Delivery of gefitinib loaded nanoparticles for effectively inhibiting prostate cancer progression

Androgen deprivation therapy is administered to suppress the growth of prostate cancer (PCa). However, some cells continue to proliferate independent of hormones, leading to the development of castration-resistant prostate cancer (CRPC). Overexpression of the epidermal growth factor receptor (EGFR) has been observed in CRPC and is associated with an unfavorable prognosis. Gefitinib (GEF) is an EGFR inhibitor used to treat patients with CRPC. Nevertheless, some clinical studies have reported that gefitinib does not result in prostate-specific antigen (PSA) or objectively measurable CRPC reactions. This lack of response may be attributed to the limited solubility in water, high side effects, low tumor aggregation, and insufficient tumor-specific reactions of GEF. In order to tackle these obstacles, we present a practical and efficient approach to administer GEF, encompassing the utilization of biocompatible nanostructures as a vehicle for drug delivery to augment its bioaccessibility and curative potency. Despite their small particle size, poly(D,L-lactide-co-glycolide) acid nanoparticles (PLGA NPs) exhibit a high drug-loading capacity, low toxicity, biocompatibility, biodegradability, and minimal immunogenicity. The drug delivery efficiency can be improved by employing GEF@PLGA NPs, which could also enhance drug cytotoxicity and impede the advancement of prostate cancer. Moreover, through experiments in vivo, it has been verified that GEF@PLGA NPs exhibit selective accumulation in the tumor and effectively restrain tumor growth. Therefore, the GEF@PLGA NPs hold great promise for the treatment of PCa.

Surgical management of high-risk, localized prostate cancer

High-risk prostate cancer is a heterogeneous disease that lacks clear consensus on its ideal management. Historically, non-surgical treatment was the preferred strategy, and several studies demonstrated improved survival among men with high-risk disease managed with the combination of radiotherapy and androgen deprivation therapy (ADT) compared with ADT alone. However, practice trends in the past 10-15 years have shown increased use of radical prostatectomy with pelvic lymph node dissection for primary management of high-risk, localized disease. Radical prostatectomy, as a primary monotherapy, offers the potential benefits of avoiding ADT, reducing rates of symptomatic local recurrence, enabling full pathological tumour staging and potentially reducing late adverse effects such as secondary malignancy compared with radiation therapy. Retrospective studies have reported wide variability in short-term (pathological) and long-term (oncological) outcomes of radical prostatectomy. Surgical monotherapy continues to be appropriate for selected patients, whereas in others the best treatment strategy probably involves a multimodal approach. Appropriate risk stratification utilizing clinical, pathological and potentially also genomic risk data is imperative in the initial management of men with prostate cancer. However, data from ongoing and planned prospective trials are needed to identify the optimal management strategy for men with high-risk, localized prostate cancer.

Systemic treatments for high-risk localized prostate cancer

The majority of patients with prostate cancer who later develop lethal metastatic disease have high-risk localized disease at presentation, emphasizing the importance of effective treatment strategies at this stage. Multimodal treatment approaches that combine systemic and local therapies offer a promising strategy for improving the clinical outcomes of patients with high-risk localized prostate cancer. Combinations of neoadjuvant and adjuvant chemotherapy, hormonal therapy, or chemohormonal therapy are considered to be the standard of care in most solid tumours and should be investigated in the future for the treatment of prostate cancer to improve patient outcomes. However, although the combination of androgen deprivation therapy and radiotherapy is a standard of care in high-risk localized or locally advanced prostate cancer, the benefit of chemotherapy or chemohormonal therapy has yet to be demonstrated outside of the metastatic setting. Moreover, the benefit of neoadjuvant and/or adjuvant systemic therapies in combination with radical prostatectomy has not been proved. The development of next-generation hormonal agents, which have been approved for the treatment of castration-resistant prostate cancer, offers further therapeutic possibilities that are being assessed in early-phase clinical trials.

The addition of chemotherapy in the definitive management of high risk prostate cancer

In attempt to improve long-term disease control outcomes for high-risk prostate cancer, numerous clinical trials have tested the addition of chemotherapy (CTX)-either adjuvant or neoadjuvant-to definitive local therapy, either radical prostatectomy (RP) or radiation therapy (RT). Neoadjuvant trials generally confirm safety, feasibility, and pre-RP PSA reduction, but rates of pathologic complete response are rare, and no indications for neoadjuvant CTX have been firmly established. Adjuvant regimens have included CTX alone or in combination with androgen deprivation therapy (ADT). Here we provide a review of the relevant literature, and also quantify utilization of CTX in the definitive management of localized high-risk prostate cancer by querying the National Cancer Data Base. Between 2004 and 2013, 177 patients (of 29,659 total) treated with definitive RT, and 995 (of 367,570 total) treated with RP had CTX incorporated into their treatment regimens. Low numbers of RT + CTX patients precluded further analysis of this population, but we investigated the impact of CTX on overall survival (OS) for patients treated with RP +/- CTX. Disease-free survival or biochemical-recurrence-free survival are not available through the National Cancer Data Base. Propensity-score matching was conducted as patients treated with CTX were a higher-risk group. For nonmatched groups, OS at 5-years was 89.6% for the CTX group vs. 95.6%, for the no-CTX group (P < 0.01). The difference in OS between CTX and no-CTX groups did not persist after propensity-score matching, with 5-year OS 89.6% vs. 90.9%, respectively (Hazard ratio 0.99; P = 0.88). In summary, CTX was not shown to improve OS in this retrospective study. Multimodal regimens-such as RP followed by ADT, RT, and CTX; or RT in conjunction with ADT followed by CTX-have shown promise, but long-term follow-up of randomized data is required.

Radical Prostatectomy for High-risk Localized or Node-Positive Prostate Cancer: Removing the Primary

PURPOSE OF REVIEW

We reviewed the literature to determine what role, if any, radical prostatectomy should play in the treatment of high-risk and/or node-positive prostate cancer.

RECENT FINDINGS

The AUA, NCCN, and EAU all include radical prostatectomy as a treatment option for high-risk prostate cancer based on evidence that has shown improvements in biochemical-free and disease-specific survival. Lymph node-positive patients may also derive benefit from radical prostatectomy with lymph node dissection, however, only retrospective studies with high risk of selection bias have been published to date. High-risk prostate cancer is a heterogeneous disease representing a wide range of disease characteristics. Radical surgery, historically avoided in such patients, may now be considered a valid treatment option for select cases. The adverse effects of surgery using modern techniques lead to similar quality of life outcomes as radiation therapy, and treatment of the primary tumor is likely beneficial when compared to ADT alone.

The role of chemotherapy and new targeted agents in the management of primary prostate cancer

While early treatment of primary prostate cancer is very effective, the incidence of primary prostate cancer continues to rise and therefore the detection of men with high-risk non-metastatic prostate cancer and their subsequent management is becoming increasingly important. There continues to be no molecularly-targeted or chemotherapeutic options with proven, statistically significant survival benefit in this setting. However, there are indications that further risk stratification using molecular features could potentially help distinguish indolent from aggressive prostate cancer, ultimately providing biological markers that could guide a more personalised approach to therapy selection.

The very-high-risk prostate cancer: a contemporary update

BACKGROUND

Treatment of high-risk prostate cancer has evolved considerably over the past two decades, yet patients with very-high-risk features may still experience poor outcome despite aggressive therapy. We review the contemporary literature focusing on current definitions, role of modern imaging and treatment alternatives in very-high-risk prostate cancer.

METHODS

We searched the MEDLINE database for all clinical trials or practice guidelines published in English between 2000 and 2016, with the following search terms: 'prostatic neoplasms' (MeSH Terms) AND ('high risk' (keyword) OR 'locally advanced' (keyword) OR 'node positive' (keyword)). Abstracts pertaining to very-high-risk prostate cancer were evaluated and 40 pertinent studies served as the basis for this review.

RESULTS

The term 'very'-high-risk prostate cancer remains ill defined. The European Association of Urology and National Comprehensive Cancer Network guidelines provide the only available definitions, categorizing those with clinical stage T3-4 or minimal nodal involvement as very high risk irrespective of PSA level or biopsy Gleason score. Modern imaging with multiparametric magnetic resonance imaging and positron emission tomography-prostate-specific membrane antigen scans has a role in pre-treatment assessment. Local definitive therapy by external beam radiation combined with androgen deprivation is supported by several randomized clinical trials, whereas the role of surgery in the very-high-risk setting combined with adjuvant radiation/androgen deprivation therapy is emerging. Growing evidence suggest neoadjuvant taxane-based chemotherapy in the context of a multimodal approach may be beneficial.

CONCLUSIONS

Men with very-high-risk tumors may benefit from local definitive treatment in the setting of a multimodal regimen, offering local control and possibly cure in well selected patients. Further studies are necessary to better characterize the 'very'-high-risk category and determine the optimal therapy for the individual patient.

Neoadjuvant therapy for localized prostate cancer: Examining mechanism of action and efficacy within the tumor

OBJECTIVES

Efforts to improve the clinical outcome for patients with localized high-risk prostate cancer have led to the development of neoadjuvant systemic therapies. We review the different modalities of neoadjuvant therapies for localized prostate cancer and highlight emerging treatment approaches including immunotherapy and targeted therapy.

METHODS

We performed a PubMed search of clinical trials evaluating preoperative systemic therapies for treating high-risk prostate cancer published after 2000, and those studies with the highest clinical relevance to current treatment approaches were selected for review. The database at clinicaltrials.gov was queried for neoadjuvant studies in high-risk prostate cancer, and those evaluating novel targeted therapies and immunotherapies are spotlighted here.

RESULTS

Neoadjuvant chemotherapy has become standard of care for treating some malignancies, including breast and bladder cancers. In prostate cancer, preoperative hormonal therapy or chemotherapy has failed to demonstrate improvements in overall survival. Nevertheless, the emergence of novel treatment modalities such as targeted small molecules and immunotherapy has spawned neoadjuvant clinical trials that provide a unique vantage from which to study mechanism of action and biological potency. Tissue-based biomarkers are being developed to elucidate the biological efficacy of these treatments. With targeted therapy, these can include phospho-proteomic signatures of target pathway activation and deactivation. With immunotherapies, including sipuleucel-T and ipilimumab, recruitment of immune cells to the tumor microenvironment can also be used as robust markers of a biological effect. Such studies can provide insight not only into mechanism of action for these therapies but can also provide paths forward to improving clinical efficacy like with rationally designed combinations and dose selection.

CONCLUSIONS

The use of neoadjuvant androgen-deprivation therapy and chemotherapy either singly or in combination before radical prostatectomy is generally safe and feasible while reducing prostate volume and tumor burden. However, pathologic complete response rates are low and no long-term survival benefit has been observed with the addition of neoadjuvant therapies over surgery alone at present, and therefore preoperative therapy is not the current standard of care in prostate cancer treatment.

Neoadjuvant luteinizing-hormone-releasing hormone agonist plus low-dose estramustine phosphate improves prostate-specific antigen-free survival in high-risk prostate cancer patients: a propensity score-matched analysis

BACKGROUND

The optimal treatment for high-risk prostate cancer (Pca) remains to be established. We previously reported favorable biochemical recurrence-free survival (BRFS) in high-risk Pca patients treated with a neoadjuvant therapy comprising a luteinizing-hormone-releasing hormone (LHRH) agonist plus low dose estramustine phosphate (EMP) (LHRH+EMP) followed by radical prostatectomy (RP). In the present study, we used a retrospective design via propensity score matching to elucidate the clinical benefit of neoadjuvant LHRH+EMP for high-risk Pca.

METHODS

The Michinoku Urological Cancer Study Group database contained data for 1,268 consecutive Pca patients treated with RP alone at 4 institutions between April 2000 and March 2011 (RP alone group). In the RP alone group, we identified 386 high-risk Pca patients. The neoadjuvant LHRH+EMP group included 274 patients with high-risk Pca treated between September 2005 and November 2013 at Hirosaki University. Neoadjuvant LHRH+EMP therapy included LHRH and EMP administration at a dose of 280 mg/day for 6 months before RP. The outcome measures were overall survival (OS) and BRFS.

RESULTS

The propensity score-matched analysis indicated 210 matched pairs from both groups. The 5-year BRFS rates were 90.4 and 65.8 % for the neoadjuvant LHRH+EMP and RP alone groups, respectively (P < 0.0001). The 5-year OS rates were 100 and 96.1 % for the neoadjuvant LHRH+EMP and RP alone groups, respectively (P = 0.110).

CONCLUSIONS

Although the present study was not randomized, neoadjuvant LHRH+EMP therapy followed by RP appeared to reduce the risk of biochemical recurrence. A prospective randomized study is warranted to determine the clinical implications of the neoadjuvant therapy described here.

Chemotherapy and novel therapeutics before radical prostatectomy for high-risk clinically localized prostate cancer

Although both surgery and radiation are potential curative options for men with clinically localized prostate cancer, a significant proportion of men with high-risk and locally advanced disease will demonstrate biochemical and potentially clinical progression of their disease. Neoadjuvant systemic therapy before radical prostatectomy (RP) is a logical strategy to improve treatment outcomes for men with clinically localized high-risk prostate cancer. Furthermore, delivery of chemotherapy and other systemic agents before RP affords an opportunity to explore the efficacy of these agents with pathologic end points. Neoadjuvant chemotherapy, primarily with docetaxel (with or without androgen deprivation therapy), has demonstrated feasibility and safety in men undergoing RP, but no study to date has established the efficacy of neoadjuvant chemotherapy or neoadjuvant chemohormonal therapies. Other novel agents, such as those targeting the vascular endothelial growth factor receptor, epidermal growth factor receptor, platelet-derived growth factor receptor, clusterin, and immunomodulatory therapeutics, are currently under investigation.

NSK-01105, a novel sorafenib derivative, inhibits human prostate tumor growth via suppression of VEGFR2/EGFR-mediated angiogenesis

The purpose of this study is to investigate the anti-angiogenic activities of NSK-01105, a novel sorafenib derivative, in in vitro, ex vivo and in vivo models, and explore the potential mechanisms. NSK-01105 significantly inhibited vascular endothelial growth factor (VEGF)-induced migration and tube formation of human umbilical vein endothelial cells at non-cytotoxic concentrations as shown by wound-healing, transwell migration and endothelial cell tube formation assays, respectively. Cell viability and invasion of LNCaP and PC-3 cells were significantly inhibited by cytotoxicity assay and matrigel invasion assay. Furthermore, NSK-01105 also inhibited ex vivo angiogenesis in matrigel plug assay. Western blot analysis showed that NSK-01105 down-regulated VEGF-induced phosphorylation of VEGF receptor 2 (VEGFR2) and the activation of epidermal growth factor receptor (EGFR). Tumor volumes were significantly reduced by NSK-01105 at 60 mg/kg/day in both xenograft models. Immunohistochemical staining demonstrated a close association between inhibition of tumor growth and neovascularization. Collectively, our results suggest a role of NSK-01105 in treatment for human prostate tumors, and one of the potential mechanisms may be attributed to anti-angiogenic activities.

Gefitinib and luteolin cause growth arrest of human prostate cancer PC-3 cells via inhibition of cyclin G-associated kinase and induction of miR-630

Cyclin G-associated kinase (GAK), a key player in clathrin-mediated membrane trafficking, is overexpressed in various cancer cells. Here, we report that GAK expression is positively correlated with the Gleason score in surgical specimens from prostate cancer patients. Embryonic fibroblasts from knockout mice expressing a kinase-dead (KD) form of GAK showed constitutive hyper-phosphorylation of the epidermal growth factor receptor (EGFR). In addition to the well-known EGFR inhibitors gefitinib and erlotinib, the dietary flavonoid luteolin was a potent inhibitor of the Ser/Thr kinase activity of GAK in vitro. Co-administration of luteolin and gefitinib to PC-3 cells had a greater effect on cell viability than administration of either compound alone; this decrease in viability was associated with drastic down-regulation of GAK protein expression. A comprehensive microRNA array analysis revealed increased expression of miR-630 and miR-5703 following treatment of PC-3 cells with luteolin and/or gefitinib, and exogenous overexpression of miR-630 caused growth arrest of these cells. GAK appears to be essential for cell death because co-administration of gefitinib and luteolin to EGFR-deficient U2OS osteosarcoma cells also had a greater effect on cell viability than administration of either compound alone. Taken together, these findings suggest that GAK may be a new therapeutic target for prostate cancer and osteosarcoma.

Surgical management of prostate cancer

Surgery remains a mainstay in the management of localized prostate cancer. This article addresses surgical aspects germane to the management of men with prostate cancer, including patient selection for surgery, nerve-sparing approaches, minimization of positive surgical margins, and indications for pelvic lymph node dissection. Outcomes for men with high-risk prostate cancer following surgery are reviewed, and the present role of neoadjuvant therapy before radical prostatectomy is discussed. In addition, there is a review of the published literature on surgical ablative therapies for prostate cancer.

[Neoadjuvant before surgery treatments: state of the art in prostate cancer]

GOAL

To study the impact of systemic treatment in neoadjuvant strategy before surgery in prostate cancer.

MATERIALS

Literature reviews with data analysis from PubMed search using the keywords "neoadjuvant", "chemotherapy", "hormonal therapy", "prostate surgery", "radical prostatectomy", but also reports from ASCO and ESMO conferences. The articles on neoadjuvant treatment before radiotherapy were excluded.

RESULTS

First studies with former therapy are more than 15-years-old and with questionable methodology: lack of power to have a clear idea of the impact on survival criteria such as overall survival or relapse-free survival. However, the impact of neoadjuvant hormone therapy on the classic risk factors for relapse (positive margins, intraprostatic disease, positive lymph nodes) was demonstrated by these studies and a Cochrane meta-analysis. The association with hormone therapy seems mandatory in comparison to treatment based solely on chemotherapy and/or targeted therapy. Promising data on the use of new drugs and their combinations arise: abiraterone acetate combined with LHRH analogue showed a fast PSA decrease and higher rates of pathologic complete response. Other results are promising with hormonal blockages at various key points.

CONCLUSION

Studies with 2nd generation anti-androgene agents or enzyme inhibitors seem to show very promising results. To provide answers about the effectiveness of current neoadjuvant strategy in terms of survival, other studies are needed: randomized phase III or phase II exploring predictive biomarkers. The design of such trials requires a multidisciplinary approach with urologists, oncologists, radiologists and methodologists.

Linking γ-aminobutyric acid A receptor to epidermal growth factor receptor pathways activation in human prostate cancer

Neuroendocrine (NE) differentiation has been attributed to the progression of castration-resistant prostate cancer (CRPC). Growth factor pathways including the epidermal growth factor receptor (EGFR) signaling have been implicated in the development of NE features and progression to a castration-resistant phenotype. However, upstream molecules that regulate the growth factor pathway remain largely unknown. Using androgen-insensitive bone metastasis PC-3 cells and androgen-sensitive lymph node metastasis LNCaP cells derived from human prostate cancer (PCa) patients, we demonstrated that γ-aminobutyric acid A receptor (GABA(A)R) ligand (GABA) and agonist (isoguvacine) stimulate cell proliferation, enhance EGF family members expression, and activate EGFR and a downstream signaling molecule, Src, in both PC-3 and LNCaP cells. Inclusion of a GABA(A)R antagonist, picrotoxin, or an EGFR tyrosine kinase inhibitor, Gefitinib (ZD1839 or Iressa), blocked isoguvacine and GABA-stimulated cell growth, trans-phospohorylation of EGFR, and tyrosyl phosphorylation of Src in both PCa cell lines. Spatial distributions of GABAAR α₁ and phosphorylated Src (Tyr416) were studied in human prostate tissues by immunohistochemistry. In contrast to extremely low or absence of GABA(A)R α₁-positive immunoreactivity in normal prostate epithelium, elevated GABA(A)R α₁ immunoreactivity was detected in prostate carcinomatous glands. Similarly, immunoreactivity of phospho-Src (Tyr416) was specifically localized and limited to the nucleoli of all invasive prostate carcinoma cells, but negative in normal tissues. Strong GABAAR α₁ immunoreactivity was spatially adjacent to the neoplastic glands where strong phospho-Src (Tyr416)-positive immunoreactivity was demonstrated, but not in adjacent to normal glands. These results suggest that the GABA signaling is linked to the EGFR pathway and may work through autocrine or paracine mechanism to promote CRPC progression.

Long-term results of a phase II study with neoadjuvant docetaxel chemotherapy and complete androgen blockade in locally advanced and high-risk prostate cancer

BACKGROUND

Patients with locally advanced and high-risk prostate cancer (LAPC) are prone to experience biochemical recurrence despite radical prostatectomy (RP). We evaluated feasibility, safety and activity of a neoadjuvant chemohormonal therapy (NCHT) with 3-weekly full dose docetaxel and complete androgen blockade (CAB) in locally advanced and high-risk prostate cancer patients (LAPC) undergoing RP.

METHODS

Patients (n = 30) were selected by Kattans' preoperative score and received trimestral buserelin 9,45 mg, bicalutamide 50 mg/day and 3 cycles docetaxel (75 mg/m²) followed by RP. Primary endpoints were biochemical (PSA) and local downstaging. Secondary endpoints included toxicity and operability assessments, pathological complete response (pCR), time to PSA progression, 5-year biochemical recurrence free survival (bRFS) and overall survival (OS).

RESULTS

Median baseline PSA was 25.8 ng/ml (2.1-293), and the predicted probability of 5-year bRFS was 10% (0-55). NCHT induced PSA-reduction was 97.3% (81.3-99.9%; p < 0.001) and post-RP 96.7% of patients were therapy responders, with undetectable PSA-values. Post- vs. pretreatment MRI indicated a median tumor volume reduction of 46.4% (-31.3-82.8; p < 0.001). A pathological downstaging was observed in 48.3%. Severe hematologic toxicities (≥CTC3) were frequent with 53.8% leucopenia, 90% neutropenia and 13.3% febrile neutropenia. RP was performed in all patients. While resectability was hindered in 26.7%, continence was achieved in 96.7%. Pathologic analyses revealed no pCR. Lymph node- and extracapsular involvement was observed in 36.7% and 56.7% with 33.3% positive surgical margins. After a median of 48.6 (19.9-87.8) months, 55.2% of therapy responders experienced PSA-recurrence. The estimated median time to PSA-progression was 38.6 months (95%CI 30.9-46.4) and 85.3 months (95%CI 39.3-131.3) for OS. The 5-year bRFS was improved to 40%, but limiting for interpretation adjuvant treatment was individualized.

CONCLUSIONS

NCHT is feasible despite high hematotoxicity, with excellent functional results. Significant downstaging was observed without pCR. NCHT seems to improve the cohort adjusted 5-year bRFS, but clinical value needs further investigation in randomized trials.

Rationale for and review of neoadjuvant therapy prior to radical prostatectomy for patients with high-risk prostate cancer

Despite state of the art local therapy, a significant portion of men with high-risk prostate cancer develop progressive disease. Neoadjuvant systemic therapy prior to radical prostatectomy (RP) is an approach that can potentially maximize survival outcomes in patients with localized disease. This approach is under investigation with a wide array of agents and provides an opportunity to assess pathologic and biologic activity of novel treatments. The aim of this review is to explore the past and present role of neoadjuvant therapy prior to definitive therapy with RP in patients with high-risk localized or locally advanced disease. The results of neoadjuvant androgen-deprivation therapy (ADT), including use of newer agents such as abiraterone, are promising. Neoadjuvant chemotherapy, primarily with docetaxel, with or without ADT has also demonstrated efficacy in men with high-risk disease. Other novel agents targeting the vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), clusterin, and the immune system are currently under investigation and have led to variable results in early clinical trials. Despite optimistic data, approval of neoadjuvant therapy prior to RP in patients with high-risk prostate cancer will depend on positive results from well designed phase III trials.

Phase II trial of neoadjuvant docetaxel and CG1940/CG8711 followed by radical prostatectomy in patients with high-risk clinically localized prostate cancer

BACKGROUND

Prostate cancer (PC) is the most commonly diagnosed noncutaneous malignancy in American men. PC, which exhibits a slow growth rate and multiple potential target epitopes, is an ideal candidate for immunotherapy. GVAX for prostate cancer is a cellular immunotherapy, composed of PC-3 cells (CG1940) and LNCaP cells (CG8711). Each of the components is a prostate adenocarcinoma cell line that has been genetically modified to secrete granulocyte-macrophage colony-stimulating factor. Hypothesizing that GVAX for prostate cancer could be effective in a neoadjuvant setting in patients with locally advanced disease, we initiated a phase II trial of neoadjuvant docetaxel and GVAX. For the trial, the clinical effects of GVAX were assessed in patients undergoing radical prostatectomy (RP).

METHODS

Patients received docetaxel administered at a dose of 75 mg/m(2) every 3 weeks for 4 cycles. GVAX was administered 2-3 days after chemotherapy preoperatively for four courses of immunotherapy. The first dose of GVAX was a prime immunotherapy of 5×10(8) cells. The subsequent boost immunotherapies consisted of 3×10(8) cells. After RP, patients received an additional six courses of immunotherapy. Pathologic complete response, toxicity, and clinical response were assessed. The primary endpoint of the trial was a pathologic state of pT0, which is defined as no evidence of cancer in the prostate.

RESULTS

Six patients completed neoadjuvant docetaxel and GVAX therapy. No serious drug-related adverse events were observed. Median change in prostate-specific antigen (PSA) following neoadjuvant therapy was 1.47 ng/ml. One patient did not undergo RP due to the discovery of positive lymph nodes during exploration. Of the five patients completing RP, four had a downstaging of their Gleason score. Undetectable PSA was achieved in three patients at 2 months after RP and in two patients at 3 years after RP.

CONCLUSIONS

Neoadjuvant docetaxel/GVAX is safe and well tolerated in patients with high-risk locally advanced PC. No evidence of increased intraoperative hemorrhage or increased length of hospital stay postoperatively was noted. These results justify further study of neoadjuvant immunotherapy.

Neoadjuvant Chemotherapy prior to Radical Prostatectomy for Patients with High-Risk Prostate Cancer: A Systematic Review

High-risk prostate cancer represents a pretentious clinical problem since a significant number of its patients will relapse and progress after radical prostatectomy. Neoadjuvant chemotherapy may be valuable since its efficacy in hormone-resistant prostate cancer has been established. In this paper, we report studies of neoadjuvant chemotherapies that have been used in high-risk patients prior to radical prostatectomy. Even though the results regarding the prognostic surrogates are not significant, the effects on clinical and pathological outcomes are promising, while toxicity in most of the studies is in the expected field.

Safety and effectiveness of neoadjuvant luteinizing hormone-releasing hormone agonist plus low-dose estramustine phosphate in high-risk prostate cancer: a prospective single-arm study

BACKGROUND

Radical prostatectomy (RP) has limited cancer control potential for the patient with high-risk prostate cancer (Pca). We prospectively examined the efficacy and safety of neoadjuvant therapy with luteinizing hormone-releasing hormone (LHRH) agonist + low-dose estramustine phosphate (EMP) (LHRH+EMP) followed by RP.

METHODS

High-risk Pca was defined by the D'Amico stratification system. A total of 142 patients with high-risk Pca were enrolled in this trial from September 2005 to March 2011. The LHRH+EMP therapy included administration of LHRH agonist and 280 mg day(-1) EMP for 6 months before RP. Pathological cancer-free (pT0) rate on the surgical specimen was the primary end point. Secondary end points were PSA-free survival and toxicity.

RESULTS

The average patient age was 67.4 years (interquartile range (IQR) 72, 65) and the median initial PSA level was 14.80 ng ml(-1) (IQR 26.22, 7.13). The median Gleason score was 9 (IQR 9, 7) and 97 patients (68.3%) had clinical stage T2c or T3. All patients completed 6 months of LHRH+EMP neoadjuvant therapy with no delays in RP. Seven patients (4.9%) achieved pT0. Surgical margins were negative in 125 patients (87.0%). At a median follow-up period of 34.9 months, PSA-free survival was 84.3%. No serious adverse events were reported during the study and there were no toxicity-related deaths.

CONCLUSIONS

Six months of LHRH+EMP neoadjuvant therapy followed by RP is safe and oncological outcomes are acceptable. Although this study was a single-arm trial with a relatively short follow-up, this treatment may have a potential to improve PSA-free survival in high-risk Pca patients. Further clinical trials are warranted.

A systematic review of the role of adjuvant and neoadjuvant pharmacotherapy in patients undergoing radical prostatectomy

INTRODUCTION

Between 25 and 30% of patients with newly diagnosed prostate cancer are classified as high risk for an adverse prognosis. A significant number of these will progress to biochemical or clinical relapse. As there is no consensus regarding the optimal treatment of these cases, a multimodal therapeutic approach, including radical prostatectomy, remains an option.

AREAS COVERED

The Pubmed/Medline database was searched to identify trials that have evaluated adjuvant and neoadjuvant pharmaceutical protocols combined with radical prostatectomy and provided information regarding efficacy and safety.

EXPERT OPINION

Improvements in adverse pathological findings, following operations in patients who received neoadjuvant treatment, have been reported in the majority of the reviewed studies. Furthermore, the addition of pharmacotherapy to radical prostatectomy has produced beneficial results in survival surrogates. However, no benefits in overall survival were observed with adjuvant or neoadjuvant protocols and toxicity was a concern, especially in combination regimens. New studies on the effects of current pharmacotherapy and of new agents on overall survival and quality of life, after defining well-established criteria for patient stratification and inclusion, are required urgently.

The prognostic value of expression of HIF1α, EGFR and VEGF-A, in localized prostate cancer for intermediate- and high-risk patients treated with radiation therapy with or without androgen deprivation therapy

Purpose

Androgens stimulate the production of hypoxia-inducible factor (HIF1α) and ultimately vascular endothelial growth factor (VEGF-A). Additionally, epithelial growth factor (EGF) mediates HIF1α production. Carbonic anhydrase IX (CAIX) expression is associated with tumor cell hypoxia in a variety of malignancies. This study assesses the prognostic relation between HIF1α, VEGF-A, EGF Receptor and CAIX expression by immunochemistry in diagnostic samples of patients with intermediate- and high-risk localized prostate cancer treated with radiation therapy, with or without androgen deprivation therapy (ADT).

Materials and methods

Between 1994 and 2004, 103 prostate cancer patients (mean age, 68.7 ± 6.2), with prostate cancer (mean PSA, 13.3 ± 3.7), were treated with radiation therapy (RT, median dose, 74 Gy). Fifty seven (55.3%) patients received ADT (median duration, 6 months; range, 0 – 24). Median follow-up was 97.6 months (range, 5.9 – 206.8).

Results

Higher EGFR expression was significantly (p = 0.04) correlated with higher Gleason scores. On univariate analysis, HIF1α nuclear expression was a significant (p = 0.02) prognostic factor for biological progression-free survival (bPFS). A trend towards significance (p = 0.05) was observed with EGFR expression and bPFS. On multivariate analysis, low HIF1α nuclear (p = 0.01) and high EGFR (p = 0.04) expression remained significant adverse prognostic factors.

Conclusions

Our study suggests that high nuclear expression of HIF1α and low EGFR expression in diagnostic biopsies of prostate cancer patients treated with RT ± ADT is associated with a good prognosis.

The role of surgery in high-risk localised prostate cancer

• The optimal management of high-risk localised prostate cancer is a major challenge for urologists and oncologists. It is clear that multimodal therapy including radical local treatment is needed in these men to achieve the best outcomes. • External beam radiotherapy (EBRT) is an essential component of therapy either as a primary or adjuvant treatment. However, the role of radical prostatectomy (RP) is more controversial. Both methods are currently valid therapy options. • There have been many individual studies of EBRT and RP in high-risk disease, but no good quality large prospective randomized trials. • In EBRT, combination with neoadjuvant plus long-term adjuvant androgen-deprivation therapy (ADT) has been conclusively shown to improve outcomes and is widely considered the standard of care. • However, the role of RP has achieved recent prominence with several important studies. Published data from prospective randomized trials in patients after RP have shown that in men with adverse pathological features at surgery, the addition of adjuvant RT improves biochemical-free and progression-free survival. • More recently, studies from large-volume centres comparing EBRT and RP have provided intriguing suggestions of better outcomes with RP as the primary treatment. • An important question therefore, is which of the two methods provides the best outcome in men with localised high-risk disease. Crucially, does the combination of RP and selective adjuvant EBRT provide clinically significant better outcomes compared with EBRT alone? • In this review we discuss the current evidence for the role of RP for high-risk localised prostate cancer and define the parameters and urgent need for a prospective trial to test the role of surgery for this group of patients.

Contemporary treatment of high-risk localized prostate cancer

High-risk prostate cancer poses a significant challenge to the treating physician and much debate exists regarding the ideal treatment approach. The purpose of this article is to enable physicians to identify patients with high-risk localized prostate cancer and evaluate whether monotherapy is sufficient for these patients. We review the current data on use of surgery, radiation therapy and hormonal therapy independently and in combination. We also discuss emerging therapeutics for high-risk disease including neoadjuvant chemotherapy and protocols under current and future investigation.

Long-term results of a prospective, Phase II study of long-term androgen ablation, pelvic radiotherapy, brachytherapy boost, and adjuvant docetaxel in patients with high-risk prostate cancer

PURPOSE

We report the long-term results of a prospective, Phase II study of long-term androgen deprivation (AD), pelvic radiotherapy (EBRT), permanent transperineal prostate brachytherapy boost (PB), and adjuvant docetaxel in patients with high-risk prostate cancer.

METHODS AND MATERIALS

Eligibility included biopsy-proven prostate adenocarcinoma with the following: prostate-specific antigen (PSA) > 20 ng/ml; or Gleason score of 7 and a PSA >10 ng/ml; or any Gleason score of 8 to 10; or stage T2b to T3 irrespective of Gleason score or PSA. Treatment consisted of 45 Gy of pelvic EBRT, followed 1 month later by PB with either iodine-125 or Pd-103. One month after PB, patients received three cycles of docetaxel chemotherapy (35 mg/m(2) per week, Days 1, 8, and 15 every 28 days). All patients received 2 years of AD. Biochemical failure was defined as per the Phoenix definition (PSA nadir + 2).

RESULTS

From August 2000 to March 2004, 42 patients were enrolled. The median overall and active follow-ups were 5.6 years (range, 0.9-7.8 years) and 6.3 years (range, 4-7.8 years), respectively. Grade 2 and 3 acute genitourinary (GU) and gastrointestinal (GI) toxicities were 50.0% and 14.2%, respectively, with no Grade 4 toxicities noted. Grade 3 and 4 acute hematologic toxicities were 19% and 2.4%, respectively. Of the patients, 85.7% were able to complete the planned multimodality treatment. The 5- and 7-year actuarial freedom from biochemical failures rates were 89.6% and 86.5%, and corresponding rates for disease-free survival were 76.2% and 70.4%, respectively. The 5- and 7-year actuarial overall survival rates were 83.3% and 80.1%, respectively. The 5- and 7-year actuarial rates of late Grade 2 GI/GU toxicity (no Grade 3-5) was 7.7%.

CONCLUSIONS

The trimodality approach of using 2 years of AD, external radiation, brachytherapy, and upfront docetaxel in high-risk prostate cancer is well tolerated, produces encouraging long-term results, and should be validated in a multi-institutional setting.

Neoadjuvant therapy preceding prostatectomy for prostate cancer: rationale and current trials

Neoadjuvant therapy improves outcomes for a number of malignancies and provides intermediate pathologic outcomes, which correlate with long-term outcomes. Neoadjuvant androgen-deprivation therapy, alone or with docetaxel chemotherapy, preceding prostatectomy for localized prostate cancer is feasible and demonstrates pathologic activity, but evidence for improved long-term outcomes is lacking. Data in support of the further exploration of neoadjuvant therapy for localized prostate cancer preceding prostatectomy are reviewed. Ongoing randomized trials are elucidating the impact of neoadjuvant androgen deprivation combined with docetaxel chemotherapy on pathologic and long-term outcomes. The correlation of pathologic and biologic outcomes with long-term outcomes in this setting is unknown. The neoadjuvant therapy approach followed by prostatectomy is feasible with a wide array of agents and provides a paradigm for evaluating the activity, and mechanism of action and resistance to new treatments. This promising modality may aid the rapid development of novel therapeutic agents. A multidisciplinary approach involving oncologists, urologists and pathologists is critical to the success of this model.

The multi-disciplinary management of high-risk prostate cancer

Prostate cancer is the most frequently diagnosed cancer and the second most common cause of cancer death in men in the United States. Such men can experience a continuum of disease presentations from indolent to highly aggressive. For physicians who care for these men, a significant challenge has been and continues to be identifying and treating those men with localized cancer who are at a higher risk of dying from their disease. We discuss the risk stratification of patients in order to better identify those patients at higher risk of progression. A comprehensive review of the literature was then performed reviewing the roles of surgery, radiotherapy, hormone therapy, and chemotherapy, as well as combinations of these modalities, in treating these challenging patients. An integrated approach combining local and systemic therapies can be beneficial in the management of high-risk localized prostate cancer. The choice of therapy or combination of therapies is dependant upon many considerations, including patient preference and quality of life aspects. It is becoming clearer that the addition of hormonal therapies or chemotherapies to established therapies, such as radiotherapy or surgery, will have significant benefits. As evidence accumulates regarding the efficacy of these new regimens, our hope is that the challenge of optimizing the management of high-risk prostate cancer will be delivered. However, many important questions remain unresolved regarding the optimal type, combination, timing of therapy, and duration of therapy. Such questions will only be answered with large, well-designed prospective clinical trials.

Locally advanced prostate cancer: the role of surgical management

Among the heterogeneous population of patients with prostate cancer, a high-risk group with locally advanced prostate cancer (LAPC) present a diagnostic and therapeutic dilemma. Although the incidence of LAPC has decreased with screening since the introduction of prostate-specific antigen (PSA) testing, significantly many patients are still diagnosed with LAPC. These patients are by definition at higher risk of metastatic disease and worse outcomes. The role of radical prostatectomy (RP) in this population has been debated, as the combination of radiotherapy and hormonal therapy is becoming used more frequently for LAPC. Unfortunately, the clinical staging and evaluation of LAPC is a challenge that results in possibly understaging or overstaging these patients. This further complicates therapeutic decision-making, and as a result no established standard treatment has been proposed. Like other patients with prostate cancer, individualized therapeutic choices are essential and depend on a multitude of factors. Herein we examine the role of RP for managing LAPC and attempt to emphasize how the risk of distant disease and difficulty with clinical staging might favour incorporating a surgical approach as part of the therapy for patients with LAPC.

Novel treatment methods for localized prostate cancer: hypofractionated robotic radiation therapy and adjuvant chemotherapy

The standard localized therapies for prostate cancer include external-beam radiation therapy, brachytherapy and radical prostatectomy. There are several novel approaches in development aimed at improving local disease control and survival, and reducing post-treatment complications. In low-to-intermediate-risk patients, new radiation approaches are being explored to include hypofractionated robotic radiation therapy. For high-risk patients, the focus is on multimodality approaches, especially the addition of chemotherapy. Recent developments in radiation therapy and adjuvant chemotherapy are the focus of this review.