ABSTRACT
OBJECTIVE: To examine germline single nucleotide polymorphisms (SNPs) as markers of response to gemcitabine platinum (GP) combination chemotherapy in urothelial carcinoma (UC). METHODS: Saliva or blood was prospectively collected from 216 patients treated with GP for UC of the bladder between 1991 and 2011. Based on reported associations with gemcitabine and cisplatin response or putative mechanisms of gemcitabine or cisplatin/carboplatin activity, we selected SNPs of interest and were able to genotype 59 SNPs (using the SequenomMass ARRAYiPLEX platform) in 261 patients randomly split 2/3 into a training set (n = 174) and 1/3 into a test set (n = 87). Logistic regression was used to test the association between response to GP and SNPs. RESULTS: The median age at diagnosis was 64 years (range: 28 - 85) for the discovery set and 67 years (range: 30 - 84) for the validation set. Males composed 76% and 69%, and white non-Hispanics composed 88% and 91% of the training and test validation sets, respectively. Three SNPs on GALNTL4 (rs7937567, rs12278731, and rs9988868) and one intergenic SNP (rs1321391) were significantly associated with response to GP in the training set and were used to build a SNP score. However, when assessed in the test set, the SNP score was not significantly associated with response. CONCLUSION: Multiple SNPs selected from previous studies failed to predict response to GP in this cohort. Larger studies capable of accounting for population-based allele frequency heterogeneity may be required for replication of genetic alterations important to pharmacogenomics.â©.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics , Carboplatin/pharmacokinetics , Carcinoma/drug therapy , Cisplatin/pharmacokinetics , Deoxycytidine/analogs & derivatives , N-Acetylgalactosaminyltransferases/genetics , Pharmacogenomic Variants , Polymorphism, Single Nucleotide , Urinary Bladder Neoplasms/drug therapy , Urothelium/drug effects , Adult , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/blood , Carboplatin/administration & dosage , Carboplatin/adverse effects , Carcinoma/genetics , Carcinoma/pathology , Cisplatin/administration & dosage , Cisplatin/adverse effects , Cisplatin/blood , Deoxycytidine/administration & dosage , Deoxycytidine/adverse effects , Deoxycytidine/blood , Deoxycytidine/pharmacokinetics , Female , Genotype , Humans , Introns , Logistic Models , Male , Middle Aged , Models, Genetic , N-Acetylgalactosaminyltransferases/metabolism , Pharmacogenetics , Phenotype , Prospective Studies , Treatment Outcome , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/pathology , Urothelium/pathology , Gemcitabine , Polypeptide N-acetylgalactosaminyltransferaseABSTRACT
UNLABELLED: What's known on the subject? and what does the study add?: No recent advances have been made in the treatment of patients with advanced bladder cancer and, to date, targeted therapies have not resulted in an improvement in outcome. The mammalian target of rapamycin pathway has been shown to be up-regulated in bladder cancer and represents a rational target for therapeutic intervention. In the present phase II study of everolimus, one near-complete response, one partial response and several minor responses suggest that everolimus possesses biological activity in a subset of patients with bladder cancer. To maximize benefit from targeted agents such as everolimus, the preselection of patients based on molecular phenotype is required. OBJECTIVE: To assess the efficacy and tolerability of everolimus in advanced urothelial carcimoma (UC). PATIENTS AND METHODS: The present study comprised a single-arm, non-randomized study in which all patients received everolimus 10 mg orally once daily continuously (one cycle = 4 weeks). In total, 45 patients with metastatic UC progressing after one to four cytotoxic agents were enrolled between February 2009 and November 2010 at the Memorial Sloan-Kettering Cancer Center. The primary endpoints were 2-month progression-free survival (PFS) and the safety of everolimus, with the secondary endpoint being the response rate. A Simon minimax two-stage design tested the null hypothesis that the true two month PFS rate was ≤ 50%, as opposed to the alternative hypothesis of ≥ 70%. RESULTS: The most common grade 3/4 toxicities were fatigue, infection, anaemia, lymphopaenia, hyperglycaemia and hypophosphataemia. There were two partial responses in nodal metastases, with one patient achieving a 94% decrease in target lesions and remaining on drug at 26 months. An additional 12 patients exhibited minor tumour regression. There were 23 of 45 (51%) patients who were progression-free at 2 months with a median (95% CI) PFS of 2.6 (1.8-3.5) months and a median (95% CI) overall survival of 8.3 (5.5-12.1) months. No clear association was observed between mammalian target of rapamycin pathway marker expression and 2-month PFS. CONCLUSIONS: Although everolimus did not meet its primary endpoint, one partial response, one near-complete response and twelve minor regressions were observed. Everolimus possesses meaningful anti-tumour activity in a subset of patients with advanced UC. Studies aiming to define the genetic basis of everolimus activity in individual responders are ongoing.