Feasibility and value of PatientViewpoint: a web system for patient-reported outcomes assessment in clinical practice

BACKGROUND

The PatientViewpoint website collects patient-reported outcomes and links them with the electronic health record to aid patient management. This pilot test evaluated PatientViewpoint's use, usefulness, and acceptability to patients and clinicians.

METHODS

This was a single-arm prospective study that enrolled breast and prostate cancer patients undergoing treatment and the clinicians who managed them. Patients completed patient-reported outcomes every 2 weeks, and clinicians could access the results for patient visits. Scores that were poor relative to norms or substantially worse than the previous assessment were highlighted. After three on-study visits, we assessed patient and clinician perspectives on PatientViewpoint using close-ended and open-ended questions.

RESULTS

Eleven out of 12 eligible clinicians (92%) and 52/76 eligible patients (68%) enrolled. Patients completed a median of 71% of assigned questionnaires; clinicians reported using the information for 79% of patients, most commonly as a source of additional information (51%). At the median, score reports identified three potential issues, of which 1 was discussed during the visit. Patients reported the system was easy to use (92%), useful (70%), aided recall of symptoms/side effects (72%), helped them feel more in control of their care (60%), improved discussions with their provider (49%), and improved care quality (39%). Patients and clinicians desired more information on score interpretation and minor adjustments to site navigation.

CONCLUSIONS

These results support the feasibility and value of PatientViewpoint. An ongoing study is using a continuous quality improvement approach to further refine PatientViewpoint. Future studies will evaluate its impact on patient care and outcomes.

Immunoexpression status and prognostic value of mammalian target of rapamycin and hypoxia-induced pathway members in papillary cell renal cell carcinomas

Dysregulation of the mammalian target of rapamycin and hypoxia-induced pathways has been consistently identified in clear cell renal cell carcinomas. However, experience with non-clear cell renal cell carcinoma subtypes is scant. In this study, we evaluated the immunohistochemical expression of upstream (PTEN and phosphorylated AKT) and downstream (phosphorylated S6 and 4EBP1) effectors of the mammalian target of rapamycin pathway, as well as related cell-cycle proteins (p27 and c-MYC), and a member of the hypoxia-induced pathway (HIF-1α) in 54 patients with papillary renal cell carcinoma treated by nephrectomy. PTEN was lower in tumor than in normal kidney, and loss of PTEN expression was found in 48% of the patients. In tumor tissues, phosphorylated S6, 4EBP1, and HIF-1α were higher than in normal kidney. Conversely, scores of p27 were lower in tumor than in normal kidney. Finally, scores of c-MYC and phosphorylated AKT were similar in tumor and in normal kidney. Overall mortality and cancer-specific mortality were 24% and 11%, respectively. Tumor progression was observed in 17% of the patients. None of the tested biomarkers predicted cancer-specific mortality or tumor progression. As expected, patients with high T-stage tumors had higher hazard ratios for cancer-specific mortality (hazard ratio, 6.9) and tumor progression (hazard ratio, 6.7). Patients with higher Fuhrman grades also had higher risks for cancer-specific mortality (hazard ratio, 11.4) and tumor progression (hazard ratio, 4.5). In summary, our study provides evidence of dysregulation of the mammalian target of rapamycin and hypoxia-induced pathways in papillary renal cell carcinoma. Immunohistochemistry for members of the mammalian target of rapamycin pathway and for HIF-1α lacked prognostic significance in our cohort.

Changes in PSA kinetics predict metastasis- free survival in men with PSA-recurrent prostate cancer treated with nonhormonal agents: combined analysis of 4 phase II trials

BACKGROUND

Several phase II trials in men with noncastrate PSA-recurrent prostate cancer have assessed the impact of novel nonhormonal agents on PSA kinetics. However, it is unknown whether changes in PSA kinetics influence metastasis-free survival (MFS).

METHODS

We performed a retrospective post hoc analysis of 146 men treated in 4 phase II trials examining the investigational agents marimastat (a matrix metalloproteinase inhibitor; n = 39), imatinib (a tyrosine kinase inhibitor; n = 25), ATN-224 (a copper/zinc-superoxide dismutase inhibitor; n = 22), and lenalidomide (an antiangiogenic/immunomodulatory drug; n = 60). We investigated factors influencing MFS, including within-subject changes in PSA kinetics (PSA slope, doubling time, and velocity) before and after treatment initiation.

RESULTS

After a median follow-up of 16.8 months, 70 patients (47.9%) developed metastases. In multivariable Cox regression models, factors that were independently predictive of MFS after adjusting for age and other clinical prognostic variables were baseline PSA doubling time (PSADT) (P = .05), baseline PSA slope (P = .01), on-study change in PSADT (P = .02), and on-study change in PSA slope (P = .03). In a landmark Kaplan-Meier analysis, median MFS was 63.5 months (95% confidence interval [CI], 34.6-not reached) and 28.9 months (95% CI, 13.5-68.0) for men with or without any decrease in PSA slope by 6 months after treatment, respectively.

CONCLUSIONS

This hypothesis generating analysis suggests that within-subject changes in PSADT and PSA slope after initiation of experimental therapy may correlate with MFS in men with biochemically recurrent prostate cancer. If validated in prospective trials, changes in PSA kinetics may represent a reasonable intermediate end point for screening new agents in these patients.

Abstract LB-224: A randomized phase 2 study of two doses of itraconazole in men with metastatic castration-resistant prostate cancer (mCRPC)

BACKGROUND: The antifungal drug itraconazole inhibits angiogenesis and Hedgehog signaling, and delays tumor growth in murine prostate cancer xenograft models. Unlike ketoconazole, it does not suppress androgen synthesis. METHODS: A phase 2 study of oral itraconazole in men with mCRPC was conducted at 4 sites. Men were randomized to low dose (LD) or high dose (HD) itraconazole (200 or 600 mg/day) until disease progression or unacceptable toxicity. The primary endpoint was PSA progression-free survival (PPFS) at 24 wk (PSA progression = 25% PSA rise above baseline/nadir); a 45% success rate in either arm was prespecified as constituting clinical significance. Secondary endpoints were progression-free survival (PFS) at 24 wk (progression = clinical/radiographic progression or death, but not rising PSA); median PFS; median PPFS; and max PSA decline. Exploratory outcomes included CTC enumeration, analysis of adrenal androgens (serum testosterone and DHEA), VEGF analysis, and GLI1 expression in skin biopsy samples. RESULTS: The HD arm enrolled to completion (N=29), but the LD arm closed early (N=17) due to a prespecified futility analysis. Table 1 shows efficacy results. In addition, 3/5 men (60%) in the HD arm and 2/3 men (67%) in the LD arm with unfavorable (≥5) CTCs at baseline converted to favorable (<5) CTC counts with treatment. Itraconazole did not reduce serum testosterone or DHEA levels. It had no effect on circulating VEGF levels. In skin biopsies, downmodulation of GLI1 was seen in 33% and 68% of men in the LD and HD arms, respectively. Median PPFS was superior in men who achieved GLI1 downmodulation compared to those who did not (P=.028). Toxicities with itraconazole included fatigue, nausea, anorexia, rash, and a syndrome of hypokalemia/hypertension/edema. CONCLUSIONS: Only the HD arm met its primary endpoint. Itraconazole 600 mg/day may have activity in men with mCRPC that is not mediated by androgen suppression, and may correlate with GLI1 downmodulation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-224. doi:1538-7445.AM2012-LB-224

Targeting angiogenesis for the treatment of prostate cancer

INTRODUCTION

While multiple therapies exist that prolong the lives of men with advanced prostate cancer, none are curative. This had led to a search to uncover novel targets for prostate cancer therapy, distinct from those of traditional hormonal approaches, chemotherapies, immunotherapies and bone-targeting approaches. The process of tumor angiogenesis is one target that is being exploited for therapeutic gain.

AREAS COVERED

The most promising anti-angiogenic approaches for treatment of prostate cancer, focusing on clinical development of selected agents. These include VEGF-directed therapies, tyrosine kinase inhibitors, tumor-vascular disrupting agents, immunomodulatory drugs and miscellaneous anti-angiogenic agents. While none of these drugs have yet entered the market for the treatment of prostate cancer, several are now being tested in Phase III registrational trials.

EXPERT OPINION

The development of anti-angiogenic agents for prostate cancer has met with several challenges. This includes discordance between traditional prostate-specific antigen responses and clinical responses, which have clouded clinical trial design and interpretation, potential inadequate exposure to anti-angiogenic therapies with premature discontinuation of study drugs and the development of resistance to anti-angiogenic monotherapies. These barriers will hopefully be overcome with the advent of more potent agents, the use of dual angiogenesis inhibition and the design of more informative clinical trials.

Contemporary experience with ketoconazole in patients with metastatic castration-resistant prostate cancer: clinical factors associated with PSA response and disease progression

BACKGROUND

Adrenal/intratumoral androgen biosynthesis contributes to ligand-dependent androgen receptor activation in metastatic castration-resistant prostate cancer (mCRCP). Compounds targeting CYP-17 hydroxylase and lyase, as ketoconazole and abiraterone, block adrenal/intratumoral androgen biosynthesis, and are used as sequential endocrine approaches in mCRCP. We aimed to describe contemporary experience and association of clinical factors with Prostate specific antigen (PSA) response and disease progression, in mCRPC progressing on GnRH-agonist, antiandrogen, antiandrogen withdrawal, and treated with ketoconazole.

METHODS

Data were retrospectively analyzed in all mCRPC patients treated with ketoconazole. Patients continued GnRH-agonist, and treated with ketoconazole 200-400 mg 3× a day until dose-limiting toxicity or disease progression. A multivariate cox regression model was used to identify clinical factors associated with PSA response and disease progression.

RESULTS

From 1999 to 2010, 114 mCRPC patients were treated with ketoconazole. With a median follow-up time of 31 months (range 5-129), 25 patients (22%) had grade 3/4 toxicity, most commonly fatigue, abdominal discomfort, nausea, and dizziness. Sixty-one patients (54%) had ≥50% PSA decline. Median time to progression was 8 months (range 1-129). Factors associated with PSA response and disease progression were response to prior antiandrogen (≥6 vs. <6 months), pre-treatment PSADT (≥3 vs. <3 months) and extent of disease (limited-axial skeleton and/or nodal vs. extensive-appendicular skeleton and/or visceral).

CONCLUSIONS

Ketoconazole is effective and safe in mCRPC. Prior response to antiandrogen, pre-treatment PSADT, and disease extent are associated with PSA response and disease progression, and further supports a therapeutic role in suppressing adrenal androgens in mCRPC.

Use of androgen deprivation therapy in prostate cancer: indications and prevalence

Androgens play a prominent role in the development, maintenance and progression of prostate cancer. The introduction of androgen deprivation therapies into the treatment paradigm for prostate cancer patients has resulted in a wide variety of benefits ranging from a survival advantage for those with clinically localized or locally advanced disease, to improvements in symptom control for patients with advanced disease. Controversies remain, however, surrounding the optimal timing, duration and schedule of these hormonal approaches. Newer hormonal manipulations such as abiraterone acetate have also been investigated and will broaden treatment options for men with prostate cancer. This review highlights the various androgen-directed treatment options available to men with prostate cancer, their specific indications and the evidence supporting each approach, as well as patterns of use of hormonal therapies.

Progression of prostate carcinogenesis and dietary methyl donors: temporal dependence

Insufficient dose of dietary methyl groups are associated with a host of conditions ranging from neural tube defects to cancer. On the other hand, it is not certain what effect excess dietary methyl groups could have on cancer. This is especially true for prostate cancer, a disease that is characterized by increasing DNA methylation changes with increasing grade of the cancer. In this three-part study in animals, we look at (i) the effect of excess methyl donors on the growth rate of prostate cancer in vivo, (ii) the ability of 5-aza-2'-deoxycytidine (AdC), a demethylating agent, to demethylate in the presence of excess dietary methyl donors, and (iii) the effect of in utero feeding of excess methyl donors to the later onset of prostate cancer. The results show that when mice are fed a dietary excess of methyl donors, we do not see (i) an increase in the growth rate of DU-145 and PC-3 xenografts in vivo, or (ii) interference in the ability of AdC to demethylate the promoters of androgen receptor or Reprimo of prostate cancer xenografts but (iii) a protective effect on the development of higher grades of prostate cancer in the "Hi-myc" mouse model of prostate cancer which were fed the increased methyl donors in utero. We conclude that the impact of dietary methyl donors on prostate cancer progression depends upon the timing of exposure to the dietary agents. When fed before the onset of cancer, that is, in utero, excess methyl donors can have a protective effect on the progression of cancer.

Phase I study of the histone deacetylase inhibitor entinostat in combination with 13-cis retinoic acid in patients with solid tumours

BACKGROUND

Preclinical studies suggest that histone deacetylase (HDAC) inhibitors may restore tumour sensitivity to retinoids. The objective of this study was to determine the safety, tolerability, and the pharmacokinetic (PK)/pharmacodynamic (PD) profiles of the HDAC inhibitor entinostat in combination with 13-cis retinoic acid (CRA) in patients with solid tumours.

METHODS

Patients with advanced solid tumours were treated with entinostat orally once weekly and with CRA orally twice daily × 3 weeks every 4 weeks. The starting dose for entinostat was 4 mg m(-2) with a fixed dose of CRA at 1 mg kg(-1) per day. Entinostat dose was escalated by 1 mg m(-2) increments. Pharmacokinetic concentrations of entinostat and CRA were determined by LC/MS/MS. Western blot analysis of peripheral blood mononuclear cells and tumour samples were performed to evaluate target inhibition.

RESULTS

A total of 19 patients were enroled. The maximum tolerated dose (MTD) was exceeded at the entinostat 5 mg m(-2) dose level (G3 hyponatremia, neutropenia, and anaemia). Fatigue (G1 or G2) was a common side effect. Entinostat exhibited substantial variability in clearance (147%) and exposure. CRA trough concentrations were consistent with prior reports. No objective responses were observed, however, prolonged stable disease occurred in patients with prostate, pancreatic, and kidney cancer. Data further showed increased tumour histone acetylation and decreased phosphorylated ERK protein expression.

CONCLUSION

The combination of entinostat with CRA was reasonably well tolerated. The recommended phase II doses are entinostat 4 mg m(-2) once weekly and CRA 1 mg kg(-1) per day. Although no tumour responses were seen, further evaluation of this combination is warranted.

Concurrent HDAC and mTORC1 inhibition attenuate androgen receptor and hypoxia signaling associated with alterations in microRNA expression

Specific inhibitors towards Histone Deacetylases (HDACs) and Mammalian Target of Rapamycin Complex 1 (mTORC1) have been developed and demonstrate potential as treatments for patients with advanced and/or metastatic and castrate resistant prostate cancer (PCa). Further, deregulation of HDAC expression and mTORC1 activity are documented in PCa and provide rational targets to create new therapeutic strategies to treat PCa. Here we report the use of the c-Myc adenocarcinoma cell line from the c-Myc transgenic mouse with prostate cancer to evaluate the in vitro and in vivo anti-tumor activity of the combination of the HDAC inhibitor panobinostat with the mTORC1 inhibitor everolimus. Panobinostat/everolimus combination treatment resulted in significantly greater antitumor activity in mice bearing androgen sensitive Myc-CaP and castrate resistant Myc-CaP tumors compared to single treatments. We identified that panobinostat/everolimus combination resulted in enhanced anti-tumor activity mediated by decreased tumor growth concurrent with augmentation of p21 and p27 expression and the attenuation of angiogenesis and tumor proliferation via androgen receptor, c-Myc and HIF-1α signaling. Also, we observed altered expression of microRNAs associated with these three transcription factors. Overall, our results demonstrate that low dose concurrent panobinostat/everolimus combination therapy is well tolerated and results in greater anti-tumor activity compared to single treatments in tumor bearing immuno-competent mice. Finally, our results suggest that response of selected miRs could be utilized to monitor panobinostat/everolimus in vivo activity.

The change of PSA doubling time and its association with disease progression in patients with biochemically relapsed prostate cancer treated with intermittent androgen deprivation

BACKGROUND

We sought to determine the change of PSA doubling time (PSADT) and its association with disease progression during intermittent androgen deprivation (IAD) therapy for prostate cancer.

METHODS

Data were retrospectively analyzed in 96 patients with biochemically relapsed prostate cancer (BRPC) treated with IAD since 1995. IAD consisted of LHRH-agonists ± antiandrogen given usually at PSA threshold (ng/ml) of 10-20, for 6-9 months. Cycles were repeated until the development of castration resistance. Mixed effects model was used to study PSADT change over cycles. Multivariate cox regression model was used to identify outcome-associated variables.

RESULTS

Patients received a mean of 2.8 treatment cycles over a mean follow-up time of 71 months. Fifty-seven (59%) remain on treatment and 39 (41%) developed PSA refractoriness (n = 8) or positive scans (n = 31). First off treatment interval PSADT (median 2.3 months) was significantly shorter than the baseline (median 7.34) but remained stable in subsequent cycles. Off treatment interval PSADT adjusted for testosterone recovery (median 3.7) was significantly longer than that based on all PSA determinations (median 2). Factors associated with disease progression were pre-treatment PSADT (≥6 vs. <6), first off treatment interval PSADT (≥3 vs. <3), and PSA nadir during the first treatment interval (<0.1 vs. ≥0.1).

CONCLUSIONS

During IAD for BRPC, PSADT becomes shorter, and is associated with testosterone recovery. PSADT before treatment and during the first off treatment interval is associated with disease progression. If prospectively validated these data may guide treatment with IAD and clinical trial design.

Phase I rapid dose-escalation study of AGS-1C4D4, a human anti-PSCA (prostate stem cell antigen) monoclonal antibody, in patients with castration-resistant prostate cancer: a PCCTC trial

PURPOSE

AGS-1C4D4 is a human monoclonal antibody against prostate stem cell antigen (PSCA), a cell-surface protein expressed by most prostate cancers. AGS-1C4D4 is produced in Chinese hamster ovary (CHO) cells and has an identical sequence to AGS-PSCA, an anti-PSCA antibody produced in mouse hybridoma cells that has completed Phase I testing. Preclinical studies demonstrated comparability of AGS-1C4D4 to AGS-PSCA with respect to pharmacokinetics (PK) and tumor inhibition. However, because of differences in antibody-dependent cellular cytotoxicity between AGS-PSCA and AGS-1C4D4, a limited Phase I trial using AGS-1C4D4 was performed evaluating safety and PK.

PATIENTS AND METHODS

Thirteen patients with metastatic castration-resistant prostate cancer were enrolled. AGS-1C4D4 was administered intravenously every 3 weeks for four planned doses at 6, 12, 24, or 48 mg/kg. Primary endpoints were safety and PK. Secondary endpoints were immunogenicity and clinical activity. Disease assessments were conducted every 12 weeks and included radiographic and PSA evaluations. Patients with stable disease could receive extended treatment beyond four infusions.

RESULTS

Adverse events were primarily grade 1-2, without any grade 3-4 drug-related toxicities or infusion reactions. Anti-AGS-1C4D4 antibodies were not detected. Similar to AGS-PSCA, serum AGS-1C4D4 concentrations declined biphasically and elimination was characterized by slow clearance (CL) and a long terminal half-life (t (1/2)). Median CL for the four dose levels ranged from 0.10 to 0.14 ml/h kg, and t (1/2) ranged from 2.2 to 2.9 weeks. No PSA reductions ≥50% were observed. Six patients (46%) had radiographically stable disease, lasting a median of 24 weeks.

CONCLUSION

AGS-1C4D4 was well-tolerated and demonstrated linear PK. Despite preclinical differences in antibody-dependent cellular cytotoxicity, AGS-1C4D4 and AGS-PSCA have similar safety and PK profiles. The recommended Phase II dose is 48 mg/kg.

The association of pre-treatment neutrophil to lymphocyte ratio with response rate, progression free survival and overall survival of patients treated with sunitinib for metastatic renal cell carcinoma

BACKGROUND

Sunitinib is a standard treatment for metastatic renal cell carcinoma (mRCC). The neutrophil to lymphocyte ratio (NLR), an index of systemic inflammation, is associated with outcome in several cancer types.

AIMS

To study the association of pre-treatment neutrophil to lymphocyte ratio with response rate, progression free survival (PFS) and overall survival (OS) of patients treated with sunitinib for mRCC.

METHODS

We retrospectively studied an unselected cohort of patients with mRCC, who were treated with sunitinib. Logistic regression model was used to analyse response rate. Cox regression models were fitted to identify risk factors associated with PFS and OS. We investigated how pre-treatment NLR is associated with these clinical outcomes after adjusting for confounding covariates. Regression tree for censored data method was used to find the best NLR cut-off value.

RESULTS

Between 2004 and 2011, 133 patients with mRCC were treated with sunitinib. One hundred and nine were included in the NLR analysis, from which were excluded patients without available data on pre-treatment NLR or with comorbidities/recent treatments known to be associated with a change of blood counts. Factors associated with PFS were low NLR ≤ 3 (HR = 0.285, p < 0.001), past nephrectomy (HR = 0.38, p = 0.035), sunitinib dose reduction/treatment interruption (HR = 0.6, p = 0.014) and the use of antiotensin system inhibitors (HR = 0.537, p = 0.008). Low NLR ≤ 3 was associated with OS (HR = 0.3, p = 0.043).

CONCLUSIONS

In patients with mRCC treated with sunitinib, pre-treatment NLR may be associated with PFS and OS. This should be investigated prospectively, and if validated applied in clinical practice and clinical trials.

Phase II randomized, double-blind, placebo-controlled study of tasquinimod in men with minimally symptomatic metastatic castrate-resistant prostate cancer

PURPOSE

The activity of the novel antitumor agent tasquinimod (TASQ) with S100A9 as a molecular target was investigated in men with metastatic castration-resistant prostate cancer (CRPC) and minimal symptoms.

PATIENTS AND METHODS

We conducted a randomized, double-blind, placebo-controlled phase II trial in men assigned (at a ratio of two to one) to either oral once-daily TASQ 0.25 mg/d escalating to 1.0 mg/d over 4 weeks or placebo. The primary end point was the proportion of patients without disease progression at 6 months, defined by Response Evaluation Criteria in Solid Tumors Group, Prostate Cancer Working Group (PCWG2), or pain criteria, excluding prostate-specific antigen.

RESULTS

Two hundred one men (134 assigned to TASQ; 67 to placebo) were evaluable, and baseline characteristics were well balanced. Six-month progression-free proportions for TASQ and placebo groups were 69% and 37%, respectively (P < .001), and median progression-free survival (PFS) was 7.6 versus 3.3 months (P = .0042). In PCWG2 CRPC clinical subgroups, PFS in months was as follows: nodal metastases, 6.1 versus 3.1; bone metastases, 8.8 versus 3.4; and visceral metastases, 6.0 versus 3.0 for patients receiving TASQ versus placebo, respectively. Bone alkaline phosphatase levels were stabilized in the TASQ group, whereas the impact on PSA kinetics was less pronounced. Adverse events (AEs) occurring more frequently in the TASQ arm included GI disorders, fatigue, musculoskeletal pains, and elevations of pancreatic and inflammatory biomarkers. Grade 3 to 4 AEs, including asymptomatic elevations of laboratory parameters, were reported in 40% of patients receiving TASQ versus 10% receiving placebo; deep vein thrombosis (4% v 0%) was more common in the TASQ arm.

CONCLUSION

TASQ significantly slowed progression and improved PFS in patients with metastatic CRPC with an acceptable AE profile.

Role of immunotherapy for renal cell cancer in 2011

High-dose interleukin-2 (IL-2) and interferon were the most commonly administered therapies before the recent introduction of targeted agents, including vascular endothelial growth factor and mammalian target of rapamycin pathway inhibitors. Although the new agents result in a progression-free survival benefit, high-dose IL-2 remains the only agent with proven efficacy in producing durable complete and partial responses in patients with metastatic renal cell carcinoma (RCC). Furthermore, although the use of single-agent interferon has decreased significantly since the introduction of targeted therapy, it remains in the frontline setting in combination with bevacizumab as a result of 2 large phase III trials. Lastly, improved understanding of immune regulation has led to the advancement of targeted immunotherapy using immune checkpoint inhibitors that have shown promising activity and are moving forward in clinical development. This article focuses on the current status of immunotherapy in the management of metastatic RCC.

Angiotensin system inhibitors and outcome of sunitinib treatment in patients with metastatic renal cell carcinoma: a retrospective examination

BACKGROUND

Sunitinib is a standard treatment for metastatic renal cell carcinoma. Angiotensin system inhibitors, including angiotensin converting enzyme inhibitors and angiotensin II receptor blockers, are widely used in hypertension, kidney disease and heart failure. Data suggests that they may inhibit tumourigenesis.

AIMS

To study the effect of angiotensin system inhibitors on sunitinib treatment outcome in metastatic renal cell carcinoma.

METHODS

We performed a retrospective study of an unselected cohort of patients with metastatic renal cell carcinoma who were treated with sunitinib. Patients were divided into angiotensin system inhibitors users (group 1) and non-users (group 2). The effect of angiotensin system inhibitors on objective response, time to disease progression and overall survival, was tested with adjustment for known confounding risk factors through logistic regression model and Cox regression model.

RESULTS

Between 2004 and 2010, 127 patients with metastatic renal cell carcinoma were treated with sunitinib, 44 group 1 and 83 group 2. The groups were balanced regarding known clinicopathologic prognostic factors. Objective response was partial response/stable disease 86% versus 72% and progressive disease 14% versus 28% (p=0.07) in group 1 versus 2, respectively. Median progression free survival was 13 versus 6 months (HR 0.537, p=0.0055), and median overall survival 30 versus 23 months (HR 0.688, p=0.21), in favour of group 1.

CONCLUSIONS

Angiotensin system inhibitors may improve the outcome of sunitinib treatment in metastatic renal cell carcinoma. This should be investigated prospectively, and if validated applied in clinical practise and clinical trials.

The natural history of metastatic progression in men with prostate-specific antigen recurrence after radical prostatectomy: long-term follow-up

OBJECTIVE

To describe metastasis-free survival (MFS) in men with prostate-specific antigen (PSA) recurrence following radical prostatectomy, and to define clinical prognostic factors modifying metastatic risk.

PATIENTS AND METHODS

We conducted a retrospective analysis of 450 men treated with prostatectomy at a tertiary hospital between July 1981 and July 2010 who developed PSA recurrence (≥0.2 ng/mL) and never received adjuvant or salvage therapy before the development of metastatic disease. We estimated MFS using the Kaplan-Meier method, and investigated factors influencing the risk of metastasis using Cox proportional hazards regression.

RESULTS

Median follow-up after prostatectomy was 8.0 years, and after biochemical recurrence was 4.0 years. At last follow-up, 134 of 450 patients (29.8%) had developed metastases, while median MFS was 10.0 years. Using multivariable regressions, two variables emerged as independently predictive of MFS: PSA doubling time (<3.0 vs 3.0-8.9 vs 9.0-14.9 vs ≥15.0 months) and Gleason score (≤6 vs 7 vs 8-10). Using these stratifications of Gleason score and PSA doubling time, tables were constructed to predict median, 5- and 10-year MFS after PSA recurrence. In different patient subsets, median MFS ranged from 1 to 15 years.

CONCLUSIONS

In men undergoing prostatectomy, MFS after PSA recurrence is variable and is most strongly influenced by PSA doubling time and Gleason score. These parameters serve to stratify men into different risk groups with respect to metastatic progression. Our findings may provide the background for appropriate selection of patients, treatments and endpoints for clinical trials.

Once-daily dasatinib: expansion of phase II study evaluating safety and efficacy of dasatinib in patients with metastatic castration-resistant prostate cancer

OBJECTIVES

To determine the activity and tolerability of 100-mg once-daily (QD) dasatinib in patients with metastatic castration-resistance prostate cancer (CRPC). Dasatinib, an oral Src family kinase inhibitor, has demonstrated both preclinical and clinical activity with twice-daily dosing in patients with metastatic CRPC.

METHODS

Chemotherapy-naive men with metastatic CRPC and increasing prostate-specific antigen levels were treated with dasatinib 100 mg QD. The primary measurement was a composite lack of disease progression, according to the Prostate Cancer Working Group 2 criteria, determined every 12 weeks during the study. The other analyses included changes in the prostate-specific antigen level, bone lesions, soft tissue disease, and bone turnover markers (urine N-telopeptide and bone alkaline phosphatase).

RESULTS

The present trial was designed before the publication of the recent Prostate Cancer Working Group 2 criteria; however, the analyses are presented to conform to the updated guidelines. A total of 48 patients received dasatinib. A lack of disease progression was observed in 21 patients (44%) at week 12 and in 8 (17%) at week 24. Urine N-telopeptide was reduced by ≥40% from baseline in 22 (51%) of 43 patients, and bone alkaline phosphatase was decreased in 26 (59%) of 44 patients. Dasatinib was well-tolerated, with only 6 patients (13%) with drug-related grade 3-4 adverse events and 3 (6%) with grade 3 adverse events. The most common treatment-related adverse events (≥20%) were fatigue, nausea, diarrhea, headache, and anorexia.

CONCLUSIONS

Dasatinib 100 mg QD has a favorable safety profile and maintains a similar degree of activity as the previously reported twice-daily dosing schedules. These data support additional study of dasatinib 100 mg QD for metastatic CRPC.

NCCN Task Force report: optimizing treatment of advanced renal cell carcinoma with molecular targeted therapy

The outcome of patients with metastatic renal cell carcinoma has been substantially improved with administration of the currently available molecularly targeted therapies. However, proper selection of therapy and management of toxicities remain challenging. NCCN convened a multidisciplinary task force panel to address the clinical issues associated with these therapies in attempt to help practicing oncologists optimize patient outcomes. This report summarizes the background data presented at the task force meeting and the ensuing discussion.

Once-daily dasatinib: expansion of phase II study evaluating safety and efficacy of dasatinib in patients with metastatic castration-resistant prostate cancer

OBJECTIVES

To determine the activity and tolerability of 100-mg once-daily (QD) dasatinib in patients with metastatic castration-resistance prostate cancer (CRPC). Dasatinib, an oral Src family kinase inhibitor, has demonstrated both preclinical and clinical activity with twice-daily dosing in patients with metastatic CRPC.

METHODS

Chemotherapy-naive men with metastatic CRPC and increasing prostate-specific antigen levels were treated with dasatinib 100 mg QD. The primary measurement was a composite lack of disease progression, according to the Prostate Cancer Working Group 2 criteria, determined every 12 weeks during the study. The other analyses included changes in the prostate-specific antigen level, bone lesions, soft tissue disease, and bone turnover markers (urine N-telopeptide and bone alkaline phosphatase).

RESULTS

The present trial was designed before the publication of the recent Prostate Cancer Working Group 2 criteria; however, the analyses are presented to conform to the updated guidelines. A total of 48 patients received dasatinib. A lack of disease progression was observed in 21 patients (44%) at week 12 and in 8 (17%) at week 24. Urine N-telopeptide was reduced by ≥40% from baseline in 22 (51%) of 43 patients, and bone alkaline phosphatase was decreased in 26 (59%) of 44 patients. Dasatinib was well-tolerated, with only 6 patients (13%) with drug-related grade 3-4 adverse events and 3 (6%) with grade 3 adverse events. The most common treatment-related adverse events (≥20%) were fatigue, nausea, diarrhea, headache, and anorexia.

CONCLUSIONS

Dasatinib 100 mg QD has a favorable safety profile and maintains a similar degree of activity as the previously reported twice-daily dosing schedules. These data support additional study of dasatinib 100 mg QD for metastatic CRPC.

Future directions in castrate-resistant prostate cancer therapy

Although several new therapies have recently become available for the treatment of castrate-resistant prostate cancer (CRPC), the disease remains universally incurable and demands novel therapeutic approaches. To this end, great strides have been made in our understanding of the biologic and molecular mechanisms driving prostate cancer growth and progression in the past few years, resulting in widespread clinical investigation of numerous new targeted therapies. This review will highlight some of the key therapeutic agents that (in the opinion of the authors) may have the largest effect on the future management of CRPC, with a focus on both molecular targets and clinical trial design. These agents include angiogenesis inhibitors, mTOR pathway inhibitors, apoptosis-inducing drugs, IGF pathway inhibitors, Src family inhibitors, Hedgehog pathway antagonists, epigenetic therapies, PARP inhibitors, and prodrug approaches. The future of CRPC therapy appears brighter than ever before.

Preventive care in prostate cancer patients: following diagnosis and for five-year survivors

INTRODUCTION

Prostate cancer is the most common male cancer. Survival rates are high, making preventive care maintenance important. Factors associated with prostate-cancer cases' preventive care in the short-term (Year 1) and long-term (Year 5), and how survivors' care compares to non-cancer controls, require study.

METHODS

This retrospective, controlled SEER-Medicare study included loco-regional prostate cancer cases age ≥ 66 in fee-for-service Medicare diagnosed in 2000 and surviving ≥ 12 months, and non-cancer controls matched to cases on socio-demographics and survival. Outcomes included influenza vaccination, cholesterol screening, and colorectal cancer screening. Independent variables were number of physician visits, physician specialties visited, initial prostate cancer treatment, socio-demographic characteristics, and case-control status.

RESULTS

There were 13,507 cases and 13,507 controls in Year 1, and 10,482 cases and 10,482 controls in Year 5. In Years 1 and 5, total number of visits (6/6 outcomes) and primary care provider (PCP) visits (5/6 outcomes) were most consistently associated with preventive care receipt. In Year 1, prostate cancer cases were more likely than controls to receive influenza vaccination (48% vs. 45%) but less likely to receive colorectal cancer screening (29% vs. 31%) (both p  <  0.0001). In Year 5, prostate cancer cases remained more likely than controls to receive influenza vaccination (46% vs. 44%; p  <  0.0001).

CONCLUSIONS

Differences in survivors' short-term preventive care did not lead to worse long-term preventive care. The number of physician visits, particularly PCP visits, are important factors associated with appropriate care.

IMPLICATIONS FOR CANCER SURVIVORS

PCP involvement in prostate cancer patients' care is critical both during treatment and for long-term survivors.

Abstract 2976: Small molecule screening of prostate and pancreatic cancer cell lines identifies tilorone dihydrochloride as a compound that selectively inhibits growth in cells with inhibited cyclin-dependent kinase 5

Cyclin-dependent kinase 5 (CDK5) has long been known to be an enzyme necessary for neuronal migration. In recent years, extraneural functions of CDK5 have been discovered, including CDK5 playing an essential role in invasion and migration in pancreatic and prostate cancer, and in tumor growth and Ras signaling through Ral in pancreatic cancer. This makes CDK5 an interesting target against cancer. We blocked CDK5 activity in prostate cancer cell line PC3 by dominant-negative constructs, and used a library consisting of 3360 compounds to screen for small molecules that differentially inhibit proliferation activity in wildtype PC3 (PC3wt) and CDK5 dominant-negative PC3 (PC3cdn) cells, by performing MTS assays. We selected for compounds in which the difference in proliferation activity between the two cell lines was more than 40% and/or compounds that inhibited both cell lines by more than 50%. With this selection, 32 compounds were identified. Topically acting compounds were excluded, the other compounds were sorted for difference in proliferation activity inhibition between the two cell lines, and a Pubmed search was performed on the compounds with the largest difference. This way, tilorone analog R 9536-DA was selected as the most potent compound, as it inhibited proliferation in PC3wt and PC3cdn cells by 72.5% (SD 0.5%) and 81.1% (SD 2.1%) respectively (a difference in proliferation activity of 32%). MTS and clonogenic assays confirmed the differential sensitivity of PC3wt and PC3cdn cells to tilorone dihydrochloride. The IC50 in PC3wt cells was around 16 μM, while in PC3cdn cells it was around 10 μM. This difference in sensitivity to tilorone dihydrochloride in the presence of CDK5 inhibition was confirmed in pancreatic and other prostate cancer cell lines as well. To examine the toxicity of tilorone dihydrochloride in normal cells, the compound was administered to normal human prostate fibroblasts, in which the IC50 was found to be higher than 20μM. Western blots were performed to investigate the mechanism behind this difference in sensitivity between cell lines. These experiments conclude that administration of tilorone dihydrochloride differentially induces PARP and the p38-MAPK signaling pathway, indicating the involvement of this pathway in tilorone induced cell death. Tilorone analogs previously have been shown in mice to inhibit metastasis and increase survival in several tumor types. This study suggests that the combination of tilorone and inhibition of CDK5 may be a promising therapeutic strategy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2976. doi:10.1158/1538-7445.AM2011-2976

Disulfiram is a DNA demethylating agent and inhibits prostate cancer cell growth

BACKGROUND

The clinical success of the nucleoside analogs 5-aza-cytidine (5-azaC) and 5-aza-2'deoxycytidine (5-aza-dC) as DNA methyltransferase (DNMT) inhibitors has spurred interest in the development of non-nucleoside inhibitors with improved pharmacologic and safety profiles. Because DNMT catalysis features attack of cytosine bases by an enzyme thiol group, we tested whether disulfiram (DSF), a thiol-reactive compound with known clinical safety, demonstrated DNMT inhibitory activity.

METHODS

Inhibition of DNMT1 activity by DSF was assessed using methyltransferase activity assays with recombinant DNMT1. Next, prostate cancer cell lines were exposed to DSF and assessed for: i) reduction of global 5-methyl cytosine ((5me)C) content using liquid chromatography/tandem mass spectrometry (LC-MS/MS); ii) gene-specific promoter demethylation by methylation-specific PCR (MSP); and iii) gene-reactivation by real-time RT-PCR. DSF was also tested for growth inhibition using prostate cancer cell lines propagated in vitro in cell culture and in vivo as xenografts in nude mice.

RESULTS

Disulfiram showed a dose-dependent inhibition of DNMT1 activity on a hemimethylated DNA substrate. In prostate cancer cells in culture, DSF exposure led to reduction of global genomic (5me)C content, increase in unmethylated APC and RARB gene promoters, and associated re-expression of these genes, but did not significantly alter prostate-specific antigen (PSA) expression. DSF significantly inhibited growth and clonogenic survival of prostate cancer cell lines in culture and showed a trend for reduced growth of prostate cancer xenografts.

CONCLUSIONS

Disulfiram is a non-nucleoside DNMT1 inhibitor that can reduce global (5me)C content, reactivate epigenetically silenced genes, and significantly inhibit growth in prostate cancer cell lines.