ERCC1 19007 Polymorphism in Greek Patients with Advanced Urothelial Cancer Treated with Platinum-Based Chemotherapy: Effect of the Changing Treatment Paradigm. A Cohort Study by the Hellenic GU Cancer Group

We previously showed that ERCC1 19007 C>T polymorphism was associated with cancer-specific survival (CSS) after platinum-based chemotherapy in patients with advanced urothelial cancer (aUC). We aimed to confirm this association in a different cohort of patients. Genotyping of the 19007C>T polymorphism was carried out by polymerase chain reaction (PCR) amplification and restriction fragment length polymorphism (RFLP) in 98 aUC patients, treated with platinum-based chemotherapy. Median age of the patients was 68.8, 13.3% of them were female, 90.8% had ECOG PS of 0 or 1, and 48% received cisplatin-based chemotherapy. In addition to chemotherapy, 32.7% of the patients received immunotherapy, and 19.4% vinflunine. Eighty-one patients (82.7%) were carriers of the 19007T polymorphic allele: 46 (46.9%) were heterozygotes, and 35 (35.7%) were homozygotes. The ERCC1 polymorphism was not associated with CSS, progression-free (PFS), or overall (OS) survival in the total population. Nevertheless, there was a significant interaction between the prognostic significance of ERCC1 polymorphism and the use of modern immunotherapy: the T allele was associated with worse outcome in patients who received chemotherapy only, while this association was lost in patients who received both chemotherapy and immune checkpoint inhibitors. Our study suggests that novel therapies may influence the significance of ERCC1 polymorphism in patients with aUC. Its determination may be useful in the changing treatment landscape of the disease.

Phase II trial of combination therapy with intravenous bevacizumab (B), oral satraplatin (S), and prednisone (P) in docetaxel-pretreated (DP) metastatic castrate-resistant prostate cancer (CRPC).

152 Background: Satraplatin is an oral platinum that has demonstrated efficacy and tolerability in metastatic CRPC. Bevacizumab has revealed safety and efficacy in advanced prostate cancer, and synergy was noted between platinum based chemotherapy and B. Methods: Primary endpoint was time to progression (TTP). Latter wasdefined per RECIST 1.0 or onset of a skeletal event, or > 2 new areas of bone metastases. DP metastatic CRPC patients were eligible. S 80mg/m2 orally on days 1-5, P 5 mg twice daily, and B 10mg/kg on day 1, and 15mg/kg on day 15 were administered in 35 day cycles. Results: 31 patients enrolled (13 African American and 18 Caucasian) to complete accrual. Median age was 67 years (range 50-85 years) and 21 patients (68%) were > 65 years of age. Median pretherapy PSA was 180.7 ng/ml (range 4.7-1,433 ng/ml). 21 (68%) had bone pain, Gleason score was > 8 in 20 (65%) patients. Pretherapy 12 patients had measurable disease progression, 17 (55%) had bone scan progression, and 8 had PSA only progression. 176 cycles have been administered; median 4 cycles (range 0-12 cycles). Grade 4 toxicities noted were, pulmonary embolism in 2 patients and thrombocytopenia in 1 patient. Grade 3 toxicities observed were neutropenia and hypertension in 3, anemia in 7 and , thrombocytopenia and diarrhea in 2 patients each. No treatment related deaths. 29 patients are response evaluable to date; 10 (34%) had a ≥30% PSA decline and 3 (10%) had a > 90% PSA decline. Of 12 patients with MD, 2 had a response and 7 had stable disease. Median TTP was 7.4 months (90% CI 4.8-12.8 months) and median survival was 11.2 months (90% CI 9.1-18.3 months). 47% of patients were alive at 12 months. Genotype characterization for excision repair cross-complementation group 1 (ERCC1) polymorphism was performed in 17 patients with 9 having homozygous (CC), 3 with heterozygous, (CT) and 2 patients with absence of ERCC expression respectively. Conclusions: The combination was tolerable and revealed promising efficacy in metastatic CRPC. ERCC1 testing will be correlated with outcome endpoints. Supported in part by Genentech Inc and GPC Biotech. [Table: see text]

ERCC1 polymorphism in patients with locally advanced head and neck squamous cell carcinoma treated with concomitant chemoradiation: Prevalence and impact on treatment efficacy

6032 Background: Excision repair cross-complementation group 1 (ERCC1) is a gene coding for the nucleotide excision repair complex. Its increased expression and polymorphism at codon 118 have been linked to poor response to chemotherapy or chemoradiation in several types of cancer. ERCC1 removes the cisplatin adducts on the DNA of cells and its polymorphism appears to be a marker of chemotherapeutic resistance to platinum-based therapy. Objectives: To determine the prevalence of the polymorphism of ERCC1 (codon 118) in patients with locally advanced HNSCC treated with concomitant platinum-based chemoradiation therapy with or without prior surgery, and its effect on eficacy evaluated by locoregional control, disease-free survival and overall survival. Methods: Prospective data on efficacy was available on 460 consecutive patients treated with concomitant chemoradiation in our institution with a minimal follow-up of 2 years. Of these, 230 fixed and paraffin embedded biopsies or surgical specimens were collected. DNA was extracted from specimens and polymorphism of codon 118 was determined using a PCR technique. All analysis were performed using Kaplan-Meier survival curves, Fisher's test for categorical data and log-rank statistics for failure times. Results: DNA extraction was successful in 222 patients. Polymorphism mapping was possible in 178 specimens. Genotypic distribution in the population was the following : AAT/AAT:40% (Gr1), AAC/AAT: 48%(Gr2), AAC/AAC: 12% (Gr3). At 3 years, evaluation of efficacy for Gr1, Gr2, and Gr3 was determined. Locoregional control was respectively 77%, 83%, and 67% (p = NS), DFS was 58%, 68% and 55% (p=NS), and OS was 70%, 69%, and 70% (p = NS). Conclusions: ERCC1 polymorphism did not have an impact in our population on response to chemoradiation therapy. It can be postulated that ERCC1 does not seem to discriminate patients for whom another treatment option should be sought for patients with locally advanced SCCHN. Further data will be presented at the meeting including a multivariate analysis using different markers tested in our laboratory (KRAS, MGMT methylation, etc). No significant financial relationships to disclose.