Molecular Testing in Patients With Castration-Resistant Prostate Cancer and Its Impact on Clinical Decision Making.

PURPOSE: Metastatic castration-resistant prostate cancer (CRPC) is the lethal form of the disease. Many groups have performed mutational or immunohistochemistry (IHC) testing in metastatic CRPC to identify treatment targets. However, the frequency with which mutational or IHC data have an impact on clinical decision making and the outcomes of molecularly guided therapy in CRPC are largely unknown. We report our institution's experience with mutational and IHC testing in patients with metastatic CRPC and its impact on clinical decision making and patient outcomes. METHODS: Between 2012 and 2015, 59 patients with CRPC underwent metastatic tissue biopsies and were genotyped with a 37-cancer gene panel in a Clinical Laboratory Improvement Amendments-certified laboratory. PTEN expression by IHC testing was also measured in 35 of these samples. A retrospective chart review was performed to determine whether the genomic information was acted upon and the outcome of patients whose treatment was guided by molecular testing. RESULTS: Forty-six of 59 patients with CRPC (78.0%) had biopsies with adequate tumor for mutational testing. Thirty-one of 46 subjects (67.4%) had mutations identified by sequencing. Of the 35 patients with CRPC whose biopsies were evaluated for PTEN expression by IHC testing, 13 had PTEN loss. Two patients had treatment on the basis of molecular testing, and one of these subjects had greater tumor control with molecularly guided therapy than his immediate prior therapy. CONCLUSION: Targeted sequencing and IHC can identify clinically informative molecular abnormalities in CRPC. Despite this, a small minority of patients in our series underwent therapies guided by mutational or IHC testing. Actionability of abnormalities identified in metastatic CRPC may be improved with access to clinical trials, insurance approval for unapproved uses of existing anticancer drugs, and larger gene sequencing panels that include more frequently mutated genes.

Cyclooxygenase-2 (COX-2) inhibition for prostate cancer chemoprevention: double-blind randomised study of pre-prostatectomy celecoxib or placebo.

OBJECTIVE: To evaluate the biological effects of selective cyclooxygenase-2 inhibition on prostate tissue in patients undergoing radical prostatectomy (RP). PATIENTS AND METHODS: Patients with localised prostate cancer were randomised to receive either celecoxib 400 mg twice daily or placebo for 4 weeks before RP. Specimens were analysed for levels of apoptosis, prostaglandins, and androgen receptor (AR). Effects on serum prostate-specific antigen (PSA) and postoperative opioid use were also measured. RESULTS: In all, 28 of 44 anticipated patients enrolled and completed treatment. One patient in the celecoxib arm had a myocardial infarction postoperatively. For this reason, and safety concerns in other studies, enrolment was halted. The apoptosis index (AI) in tumour cells was 0.29% [95% confidence interval (CI) 0.11-0.47%] vs 0.39% (95% CI 0.00-0.84%) in the celecoxib and placebo arms, respectively (P = 0.68). The AI in benign cells was 0.18% (95% CI 0.03-0.32%) vs 0.13% (95% CI 0.00-0.28%) in the celecoxib and placebo arms, respectively (P = 0.67). Prostaglandin E2 and AR levels were similar in cancerous and benign tissues when comparing the two arms. The median baseline PSA level was 6.0 and 6.2 ng/mL for the celecoxib and placebo groups, respectively, and did not significantly change after celecoxib treatment. There was no difference in postoperative opiate usage between arms. CONCLUSION: Celecoxib had no effect on apoptosis, prostaglandins or AR levels in cancerous or benign prostate tissues. These findings coupled with drug safety concerns should serve to limit interest in these selective drugs as chemopreventive agents.

C-reactive protein as an adverse prognostic marker for men with castration-resistant prostate cancer (CRPC): confirmatory results.

We previously reported that higher serum concentrations of C-reactive protein (CRP) are associated with shorter survival in men with castration-resistant prostate cancer (CRPC). To confirm this finding in an independent data set, we used 119 CRPC patients enrolled in 6 phase II clinical trials and examined the relationship of CRP, alkaline phosphatase, hemoglobin, age, ECOG PS, and prostate specific antigen (PSA) with survival. Median follow-up was 19.7 months (0.9-98.5 months), and 89% have died. After analyzing the form of the risk function using the generalized additive model method, univariate and multivariate Cox proportional hazard models were used to assess associations between baseline individual categorical and continuous variables. Quartiles of CRP were: 0-1.0, 1.1-4.9, 5.0-17.0, and 17.1-311 mg/L. In a Cox multivariate model, log(2) (CRP) (HR 1.106, P = 0.013) as well as hemoglobin and alkaline phosphatase were independently associated with survival, confirming that higher CRP is associated with shorter survival in CRPC. Since CRP is a marker of inflammation, this finding suggests that inflammation may play an important role in the natural history of advanced prostate cancer. CRP is a readily measurable biomarker that has the potential to improve prognostic models and should be validated in a prospective clinical trial.

Acupuncture for hot flashes in patients with prostate cancer.

OBJECTIVES: To determine the effect of acupuncture on hot flash frequency and intensity, quality of life, and sleep quality in patients undergoing hormonal therapy for prostate cancer. Hot flashes are a common adverse effect of hormonal therapy for prostate cancer. METHODS: Men who had a hot flash score > 4 who were receiving androgen deprivation therapy for prostate cancer underwent acupuncture with electrostimulation biweekly for 4 weeks, then weekly for 6 weeks, using a predefined treatment plan. The primary endpoint was a 50% reduction in the hot flash score after 4 weeks of therapy, calculated from the patients' daily hot flash diaries. The hot flash-related quality of life and sleep quality and biomarkers potentially related to hot flashes, including serotonin, calcitonin gene-related peptide, and urinary 5-hydroxyindoleacetic acid, were examined. RESULTS: A total of 25 men were enrolled from September 2003 to April 2007. Of these, 22 were eligible and evaluable. After 4 weeks, 9 (41%, 95% confidence interval 21%-64%) of 22 patients had had a > 50% reduction in the hot flash score. Of the 22 patients, 12 (55%, 95% confidence interval 32%-76%) met this response definition at any point during the therapy course. No patient had a significant increase in hot flash score during therapy. A reduced hot flash score was associated with improvement in the hot flash-related quality of life and sleep quality. CONCLUSIONS: Multiple placebo-controlled trials have demonstrated a 25% response rate to placebo treatment for hot flashes. Of the 22 patients, 41% had responded by week 4 and 55% overall in the present pilot study, providing evidence of a potentially meaningful benefit. Additional studies of acupuncture for hot flashes in this population are warranted.

A phase II study of paclitaxel poliglumex in combination with transdermal estradiol for the treatment of metastatic castration-resistant prostate cancer after docetaxel chemotherapy.

Taxanes remain the only agents to extend survival in castration-resistant metastatic prostate cancer, but their impact on the natural history of this disease is modest. We sought to test the hypothesis that increased delivery of taxane chemotherapy to the tumor through the use of a macromolecular polymer-drug conjugate of paclitaxel modulated by estradiol could extend the utility of this class of drugs. Patients with metastatic adenocarcinoma of the prostate who progressed despite standard hormonal therapy and after docetaxel-containing chemotherapy were treated with transdermal estradiol (0.2 mg/24 h) for 4 weeks followed by the same dose of transdermal estradiol and paclitaxel poliglumex (PPX; 150 mg/m intravenous) every 28 days. The primary objective was to determine the level of activity of the regimen measured using a fraction of patients who experienced a confirmed decline in serum prostate-specific antigen (PSA) of 50% or more. A two-stage phase II study designed to identify a response rate of > or =25% required three responders among 21 patients in the first stage. Twenty-one patients who received a median of two earlier chemotherapy regimens were enrolled in the trial between March 2007 and May 2008. During the estradiol-only treatment phase, no patient had a PSA decline in excess of 50% and lesser PSA declines that ranged from 8.8 to 34.1% were seen in five patients. No patients achieved a > or =50% PSA decline following the addition of PPX and there were no responses in measurable disease. The median time to progression was 4 weeks. In conclusion, this regimen of low-dose transdermal estradiol induction followed by PPX does not have activity in taxane pretreated patients with castration-resistant prostate cancer.

C-reactive protein as a prognostic marker for men with androgen-independent prostate cancer: results from the ASCENT trial.

BACKGROUND: Studies of cancer risk and molecular carcinogenesis suggest a role for inflammation in cancer development and progression. The authors sought to determine whether specific blood proteins associated with inflammation predict for outcomes in men with metastatic androgen-independent prostate cancer (AIPC) who are initiating docetaxel-based chemotherapy. METHODS: Baseline plasma samples were stored (-80 degrees C) from 160 of 250 patients enrolled in the AIPC Study of Calcitriol ENhancing Taxotere (ASCENT) trial, a randomized, placebo-controlled trial comparing weekly docetaxel plus high-dose calcitriol with weekly docetaxel. Multiplex immunoassays measured 16 cytokine, chemokine, cardiovascular, or inflammatory markers. The Cox proportional hazards model was used to assess associations between baseline biomarkers, clinical characteristics, and survival. Logistic regression was used for analyses of associations with prostate-specific antigen (PSA) decline. RESULTS: C-reactive protein (CRP) was found to be significantly predictive of a shorter overall survival (hazards ratio [HR] of 1.41 for each natural logarithm [ln] [CRP] increase; 95% confidence interval [95% CI], 1.20-1.65 [P < .0001]). When CRP (continuous) was entered into a multivariate model using 13 baseline clinical variables, only elevated CRP remained a significant predictor (P < .0001) of shorter overall survival. When categorized as normal (8 mg/L), elevated CRP was found to be a significant predictor of shorter overall survival (HR of 2.96; 95% CI, 1.52-5.77 [P = .001]), as was hemoglobin (P = .007). Elevated CRP was also associated with a lower probability of PSA decline (odds ratio of 0.74 for each ln(CRP) increase; 95% CI, 0.60-0.92 [P = .007]). CONCLUSIONS.: Elevated plasma CRP concentrations appear to be a strong predictor of poor survival and lower probability of PSA response to treatment in patients with AIPC who are receiving docetaxel-based therapy.

Effect of calcitriol on prostate-specific antigen in vitro and in humans.

BACKGROUND: Calcitriol, the natural ligand for the vitamin D receptor, has significant potential in prostate cancer treatment. Measurement of its antineoplastic activity in prostate cancer clinical trials may be complicated by effects of calcitriol on prostate-specific antigen (PSA) production. We examined the effects of calcitriol at similar concentration on cell proliferation, androgen receptor (AR) expression, and PSA production in vitro and on PSA concentrations in prostate cancer patients. EXPERIMENTAL DESIGN: LNCaP prostate cancer cell proliferation was examined by cell counts 6 days after exposure to a range of concentrations of calcitriol. AR and PSA protein was quantified in LNCaP cells over 96 hours after exposure to 1 nmol/L calcitriol. Serum PSA and free PSA was serially measured by immunoassay over a period of 8 days in patients with hormone-naïve prostate cancer after a single dose of 0.5 microg/kg calcitriol. RESULTS: Calcitriol treatment resulted in dose-dependent growth inhibition of LNCaP with approximately 50% growth inhibition at the clinically achievable concentration of 1 nmol/L. Time-dependent up-regulation of AR expression and of PSA production in LNCaP cells was shown at the same concentration. No significant change in serum PSA or free PSA over 8 days was seen in eight subjects treated with a single dose of 0.5 microg/kg calcitriol. The analysis was powered to detect a 1.23-fold change between the baseline and day 8 serum PSA. CONCLUSIONS: At clinically achievable concentrations, calcitriol inhibits growth and induces AR and PSA expression in LNCaP cells. We did not detect similar changes in serum PSA or free PSA in patients exposed to similar concentrations of calcitriol. Thus, a PSA flare, predicted by preclinical systems, is unlikely to occur in patients and therefore unlikely to complicate interpretation of clinical trial outcomes.

Prostate-specific antigen decline after gonadotropin-releasing hormone antagonist withdrawal in androgen-independent prostate cancer.

A 66-year-old man with androgen-independent prostate cancer was treated with abarelix, a gonadotropin-releasing hormone antagonist, for 20 weeks in an experimental protocol. He did not respond to therapy, but his serum prostate-specific antigen level dropped from 15.8 ng/mL to a confirmed 0.8 ng/mL after abarelix was stopped. His prostate-specific antigen level did not return to greater than 15.8 ng/mL for 14 months. This is the first report of a withdrawal response after therapy with a gonadotropin-releasing hormone antagonist, a new class of agents for prostate cancer. Additional observations are needed to determine whether this is an isolated case or a harbinger of a more common phenomenon.

Rationale for the development and current status of calcitriol in androgen-independent prostate cancer.

Calcitriol, the principal active metabolite of vitamin D, has significant antineoplastic activity in pre-clinical models of prostate cancer and many other tumor types. Reported mechanisms of activity include inhibition of proliferation and cell cycle arrest, induction of apoptosis, and reduction of invasiveness and angiogenesis. Different mechanisms may be responsible in different tumor types and under different experimental conditions. Importantly, preclinical data suggest that calcitriol acts in a synergistic and/or additive manner when combined with antineoplastic agents that are relevant to prostate cancer, including dexamethasone and several classes of cytotoxic agents. The antineoplastic effects of calcitriol occur at concentrations that substantially exceed the normal physiologic range and cannot be safely achieved with conventional daily dosing. Intermittent administration of calcitriol has allowed significant dose escalation. In combination with weekly docetaxel, the agent produced encouraging results in a single-institution phase II study. An international placebo-controlled randomized trial that is currently under way will provide more robust information about the safety and efficacy of this combination.

How accurate is clinician reporting of chemotherapy adverse effects? A comparison with patient-reported symptoms from the Quality-of-Life Questionnaire C30.

PURPOSE: Adverse events in chemotherapy clinical trials are assessed and reported by clinicians, yet clinician accuracy in assessing symptoms has been questioned. We compared patient reporting of eight symptoms using a validated instrument, the European Organization for the Research and Treatment of Cancer Quality-of-Life Questionnaire C30 (QLQ-C30 or QLQ) with physicians' reporting of the same symptoms in the study's adverse events log. PATIENTS AND METHODS: Thirty-seven men with metastatic, androgen-independent prostate cancer enrolled onto a phase II trial of weekly calcitriol and docetaxel completed the QLQ every 4 weeks for up to 28 weeks. A patient-reported symptom was defined as an increase in a QLQ symptom score by at least 10 points (0 to 100 scale), sustained for at least 4 weeks. A physician-reported symptom was considered present if it was ever documented in the adverse event log. RESULTS: Forty-nine (new or worsened) symptoms were detected by both physician and QLQ, 48 symptoms were detected by the physician alone, and 55 symptoms were detected by the QLQ alone. They agreed on the absence of a symptom in 102 instances of 254 possible opportunities. Their uncorrected agreement was 59.4%, but Cohen's kappa, a coefficient of agreement that corrects for chance, was 0.15, indicating only slight agreement. Using the QLQ as the standard, overall physician sensitivity and specificity was 47% and 68%, respectively, although it varied considerably among symptoms. CONCLUSION: Even in a tightly controlled clinical trial, physician reporting was neither sensitive nor specific in detecting common chemotherapy adverse effects. Tools for collecting patient-reported adverse event data in chemotherapy clinical trials should be developed.

Quality of life and pain relief during treatment with calcitriol and docetaxel in symptomatic metastatic androgen-independent prostate carcinoma.

BACKGROUND: The current study evaluated the analgesic activity and impact on quality of life (QOL) of a new chemotherapy regimen of calcitriol and docetaxel in men with androgen-independent prostate carcinoma. METHODS: Analgesic response was defined as a 2-point reduction on the Present Pain Intensity (PPI) scale (or compete relief if baseline PPI was 1) without an increase in analgesic use or a 50% decrease in analgesic medication use without an increase in pain, maintained for > or = 4 weeks. Pain, pain medication consumption, and QOL (measured by the European Organization for Research and Treatment of Cancer QLQ-C30) were evaluated every 4 weeks. RESULTS: Treatment resulted in an analgesic response in 14 of 29 evaluable patients (48%; 95% confidence interval [95% CI], 30-67%). The median time to symptomatic progression in the 14 patients who met criteria for analgesic response was 41 weeks (95% CI, 26-56 weeks). Worsening in physical and role functioning, fatigue, appetite, and global health status and improvement in constipation were detected using the QLQ-C30 QOL questionnaire. CONCLUSIONS: Significant analgesic activity was demonstrated, although worsening in several QOL domains was observed in a patient population with relatively low pain intensity (median PPI, 2).

Docetaxel (taxotere) in the treatment of prostate cancer.

Docetaxel (Taxotere) is a taxoid derived from the needles of the European yew tree, Taxus baccata. With an overall prostate-specific antigen response rate of 42% in four Phase II studies, docetaxel has important single-agent activity in androgen-independent prostate cancer. Phase II studies suggest that the addition of estramustine (Emcyt) to docetaxel results in higher response rates but also increased toxicity. Docetaxel with and without estramustine is being evaluated in Phase III studies that will provide definitive information about its role in androgen-independent prostate cancer. Novel combinations of docetaxel with biologic response modifiers are in early stages of development. Similarly, a number of investigators are conducting exploratory trials that incorporate docetaxel into multimodality approaches to high-risk localized prostate cancer treatment.

Weekly high-dose calcitriol and docetaxel in metastatic androgen-independent prostate cancer.

PURPOSE: To determine the safety and efficacy of weekly high-dose oral calcitriol (Rocaltrol, Roche Pharmaceuticals, Basel, Switzerland) and docetaxel (Taxotere, Aventis Pharmaceuticals, Bridgewater, NJ) in patients with metastatic androgen-independent prostate cancer (AIPC). PATIENTS AND METHODS: Thirty-seven patients were treated with oral calcitriol (0.5 micro g/kg) on day 1 followed by docetaxel (36 mg/m(2)) on day 2, repeated weekly for 6 weeks of an 8-week cycle. Patients maintained a reduced calcium diet and increased oral hydration. Prostate-specific antigen (PSA) response was the primary end point, which was defined as a 50% reduction in PSA level confirmed 4 weeks later. RESULTS: Thirty of 37 patients (81%; 95% confidence interval [CI], 68% to 94%) achieved a PSA response. Twenty-two patients (59%; 95% CI, 43% to 75%) had a confirmed > 75% reduction in PSA. Eight of the 15 patients with measurable disease (53%; 95% CI, 27% to 79%) had a confirmed partial response. Median time to progression was 11.4 months (95% CI, 8.7 to 14 months), and median survival was 19.5 months (95% CI, 15.3 months to incalculable). Overall survival at 1 year was 89% (95% CI, 74% to 95%). Treatment-related toxicity was generally similar to that expected with single-agent docetaxel. Pharmacokinetics of either calcitriol or docetaxel were not affected by the presence of its companion drug in an exploratory substudy. CONCLUSION: The combination of weekly oral high-dose calcitriol and weekly docetaxel is a well-tolerated regimen for AIPC. PSA and measurable disease response rates as well as time to progression and survival are promising when compared with contemporary phase II studies of single-agent docetaxel in AIPC. Further study of this regimen is warranted.