include time-to-treatment failure (TTF), overall survival (OS), and biomarker correlates. Forty-three patients were included: papillary (n = 14; 33%), chromophobe (n = 10; 23%), unclassified (n = 9; 21%), translocation (n = 3; 7%), and ccRCC with sarcomatoid differentiation (n = 7, 16%). Of those 43 patients, 11 patients (26%) had sarcomatoid and/or rhabdoid differentiation (n = 7 with ccRCC; n = 4 nccRCC). Overall, 8 patients (19%) objectively responded, including 4 patients (13%) who received PD-1/PD-L1 monotherapy. Responses were observed in patients with ccRCC with sarcomatoid and/or rhabdoid differentiation (n = 3/7, 43%), translocation RCC (n = 1/3, 33%), and papillary RCC (n = 4/14, 29%). The median TTF was 4.0 months [95% confidence interval (CI), 2.8-5.5] and median OS was 12.9 months (95% CI, 7.4-not reached). No specific genomic alteration was associated with clinical benefit. Modest antitumor activity for PD-1/PD-L1-blocking agents was observed in some patients with nccRCC. Further prospective studies are warranted to investigate the efficacy of PD-1/PD-L1 blockade in this heterogeneous patient population. Cancer Immunol Res; 6(7); 758-65. ©2018 AACR.

Programmed cell death-1 pathway inhibitors in genitourinary malignancies: specific side-effects and their management

PURPOSE OF REVIEW

Immune checkpoint inhibitors such as those that target the programmed cell death (PD)-1 pathway harness the host immune system to elicit an antitumor response. Their remarkable clinical benefit has led to regulatory approvals in several malignancies including the genitourinary cancers, renal cell carcinoma, and urothelial carcinoma. This review will focus on the management of the toxicities encountered with these agents.

RECENT FINDINGS

Although generally well tolerated, a small proportion of patients (10-20%) treated with PD-1 directed agents as monotherapy can develop severe autoimmune manifestations, also known as, immune-related adverse events. These include but are not limited to rashes, pneumonitis, endocrinopathy, colitis, and immune-mediated hepatic dysfunction. Combining these agents with the anti-CTLA-4 antibody ipilimumab can be associated with a higher incidence of these toxicities. Early initiation of immunosuppression with corticosteroids and other agents when needed can help mitigate these toxicities and to date has not been shown to compromise their clinical benefit.

SUMMARY

The development of immune checkpoint inhibitors represents significant advances in anticancer therapy but their efficacy may come at the cost of autoimmune toxicities secondary to their induction of the immune system. Early recognition of these effects and aggressive upfront management is essential to safely administer these agents in routine clinical practice.

Radical cystectomy or bladder preservation with radiochemotherapy in elderly patients with muscle-invasive bladder cancer: Retrospective International Study of Cancers of the Urothelial Tract (RISC) Investigators

BACKGROUND

Radical cystectomy (RC) and radiochemotherapy (RCT) are curative options for muscle-invasive bladder cancer (MIBC). Optimal treatment strategy remains unclear in elderly patients.

MATERIAL AND METHODS

Patients aged 80 years old and above with T2-T4aN0-2M0-Mx MIBC were identified in the Retrospective International Study of Cancers of the Urothelial Tract (RISC) database. Patients treated with RC were compared with those treated with RCT. The impact of surgery on overall survival (OS) was assessed using a Cox proportional hazard model. Progression included locoregional and metastatic relapse and was considered a time-dependent variable.

RESULTS

Between 1988 and 2015, 92 patients underwent RC and 72 patients had RCT. Median age was 82.5 years (range 80-100) and median follow-up was 2.90 years (range 0.04-11.10). Median OS was 1.99 years (95%CI 1.17-2.76) after RC and 1.97 years (95%CI 1.35-2.64) after RCT (p = .73). Median progression-free survival (PFS) after RC and RCT were 1.25 years (95%CI 0.80-1.75) and 1.52 years (95%CI 1.01-2.04), respectively (p = .54). In multivariate analyses, only disease progression was significantly associated with worse OS (HR = 10.27 (95%CI 6.63-15.91), p < .0001). Treatment modality was not a prognostic factor.

CONCLUSIONS

RCT offers survival rates comparable to those observed with RC for patients aged ≥80 years.

Durable Clinical Benefit in Metastatic Renal Cell Carcinoma Patients Who Discontinue PD-1/PD-L1 Therapy for Immune-Related Adverse Events

The current standard of care for treatment of metastatic renal cell carcinoma (mRCC) patients is PD-1/PD-L1 inhibitors until progression or toxicity. Here, we characterize the clinical outcomes for 19 mRCC patients who experienced an initial clinical response (any degree of tumor shrinkage), but after immune-related adverse events (irAE) discontinued all systemic therapy. Clinical baseline characteristics, outcomes, and survival data were collected. The primary endpoint was time to progression from the date of treatment cessation (TTP). Most patients had clear cell histology and received anti-PD-1/PD-L1 therapy as second-line or later treatment. Median time on PD-1/PD-L1 therapy was 5.5 months (range, 0.7-46.5) and median TTP was 18.4 months (95% CI, 4.7-54.3) per Kaplan-Meier estimation. The irAEs included arthropathies, ophthalmopathies, myositis, pneumonitis, and diarrhea. We demonstrate that 68.4% of patients (n = 13) experienced durable clinical benefit off treatment (TTP of at least 6 months), with 36% (n = 7) of patients remaining off subsequent treatment for over a year after their last dose of anti-PD-1/PD-L1. Three patients with tumor growth found in a follow-up visit, underwent subsequent surgical intervention, and remain off systemic treatment. Nine patients (47.4%) have ongoing irAEs. Our results show that patients who benefitted clinically from anti-PD-1/PD-L1 therapy can experience sustained beneficial responses, not needing further therapies after the initial discontinuation of treatment due to irAEs. Investigation of biomarkers indicating sustained benefit to checkpoint blockers are needed. Cancer Immunol Res; 6(4); 402-8. ©2018 AACR.

Seven-Month Prostate-Specific Antigen Is Prognostic in Metastatic Hormone-Sensitive Prostate Cancer Treated With Androgen Deprivation With or Without Docetaxel

Purpose We evaluated the relationship between prostate-specific antigen (PSA) and overall survival in the context of a prospectively randomized clinical trial comparing androgen-deprivation therapy (ADT) plus docetaxel with ADT alone for initial metastatic hormone-sensitive prostate cancer. Methods We performed a landmark survival analysis at 7 months using the E3805 Chemohormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) database ( ClinicalTrials.gov identifier: NCT00309985). Inclusion required at least 7 months of follow-up and PSA levels at 7 months from ADT initiation. We used the prognostic classifiers identified in a previously reported trial (Southwest Oncology Group 9346) of PSA ≤ 0.2, > 0.2 to 4, and > 4 ng/mL. Results Seven hundred nineteen of 790 patients were eligible for this subanalysis; 358 were treated with ADT plus docetaxel, and 361 were treated with ADT alone. Median follow-up time was 23.1 months. On multivariable analysis, achieving a 7-month PSA ≤ 0.2 ng/mL was more likely with docetaxel, low-volume disease, prior local therapy, and lower baseline PSAs (all P ≤ .01). Across all patients, median overall survival was significantly longer if 7-month PSA reached ≤ 0.2 ng/mL compared with > 4 ng/mL (median survival, 60.4 v 22.2 months, respectively; P < .001). On multivariable analysis, 7-month PSA ≤ 0.2 and low volume disease were prognostic of longer overall survival (all P < 0.01). The addition of docetaxel increased the likelihood of achieving a PSA ≤ 0.2 ng/mL at 7 months (45.3% v 28.8% of patients on ADT alone). Patients on ADT alone who achieved a 7-month PSA ≤ 0.2 ng/mL had the best survival and were more likely to have low-volume disease (56.7%). Conclusion PSA ≤ 0.2 ng/mL at 7 months is prognostic for longer overall survival with ADT for metastatic hormone-sensitive prostate cancer irrespective of docetaxel administration. Adding docetaxel increased the likelihood of a lower PSA and improved survival.

Change in Neutrophil-to-lymphocyte ratio (NLR) in response to immune checkpoint blockade for metastatic renal cell carcinoma

Background

An elevated Neutrophil-to-lymphocyte ratio (NLR) is associated with worse outcomes in several malignancies. However, its role with contemporary immune checkpoint blockade (ICB) is unknown. We investigated the utility of NLR in metastatic renal cell carcinoma (mRCC) patients treated with PD-1/PD-L1 ICB.

Methods

We examined NLR at baseline and 6 (±2) weeks later in 142 patients treated between 2009 and 2017 at Dana-Farber Cancer Institute (Boston, USA). Landmark analysis at 6 weeks was conducted to explore the prognostic value of relative NLR change on overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Cox and logistic regression models allowed for adjustment of line of therapy, number of IMDC risk factors, histology and baseline NLR.

Results

Median follow up was 16.6 months (range: 0.7–67.8). Median duration on therapy was 5.1 months (<1–61.4). IMDC risk groups were: 18% favorable, 60% intermediate, 23% poor-risk. Forty-four percent were on first-line ICB and 56% on 2nd line or more. Median NLR was 3.9 (1.3–42.4) at baseline and 4.1 (1.1–96.4) at week 6. Patients with a higher baseline NLR showed a trend toward lower ORR, shorter PFS, and shorter OS. Higher NLR at 6 weeks was a significantly stronger predictor of all three outcomes than baseline NLR. Relative NLR change by ≥25% from baseline to 6 weeks after ICB therapy was associated with reduced ORR and an independent prognostic factor for PFS (p < 0.001) and OS (p = 0.004), whereas a decrease in NLR by ≥25% was associated with improved outcomes.

Conclusions

Early decline and NLR at 6 weeks are associated with significantly improved outcomes in mRCC patients treated with ICB. The prognostic value of the readily-available NLR warrants larger, prospective validation.

Evaluation of disease-free survival as an intermediate metric of overall survival in patients with localized renal cell carcinoma: A trial-level meta-analysis

BACKGROUND

Overall survival (OS) is a critical endpoint in adjuvant trials but requires long durations to events and significant patient resources. In the current study, the authors assessed whether disease-free survival (DFS) can be an early clinical surrogate for OS in the adjuvant setting for localized renal cell carcinoma (RCC).

METHODS

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the authors performed a systematic literature review of PubMed and the American Society of Clinical Oncology, European Society for Medical Oncology, and ClinicalTrial.gov Web sites (1996-2016). Inclusion in the current study required randomized controlled trials (RCTs) of adjuvant systemic therapy for localized RCC after nephrectomy with ≥3 years of outcomes data. Data regarding hazard ratios (HRs) and 5-year event-free rates from Kaplan-Meier estimates were extracted. A trial-level meta-analysis correlated estimates of 5-year DFS and 5-year OS as well as treatment effects (HRs) on these endpoints, weighted by the number of DFS events. R-squared ≥ 0.7 was prespecified as being indicative of a strong correlation and the potential for surrogacy.

RESULTS

Thirteen RCTs encompassing 6473 patients who were treated with a variety of systemic therapies met eligibility. Only a modest correlation was observed between 5-year DFS and 5-year OS rates (R-squared, 0.48; 95% confidence interval, 0.14-0.67) and between treatment effects as measured by DFS and OS HRs (R-squared, 0.44; 95% confidence interval, 0.00-0.69).

CONCLUSIONS

Across RCTs of adjuvant systemic therapy for localized RCC, there was no strong correlation noted between 5-year DFS and 5-year OS rates or between treatment effects on these endpoints. These results highlight the need to identify alternative and more rapid clinical or biologic endpoints to hasten drug development and improve clinical outcomes. Cancer 2018;124:925-33. © 2017 American Cancer Society.

Bone Metastases as the Only Metastatic Site in Patients With Urothelial Carcinoma: Focus on a Special Patient Population

BACKGROUND

Patients with exclusive bone metastatic spread from urothelial carcinoma (UC) throughout their disease course represent a rare subgroup with unique clinical features. These patients deserved special consideration in a retrospective multicenter study.

PATIENTS AND METHODS

Analyses were made from a pool of 1911 patients with a diagnosis of metastatic UC, from 23 centers. Baseline characteristics, access to treatment, and outcomes were analyzed according to metastatic spread. Univariable and multivariable Cox analyses were performed.

RESULTS

A total of 128 evaluable patients (6.7%), diagnosed between February 1997 and April 2013, were identified. Eastern Cooperative Oncology Group performance status (PS) was ≥ 2 in 33.3% versus 17.7% of the remaining patients. Seventy-three (57%) received first-line chemotherapy, that was platinum-based in 50 patients (69%). Twenty-eight (21.9%) received second-line chemotherapy (vs. 75.9% and 32.2%, respectively, of the remaining patients). In multivariable analyses, no clinical factor was significantly associated with overall survival (OS). Among platinum chemotherapy-treated patients (total evaluable n = 972), significantly different relapse-free survival (RFS) and OS were observed according to bone metastases status (no bone metastases vs. bone metastases only vs. bone and other sites, P < .001). In these groups, 2-year RFS was 37.4%, 28.8%, and 25.9%, respectively. Two-year OS was 35.5%, 15.8%, and 23%, respectively.

CONCLUSION

Patients with metastatic UC and bone-only metastases are less likely to receive systemic therapy than those with other metastases, likely because of their lower PS. The prognostic effect of having exclusive bone metastases or additional sites seems to be equally poor. These patients deserve new effective and tolerable agents, and improvements in the knowledge of their disease.

Beyond the androgen receptor II: New approaches to understanding and treating metastatic prostate cancer; Report from the 2017 Coffey-Holden Prostate Cancer Academy Meeting

INTRODUCTION

The 2017 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Beyond the Androgen Receptor II: New Approaches to Understanding and Treating Metastatic Prostate Cancer," was held in Carlsbad, California from June 14-17, 2017.

METHODS

The CHPCA is an annual scientific conference hosted by the Prostate Cancer Foundation (PCF) that is uniquely designed to produce extensive and constructive discussions on the most urgent and impactful topics concerning research into the biology and treatment of metastatic prostate cancer. The 2017 CHPCA Meeting was the 5th meeting in this annual series and was attended by 71 investigators focused on prostate cancer and a variety of other fields including breast and ovarian cancer.

RESULTS

The discussions at the meeting were concentrated on topics areas including: mechanisms and therapeutic approaches for molecular subclasses of castrate resistant prostate cancer (CRPC), the epigenetic landscape of prostate cancer, the role of DNA repair gene mutations, advancing the use of germline genetics in clinical practice, radionuclides for imaging and therapy, advances in molecular imaging, and therapeutic strategies for successful use of immunotherapy in advanced prostate cancer.

DISCUSSION

This article reviews the presentations and discussions from the 2017 CHPCA Meeting in order to disseminate this knowledge and accelerate new biological understandings and advances in the treatment of patients with metastatic prostate cancer.

Differential expression of c-Met between primary and metastatic sites in clear-cell renal cell carcinoma and its association with PD-L1 expression

In preclinical models, c-Met promotes survival of renal cancer cells through the regulation of programmed death-ligand 1 (PD-L1). However, this relationship in human clear cell renal cell carcinoma (ccRCC) is not well characterized. We evaluated c-Met expression in ccRCC patients using paired primary and metastatic samples and assessed the association with PD-L1 expression and other clinical features. Areas with predominant and highest Fuhrman nuclear grade (FNG) were selected. c-Met expression was evaluated by IHC using an anti-Met monoclonal antibody (MET4 Ab) and calculated by a combined score (CS, 0-300): intensity of c-Met staining (0-3) x % of positive cells (0-100). PD-L1 expression in tumor cells was previously assessed by IHC and PD-L1+ was defined as PD-L1 > 0% positive cells. Our cohort consisted of 45 pairs of primary and metastatic ccRCC samples. Overall, c-Met expression was higher in metastatic sites compared to primary sites (average c-Met CS: 55 vs. 28, p = 0.0003). Higher c-Met expression was associated with higher FNG (4 vs. 3) in primary tumors (average c-Met CS: 52 vs. 20, p = 0.04). c-Met expression was numerically greater in PD-L1+ vs. PD-L1- tumors. Higher c-Met expression in metastatic sites compared to primary tumors suggests that testing for biomarkers of response to c-Met inhibitors should be conducted in metastases. While higher c-Met expression in PD-L1+ tumors requires further investigation, it supports exploring these targets in combination clinical trials.

Venous Thromboembolism Risk in Patients With Locoregional Urothelial Tract Tumors

BACKGROUND

Venous thromboembolism (VTE) is common in cancer patients, but there is limited data on patients with urothelial tract tumors (UTT). We previously identified several associative factors for increased VTE rates in patients with metastatic UTT. In this study, we assessed the frequency, associative factors, and impact on survival of VTE in patients with locoregional UTT.

METHODS

Patients with locoregional bladder, upper urinary tract, or urethral cancer were included in this multi-center study from 29 academic institutions. Patients with < cT2, > N1, or M1 disease at diagnosis were excluded. Patients with incomplete clinical staging or miscoded/missing data were excluded. Cumulative, unadjusted VTE incidence was calculated from time of diagnosis of muscle-invasive disease, excluding VTEs diagnosed in the metastatic setting. χ2 statistics tested differences in VTE rates across baseline and treatment-related factors. Significant covariates were incorporated into a multivariate, logistic regression model. Overall survival stratified by VTE was estimated using Kaplan-Meier methods and evaluated using the log-rank test.

RESULTS

A total of 1732 patients were eligible. There were 132 (7.6%) VTEs. On multivariate analysis, non-urothelial histology (P < .001), clinical Nx stage (P < .001), cardiovascular disease (P = .01), and renal dysfunction (P = .04) were statistically significant baseline factors associated with VTE. Using surgery alone as reference, surgery with perioperative chemotherapy (P = .04) and radiation with concurrent chemotherapy (P = .04) also were significant.

CONCLUSIONS

The VTE incidence of 7.6% in locoregional disease is comparable with our previously reported rate in the metastatic setting (8.2%). Similar to our findings in metastatic UTT, non-urothelial histology, renal dysfunction, and CVD was associated with increased VTE risk.

Response to single agent PD-1 inhibitor after progression on previous PD-1/PD-L1 inhibitors: a case series

Background

Monoclonal antibodies targeting the PD-1/PD-L1 axis have gained increasing attention across many solid tumors and hematologic malignancies due to their efficacy and favorable toxicity profile. With more than 1 agent now FDA-approved in a wide variety of tumor types, and with others in clinical trials, it is becoming more common that patients present to clinic for potential treatment with a second PD-1/PD-L1 inhibitor.

Case presentation

In this report, we present two patients with renal cell carcinoma and one with melanoma who received PD-1/PD-L1 inhibitors. Upon progression on their first-line PD-1/PD-L1 inhibitors, these patients received a different PD-1 inhibitor (nivolumab in all cases) and all had progressive disease as their best response to the subsequent PD-1 inhibitor. The reported clinical information focuses on the course of the disease and the responses to all treatment regimens.

Conclusions

Clinicians should refrain from using multiple PD-1/PD-L1 inhibitors sequentially outside of clinical trials until there is sufficient data to support this practice routinely. Prospective studies that allow prior treatment with PD-1/PD-L1 are needed to validate the efficacy and safety of these drugs in the second line or later setting. Furthermore, ongoing efforts that aim to identify mechanisms of resistance to immunotherapy will be informative and may ultimately assist physicians in select the optimal treatment following progression on PD-1/PD-L1 inhibitor.

Lack of Effectiveness of Postchemotherapy Lymphadenectomy in Bladder Cancer Patients with Clinical Evidence of Metastatic Pelvic or Retroperitoneal Lymph Nodes Only: A Propensity Score-based Analysis

BACKGROUND

Limited data is available on the role, and extent of, postchemotherapy lymphadenectomy (PC-LND) in patients with clinical evidence of pelvic (cN1-3) or retroperitoneal (RP) lymph node spread from urothelial bladder carcinoma.

OBJECTIVE

To compare the outcomes of operated versus nonoperated patients after first-line chemotherapy.

DESIGN, SETTING, AND PARTICIPANTS

Data from 34 centers was collected, totaling 522 patients, treated between January 2000 and June 2015. Criteria for patient selection were the following: bladder primary tumor, lymph node metastases (pelvic±RP) only, first-line platinum-based chemotherapy given.

INTERVENTION

LND (with cystectomy) versus observation after first-line chemotherapy for metastatic urothelial bladder carcinoma.

OUTCOME MEASURES AND STATISTICAL ANALYSIS

Overall survival (OS) was the primary endpoint. Multiple propensity score techniques were adopted, including 1:1 propensity score matching and inverse probability of treatment weighting. Additionally, the inverse probability of treatment weighting analysis was performed with the inclusion of the covariates, that is, with doubly robust estimation.

RESULTS AND LIMITATIONS

Overall, 242 (46.4%) patients received PC-LND and 280 (53.6%) observation after chemotherapy. There were 177 (33.9%) and 345 (66.1%) patients with either RP or pelvic LND only, respectively. Doubly robust estimation-adjusted comparison was not significant for improved OS for PC-LND (hazard ratio [HR]: 0.86, 95% confidence interval [CI]: 0.56-1.31, p=0.479), confirmed by matched analysis (HR: 0.91, 95% CI: 0.60-1.36, p=0.628). This was also observed in the RP subgroup (HR: 1.12, 95% CI: 0.68-1.84). The retrospective nature of the data and the heterogeneous patient population were the major limitations.

CONCLUSIONS

Although there were substantial differences between the two groups, after accounting for major confounders we report a nonsignificant OS difference with PC-LND compared with observation only. These findings may be hypothesis-generating for future prospective trials.

PATIENT SUMMARY

We found no differences in survival by adding postchemotherapy lymphadenectomy in patients with pelvic or retroperitoneal lymph node metastatic bladder cancer. The indication to perform postchemotherapy lymphadenectomy in the most suitable patients requires additional studies.

The impact of statin use on the efficacy of abiraterone acetate in patients with castration-resistant prostate cancer

BACKGROUND

Statins compete with DHEAS for influx through the SLCO2B1 transporter, which may prolong time to progression (TTP) on androgen deprivation therapy. Abiraterone acetate (AA) may also undergo SLCO-mediated transport. Based on preclinical findings showing antagonism, we hypothesized that statins may compete with AA for influx via SLCO2B1 and could negatively impact drug efficacy.

METHODS

We queried two institutional clinical databases (Dana-Farber Cancer Institute [DFCI], Johns Hopkins University [JHU]) for CRPC patients treated with AA. Treatment duration was a surrogate for TTP. Associations between statin use and AA duration were estimated using the Kaplan-Meier method. Multivariable Cox regression modeling adjusted for known prognostic factors.

RESULTS

Of the 224 DFCI and 270 JHU patients included, the majority (96%) had metastatic disease. Nearly half (41% and 45%) were statin users. In the DFCI cohort, there was a trend toward longer AA duration in statin users: 14.2 versus 9.2 months (HR 0.79, 95%CI: 0.57-1.09, P = 0.14). There was no association between statin use and AA duration in the JHU cohort: 8.3 versus 8.0 months (HR 0.89, 95%CI: 0.69-1.16, P = 0.38) in the statin users versus non-users, except for a trend in patients that had not previously received docetaxel or enzalutamide (HR 0.79; 95%CI: 0.57-1.10).

CONCLUSIONS

Contrary to our initial hypothesis, there was a trend toward longer (rather than shorter) AA duration in statin users in the entire DFCI cohort and in the enzalutamide- and docetaxel-naïve JHU patients. Together, these results do not support the hypothesis that statins interfere with AA efficacy.

Risk Assessment in Small Renal Masses: A Review Article

The incidence of localized renal cell carcinoma (RCC) has been steadily increasing, in large part because of the increased use of imaging. Optimizing the management of localized RCC has become one of the leading priorities and foremost challenges within the urologic-oncologic community. Adequate risk stratification of patients following the diagnosis of localized RCC has become meaningful in deciding whether to treat, how to treat, and how intensively to treat. This article characterizes the existing risk assessment models that can be useful as treatment decision aids for patients with localized RCC.

Robot-assisted Versus Open Radical Cystectomy in Patients Receiving Perioperative Chemotherapy for Muscle-invasive Bladder Cancer: The Oncologist's Perspective from a Multicentre Study

BACKGROUND

Little is known about the outcomes of robot-assisted radical cystectomy (RARC) compared to open radical cystectomy (ORC) combined with perioperative chemotherapy for muscle-invasive urothelial bladder cancer (UBC).

OBJECTIVE

To evaluate surgical and oncological outcomes for RARC and ORC in multimodal treatment.

DESIGN, SETTING, AND PARTICIPANTS

Data from 28 centres were collected for cystectomies performed between January 2000 and July 2013.

INTERVENTION

RARC or ORC combined with perioperative chemotherapy for UBC.

OUTCOME MEASURES AND STATISTICAL ANALYSIS

Fisher's exact tests, χ² tests, and Wilcoxon rank-sum tests were used to compare the RARC and ORC groups. Logistic and Cox regression analyses were performed to evaluate potential prognostic factors.

RESULTS AND LIMITATIONS

A total of 688 patients (n=603 ORC and n=85 RARC) were analysed; 60.6% received neoadjuvant chemotherapy, and 45.1% adjuvant chemotherapy. No significant differences in baseline characteristics were found between the groups. The median time from surgery to adjuvant chemotherapy was 1.9 mo for both RARC and ORC groups. The median number of lymph nodes removed was 21 (interquartile range [IQR] 14-35) for RARC and 13 (IQR 8-21) for ORC (p<0.001); the results were confirmed in subgroup analyses. Multivariable analyses revealed no difference in the rate of positive surgical margins (p=0.54 and p=0.78), rate of neobladder diversion (p=0.33 and p=0.51), relapse-free survival (p=0.31 and p=0.23), and overall survival (p=0.63 and p=0.69). The retrospective nature of the data is the major limitation.

CONCLUSIONS

In this study, no differences in efficacy outcomes or ability to deliver adjuvant chemotherapy were observed between RARC and ORC. The increasing use of RARC is justifiable from an oncological viewpoint.

PATIENT SUMMARY

In a retrospective study of patients who received perioperative chemotherapy for urothelial bladder cancer, we found no difference in key outcomes between robot-assisted radical cystectomy (RARC) and open radical cystectomy. Performing RARC seems to be justifiable in the multidisciplinary setting.

Characterization of efficacy and toxicity after high-dose pelvic reirradiation with palliative intent for genitourinary second malignant neoplasms or local recurrences after full-dose radiation therapy in the pelvis: A high-volume cancer center experience

Purpose

The use of large-field external beam reirradiation (re-RT) after pelvic radiation therapy (RT) for genitourinary (GU) cancers has not been reported. We report the results of such treatment in patients with either symptomatic GU second malignant neoplasms or locally recurrent pelvic tumors after initial RT for whom surgery or further systemic therapy was not an option.

Methods and materials

The records of 28 consecutive patients with advanced, bulky GU malignancies treated with high-dose, large-field re-RT with palliative intent between 2008 and 2014 were retrospectively reviewed. Descriptive outcome analyses focused on toxicities and symptom control, and responses were evaluated by 2 independent observers.

Results

Twenty-seven male patients (96%) were included. Median initial external beam RT dose was 64 Gy (range, 30-75.6 Gy). The median time between initial RT and re-RT was 9.5 years (range, 0.2-32 years). At the time of re-RT, there were 16 local recurrences and 12 second malignant neoplasms together comprising 16 bladder, 10 prostate, 1 ureteral, and 1 penile cancer. Indications for re-RT were pain and bleeding/hemorrhage. The median equivalent sphere diameter planning target volume for re-RT was 8.6 cm (range, 4.7-16.3 cm). Given the severity of the symptoms and the bulk of the disease at the time of re-RT, a higher dose of RT was administered. The median re-RT dose was 50 Gy (range, 27.5-66 Gy). For patients who received <60 Gy, hypofractionation of 250 cGy was used. The median cumulative dose was 113.9 Gy (range, 81.5-132.8 Gy). Re-RT was well tolerated with no Radiation Therapy Oncology Group grade 3-4 toxicities. Twenty-four patients (92%) had complete resolution of symptoms, and relief was durable in 67% of patients. The median overall survival was 5.8 months (range, 0.3-38.9 months). Of those patients who are still alive, 100% remain free of initial symptoms.

Conclusion

This small series suggests that aggressive re-RT of inoperable and symptomatic GU malignancies that is undertaken with meticulous treatment planning is well tolerated and provides excellent, durable relief without undue short-term toxicity. Validation in a larger prospective cohort is required.

Venous thromboembolism in metastatic urothelial carcinoma or variant histologies: incidence, associative factors, and effect on survival

Venous thromboembolism (VTE) is common in cancer patients. However, little is known about VTE risk in metastatic urothelial carcinoma or variant histologies (UC/VH). We sought to characterize the incidence, associative factors, including whether various chemotherapy regimens portend different risk, and impact of VTE on survival in metastatic UC/VH patients. Patients diagnosed with metastatic UC/VH from 2000 to 2013 were included in this multicenter retrospective, international study from 29 academic institutions. Cumulative and 6‐month VTE incidence rates were determined. The association of first‐line chemotherapy (divided into six groups) and other baseline characteristics on VTE were analyzed. Each chemotherapy treatment group and statistically significant baseline clinical characteristics were assessed in a multivariate, competing‐risk regression model. VTE patients were matched to non‐VTE patients to determine the impact of VTE on overall survival. In all, 1762 patients were eligible for analysis. There were 144 (8.2%) and 90 (5.1%) events cumulative and within the first 6 months, respectively. VTE rates based on chemotherapy group demonstrated no statistical difference when gemcitabine/cisplatin was used as the comparator. Non‐urotheilal histology (SHR: 2.67; 95% CI: 1.72–4.16, P < 0.001), moderate to severe renal dysfunction (SHR: 2.12; 95% CI: 1.26–3.59, P = 0.005), and cardiovascular disease (CVD) or CVD risk factors (SHR: 2.27; 95% CI: 1.49–3.45, P = 0.001) were associated with increased VTE rates. Overall survival was worse in patients with VTE (median 6.0 m vs. 10.2 m, P < 0.001). Thus, in metastatic UC/VH patients, VTE is common and has a negative impact on survival. We identified multiple associated potential risk factors, although different chemotherapy regimens did not alter risk.

Prognostic Significance of Increases in Hemoglobin in Renal Cell Carcinoma Patients During Treatment With VEGF-directed Therapy

BACKGROUND

Increases in hemoglobin have been reported in renal cell carcinoma (RCC) patients treated with vascular endothelial growth factor (VEGF) pathway-targeted therapies and have been associated with increased progression-free survival (PFS). We retrospectively evaluated its significance as a predictive biomarker of clinical response in RCC.

PATIENTS AND METHODS

Patients with advanced RCC treated with VEGF receptor tyrosine kinase inhibitors (TKIs) or bevacizumab as a first-line therapy were identified. Hemoglobin levels were retrieved at baseline and then at monthly intervals for 6 months. Absolute and percentage increases over baseline were evaluated as predictors of objective response rate, PFS, time to treatment failure, and overall survival. Cox regression was used to estimate change status hazard ratios (HR) in univariate and multivariable models.

RESULTS

Among the 71 eligible patients, elevations in hemoglobin were observed in 83%, with a median time to increase of 2.4 weeks since treatment initiation. Changes in hemoglobin at time of response were not associated with objective response rate. Landmark analysis at 3 months showed that increases in hemoglobin were associated with worse PFS (8.0 vs. 19.4 months; HR = 2.29; 95% confidence interval, 1.01-5.16; P = .05) and time to treatment failure (6.4 vs. 18.1 months; HR = 2.14; 95% confidence interval, 0.99-4.60, P = .05). Patients with greater increases (15% or more) had significantly shorter PFS (5.5 vs. 13.6 months) and overall survival (20.8 vs. 30.4 months) compared to those with lesser degree of elevations.

CONCLUSION

Contrary to prior reports, elevation in hemoglobin on VEGF-directed therapy was associated with worse clinical outcomes, and the greater the degree of elevation, the poorer the prognosis.

Patterns of Bladder Preservation Therapy Utilization for Muscle-Invasive Bladder Cancer

Background: Trimodality bladder preservation therapy (BPT) in muscle invasive bladder cancer (MIBC) includes a maximal transurethral resection followed by concurrent chemoradiotherapy as an alternative to radical cystectomy (RC) in appropriately selected patients, or as a treatment option in non-cystectomy candidates. Several chemotherapy regimens can be used in BPT, but little is known about current practice patterns. Objective: To describe utilization patterns of BPT and associated survival outcomes in MIBC. Methods: Data were collected from the Retrospective International Study of Cancers of the Urothelial Tract (RISC), a database of 3,024 consecutive patients from 29 international academic centers from 2005 to 2013. Patients with clinical T2-T4aN0M0 urothelial cancer of the bladder were included. Results: 265 patients received BPT. Compared with the 1,447 patients who received RC, BPT patients were older, had poorer performance status, and had more comorbidities (p < 0.01 for all). Median overall survival (OS) was similar for patients treated with curative radiation doses in BPT and patients treated with RC (41 vs 46 months, p = 0.33, respectively). 45% of BPT patients received concurrent chemotherapy with radiation. The most common regimens included cisplatin alone (23%), carboplatin alone (22%), gemcitabine alone (10%), paclitaxel alone (9%), and 5-FU+mitomycin (5%). There were no significant differences in survival among chemotherapy regimens. Only 10 patients (4% of BPT patients) underwent salvage cystectomy. Conclusions: In clinical practice, BPT patients have similar survival to RC patients when treated with curative radiotherapy doses. Choice of concurrent chemotherapy regimen varied widely with no clear standard. Salvage cystectomy is rarely performed. Continued research is needed on the comparative effectiveness among BPT and RC, and among chemotherapy regimens in BPT.

Nomogram-based Prediction of Overall Survival in Patients with Metastatic Urothelial Carcinoma Receiving First-line Platinum-based Chemotherapy: Retrospective International Study of Invasive/Advanced Cancer of the Urothelium (RISC)

BACKGROUND

The available prognostic models for overall survival (OS) in patients with metastatic urothelial carcinoma (UC) have been derived from clinical trial populations of cisplatin-treated patients.

OBJECTIVE

To develop a new model based on real-world patients.

DESIGN, SETTING, AND PARTICIPANTS

Individual patient-level data from 29 centers were collected, including metastatic UC and first-line cisplatin- or carboplatin-based chemotherapy administered between January 2006 and January 2011.

INTERVENTION

First-line, platinum-based, combination chemotherapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The population was randomly split into a development and a validation cohort. Generalized boosted regression modelling was used to screen out irrelevant variables and address multivariable analyses. Two nomograms were built to estimate OS probability, the first based on baseline factors and platinum agent, the second incorporating objective response (OR). The performance of the above nomograms and that of other available models was assessed. We plotted decision curves to evaluate the clinical usefulness of the two nomograms.

RESULTS AND LIMITATIONS

A total of 1020 patients were analyzed (development: 687, validation: 333). In a platinum-stratified Cox model, significant variables for OS were performance status (p<0.001), white blood cell count (p=0.013), body mass index (p=0.003), ethnicity (p=0.012), lung, liver, or bone metastases (p<0.001), and prior perioperative chemotherapy (p=0.012). The c-index was 0.660. The distribution of the nomogram scores was associated with OR (p<0.001), and incorporating OR into the model further improved the c-index in the validation cohort (0.670).

CONCLUSIONS

We developed and validated two nomograms for OS to be used before and after completion of first-line chemotherapy for metastatic UC.

PATIENT SUMMARY

We proposed two models for estimating overall survival of patients with metastatic urothelial carcinoma receiving first-line, platinum-based chemotherapy. These nomograms have been developed on real-world patients who were treated outside of clinical trials and may be used irrespective of the chemotherapeutic platinum agent used.

The Khorana Score in Predicting Venous Thromboembolism for Patients With Metastatic Urothelial Carcinoma and Variant Histology Treated With Chemotherapy

BACKGROUND

The Khorana score is a predictive risk model for venous thromboembolism (VTE) in patients with cancer planning to receive chemotherapy. Urothelial carcinoma and variant histologies (UC/VH) were underrepresented in the model. We sought to evaluate whether the Khorana score predicts for VTE in a retrospective multinational data set of patients with metastatic UC/VH.

METHODS

Patients diagnosed with metastatic UC/VH who received chemotherapy were eligible. Those with incomplete or miscoded data were excluded. Khorana scores were calculated based on the pretreatment data and categorized into high (≥3) or intermediate (1-2) VTE risk. Other patient-, tumor-, and therapy-related factors were also analyzed. The χ² and logistic regression analyses were used to assess differences in VTE rates based on the clinical characteristics. Subgroup analyses were performed to evaluate the Khorana score and associated variables for early (<3 months) and late (>3 months) VTE.

RESULTS

A total of 943 patients were eligible for analysis. The cumulative VTE rate was 9.9%. There was no statistical difference in overall VTE rate between Khorana high- and intermediate-risk groups ( P = .16). In the multivariate analysis, nonurothelial histology (odds ratio [OR] = 2.56; P = .002) and the presence of cardiovascular disease (CVD) or CVD risk factors (OR = 2.14; P = .002) were associated with increased VTE risk. In the first 3 months from initiation of chemotherapy, Khorana high risk (OR = 2.08; P = .04) was associated with higher VTE rates. White blood cell (WBC) count (OR = 1.05; P = .04) was the only significant Khorana variable for early VTE.

CONCLUSIONS

The Khorana score stratifies early but not overall VTE risk in patients with metastatic UC/VH. The WBC count drives the increased early VTE risk seen with the Khorana score.

Diagnosis of Bladder Carcinoma: A Clinician's Perspective

In 2014, more than 74,000 new cases and 15,000 deaths from bladder cancer were estimated to occur. The most reliable prognostic factors for survival are pathologic stage and histologic grade. Accordingly, a good understanding of the pathologic features of these cancers is essential to guide optimal clinical treatment, which requires a multidisciplinary team of pathologists, urologists, radiation oncologists, and medical oncologists. This review highlights several clinical scenarios in which detailed pathologic evaluation and accurate reporting impact clinical management.

Abstract LB-136: High concordance of whole-exome sequencing of cell-free DNA and matched biopsies enables genomic discovery in metastatic cancer

Background: Circulating cell-free DNA (cfDNA) has largely been used to monitor blood for specific tumor mutations, but genome-wide discovery from cfDNA has not been well established. Here, we establish a scalable approach for whole-exome sequencing (WES) of cfDNA, making it possible to perform comprehensive genomic characterization of metastatic cancer in a routine and minimally-invasive manner.

Comprehensive genomic characterization of metastatic cancer stands to uncover novel alterations of clinical significance. A major challenge is that metastatic tumors are infrequently biopsied. Cell-free DNA is shed abundantly into the bloodstream from metastatic tumors, presenting an opportunity for genomic discovery in advanced cancers that are rarely biopsied in routine clinical care. We report an efficient process to qualify and sequence whole-exomes from cfDNA at scale and systematically compare the somatic mutations, indels, and copy number alterations detected in WES of cfDNA to WES of matched tumor biopsies.

Methods: We consented 86 patients with metastatic breast or prostate cancers for blood collection. We isolated cfDNA and germline DNA from blood and performed low coverage sequencing to estimate tumor content based on genome-wide copy number. We screened patient blood samples and prioritized those with higher tumor fractions for WES. In parallel, we analyzed cfDNA and germline DNA from healthy donors to calibrate our methods and assess false positive rate for genomic alterations.

Results: We found the vast majority of patients with metastatic prostate or breast cancer to have detectable tumor-derived cfDNA. WES of cfDNA from healthy donors revealed very low false positive rates for somatic mutations, indels and copy number alterations (SCNAs). By analyzing WES of cfDNA and tumor biopsies from dozens of patients with metastatic breast or prostate cancers, we established guidelines for the coverage and tumor fraction required for mutation discovery in WES of cfDNA. We found WES of cfDNA to uncover 91% of the clonal mutations, 59% of the subclonal mutations, and 75% of the SCNAs detected in WES of matched tumor biopsies. In several cases, we observed mutations exclusive to cfDNA that were confirmed in later blood draws, suggesting that cfDNA-exclusive mutations may be derived from unsampled metastases. In some cases, cfDNA revealed clinically actionable mutations that were not detected in matched tumor biopsies.

Conclusions: WES of cfDNA uncovers the majority of somatic mutations, indels, and SCNAs found in matched tumor biopsies of metastatic cancer. The high degree of concordance suggests that comprehensive sequencing of cfDNA can be leveraged for genomic discovery in settings where conventional biopsies are difficult to access. Furthermore, the detection of mutations in cfDNA that are not detected in concurrent biopsies suggests that cfDNA may be complementary to tumor biopsies for both translational studies and precision cancer medicine.

Citation Format: Viktor A. Adalsteinsson, Gavin Ha, Sam Freeman, Atish D. Choudhury, Daniel G. Stover, Heather A. Parsons, Gregory Gydush, Sarah Reed, Denis Loginov, Dimitri Livitz, Daniel Rosebrock, Ignat Leshchiner, Ofir Cohen, Coyin Oh, Jaegil Kim, Chip Stewart, Mara Rosenberg, Huiming Ding, Maxwell R. Lloyd, Sairah Mahmud, Karla E. Helvie, Margaret S. Merrill, Rebecca A. Santiago, Edward P. O’Connor, Seong H. Jeong, Joseph F. Kramkowski, Jens G. Lohr, Laura Polacek, Nelly Oliver, Lori Marini, Joshua Francis, Lauren C. Harshman, Eliezer M. Van Allen, Eric P. Winer, Nancy U. Lin, Mari Nakabayashi, Mary-Ellen Taplin, Levi A. Garraway, Todd R. Golub, Jesse S. Boehm, Nikhil Wagle, Gad Getz, Matthew Meyerson, Christopher J. Love. High concordance of whole-exome sequencing of cell-free DNA and matched biopsies enables genomic discovery in metastatic cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-136.

Statin Use at the Time of Initiation of Androgen Deprivation Therapy and Time to Progression in Patients With Hormone-Sensitive Prostate Cancer

IMPORTANCE

Statin use has been associated with improved prostate cancer outcomes. Dehydroepiandrosterone sulfate (DHEAS) is a precursor of testosterone and a substrate for SLCO2B1, an organic anionic transporter. We previously demonstrated that genetic variants of SLCO2B1 correlated with time to progression (TTP) during receipt of androgen deprivation therapy (ADT). Statins also use SLCO2B1 to enter cells, and thus we hypothesized that they may compete with DHEAS uptake by the tumor cells.

OBJECTIVE

To evaluate whether statin use prolongs TTP during ADT for hormone-sensitive prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

In vitro studies were performed using prostate cancer cell lines at an academic, comprehensive cancer center. Statin use was retrospectively analyzed in 926 patients who had received ADT for biochemical or metastatic recurrence or de novo metastatic prostate cancer between January 1996 and November 2013.

MAIN OUTCOMES AND MEASURES

To determine whether statins interfere with DHEAS uptake, we performed in vitro studies using prostate cancer cell lines. Next, we queried our institutional clinical database to assess for an association between statin use and TTP during ADT using multivariable Cox regression analysis and adjusted for known prognostic factors.

RESULTS

In vitro, we demonstrated that statins block DHEAS uptake by competitively binding to SLCO2B1. In our ADT cohort of 926 patients, 283 (31%) were taking a statin at ADT initiation. After a median follow-up of 5.8 years, 644 patients (70%) had experienced disease progression while receiving ADT. Median TTP during ADT was 20.3 months (95% CI, 18-24 months). Men taking statins had a longer median TTP during ADT compared with nonusers (27.5 [95% CI, 21.1-37.7] vs 17.4 [95% CI, 14.9-21.1] months; P < .001). The association remained statistically significant after adjusting for predefined prognostic factors (adjusted hazard ratio, 0.83 [95% CI, 0.69-0.99]; P = .04). The positive statin effect was observed for both patients with and without metastases (adjusted hazard ratio, 0.79 [95% CI, 0.58-1.07] for M0 disease and 0.84 [95% CI, 0.67-1.06] for M1 disease; P for interaction = .72).

CONCLUSIONS AND RELEVANCE

Statin use at the time of ADT initiation was associated with a significantly longer TTP during ADT even after adjustment for known prognostic factors. Our in vitro finding that statins competitively reduce DHEAS uptake, thus effectively decreasing the available intratumoral androgen pool, affords a plausible mechanism to support the clinical observation of prolonged TTP in statin users.

Association of SLCO2B1 Genotypes With Time to Progression and Overall Survival in Patients Receiving Androgen-Deprivation Therapy for Prostate Cancer

PURPOSE

To validate the association of three previously demonstrated SLCO2B1 germline variants with time to progression (TTP) in patients receiving androgen-deprivation therapy (ADT), and to evaluate if the SLCO2B1 genetic variants impacted overall survival (OS) for prostate cancer (PC).

PATIENTS AND METHODS

Three single nucleotide polymorphisms (SNPs), exonic SNP rs12422149 and intronic SNPs rs1789693 and rs1077858, were genotyped in an independent validation cohort of 616 patients with PC who were treated with ADT at the Dana-Farber Cancer Institute from 1996 to 2013. Multivariable Cox proportional hazards regression adjusting for known prognostic factors estimated the association of these genetic variants with TTP and OS in patients receiving ADT. The expression of SLCO2B1 was examined in prostatectomy samples, and the impact of SLCO2B1 expression level on DHEAS (dehydroepiandrosterone sulfate) uptake was evaluated in cell lines.

RESULTS

The association between exonic SNP rs12422149 and TTP in patients treated with ADT was confirmed in univariable (P = .019) and multivariable analyses (adjusted hazard ratio, 1.31; 95% CI, 1.00 to 1.72 for GG v AA/AG; P = .049). Because OS had not been previously evaluated, we examined the association in the combined initial and validation cohorts (N = 1,094). The intronic SNP rs1077858 was associated with OS in both univariable (P = .009; Bonferroni's method adjusted P = .027) and multivariable analyses (adjusted hazard ratio, 1.35; 95% CI, 1.07 to 1.71 for GG v AA/AG; P = .012). SLCO2B1 expression in normal prostate tissue and in 22RV1 cells carrying the major allele of SNP rs1077858 was significantly lower than in cells carrying the risk allele. We show in vitro that SLCO2B1 expression levels correlated with DHEAS uptake by PC cells.

CONCLUSION

The association of SNP rs1077858 with OS may be a result of differential SLCO2B1 expression and the consequent increased uptake of DHEAS and subsequent resistance to ADT, which, in turn, may contribute to decreased OS.

Contemporary trends in high-dose interleukin-2 use for metastatic renal cell carcinoma in the United States

BACKGROUND

Targeted therapies (TTs) have revolutionized metastatic renal cell carcinoma (mRCC) treatment in the past decade, largely replacing immunotherapy including high-dose interleukin-2 (HD IL-2) therapy. We evaluated trends in HD IL-2 use for mRCC in the TT era.

METHODS

Our cohort comprised a weighted estimate of all patients undergoing HD IL-2 treatment for mRCC from 2004 to 2012 using the Premier Hospital Database. We assessed temporal trends in HD IL-2 use including patient, disease, and hospital characteristics stratified by era (pre-TT uptake: 2004-2006, uptake: 2007-2009, and post-TT uptake: 2010-2012) and fitted multivariable regression models to identify predictors of treatment toxicity and tolerability.

RESULTS

An estimated 2,351 patients received HD IL-2 therapy for mRCC in the United States from 2004 to 2012. The use decreased from 2004 to 2008. HD IL-2 therapy became increasingly centralized in teaching hospitals (24% of treatments in 2004 and 89.5% in 2012). Most patients who received HD IL-2 therapy were men, white, younger than 60 years, had lung metastases, and were otherwise healthy. Vasopressors, intensive care unit admission, and hemodialysis were necessary in 53.4%, 33.0%, and 7.1%, respectively. Factors associated with toxicities in multivariable analyses included being unmarried, male sex, and multiple metastatic sites. African Americans and patients with single-site metastases were less likely to receive multiple treatment cycles.

CONCLUSIONS

HD IL-2 therapy is used infrequently for mRCC in the United States, and its application has diminished with the uptake of TT. Patients are being increasingly treated in teaching hospitals, suggesting a centralization of care and possible barriers to access. A recent slight increase in HD IL-2 therapy use likely reflects recognition of the inability of TT to effect a complete response.

Non-clear cell renal cell carcinoma, part 2: therapy

Non-clear cell renal cell carcinomas (RCCs) represent a heterogeneous group of diseases with distinct molecular drivers, histologies, and clinical outcomes. Their low incidence and heterogeneity have resulted in a lack of studies that address the optimal strategies for each subtype. This article (the second in a 2-part series) reviews the current targeted therapies approved for RCC, such as the vascular endothelial growth factor receptor tyrosine kinase inhibitors and the mammalian target of rapamycin inhibitors. Ongoing studies will provide more information regarding the role of these agents in non-clear cell RCC. Ultimately, enhanced understanding of genetic triggers and the development of more tailored treatments remain imperative to improve outcomes in non-clear cell RCC.

Non-clear cell renal cell carcinoma, part 1: histology

Non-clear cell renal cell carcinomas (RCCs) represent up to 20% of all RCCs. Despite often being clustered as a single entity, these tumors represent a heterogeneous group of diseases with distinct molecular drivers, histologies, and clinical outcomes. Their low incidence and heterogeneity have resulted in a lack of studies that address the optimal strategies for each subtype. This article (the first in a 2-part series) reviews the histology of RCC, whereas the second article reviews current targeted therapies approved for RCC, such as the vascular endothelial growth factor receptor tyrosine kinase inhibitors and the mammalian target of rapamycin inhibitors. Ongoing studies will provide more information regarding the role of these agents in non-clear cell RCC.

Second-line therapies in metastatic urothelial carcinoma

Patients with relapsed or refractory urothelial carcinoma (UC) face a poor prognosis and a dearth of available treatment options that improve their survival. End-organ function and performance status play a vital role in the choice of second-line therapies. Evidence supporting the use of cytotoxic chemotherapy, as single agents or in combination, arises from small phase 2 studies with modest responses. With the evolution of genomic testing in UC, several pathways amenable to available targeted therapies have emerged. Encouraging patient participation in clinical trials is critical to improve patient outcomes and to advance the current modest treatment armamentarium.

PD-1 blockade in renal cell carcinoma: to equilibrium and beyond

The past several years have witnessed a resurgence of interest in cancer immunotherapy. The development of blocking antibodies against the inhibitory programmed death-1 (PD-1) pathway represents a clinical breakthrough in the treatment of solid tumors such as melanoma, and these agents show great promise in renal cell carcinoma (RCC). The early data have been surprising in that they demonstrate that blockade of a single immune checkpoint can elicit objective responses in patients with RCC, despite the recognized complexity of the immunosuppressive tumor microenvironment. Reinvigorating the patient's own immune cells to reactivate and to target the tumor has the potential advantages of more selective killing and thus decreased toxicity. In addition, checkpoint blockade immunotherapy has the advantage of inducing a memory response that is unattainable with our current cytotoxic and targeted therapies. This Crossroads overview will highlight the emerging investigation of PD-1 blockade in RCC and how this T cell-targeted strategy may thwart the tumor's escape mechanisms and shift the immune system/tumor balance back to a state of equilibrium and even to tumor elimination.

Cancer immunotherapy highlights from the 2014 ASCO Meeting

The promise of cancer immunotherapy was validated officially in March 2011 when the FDA approved Yervoy (ipilimumab; Bristol-Myers Squibb) for the treatment of unresectable or metastatic melanoma. The approval was based on results of a randomized, double-blind clinical trial establishing that ipilimumab (a humanized anti-CTLA-4 monoclonal antibody) treatment extended the overall survival of patients with advanced melanoma. CTLA-4 is a member of the so-called family of checkpoint regulators, which are expressed on immune cells that activate or inhibit an immune response. An increasing number of immune checkpoint regulators are now being identified and targeted for immunotherapy. At the 2014 meeting of the American Society of Clinical Oncology (ASCO), it was reported that checkpoint blockade as a monotherapy or combination therapy was used successfully to treat advanced melanoma and non-small cell lung cancer. Checkpoint blockade immunotherapy was also used successfully for the treatment of other cancers, most notably genitourinary cancers such as urothelial bladder cancer and metastatic renal cell carcinoma. This report is a compiled summary of cancer immunotherapy highlights presented at the 2014 ASCO meeting by various investigators.

Elevated IL-8, TNF-α, and MCP-1 in men with metastatic prostate cancer starting androgen-deprivation therapy (ADT) are associated with shorter time to castration-resistance and overall survival

BACKGROUND

Chemokines and cytokines have been implicated in progression to castration-resistant prostate cancer (CRPC).

METHODS

Retrospective data were accessed from 122 men with serum samples drawn at a median of 0.5 months after starting ADT for metastatic prostate cancer. MCP-1, IL-1-β, IL-2, IL-8, IL-6, and TNF-α levels were measured by multiplex electrochemiluminescence assays. A multivariable Cox model assessed the association of time to CRPC and overall survival by the protein levels and adjusted for clinical variables (age and prostate specific antigen (PSA) levels at start of ADT, race, ECOG status, and extent of metastases). Associations were reported as hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

Median follow-up and overall survival were 44 and 42.2 months, respectively. ECOG performance status (≥1 vs. 0) was negatively associated with overall survival [HR = 2.8 (1.1-7.0), P = 0.03], and PSA nadir < 0.2 was predictive of longer time to development of CRPC [HR = 0.3 (0.2-0.5), P < 0.0001]. The HR for time to CRPC by protein above the median was 1.4 (95% CI: 0.9, 2.2, P = 0.13) for IL-8; 1.3 (95% CI: 0.8, 2, P = 0.18) for TNF-α; 1.0 (95% CI: 0.7, 1.6, P = 0.95) for MCP-1. The HR for median overall survival for protein levels above the median was: 1.9 (95% CI: 1.0, 3.5, P = 0.04) for IL-8; 2.0 (95% CI: 1.1, 3.5, P = 0.02) for TNF-α; 1.7 (95% CI: 1.7, 3.0, P = 0.08) for MCP-1. There was no association with IL-1-β, IL-2, or IL-6.

CONCLUSION

Higher levels of inflammation-associated cytokines correlate with poorer prostate cancer outcomes and may guide strategies to improve prostate cancer therapy.

First-, second-, third-line therapy for mRCC: benchmarks for trial design from the IMDC

BACKGROUND

Limited data exist on outcomes for metastatic renal cell carcinoma (mRCC) patients treated with multiple lines of therapy. Benchmarks for survival are required for patient counselling and clinical trial design.

METHODS

Outcomes of mRCC patients from the International mRCC Database Consortium database treated with 1, 2, or 3+ lines of targeted therapy (TT) were compared by proportional hazards regression. Overall survival (OS) and progression-free survival (PFS) were calculated using different population inclusion criteria.

RESULTS

In total, 2705 patients were treated with TT of which 57% received only first-line TT, 27% received two lines of TT, and 16% received 3+ lines of TT. Overall survival of patients who received 1, 2, or 3+ lines of TT were 14.9, 21.0, and 39.2 months, respectively, from first-line TT (P<0.0001). On multivariable analysis, 2 lines and 3+ lines of therapy were each associated with better OS (HR=0.738 and 0.626, P<0.0001). Survival outcomes for the subgroups were as follows: for all patients, OS 20.9 months and PFS 7.2 months; for those similar to eligible patients in the first-line ADAPT trial, OS 14.7 months and PFS 5.6 months; for those similar to patients in first-line TIVO-1 trial, OS 24.8 months and PFS 8.2 months; for those similar to patients in second-line INTORSECT trial, OS 13.0 months and PFS 3.9 months; and for those similar to patients in the third-line GOLD trial, OS 18.0 months and PFS 4.4 months.

CONCLUSIONS

Patients who are able to receive more lines of TT live longer. Survival benchmarks provide context and perspective when interpreting and designing clinical trials.

First-line Mammalian target of rapamycin inhibition in metastatic renal cell carcinoma: an analysis of practice patterns from the International Metastatic Renal Cell Carcinoma Database Consortium

INTRODUCTION/BACKGROUND

Approval of the mTOR inhibitors for the treatment of mRCC was based on efficacy in poor-risk patients in the first-line setting for temsirolimus and in vascular endothelial growth factor inhibitor-refractory patients for everolimus. We strove to characterize temsirolimus and everolimus use and effectiveness in the first-line setting.

PATIENTS AND METHODS

We performed a retrospective database analysis of mRCC patients who received mTOR inhibitors as first-line targeted therapy. The Kaplan-Meier product-limit method was used to estimate the distribution of progression-free survival (PFS) and overall survival (OS).

RESULTS

We identified 127 mRCC patients who had received a first-line mTOR inhibitor. Temsirolimus was administered in 93 patients (73%) and everolimus in 34 patients (27%). The main reasons for choice of temsirolimus were poor-risk disease (38%), non-clear cell histology (27%), and clinical trial availability (15%), whereas clinical trial (82%) and non-clear cell histology (6%) drove everolimus selection. Of the temsirolimus and everolimus patients, 58% and 32% were poor-risk according to the International mRCC Database Consortium criteria, respectively. The median PFS and OS were 3.4 and 12.5 months and 4.8 and 15.9 months with temsirolimus and everolimus, respectively. Although limited by small numbers, this study characterizes a real-world, international experience with the use of mTOR inhibition in treatment-naive mRCC patients.

CONCLUSION

Poor-risk RCC, non-clear cell histology, and clinical trials were the predominant reasons for mTOR inhibitor selection in the front-line setting. Because of the different patient populations in which they were administered, direct comparisons of the front-line efficacy of temsirolimus and everolimus cannot be made.

Prognostic risk stratification derived from individual patient level data for men with advanced penile squamous cell carcinoma receiving first-line systemic therapy

BACKGROUND

Prognostic factors in men with penile squamous cell carcinoma (PSCC) receiving systemic therapy are unknown. A prognostic classification system in this disease may facilitate interpretation of outcomes and guide rational drug development. We performed a retrospective analysis to identify prognostic factors in men with PSCC receiving first-line systemic therapy for advanced disease.

PATIENTS AND METHODS

Individual patient level data were obtained from 13 institutions to study prognostic factors in the context of first-line systemic therapy for advanced PSCC. Cox proportional hazards regression analysis was conducted to examine the prognostic effect of these candidate factors on progression-free survival (PFS) and overall survival (OS): age, stage, hemoglobin, neutrophil count, lymphocyte count, albumin, site of metastasis (visceral or nonvisceral), smoking, circumcision, regimen, ECOG performance status (PS), lymphovascular invasion, precancerous lesion, and surgery following chemotherapy. The effect of different treatments was then evaluated adjusting for factors in the prognostic model.

RESULTS

The study included 140 eligible men. Mean age across all men was 57.0 years. Among them, 8.6%, 21.4%, and 70.0% of patients had stage 2, 3, and 4 diseases, respectively; 40.7% had ECOG PS ≥ 1, 47.4% had visceral metastases, and 73.6% received cisplatin-based chemotherapy. The multivariate model of poor prognostic factors included visceral metastases (P<0.001) and ECOG PS ≥ 1 (P<0.001) for both PFS and OS. A risk stratification model constructed with 0, 1, and both poor prognostic factors was internally validated and demonstrated moderate discriminatory ability (c-statistic of 0.657 and 0.677 for OS and PFS, respectively). The median OS for the entire population was 9 months. Median OS was not reached, 8, and 7 months for those with 0, 1, and both risk factors, respectively. Cisplatin-based regimens were associated with better OS (P = 0.017) but not PFS (P = 0.37) compared with noncisplatin-based regimens after adjusting for the 2 prognostic factors.

CONCLUSIONS

In men with advanced PSCC receiving first-line systemic therapy, visceral metastases and ECOG PS ≥ 1 were poor prognostic factors. A prognostic model including these factors exhibited moderate discriminatory ability for outcomes and warrants external validation. Patients receiving cisplatin-based regimens exhibited better outcomes compared with noncisplatin-based regimens after adjusting for prognostic factors.

The impact of prior platinum therapy on survival in patients with metastatic urothelial cancer receiving vinflunine

Background:

A phase III trial demonstrated an overall survival advantage with the addition of vinflunine to best supportive care (BSC) in platinum-refractory advanced urothelial cancer. We subsequently examined the impact of an additional 2 years of survival follow-up and evaluated the influence of first-line platinum therapy on survival.

Methods:

The 357 eligible patients from the phase III study were categorised into two cohorts depending on prior cisplatin treatment: cisplatin or non-cisplatin. Survival was calculated using the Kaplan–Meier method.

Results:

The majority had received prior cisplatin (70.3%). Survival was higher in the cisplatin group (HR: 0.76; CI 95% 0.58–0.99; P=0.04) irrespective of treatment arm. Multivariate analysis including known prognostic factors (liver involvement, haemoglobin, performance status) and prior platinum administration did not show an independent effect of cisplatin. Vinflunine reduced the risk of death by 24% in the cisplatin-group (HR: 0.76; CI 95% 0.58–0.99; P=0.04) and by 35% in non-cisplatin patients (HR: 0.65; CI 95% 0.41–1.04; P=0.07).

Interpretation:

Differences in prognostic factors between patients who can receive prior cisplatin and those who cannot may explain the survival differences in patients who undergo second line therapy. Prior cisplatin administration did not diminish the subsequent benefit of vinflunine over BSC.

Abstract 2283: Nano-scale proteomic profiles of response to targeted therapy in patients with RCC

Novel agents that inhibit targets in the hypoxia and MTOR pathways can achieve response rates of 30-60% in renal cell carcinoma (RCC); however, biomarkers have not yet been identified to measure degree of target inhibition and mechanism of biologic response in individual patients. We developed the use of a high-throughput, nanoscale immunoassay (NIA, Nanopro1000 Instrument, Protein Simple) to profile hypoxia pathways and downstream signaling in serially sampled clinical specimens from patients with RCC. NIA uses charge-based separation to distinguish multiple charged modifications of individual proteins, and measure relative ratios of individual unphosphorylated and phosphorylated isoforms. We first developed and optimized assays to measure therapeutic targets and proteins in hypoxia, proliferation and metabolic pathways (including CaIX, HIF, VEGFR, ERK, AKT, MYC, glutaminase) to analyze frozen surgical specimens, fine needle aspirates (FNA's) and blood PBMC specimens from patients with RCC. Next, we analyzed more than 200 FNA's from solid tumors, comparing RCC with paired adjacent non-tumor tissue and other epithelial malignancies. Basal MAPK signaling across the samples ranged across 3 logs for both normal and tumor tissue, demonstrating the difficulty in setting a threshold predictive of response based on a single pre-treatment measurement. To test whether analysis of serial specimens could detect changes, we prospectively collected and analyzed blood peripheral mononuclear cells from 20 RCC patients before and during treatment with standard targeted therapies including MTOR and tyrosine kinase inhibitors. We report for the first time that targeted inhibitors can preferentially inhibit or activate specific protein phospho-isoforms in patients with RCC. Our studies demonstrate that rapid and quantitative nanoproteomic profiling in very small amounts of serially sampled clinical specimen may accelerate translational studies for predictive proteomic biomarkers of response to targeted therapy.

Citation Format: Alice C. Fan, John Leppert, Joanna E. Liliental, Liwen Xu, Thomas J. Metzner, Emelyn Shroff, Alia Yaghi, Christine Yost, James D. Brooks, Lauren C. Harshman, Chiara Sabatti, Sandhya Srinivas, Dean W. Felsher. Nano-scale proteomic profiles of response to targeted therapy in patients with RCC. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2283. doi:10.1158/1538-7445.AM2013-2283

The frequency and severity of cardiovascular toxicity from targeted therapy in advanced renal cell carcinoma patients

OBJECTIVES

The purpose of this study was to document the incidence and extent of cardiovascular toxicity among advanced renal cell carcinoma patients treated with newer targeted cancer agents.

BACKGROUND

The potential for targeted cancer agents to induce cardiovascular toxicity has been increasingly recognized, but the overall incidence and extent of toxicity have not been well characterized. Early detection of asymptomatic patients could preempt symptomatic toxicity and reduce treatment-related morbidity and mortality.

METHODS

The incidence of hypertension, left ventricular dysfunction, and heart failure was assessed for all advanced renal cell carcinoma patients treated with targeted therapies at our institution between 2004 and 2011. Grading was performed according to the Common Terminology Criteria for Adverse Events version 4.0.

RESULTS

Cardiovascular toxicity developed in 116 of 159 patients (73%), including 52 of 159 patients (33%) when hypertension was excluded. Toxicity varied from occurrences of asymptomatic drops in left ventricular ejection fraction to rises in N-terminal-pro-B-type natriuretic peptide to severe heart failure. The tyrosine kinase inhibitor sunitinib was the agent most frequently used, with 66 of 101 sunitinib-treated patients (65%) developing a form of cardiovascular toxicity, including 32 of 101 patients (32%), excluding hypertension. Other VEGF inhibitors such as bevacizumab, sorafenib, and pazopanib also elicited significant cardiovascular toxicity with incidences ranging from 51% to 68%.

CONCLUSIONS

The frequency and severity of cardiovascular toxicity in advanced renal cell carcinoma patients treated with targeted cancer therapies are high.