Commentary on "Prognostic effect of carcinoma in situ in muscle-invasive urothelial carcinoma patients receiving neoadjuvant chemotherapy."

BACKGROUND

Carcinoma in situ (CIS) is a poor prognostic finding in urothelial carcinoma. However, its significance in muscle-invasive urothelial carcinoma (MIUC) treated with neoadjuvant chemotherapy (NAC) is uncertain. We assessed the effect of CIS found in pretreatment transurethral resection of bladder tumor (TURBT) biopsies on the pathologic and clinical outcomes.

MATERIALS AND METHODS

Subjects with MIUC treated with NAC before cystectomy were identified. The pathologic complete response (pCR) rates stratified by TURBT CIS status were compared. The secondary analyses included tumor response, progression-free survival (PFS), overall survival (OS), and an exploratory post hoc analysis of patients with pathologic CIS only (pTisN0) at cystectomy.

RESULTS

A total of 137 patients with MIUC were identified. TURBT CIS was noted in 30.7% of the patients. The absence of TURBT CIS was associated with a significantly increased pCR rate (23.2% vs. 9.5%; odds ratio = 4.08; 95% CI: 1.19-13.98; P = 0.025). Stage pTisN0 disease was observed in 19.0% of the TURBT CIS patients. TURBT CIS status did not significantly affect the PFS or OS outcomes. Post hoc analysis of the pTisN0 patients revealed prolonged median PFS (104.5 vs. 139.9 months; P = 0.055) and OS (104.5 vs. 152.3 months; P = 0.091) outcomes similar to those for the pCR patients.

CONCLUSION

The absence of CIS on pretreatment TURBT in patients with MIUC undergoing NAC was associated with increased pCR rates, with no observed differences in PFS or OS. Isolated CIS at cystectomy was frequently observed, with lengthy PFS and OS durations similar to those for pCR patients. Further studies aimed at understanding the biology and clinical effect of CIS in MIUC are warranted.

Use of germ-line single nucleotide polymorphisms (SNPs) in drug transporters (ABCG2/ABCB1) and tubulin (TUBB4) to predict survival in patients with metastatic castrate-resistant prostate cancer (CRPC) receiving docetaxel

58

Background: Multiple treatment options now exist for metastatic CRPC patients (pts). Germ-line SNPs in docetaxel (D) transport, metabolism, binding site, and degradation genes may contribute to variability in outcomes observed in D treated CRPC pts.

Methods: Between 1/07 and 10/08, all PCa pts seen in the Indiana University Simon Cancer Center oncology clinics were approached for recruitment to the Prostate Cancer Genetic Risk Evaluation of SNPs Study (PROGRESS). Participants completed a demographic and clinical questionnaire and provided a blood sample. Only CRPC pts treated with D were included in this analysis. Germ-line DNA was analyzed for SNP genotyping on a 128-SNP chip using a TaqMan OpenArray GT Kit (Applied Biosystems). The chip included genes critical to D signaling, transport, and elimination with minor allele frequencies > 5%. Pts were followed for progression-free (PFS) and overall survival (OS). Univariable analyses were performed to identify significant associations between SNP genotype, clinical parameters, and PFS and OS outcomes.

Results: 60 pts with metastatic CRPC initiated on D enrolled. Demographics included: age (median) – 69 yrs, ECOG PS 0– 40%, prostate specific antigen (PSA) (median) – 129.9 ng/ml, PSA doubling time (median) – 1.8 months, visceral mets –25%. No clinical parameters were associated with PFS and OS. Significant SNP associations are summarized below.

Conclusions: Differences in germ-line ABCG2, ABCB1, and TUBB4 SNPs may contribute to variation in clinical outcomes in CRPC pts treated with D.

[Table: see text]

[Table: see text]

A double-blind randomized trial of docetaxel plus vandetanib versus docetaxel plus placebo in platinum-pretreated advanced urothelial cancer

LBA239

Background: Vandetanib (V) is a novel small-molecule inhibitor that targets key signaling pathways in cancer including VEGF and EGF. V in combination with docetaxel (D) was assessed in patients (pts) who received prior platinum-based chemotherapy for advanced urothelial cancer (UC).

Methods: Patients eligible for this randomized, multicenter, double-blind, investigator-initiated trial had metastatic UC after failure of prior platinum-based chemotherapy. Up to 3 prior therapies were allowed including paclitaxel. The primary objective was to determine whether once-daily oral V (100 mg) + D (75 mg/m2 IV q21 days) prolonged progression-free survival (PFS) vs. placebo (P) + D (80% power to detect 60% improvement in median PFS with 1-sided α=0.05). Patients on D+P, had the option to cross over to single agent V. Overall survival (OS), overall response rate (ORR), stable disease (SD), and safety were secondary objectives.

Results: One-hundred and forty-two pts were enrolled at 16 institutions, 68% men; median age 65y; ECOG PS 0/1: 52%/48%; visceral involvement: 66%. 80% of patients had ECOG PS 1 and/or visceral metastases. 44% of patients had 2 or more prior systemic therapies and 15% had prior paclitaxel. Baseline characteristics were balanced in both arms. Median PFS was 11.1 weeks (wks) for D+V arm vs. 6.9 wks for D+P arm (HR=1.04, p=0.92). Median OS was 25.4 wks for the D+V arm vs. 30.6 wks for the D+P arm (HR 1.21, p=0.35). ORR was 7.1% for the D+V arm vs. 11.1% for the D+P arm (OR=0.6, 90% CI [0.2–1.6]). SD or better rates were 50.0% vs. 37.5% on D+V and D+P, respectively. As of December 2010, 5 pts were on therapy and 70% of pts died. Median follow-up for pts still alive is 7.2 months. Treatment-related grade >3 toxicities for D+V arm was 60% vs. 36% for the D+P arm (p=0.055) and were generally manageable (grade 4, 14% vs. 11%). Grade >3 toxicities that were more commonly seen in the D+V arm were rash/photosensitivity (11% vs. 0%) and diarrhea (7% vs. 0%).

Conclusions: In this platinum-pretreated population of advanced UC, the addition of vandetanib to docetaxel did not result in a significant improvement in PFS, ORR or OS. Toxicities were greater but manageable.

[Table: see text]

Germ-line single nucleotide polymorphism (SNP) predictors of progression-free survival and overall survival in patients with advanced prostate cancer treated with androgen-deprivation therapy (ADT)

51

Background: Significant variation in response duration and overall survival exists among prostate cancer (PCa) patients treated with ADT. Germ-line SNPs affecting function of genes critical to hormone synthesis, transport, metabolism, binding sites, and degradation may contribute to variability in clinical outcomes observed in PCa patients treated with ADT.

Methods: Between 1/07 and 10/08, all PCa patients seen in the Indiana University Simon Cancer Center oncology clinics were approached for recruitment to the Prostate Cancer Genetic Risk Evaluation of SNPs Study (PROGRESS). Participants completed a demographic and clinical questionnaire and provided a peripheral blood sample. Only patients with confirmed ADT initiation dates were included in this analysis. Germ-line DNA was analyzed for SNP genotyping on a 128-SNP chip using a TaqMan OpenArray GT Kit (Applied Biosystems). The chip included genes critical to hormone signaling, transport, and elimination pathways with minor allele frequencies > 5%. Patients were followed for progression-free survival (PFS) and overall survival (OS) endpoints. Univariable analyses were performed to identify significant associations between SNP genotype, clinical parameters, and PFS and OS outcomes.

Results: 107 patients with PCa initiated on ADT enrolled. Demographics included: age (median)–69 yrs, prostate specific antigen (PSA) (median)–28.0 ng/ml, PSA doubling time (median)–4.9 months, biochemical/metastatic–25%/75%, concurrent anti-androgen therapy–44%. No clinical parameters were associated with PFS and OS. Significant SNP associations with PFS and OS are summarized in the Table.

Conclusions: Interpatient differences in hormone pathway germ-line SNPs may contribute to variability in clinical outcomes in patients treated with ADT.

[Table: see text]

[Table: see text]

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.

Androgen pathway constitutional polymorphism predictors of progression-free and overall survivals in advanced castrate-resistant prostate cancer (CRPC) patients treated with ketoconazole (KC)

54

Background: Recent trials have highlighted the clinical utility of second-line hormonal therapies for CRPC. KC, an oral inhibitor of CYP3A4 and CYP17, is commonly used in this setting. Germline SNPs in genes critical to hormone synthesis, transport, metabolism, binding sites, and degradation may contribute to variability in outcomes observed in KC treated CRPC pts.

Methods: Between 1/07 and 10/08, all PCa pts seen in the Indiana University Simon Cancer Center oncology clinics were approached for recruitment to the Prostate Cancer Genetic Risk Evaluation of SNPs Study (PROGRESS). Participants completed a demographic and clinical questionnaire and provided a peripheral blood sample. Only pts with initiated on KC were included in this analysis. Germline DNA was analyzed for SNP genotyping on a 128-SNP chip using a TaqMan OpenArray GT Kit. The chip included genes critical to hormone signaling, transport, and elimination pathways with minor allele frequencies > 5%. Pts were followed for progression-free survival (PFS) and overall survival (OS) endpoints. Univariable analyses were performed to identify significant associations between SNP genotype, clinical parameters, and PFS and OS outcomes.

Results: Between January 2007 and October 2008, 39 pts with CRPC initiated on KC therapy enrolled. Demographics included: age (median) – 70 yrs, prostate specific antigen (PSA) (median) – 13.0 ng/ml, PSA doubling time (median) – 2.9 months, metastatic –85%, ECOG PS 0– 74%. Age < 70 was associated with shorter PFS (p=0.010) and age > 70 was associated with shorter OS (p=0.030). SNPs significantly associated with PFS and OS are summarized in the table.

Conclusions: Interpatient differences in hormonal pathway germline SNPs may contribute to variability in clinical outcomes in pts treated with KC.

[Table: see text]

No significant financial relationships to disclose.

A phase II study of pemetrexed as second-line chemotherapy for the treatment of metastatic castrate-resistant prostate cancer (CRPC); Hoosier Oncology Group GU03-67

BACKGROUND

No standard therapy exists for post-docetaxel castrate-resistant prostate cancer (CRPC) patients. This trial aimed to determine the safety and efficacy of pemetrexed in post-docetaxel CRPC patients.

MATERIALS AND METHODS

CRPC patients with progression after docetaxel (Taxotere) therapy received pemetrexed (500 mg/m2) i.v. every 3 weeks. The primary end point was prostate-specific antigen (PSA) response. A pharmacogenetic analysis of the reduced folate carrier-1 gene (RFC1) G80A polymorphism was also carried out.

RESULTS

Forty-nine patients were enrolled: median age 68 years, median baseline PSA 72 ng/ml, and median Karnofsky performance status of 90. Grade 3 or 4 toxicity occurred in 20 (43%) and four patients (8%), respectively. Confirmed >50% PSA decline occurred in four patients (8%), stable PSA lasting at least 12 weeks in 10 patients (20%). A significant relationship was observed between time from prior docetaxel therapy and overall survival. Pharmacogenetic analyses of RFC1 G80A genotype frequencies showed no relationship between genotypes and clinical efficacy.

CONCLUSIONS

Pemetrexed treatment of CRPC patients after docetaxel therapy was associated with only modest clinical activity. Further investigation of pemetrexed as a single agent in a nonenriched CRPC population is unlikely to add significant clinical benefit over that seen with traditional second-line chemotherapy agents such as mitoxantrone.

A multicenter phase II study of cisplatin (C), gemcitabine (G), and bevacizumab (B) as first-line chemotherapy for metastatic urothelial carcinoma (UC): Hoosier Oncology Group GU-0475

5018

Background: Despite CG therapy, most metastatic UC patients die from their disease. Novel approaches are needed. Combining anti-angiogenic therapy with chemotherapy has improved outcomes in other malignancies, offering hope for similar improvements in UC patients. Methods: Metastatic or unresectable chemonaive UC patients (pts) with an ECOG performance status of 0–1 received C 70 mg/m2 iv d1, G 1,000–1,250 mg/m2 iv d1, 8, and B 15 mg/kg iv d1 on a q21d cycle for up to 8 cycles. Gemcitabine was reduced to 1,000 mg/m2 iv d1, 8 for all subsequent pts after 7 thromboembolic events were noted in the first 17 pts. The primary endpoint was progression free survival (PFS). The trial was designed to detect a 33% improvement in PFS from 7.5 months with traditional CG therapy to 11.25 months with CGB. Results: By December 2008, 45 pts were enrolled, with 43 evaluable for toxicity, 36 for response. Demographics include: 33 (77%) male, 10 (23%) female; median age 66 (Range: 41 - 78); 26 (60%) and 17 (40%) ECOG 0/1; 19 (44%) and 24 (56%) lymph node only / visceral metastases. PFS will be evaluated in May 2009 when all pts will have more than 6 month follow-up data. 14 (33%) and 6 (14%) pts experienced grade 3 or 4 hematologic toxicity (4 pts - thrombocytopenia, 2 pts - neutropenic fever). Grade 3 or 4 nonhematologic toxicity was observed in 24 (56%) and 9 (21%) pts (DVT/PE - 9 pts, CNS hemorrhage/proteinuria/hypertension - 1 pt each) Best RECIST response was: complete response 6 pts (17%, 95% CI 6–33%), partial response 18 pts (50%, 95% CI 33–67%); with overall response rate of 67% (95% CI 51–82%). Stable disease lasting at least 12 weeks was observed in 10 pts (28%, 95% CI 14–45%) and progressive disease in 2 pts (5%, 95% CI 1–19%). Conclusions: CGB demonstrates significant clinical activity in the first-line treatment of metastatic UC patients at the expense of considerable toxicity. The durability of disease control will be determined by assessment of PFS. A phase III trial to further define the toxicity risk vs. clinical benefit of bevacizumab addition to platinum-based doublets is planned in this population.

[Table: see text]

Second-line pemetrexed (P) for the treatment of hormone refractory prostate cancer (HRPC): A Hoosier Oncology Group phase II study—Preliminary analysis

4644

Background: We evaluated the efficacy and toxicity of pemetrexed in men with HRPC who had progressed on one prior taxane chemotherapy regimen. Methods: Patients with HRPC received P 500 mg/m2 IV d1 q21d cycle with B12 and folate supplementation until progression or dose-limiting toxicity. The primary outcome measure was PSA response rate (PSAr) defined as a > 50% decline from baseline PSA that was confirmed at least four weeks later. Pts were required to have documented PSA progression prior. If no metastatic disease, a PSA > 20 ng/dL was required. A two-stage Simon phase II design with early stopping rules is being utilized with a PSA response rate of 20% deemed to be clinically relevant. Results: Patient characteristics: To date, 21 of the planned 42 patients have been treated with a median age of 67 years (53–79), median baseline PSA 97.8 (0.7–754.3), and median Karnofsky performance status of 90 (70–100). Treatment Cycles: A total of 83 treatment cycles have been administered with a median of 3 cycles per patient (0–12). Toxicity: 6 of 21 (28.6%) patients experienced a total of 17 grade 3 events. Treatment related grade 3 events included thrombocytopenia (1), anemia (2), mucositis (1), rash (1), and fatigue (1). 3 of 21 (14.3%) patients experienced a total of 8 grade 4 events. Treatment related grade 4 events included neutropenia (2), thrombocytopenia (3), anemia (1), and neutropenic fever (1). Response: Best response observed included 4 PSAr (19.0%, 95% CI 2.2–35.8%), 8 stable disease (SD) (38.1%, 95% CI 17.3–58.8%) and 9 progressive disease (PD) (42.9%, 95% CI 21.7–64.1%). PSAr were maintained at 5, 12+, 5+, and 3+ weeks with sustained SD seen at 15, 12, 15, 21+, 18+, and 12+ weeks. Survival data is immature at this time. Conclusion: This preliminary analysis reveals that pemetrexed has met criteria to move into the second stage of the study and has an acceptable toxicity profile in this patient population.

[Table: see text]