Comparative effectiveness of cisplatin-based and carboplatin-based chemotherapy for treatment of advanced urothelial carcinoma

BACKGROUND

Cisplatin-based chemotherapy is a standard treatment of metastatic urothelial carcinoma (UC), though carboplatin-based chemotherapy is frequently substituted due to improved tolerability. Because comparative effectiveness in clinical outcomes of cisplatin- versus carboplatin-based chemotherapy is lacking, a meta-analysis was carried out.

METHODS

PubMed was searched for articles published from 1966 to 2010. Eligible studies included prospective randomized trials evaluating cisplatin- versus carboplatin-based regimens in patients with metastatic UC. Individual patient data were not available and survival data were inconsistently reported. Therefore, the analysis focused on overall response (OR) and complete response (CR) rates. The Mantel-Haenszel method was used for combining trials and calculating pooled risk ratios (RRs).

RESULTS

A total of 286 patients with metastatic UC from four randomized trials were included. Cisplatin-based chemotherapy was associated with a significantly higher likelihood of achieving a CR [RR = 3.54; 95% confidence interval (CI) 1.48-8.49; P = 0.005] and OR (RR = 1.34; 95% CI 1.04-1.71; P = 0.02). Survival end points could not be adequately assessed due to inconsistent reporting among trials.

CONCLUSIONS

Cisplatin-based, as compared with carboplatin-based, chemotherapy significantly increases the likelihood of both OR and CR in patients with metastatic UC. The impact of improved response proportions on survival end points could not be assessed.

Correlation of serum cytokines with clinical responses in patients treated with BPX-101, a drug-activated vaccine for metastatic castration-resistant prostate cancer (mCRPC)

167

Background: We report the correlation of clinical and immune monitoring results for subjects enrolled in a phase I/IIa clinical trial of BPX-101, a drug-activated dendritic cell vaccine for mCRPC.

Methods: Men with progressive mCRPC were enrolled in a 3+3 dose escalation trial evaluating BPX-101 and activating agent AP1903. BPX-101 was administered intradermally every 2 weeks for 6 doses, during the induction phase, and for non-progressing patients, every 8 weeks for up to 5 doses during the maintenance phase. AP1903 (0.4 mg/kg) was infused 24 hours after each BPX-101 dose. Blood samples for immune monitoring were collected weekly during the induction phase, and before and one week after each maintenance dose. GM-CSF, TNF-α, IFN-γ, IP-10, MCP-1, MIP-1α, MIP-1β, and RANTES levels were measured by Luminex microspheres, and IL-6 by ELISA.

Results: Planned enrollment of 12 subjects is complete, including 3 each at 4 × 106 and 12.5 × 106 cells/dose, and 6 at 25 x 106 cells/dose. A pattern of spiking levels of serum cytokines one week after each dose, returning to baseline the following week, was observed in subjects with greater disease burden. In one low dose subject who experienced a PR after one year on study, panel cytokines spiked 4-fold on average after each induction phase dose, less than 2-fold after the first two boosters, and between 6-fold and 56-fold after the final three boosters. IL-6, which had declined during the induction phase to below 1 pg/mL through two boosters, spiked between 1,680-fold and 13,000-fold after each of the last three boosters. In a second, high dose subject (#1008), who experienced a near CR of multiple lung metastases with otherwise stable disease, panel cytokines spiked 150-fold on average during the induction phase. In both cases, TNF-α, MIP-1α and MIP-1β spiked the most, including a more than 1,000-fold average spike in TNF-α for subject 1008. Cytokine spikes were not associated with AEs.

Conclusions: BPX-101 induces a spiking pattern of cytokine elevations after each dose. In patients who experienced measurable disease reductions, more dramatic spikes in serum inflammatory cytokine levels were seen.

[Table: see text]

Meta-analysis of randomized trials comparing cisplatin versus carboplatin-based regimens for the first-line therapy of metastatic transitional cell carcinoma of the urothelium (TCCU)

247

Background: Cisplatin-based chemotherapy is the first-line treatment standard for metastatic TCCU, although carboplatin is substituted for cisplatin-ineligibility, tolerability, and ease of administration. Since definitive data comparing cisplatin- versus carboplatin-based chemotherapy are lacking, a meta-analysis of published randomized trials was performed.

Methods: PubMed was searched for articles published in the English language from 1966 until 2010 and abstracts presented at the American Society of Clinical Oncology Annual Meeting between 2000 and 2010 were searched to identify relevant trials. Eligible studies included prospective randomized trials evaluating cisplatin- versus carboplatin-based regimens in cisplatin-eligible patients with metastatic TCCU. Individual patient data were not available and progression and survival data were inconsistently reported. Therefore, the analysis focused on overall (OR) and complete response (CR). The Mantel-Haenszel method was used for combining trials and calculating pooled risk ratios (RR).

Results: A total of 286 patients with metastatic TCCU from 4 randomized trials (3 phase II and 1 phase III trial) were included. Chemotherapy regimens included MVEC (methotrexate, vinblastine, epirubicin, cisplatin) vs. MVECa (methotrexate, vinblastine, epirubicin, carboplatin), MVAC (methotrexate, vinblastine, doxorubicin, cisplatin) vs. MCAVI (methotrexate, carboplatin, vinblastine), MVAC vs. paclitaxel plus carboplatin, and gemcitabine plus cisplatin vs. gemcitabine plus carboplatin. Cisplatin-based chemotherapy was associated with a significant improvement in the likelihood of CR (RR=3.973 [95%CI: 1.562 – 10.110], p =0.004) and OR (RR=1.336 [95%CI: 1.043 – 1.712], p=0.025).

Conclusions: Cisplatin-based as compared with carboplatin-based combination chemotherapy significantly increases the likelihoods of both OR and CR, in patients with metastatic TCCU. In the absence of definitive phase 3 trials, these results support cisplatin-based regimens as the preferred first-line treatment for cisplatin-eligible patients with metastatic TCCU.

No significant financial relationships to disclose.

Defining “cisplatin ineligible” patients with metastatic bladder cancer

238

Background: Cisplatin-based chemotherapy is standard first-line treatment for patients (pts) with metastatic urothelial carcinoma (UC). However, a large proportion of pts with UC are considered “unfit” for cisplatin, leading to clinical trials designed specifically for cisplatin-ineligible pts, with substantial variability in eligibility criteria. A clear and consistent definition of pts “unfit” for cisplatin-based therapy will aid in the development of standard eligibility criteria.

Methods: We assembled a panel of GU medical oncologists and followed a three-fold approach. First, we surveyed 120 international GU medical oncologists. Subsequently, we reviewed the literature regarding ‘cisplatin ineligibility‘ in solid tumors. Finally, the panel reconciled the survey results and available literature and generated a consensus definition.

Results: Responses were received from 65/120 (54%) of those surveyed. The survey results are shown in the Table . Reconciling the survey results with the available literature, the panel recommended the following be used to consistently define pts with metastatic UC “unfit” for cisplatin-based chemotherapy for clinical trial purposes: (1) ECOG performance status of 2 and/or (2) creatinine-clearance < 60 ml/min and/or (3) CTCAE Gr ≥ 2 hearing loss and/or (4) CTCAE Gr ≥ 2 neuropathy.

Conclusions: Substantial variability exists in investigators' definitions of pts with metastatic UC “unfit” for cisplatin. A consensus definition is proposed for standardization of eligibility criteria.

[Table: see text]

No significant financial relationships to disclose.

Assessment of two prognostic risk group methods to predict outcomes with docetaxel-based therapy in men with metastatic castration-resistant prostate cancer (mCRPC)

185

Background: Threeprognosticrisk groups have been identified in men with mCRPC (good [GR]/intermediate [IR]/poor [PR]) based on 0-1, 2 or 3-4 factors (visceral disease, pain, anemia, bone scan progression). Prostate Cancer Working Group (PCWG)-2 defines clinical subtypes with visceral disease, bone metastases ± nodal metastases and nodal disease only. The prognostic ability of risk grouping or PCWG2 subtypes was evaluated in a large, independent phase II trial.

Methods: A randomized phase IItrial of 221 men with mCRPC that received docetaxel-prednisone (DP) + AT-101 (Bcl-2 inhibitor) or DP + placebo was retrospectively analyzed using Cox regression and χ2 tests. Additional outcomes, tests and measures of discriminatory ability were assessed and will be presented. Patients from both groups were combined for analysis, as no significant differences in outcomes were observed.

Results: 93, 81 and 38 men had GR, IR and PR disease. GR men were more likely than IR/PR men to be ECOG-PS 0 (48%, 27%, 21%) and had a lower median baseline PSA (63, 85, 193 ng/ml). Significant differences between risk groups were observed for progression-free survival (PFS, p=0.009) and overall survival (OS, p<0.001), while PCWG2 subtypes did not discriminate for these outcomes. Both risk groups and PCWG2 subtypes inconsistently predicted PSA declines (table).

Conclusions: Prognostic risk groups significantly distinguished between outcomes in men with mCRPC receiving DP-based therapy, while PCWG2 subtypes did not. Risk groups may enhance stratification of patients in randomized trials and enable tailored drug development. Prognostic models that incorporate tumor molecular features may improve discriminatory ability.

[Table: see text]

[Table: see text]

Association between radiographic response and overall survival in men with metastatic castration-resistant prostate cancer receiving chemotherapy

118

Background: In men with metastatic castration resistant prostate cancer (CRPC),the association of measurable tumor responses with overall survival (OS) is unknown. We retrospectively evaluated the TAX327 phase III trial to study this relationship.

Methods: Eligible patients for this analysis included those with WHO-defined measurable metastatic disease randomized to receive either docetaxel or mitoxantrone. OS was estimated using the Kaplan-Meier method and the prognostic relationship of WHO-defined radiologic response with OS was performed using Cox proportional hazards regression. Landmark analyses evaluated survival from baseline and 2, 3, 4 and 6 months after baseline.

Results: Four hundred and twelve patients enrolled on the TAX327 trial had measurable tumors. Thirty-seven patients exhibited a complete or partial objective response (CR/PR, 9.0%), 116 had stable disease (SD, 28.2%), 99 had progressive disease (PD,24%) and 160 (38.8%) did not have a post-baseline objective assessment. Partial responders demonstrated longer median OS (29.0 months) than patients with SD (22.1 months), or those with PD (10.8 months) or those who were not assessed (12.7 months). These results remained after landmark analysis. We found a significant association between ≥30% PSA declines and radiologic response, with ≥30% PSA declines occurring in all patients with CR/PR, 79.8% of patients with SD and 34.4% with PD. Radiologic response remained a significant but modest post-treatment prognostic factor for OS after adjusting for treatment, pain-response and ≥30% PSA-decline (p=0.009).

Conclusions: In men with metastatic CRPC and measurable disease receiving chemotherapy, objective tumor response was prognostic for OS, and appears to complement PSA assessment.

[Table: see text]

Antigen-specific immunity and tumor inflammation after vaccination with BPX-101, a drug-activated dendritic cell vaccine for metastatic castration-resistant prostate cancer (mCRPC)

176

Background: We report evidence of antigen-specific immunity and severe prostate cancer inflammation and necrosis after vaccination in patients enrolled in a phase I-IIa clinical trial of BPX-101, a drug-activated DC vaccine for mCRPC.

Methods: Twelve men with progressive, mCRPC were enrolled in a 3+3 dose escalation trial evaluating BPX-101 and activating agent AP1903. BPX-101, which targets prostate-specific membrane antigen (PSMA), was administered intradermally every 2 weeks for 6 doses, followed 24 hours after each dose by infusion of AP1903 (0.4 mg/kg). Injection site skin biopsies were performed after the fourth vaccination. T cells cultured from the skin biopsy ex vivo were stimulated with PSMA protein or control antigens, and were analyzed using Luminex microspheres for 30 inflammatory cytokines/chemokines. One patient (#1007) with an intact prostate developed lower urinary tract bleeding after the fifth vaccination and underwent a transurethral resection of bleeding prostate cancer tissue. Paraffin-embedded blocks were stained for hematoxylin and eosin (H&E). Immunohistochemical stains for CD3, CD4, CD8 and CD34 were also performed.

Results: Of 5 subjects with evaluable injection site biopsy results, all exhibited PSMA-specific immunity (3 TH1-biased and 2 TH2- biased). Subject 1007's injection site biopsy demonstrated a significant >10-fold increase in IFN-gamma and IL-2 after stimulation by PSMA, compared to stimulation by ovalbumin, consistent with induction of a strong PSMA-specific CTL or TH1-biased immune response. H&E stained resected prostate tissue demonstrated Gleason 8 (4+4) prostate adenocarcinoma exhibiting a severe inflammatory response, consisting of infiltrating plasma cells and CD4+ and CD8+ T cells. Large areas of necrosis were seen adjacent to inflamed prostate cancer tissue.

Conclusions: Vaccination with BPX-101 followed by AP1903 can induce a strong, PSMA-specific immune response. Furthermore, evidence of severe prostate cancer-specific inflammation and necrosis, associated with a strong PSMA-specific immune response has been observed after multiple doses of BPX-101.

[Table: see text]

A randomized, double-blind phase II trial of docetaxel plus prednisone (DP) combined with either AT101 or placebo for the first-line therapy of metastatic castration-resistant prostate cancer (CRPC)

125

Background: AT-101 (A), a small molecule oral inhibitor of the Bcl-2 protein family has broad preclinical activity including synergy with docetaxel (D). AT-101 has demonstrated activity alone and in combination with D in D-refractory patients with metastatic CRPC.

Methods: A randomized, double-blind, placebo-controlled phase II trial was conducted to compare the combination of DP with either A or placebo in chemo-naive men with progressive metastatic CRPC. A key requirement was progression (bone scan, RECIST or rising PSA ≥ 2 ng/mL) despite androgen deprivation. Stratification factors were pain and performance status. Patients received DP (75mg/m2 day 1; 5mg PO b.i.d.) Q 21 days (1 cycle) with either A (40 mg b.i.d.) or placebo PO on days 1–3. Radiological assessments were performed every 3 cycles. Primary endpoint was overall survival (OS) and 221 patients were planned for 110 events (80% power, HR 0.67, 1-sided alpha 0.1).

Results: 221 patients were randomized to ADP or placebo-DP and baseline factors were balanced. Efficacy outcomes (OS, PFS, PSA declines, disease control) were not significantly different ( Table ). In a subgroup of patients with poor-risk CRPC (n=34), efficacy endpoints appeared to favor ADP with a median OS of 19 months vs.14 months for placebo-DP. Grade 3/4 AEs that occurred with higher incidence in the ADP arm compared to placebo-DP included cardiac AEs (5% vs. 2%), lymphopenia (23% vs. 16%), neutropenia (47% vs. 40%), ileus (2% vs. 0%) and pulmonary embolism (6% vs. 2%).

Conclusions: The combination of AT-101 with DP in men with chemonaive metastatic CRPC was well tolerated but did not extend OS compared to placebo-DP. There was a potential benefit in a subset of high-risk patients.

[Table: see text]

[Table: see text]

Results of a phase I/II clinical trial of BPX-101, a novel drug-activated dendritic cell (DC) vaccine for metastatic castration-resistant prostate cancer (mCRPC)

132

Background: We report results of a phase I/II clinical trial of BPX-101, a drug- activated autologous DC vaccine targeting PSMA.

Methods: Men with progressive mCRPC following up to one prior chemotherapy regimen were enrolled in a 3+3 dose escalation trial evaluating BPX-101 and CD40 activating agent AP1903. BPX-101 was administered intradermally every 2 weeks for 6 doses, during the induction phase, and for nonprogressing patients, every 8 weeks for up to 5 doses during the maintenance phase. AP1903 (0.4 mg/kg) was infused 24 hours after each BPX-101 dose. Radiologic evaluation was performed every 12 weeks.

Results: Planned enrollment of 12 subjects has been completed, including 3 each at 4 × 106 and 12.5 × 106 cells/dose, and 6 at 25 × 106 cells/dose. All vaccine products were releasable. Median Halabi- predicted survival was 13.8 months. Two subjects went off protocol prior to the end of induction due to progression, 8 reached end of induction, and 2 are nearing completion of induction. Toxicities (e.g. injection site reactions) were generally mild. One high dose subject experienced a single acute cytokine reaction during infusion of AP1903 at the second vaccination, but continued induction without further drug-related adverse events. Notably, one post- docetaxel subject in the low dose cohort achieved a RECIST PR, and one chemo-naive subject in the mid-dose cohort with extensive visceral, nodal, and bone metastases experienced a RECIST CR with docetaxel-based chemotherapy after induction and maintains an undetectable ultrasensitive PSA (0.009 ng/mL) 10 months after enrollment. A third subject, in the high-dose cohort, experienced near complete elimination of multiple lung metastases with otherwise stable disease by the end of induction. Robust immune responses were seen in all three.

Conclusions: BPX-101 can be reliably manufactured and safely administered, followed by AP1903, at doses of at least 25 × 106 cells. Contrary to the observation that cancer vaccine therapy improves survival without short-term response, BPX-101-treated patients have experienced measurable disease responses, including near elimination of poor-risk visceral disease.

[Table: see text]

Phase II study of single-agent volasertib (BI 6727) for second-line treatment of urothelial cancer (UC)

253

Background: Polo-like kinase 1 (Plk1) controls multiple essential steps of mitosis. Volasertib (BI 6727) is a first-in-class, selective inhibitor of Plk1. In vitro, Plk1 depletion in cancer cells leads to activation of the mitotic checkpoint, prolonged mitotic arrest, and eventually apoptosis. No standard therapy exists for metastatic urothelial cancer (UC) progressing after initial chemotherapy. Thus, there is an urgent need for novel treatment options. Interim efficacy and tolerability results are presented from an open-label, single-arm, multi-center phase II trial of volasertib in patients (pts) with previously treated advanced UC.

Methods: Pts progressing after one prior systemic chemotherapy for locally advanced or metastatic UC or relapsing within 2 years of adjuvant/ neoadjuvant treatment received 300 mg volasertib (2-hour intravenous infusion) on day 1 every 21 days. If well tolerated, dose escalation to 350 mg in cycle 2 was encouraged. Primary endpoint was objective tumor response, defined by RECIST. The trial follows a modified Gehan-two-stage design with an early stopping rule based on the observed response rate of the first 20 pts receiving up to 4 courses of treatment. A minimum response rate of 10% (2/20) was required to recommend additional study.

Results: This trial is ongoing: 31 pts (median age 67) were treated between December 2009 and August 2010. All pts were eligible for interim safety/efficacy analysis. As of August 2010, 6 pts (19%) demonstrated a partial response, 7 pts (23%) had stable disease and 16 (52%) progressed between 3-6 weeks after study initiation. Thirteen (42%) pts remain on trial between 13-41 weeks (median time on trial 5 months) without disease progression. Major grade 3 or 4 adverse events (irrespective of drug relatedness) were neutropenia (10 pts, 32%), thrombocytopenia (7 pts, 23%), anemia (5 pts, 16%), hyponatremia (3 pts, 10%), dehydration (2 pts, 7%), and urinary tract infection (2 pts, 7%).

Conclusions: Single-agent volasertib was well tolerated and demonstrates clinical activity in the second-line treatment of pts with advanced UC. The early signs of clinical benefit allows proceeding per protocol to the second stage of the trial.

[Table: see text]

Tissue-based molecular markers for bladder cancer

Bladder cancer is the second most common genitourinary malignancy in the United States, and is a major cause of morbidity and mortality. Despite aggressive treatment, survival for patients with muscle-invasive urothelial carcinoma of the bladder remains poor. Cancer stage, grade, and other clinical and pathological characteristics provide only limited prognostic information, and there is significant heterogeneity in patient outcomes using current risk stratification. Recent research into the profiling of bladder cancer at the molecular level has begun to shed light on important mechanisms of pathogenesis, as well as providing a number of potential tissue markers. These may provide useful prognostic information and guide patient selection for therapeutic strategies. This review explores recent advances in tissue-based molecular markers in bladder cancer and their potential utility. We also discuss design and statistical consideration for development and validation of molecular markers. A combination of complementary and yet independent molecular markers will likely better capture the biologic potential of each individual bladder tumor resulting in improved clinical decision-making.

Bortezomib as brief neoadjuvant therapy for localized high-risk prostate cancer (PCa) followed by radical prostatectomy (RP)

5127

Background: Neoadjuvant therapy may provide an important paradigm for the discovery of active agents for the therapy of PCa. Bortezomib is a proteasome inhibitor with preclinical activity in PCa. A rationale can be made to study brief preoperative bortezomib before RP to determine feasibility and biologic activity. Methods: A phase II trial was designed to evaluate bortezomib 1.6mg/m2 as intravenous bolus weekly for 4 weeks followed by RP 24–72 hours after the last dose. Histological evidence of adenocarcinoma of the prostate was required with clinical stage T1c or T2a with Gleason 8–10 disease, or clinical stage T2b-T2c with Gleason grade 7 and PSA of >10 ng/mL, or clinical stage T3. Results: Accrual is complete with 40 patients enrolled, of whom 38 completed neoadjuvant bortezomib followed by RP and are evaluable. The median age was 60.2 years. No pathologic complete responses were noted. Cytopathic effects (cytolysis, nuclear pyknosis) were commonly seen compared to baseline tumor. Upregulation of apoptosis, proliferation and phosphorylated (p)-Akt have been previously reported in a subset of patients by our group (Ayala GE et al, Clin Cancer Res. 2008;14:7511–8). Two of 8 evaluable patients had a >50% decrease in serum PSA with bortezomib treatment; 3 others had PSA declines of 14%, 25%, and 45%, respectively; 1 patient had no change, and 2 displayed PSA increases. Therapy was feasible with generally manageable toxicities, and surgical morbidities did not increase. A comprehensive toxicity analysis will be presented. Feasibility of surgery, extraprostatic extension, positive margin and lymph node positive rates will be compared with matched historical controls and these data will be presented. Conclusions: Bortezomib is feasible as neoadjuvant therapy preceding RP for PCa and demonstrates biologic activity. Given the upregulation of proliferation and pAkt, the further evaluation of bortezomib may be warranted in randomized trials in combination with chemotherapy or Akt inhibitors.

[Table: see text]

Preclinical antitumor and antiangiogenic activity of a metronomic schedule of cisplatin against human transitional cell carcinoma (TCC)

e16018

Background: Conventional cisplatin every 3 weeks is frequently precluded in patients with TCC due to renal dysfunction. A metronomic schedule of other chemotherapeutic agents demonstrates anti-angiogenic and anti-tumor activity coupled with better tolerability. A rationale can be made to preclinically evaluate the activity of a metronomic (weekly or 3 days a week) schedule of cisplatin in a preclinical system of TCC. Methods: The activity of cisplatin was assessed in vitro against HUVECs (human umbilical vein endothelial cells). MTT, flow cytometry with Annexin-FITC and scratch assays were employed to assess proliferation, apoptosis and migration, respectively. The activity of cisplatin was evaluated in vivo in murine xenograft models of TCC. The subcutaneous xenografts included 5 × 106 RT4 or 5637 human TCC cells injected into 6- to 8-week-old female athymic BALB/c nu/nu mice. Cisplatin was administered 4 mg/kg IP (intraperitoneal) weekly for up to 6 weeks and compared with untreated mice. Then, 3 groups of tumor-bearing mice received either no therapy, cisplatin 6 mg/kg weekly or cisplatin 2 mg/kg for 3 days a week for up to 6 weeks. Tumor size is measured twice a week. Nephrotoxicity is assessed by serum creatinine and kidney histopathological examination. IHC (immunohistochemistry) of xenografts is performed to measure proliferation (ki-67), apoptosis (cleaved caspase-3) and angiogenesis (CD31). Results: Cisplatin demonstrated significant anti-proliferative, anti-migration and pro-apoptotic activity against HUVECs in vitro. Cisplatin 4 mg/kg weekly inhibited tumor growth, induced higher apoptosis and down-regulated angiogenesis and proliferation in vivo compared to controls. Results from the experiment comparing cisplatin 6 mg/kg weekly with 2 mg/kg 3 days a week (i.e. more metronomic, with potentially more anti-angiogenic and anti-tumor activity and less nephrotoxic) will be presented. Conclusions: A metronomic schedule of cisplatin inhibits tumor growth and demonstrates anti-angiogenic activity in a preclinical model of human TCC. The clinical evaluation of a metronomic schedule of cisplatin may be warranted.

No significant financial relationships to disclose.

Residual pathologic stage at radical cystectomy and risk stratification of patients with pT2N0 bladder cancer

5076

Background: We hypothesized that in patients with pT2N0 transitional cell carcinoma (TCC) of the urinary bladder, residual muscle-invasive disease at radical cystectomy (RC) may confer poorer outcomes than residual non-muscle invasive disease due to larger tumor volume and/or biologically more aggressive disease. Patients with high-risk pT2N0 disease may be candidates for trials of adjuvant therapy. Methods: Patients from the BCRC database with pT2N0 stage (N = 208) at TUR (transurethral resection) whose tumors were organ-confined at RC (≤pT2N0) were analyzed. T1N0 patients (N=33) with pT2 disease at RC were also examined in order to include all pT2 patients. None of the patients had received perioperative chemotherapy. The effect of residual pT-stage at RC on outcomes was evaluated in Kaplan-Meier, as well as in univariable and multivariable Cox-regression models. Covariates consisted of age, gender, grade, lymphovascular invasion, concomitant carcinoma-in-situ (CIS), number of lymph nodes removed, and the year of surgery. Results: Among baseline T2N0 patients, residual pT-stage at RC was pT0 in 24 (11.5%), pTa in 9 (4.3%), pCIS in 22 (10.6%), pT1 in 35 (16.8%), and pT2 in 118 patients (56.7%). The median follow-up was 50.1 months. The 5-year recurrence-free survivals of patients with residual pT0/pTa/pCis, pT1 and pT2 were 100%, 85% and 75%, respectively. The 5-year cancer-specific survival rates for the same patient cohorts were 100%, 93%, and 81%, respectively. In multivariable analyses, the effect of residual stage <pT2 at RC achieved independent predictor status for recurrence (adjusted HR 0.20; p = 0.002), as well as for cancer-specific survival (adjusted HR: 0.24; p = 0.02). Initial T1 patients who were pT2 at RC did not have statistically different outcomes compared to initial T2 followed by pT2 at RC. Conclusions: Patients with pT2N0 TCC of the urinary bladder with residual non-muscle invasive disease at RC have significantly better long-term outcomes compared to residual muscle-invasive disease. With further validation, these data may facilitate the risk-stratification of patients with pT2N0 disease and enable the selection of high-risk patients for trials of adjuvant therapy.

No significant financial relationships to disclose.

Phase II multicenter, two-stage study of E7389 in patients with hormone refractory prostate cancer with advanced and/or metastatic disease stratified by prior chemotherapy

15513

Background: E7389 is a synthetic macrocyclic ketone derivative of the marine sponge product halichondrin B. A unique tubulin depolymerizer, E7389 induces nonproductive tubulin aggregates and inhibits tubulin polymerization. E7389 has demonstrated activity in refractory breast cancer and non small cell lung cancer with response rates of 14.7% and 9.7%, respectively. E7389 inhibits the growth of prostate cancer cell lines, including those (DU145) with over-expression of beta-tubulin III, which may confer resistance to taxanes. Methods: Phase II Simon two-stage study explores the activity and safety of E7389 as monotherapy without concomitant steroids in patients with histologically proven adenocarcinoma of the prostate that has progressed despite maintained castration. Patients are stratified into two groups that are analyzed separately, including those who failed either no prior chemotherapy (except mitoxanthrone or estramustine) or no more than one prior regimen with a tubulin binding agent, such as docetaxel. E7389 1.4 mg/m2 is administered as a 2 to 5 minute bolus IV infusion on Days 1 and 8 of 21-day cycles. PSA measurements are obtained at the end of each cycle. The primary objective is to assess PSA response using Bubley criteria. Results: Thus far, 57 patients (37 taxane pretreated and 20 taxane naïve) have been treated. The median age is 71 (range 48–91) with 43% of patients over 75. A total of 160 treatment cycles have been given (median: 2; range: 2–7). Twelve study drug related serious adverse events have been reported in 9 patients: PE (2), melena (2), fever, neutropenia, febrile neutropenia, UTI, anemia, DVT, chest pain, and renal failure (1). Based on preliminary data, the taxane-treated group has 2 PSA responses in the first 21 patients, and the taxane-naïve group has 4 PSA responses in the first 14 patients, allowing both groups to progress to Stage 2 with further accrual. Conclusions: In patients with hormone refractory prostate cancer, there is some evidence of single agent activity for E7389 in taxane naïve and taxane pretreated patients with acceptable toxicity. Preliminary results of activity allow further recruitment to proceed.

[Table: see text]

Sunitinib malate is active and synergistic with cisplatin against human urothelial carcinoma in a preclinical model

15632

Background: Sunitinib malate is an oral, multitargeted tyrosine kinase inhibitor of VEGFRs, PDGFRs, KIT, RET, and FLT3, approved multinationally for the treatment of advanced RCC and imatinib-resistant or -intolerant GIST. Angiogenesis and plasma VEGF correlate with poor outcomes in human urothelial carcinoma. We designed a preclinical study to examine the efficacy of sunitinib malate alone and in combination with cisplatin against human urothelial carcinoma in vitro and in a murine xenograft model. Methods: The IC50 for sunitinib malate and cisplatin was determined separately against two human urothelial carcinoma cell lines (TCC-SUP and 5637). Sunitinib malate and cisplatin were also applied concurrently to determine activity of the combination. Immunohistochemical staining was performed to detect expression of VEGFR2 on the cell lines, and to measure modulation of this pathway by sunitinib by measuring phosphorylated (p)VEGFR2. Anti-tumor activity of sunitinib malate alone and in combination with cisplatin was determined in a murine xenograft model bearing 5,637 cells. Results: Both human urothelial carcinoma cell lines were found to express VEGFR2. Sunitinib malate displayed significant activity against both urothelial carcinoma cell lines in vitro at low nanomolar concentrations. Furthermore, sunitinib malate in combination with cisplatin was synergistic in vitro. We observed primarily cytostatic activity for sunitinib malate at both 20 mg/kg and 40 mg/kg orally once daily against a murine xenograft model bearing subcutaneous 5,637 cell tumors during 4 weeks of treatment. Anti-tumor activity of sunitinib malate in combination with cisplatin and correlative studies are being evaluated in the murine xenograft model. Conclusion: Sunitinib malate has anti-tumor activity against human urothelial carcinoma as a single agent and is synergistic in combination with cisplatin in vitro. Sunitinib also has significant efficacy in a murine xenograft model of human urothelial carcinoma. These results warrant further exploration of sunitinib malate as a single agent and in combination with cisplatin chemotherapy in human urothelial carcinoma.

No significant financial relationships to disclose.

Clinical experience with extended lymph node dissection during radical prostatectomy

14545

Background: The value of the extent of lymph node dissection at radical prostatectomy remains controversial. We report our experience with extended lymph node dissection in patients undergoing open radical prostatectomy. Methods: 201 consecutive patients with cT1c-cT3a prostate cancer who underwent open radical prostatectomy with an extended regional lymph node (LN) dissection of up to six packets (iliac, hypogastric, and obturator; right and left) by a single surgeon at The Methodist Hospital between July 2002 and April 2004 were studied. No patient was treated with adjuvant radiation or hormonal therapy before elevated PSA levels were observed. Ultrasensitive PSA (uPSA) using the 3rd generation Immulite assay (DPC) was performed periodically beginning at 6 weeks post operatively. A uPSA level ≥ 0.03 ng/mL and rising on at least one subsequent uPSA obtained at least six weeks later was classified as a biochemical recurrence (BCR). Results: The mean patient age was 59 years at the time of surgery (median, 59; range, 39 to 73 years). Median follow-up after surgery was 21 months (range 1–37 months). Gleason Score was ≤ 6, 7, and 8–10 in 37%, 53% and 10% of patients, respectively. Sixty-two patients had extra prostatic extension and 16 patients had seminal vesicle involvement. A total of 3125 pelvic lymph nodes were removed (per patient: mean, 15.64; median, 15; range 4–42). Of these 22 LN (0.71%) were positive in 11 (5.5%) patients. By specified region, 2/1775 (0.23%) of iliac nodes, 6/642 (0.93%) of hypogastric nodes and 9/708 (1.27%) of obturator nodes were positive. Of the 11 patients with positive LN, 3/11 (27.27%) had positive iliac nodes, 6/11 (54.54%) had positive hypogastric nodes, and 6/11 (54.54%) had positive obturator nodes. Using a very stringent definition of BCR in order to compensate for the relatively short follow-up period, the 2 year progression-free survival (PFS) for patients with at least one positive LN was 37.5%. Conclusions: Extended LN dissection may alter the biology of early nodal metastatic prostate cancer and lead to longterm PFS without additional therapy. A higher percentage of patients and nodes are positive in the hypogastric and obturator regions, supporting the rationale to include these with the iliac nodes when performing LN dissection.

No significant financial relationships to disclose.

Antileukemic activity of Flt3 ligand in murine leukemia

Flt3-ligand (Flt3-L) is an early acting costimulatory cytokine that has been shown to possess antitumor properties in murine solid tumor models. Flt3-L is a trans-membrane protein (tm) but can be proteolytically cleaved to a soluble form, which is also biologically active. In this study, the antitumor effect of both soluble and tmFlt3-L was evaluated in a mouse leukemia model. To mimic the multiorgan involvement characteristic of human leukemia, a factor-dependent cell line FDC.P1 was made leukemogenic by transfection with the human BCR/ABL gene. The resulting cell line, AW, expresses BCR/ABL RNA and protein. It maintains a similar in vitro growth rate as the parent cell line, but unlike the parent cell line, AW cells are factor independent and tumorigenic. Growth of FDC.P1 and AW cells are unaffected by the addition of soluble human Flt3-L to the culture medium. Also, AW growth is unaltered after transduction with a retroviral vector expressing the tm isoform of human Flt3-L (AW/tmFlt3-L). When 10(5) AW cells were i.v. injected into syngeneic DBA/2 mice, fatal leukemia developed in nine of nine (100%) mice within 4-6 weeks with involvement of the blood, bone marrow, spleen, and thymus. Systematic administration of soluble human Flt3-L (500 microg/kg/day) for 10 days protected mice from leukemia, with 11 of 17 mice tumor free at week 8 (64.7%) The tm isoform of Flt3-L also was protective. When 10(4) AW/tmFlt3-L cells were injected i.v. into mice, only 35.7% (5 of 14) developed leukemia versus 100% in control groups. Adoptive transfer of immunity was also demonstrated; T cells obtained from tumor-free animals conferred protection to 87% (seven of eight) naive mice challenged with AW cells. These results demonstrate that both soluble and membrane-bound human Flt3-L has antitumor activity in this leukemia model.

Phase II study of doxorubicin and paclitaxel as second-line chemotherapy of small-cell lung cancer: a Hoosier Oncology Group Trial

Forty-six evaluable patients with recurrent small-cell lung cancer were entered on a phase II Hoosier Oncology Group (HOG) protocol evaluating bolus doxorubicin 40 mg/m2 followed by paclitaxel 175 mg/m2 over 3 hours. Courses were repeated every 3 weeks for a maximum of 6 courses. Therapy was well-tolerated with grade III neurotoxicity in 5 patients (11%), grade III/IV emesis in 5 (11%), and grade III mucositis in 2 patients. One patient had grade IV myalgias and one patient had grade III cardiotoxicity. The main toxicity was myelosuppression. Twenty-nine patients (63%) had grade IV and 8 (17%) grade III granulocytopenia. Nine patients (20%) were hospitalized for granulocytopenic fever. There was no treatment-related mortality. Nineteen of 46 patients (41%) had an objective response, including 3 complete remissions. Two of 14 patients with refractory disease (progression less than 3 months after initial therapy) responded, compared to 17 of 32 (52%) with sensitive disease (progression beyond 3 months of initial chemotherapy regimen).

What to do when you discover testicular cancer. Helping patients overcome fear and choose treatment

As one patient put it after hearing his treatment options for a stage I testicular tumor, "If you're gonna have cancer, this is about as easy a road as you get." With recognition of the importance of orchiectomy, development of the nerve-sparing lymph node dissection procedure, and availability of modern chemotherapy regimens, testicular cancer has become one of the most curable neoplasms. In this article, two oncologists discuss types of testicular tumor, patient evaluation, disease staging, risk categorization, and treatment selection. A patient handout on self-examination follows.