Todd M. Morgan

Targeted Therapy for Advanced Prostate Cancer: Inhibition of the PI3K/Akt/mTOR Pathway

A large number of novel therapeutics is currently undergoing clinical evaluation for the treatment of prostate cancer, and small molecule signal transduction inhibitors are a promising class of agents. These inhibitors have recently become a standard therapy in renal cell carcinoma and offer significant promise in prostate cancer. Through an understanding of the key pathways involved in prostate cancer progression, a rational drug design can be aimed at the molecules critical to cellular signaling. This may enable administration of selective therapies based on the expression of molecular targets, more appropriately individualizing treatment for prostate cancer patients. One pathway with a prominent role in prostate cancer is the PI3K/Akt/mTOR pathway. Current estimates suggest that PI3K/Akt/mTOR signaling is upregulated in 30-50% of prostate cancers, often through loss of PTEN. Molecular changes in the PI3K/Akt/mTOR signaling pathway have been demonstrated to differentiate benign from malignant prostatic epithelium and are associated with increasing tumor stage, grade, and risk of biochemical recurrence. Multiple inhibitors of this pathway have been developed and are being assessed in the laboratory and in clinical trials, with much attention focusing on mTOR inhibition. Current clinical trials in prostate cancer are assessing efficacy of mTOR inhibitors in combination with multiple targeted or traditional chemotherapies, including bevacizumab, gefitinib, and docetaxel. Completion of these trials will provide substantial information regarding the importance of this pathway in prostate cancer and the clinical implications of its targeted inhibition. In this article we review the data surrounding PI3K/Akt/mTOR inhibition in prostate cancer and their clinical implications.

Disseminated Tumor Cells in Prostate Cancer Patients after Radical Prostatectomy and without Evidence of Disease Predicts Biochemical Recurrence

Purpose: Men with apparently localized prostate cancer often relapse years after radical prostatectomy. We sought to determine if epithelial-like cells identified from bone marrow in patients after radical prostatectomy, commonly called disseminated tumor cells (DTC), were associated with biochemical recurrence. Experimental Design: We obtained bone marrow aspirates from 569 men prior to radical prostatectomy and from 34 healthy men with prostate-specific antigens <2.5 ng/mL to establish a comparison group. Additionally, an analytic cohort consisting of 98 patients with no evidence of disease (NED) after radical prostatectomy was established to evaluate the relationship between DTC and biochemical recurrence. Epithelial cells in the bone marrow were detected by magnetic bead enrichment with antibodies to CD45 and CD61 (negative selection) followed by antibodies to human epithelial antigen (positive selection) and confirmation with FITC-labeled anti-BerEP4 antibody. Results: DTC were present in 72% (408 of 569) of patients prior to radical prostatectomy. There was no correlation with pathologic stage, Gleason grade, or preoperative prostate-specific antigens. Three of 34 controls (8.8%) had DTC present. In patients with NED after radical prostatectomy, DTC were present in 56 of 98 (57%). DTC were detected in 12 of 14 (86%) NED patients after radical prostatectomy who subsequently suffered biochemical recurrence. The presence of DTC in NED patients was an independent predictor of recurrence (hazard ratio 6.9; 95% confidence interval, 1.03-45.9). Conclusions: Approximately 70% of men undergoing radical prostatectomy had DTC detected in their bone marrow prior to surgery, suggesting that these cells escape early in the disease. Although preoperative DTC status does not correlate with pathologic risk factors, persistence of DTC after radical prostatectomy in NED patients was an independent predictor of recurrence.

NCCN Guidelines Insights: Prostate Cancer Early Detection, Version 2.2016

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Prostate Cancer Early Detection provide recommendations for prostate cancer screening in healthy men who have elected to participate in an early detection program. The NCCN Guidelines focus on minimizing unnecessary procedures and limiting the detection of indolent disease. These NCCN Guidelines Insights summarize the NCCN Prostate Cancer Early Detection Panels most significant discussions for the 2016 guideline update, which included issues surrounding screening in high-risk populations (ie, African Americans, BRCA1/2 mutation carriers), approaches to refine patient selection for initial and repeat biopsies, and approaches to improve biopsy specificity.

Preoperative Nutritional Status Is an Important Predictor of Survival in Patients Undergoing Surgery for Renal Cell Carcinoma

BACKGROUND The role of malnutrition has not been well studied in patients undergoing surgery for renal cell carcinoma (RCC). OBJECTIVE Our aim was to evaluate whether nutritional deficiency (ND) is an important determinant of survival following surgery for RCC. DESIGN, SETTING, AND PARTICIPANTS A total of 369 consecutive patients underwent surgery for locoregional RCC from 2003 to 2008. ND was defined as meeting one of the following criteria: body mass index <18.5 kg/m(2), albumin <3.5 g/dl, or preoperative weight loss ≥ 5% of body weight. INTERVENTION All patients underwent radical or partial nephrectomy. MEASUREMENTS Primary outcomes were overall and disease-specific mortality. Covariates included age, Charlson comorbidity index (CCI), preoperative anemia, tumor stage, Fuhrman grade, and lymph node status. Multivariate analysis was performed using a Cox proportional hazards model. Mortality rates were estimated using the Kaplan-Meier product-limit method. RESULTS AND LIMITATIONS Eighty-five patients (23%) were categorized as ND. Three-year overall and disease-specific survival were 58.5% and 80.4% in the ND cohort compared with 85.4% and 94.7% in controls, respectively (p<0.001). ND remained a significant predictor of overall mortality (hazard ratio [HR]: 2.41, 95% confidence interval [CI], 1.40-4.18) and disease-specific mortality (HR: 2.76; 95% CI, 1.17-6.50) after correcting for age, CCI, preoperative anemia, stage, grade, and nodal status. This study is limited by its retrospective nature. CONCLUSIONS ND is associated with higher mortality in patients undergoing surgery for locoregional RCC, independent of key clinical and pathologic factors. Given this mortality risk, it may be important to address nutritional status preoperatively and counsel patients appropriately.

Multicenter Assessment of Neoadjuvant Chemotherapy for Muscle-invasive Bladder Cancer

BACKGROUND The efficacy of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (BCa) was established primarily with methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC), with complete response rates (pT0) as high as 38%. However, because of the comparable efficacy with better tolerability of gemcitabine and cisplatin (GC) in patients with metastatic disease, GC has become the most commonly used regimen in the neoadjuvant setting. OBJECTIVE We aimed to assess real-world pathologic response rates to NAC with different regimens in a large, multicenter cohort. DESIGN, SETTING, AND PARTICIPANTS Data were collected retrospectively at 19 centers on patients with clinical cT2-4aN0M0 urothelial carcinoma of the bladder who received at least three cycles of NAC, followed by radical cystectomy (RC), between 2000 and 2013. INTERVENTION NAC and RC. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The primary outcome was pathologic stage at cystectomy. Univariable and multivariable analyses were used to determine factors predictive of pT0N0 and ≤pT1N0 stages. RESULTS AND LIMITATIONS Data were collected on 935 patients who met inclusion criteria. GC was used in the majority of the patients (n=602; 64.4%), followed by MVAC (n=183; 19.6%) and other regimens (n=144; 15.4%). The rates of pT0N0 and ≤pT1N0 pathologic response were 22.7% and 40.8%, respectively. The rate of pT0N0 disease for patients receiving GC was 23.9%, compared with 24.5% for MVAC (p=0.2). There was no difference between MVAC and GC in pT0N0 on multivariable analysis (odds ratio: 0.89 [95% confidence interval, 0.61-1.34]; p=0.6). CONCLUSIONS Response rates to NAC were lower than those reported in prospective randomized trials, and we did not discern a difference between MVAC and GC. Without any evidence from randomized prospective trials, the best NAC regimen for invasive BCa remains to be determined. PATIENT SUMMARY There was no apparent difference in the response rates to the two most common presurgical chemotherapy regimens for patients with bladder cancer.

Predicting the Probability of 90-Day Survival of Elderly Patients With Bladder Cancer Treated With Radical Cystectomy

PURPOSE Despite the increased morbidity and mortality of radical cystectomy in elderly individuals with bladder cancer numerous studies show that surgery can provide a survival benefit. We sought to better identify patients at substantial risk for postoperative mortality. MATERIALS AND METHODS We evaluated 220 consecutive patients 75 years old or older treated with radical cystectomy for bladder cancer at a single institution from 2000 to 2008. The analytical cohort comprised 169 patients with complete preoperative data available. A Cox proportional hazards model was used to determine the value of precystectomy clinical information to predict 90-day survival after radical cystectomy. Results were used to create a nomogram predicting the probability of 90-day survival after radical cystectomy. The model was then subjected to 200 bootstrap resamples for internal validation. RESULTS Of the 220 patients 28 (12.7%) died within 90 days of surgery. Older age (HR 2.30, 95% CI 1.22-4.32) and lower preoperative albumin (HR 2.50, 95% CI 1.40-4.45) were significant predictors of 90-day mortality. We developed a nomogram based on patient age, clinical stage, Charlson comorbidity index and albumin to predict the likelihood of 90-day mortality with 75% accuracy. Internal validation showed a bootstrap adjusted concordance index of 71%. CONCLUSIONS We developed a nomogram that provides individualized risk estimations to predict the probability of 90-day mortality, potentially enhancing preoperative counseling and providing clinicians with an added tool to individualize treatment decisions in this challenging patient population. These data suggest that albumin is a strong predictor of postoperative mortality and show the importance of assessing this variable before surgery.

The relationship between perioperative blood transfusion and overall mortality in patients undergoing radical cystectomy for bladder cancer

OBJECTIVES The relationship between perioperative blood transfusion (PBT) and oncologic outcomes is controversial. In patients undergoing surgery for colon cancer and several other solid malignancies, PBT has been associated with an increased risk of mortality. Yet, the urologic literature has a paucity of data addressing this topic. We sought to evaluate whether PBT affects overall survival following radical cystectomy (RC) for patients with bladder cancer. METHODS The medical records of 777 consecutive patients undergoing RC for urothelial carcinoma of the bladder were reviewed. PBT was defined as transfusion of red blood cells during RC or within the postoperative hospitalization. The primary outcome was overall survival. Clinical and pathologic variables were compared using χ(2) tests, and Cox multivariate survival analyses were performed. RESULTS A total of 323 patients (41.6%) underwent PBT. In the univariate analysis, PBT was associated with increased overall mortality (HR 1.40, 95% CI 1.11-1.78). Additionally, an independent association was demonstrated in a non-transformed Cox regression model (HR, 95% CI 1.01-1.36) but not in a model utilizing restricted cubic splines (HR 1.03, 95% CI 0.77-1.38). The c-index was 0.78 for the first model and 0.79 for the second. CONCLUSIONS In a traditional multivariate model, mirroring those that have been applied to this question in the general surgery literature, we demonstrated an association between PBT and overall mortality after RC. However, this relationship is not observed in a second statistical model. Given the complex nature of adequately controlling for confounding factors in studies of PBT, a prospective study will be necessary to fully elucidate the independent risks associated with PBT.

RAD001 (Everolimus) inhibits growth of prostate cancer in the bone and the inhibitory effects are increased by combination with docetaxel and zoledronic acid

mTOR activity is increased in advanced prostate cancer (CaP) as a result of a high rate of PTEN mutations. RAD001 (Everolimus) is a new orally available mTOR inhibitor. The objective of our study was to evaluate the effects of RAD001 on the growth of CaP in the bone, both alone and in combination with docetaxel and zoledronic acid.

Detection and characterization of circulating and disseminated prostate cancer cells.

The dissemination of prostate cancer cells to secondary sites appears to be an intermediate step in the formation of tumor metastases. However, the significance of tumor cell dissemination into the blood and bone marrow as well as the characteristics of these cells remains largely unknown. In attempts to correlate the presence of disseminated tumor cells with disease prognosis, studies have utilized a range of molecular and histologic techniques. The results of this research have been largely inconclusive in terms of clinical utility. Nevertheless, they have demonstrated that these cells are detectable and present much more often than would be expected based on the rate of prostate cancer recurrence. Further research has thus begun to focus on the isolation of individual disseminated tumor cells which can then be analyzed with techniques such as gene expression microarrays and comparative genomic hybridization in order to better characterize the cells. This review paper will examine the various methods of detecting disseminated tumor cells in patients with prostate cancer and the results of studies correlating these cells with clinical variables. Additionally, we discuss the isolation and analysis of disseminated cells and examine their potential value in helping to understand the relationship between these cells and tumor metastasis.

Treatment of Non-Metastatic Muscle-Invasive Bladder Cancer: AUA/ASCO/ASTRO/SUO Guideline

Purpose: This multidisciplinary, evidence‐based guideline for clinically non‐metastatic muscle‐invasive bladder cancer focuses on the evaluation, treatment and surveillance of muscle‐invasive bladder cancer guided toward curative intent. Materials and Methods: A systematic review utilizing research from the Agency for Healthcare Research and Quality as well as additional supplementation by the authors and consultant methodologists was used to develop the guideline. Evidence‐based statements were based on body of evidence strengths Grade A, B or C and were designated as Strong, Moderate and Conditional Recommendations with additional statements presented in the form of Clinical Principles or Expert Opinions. Results: For the first time for any type of malignancy, the American Urological Association, American Society of Clinical Oncology, American Society for Radiation Oncology and Society of Urologic Oncology have formulated an evidence‐based guideline based on a risk‐stratified clinical framework for the management of muscle‐invasive urothelial bladder cancer. This document is designed to be used in conjunction with the associated treatment algorithm. Conclusions: The intensity and scope of care for muscle‐invasive bladder cancer should focus on the patient, disease and treatment response characteristics. This guideline attempts to improve a clinicians ability to evaluate and treat each patient, but higher quality evidence in future trials will be essential to improve level of care for these patients.