RESUMO
PURPOSE: Rapid advances in the understanding of cancer biology have transformed drug development thus leading to the approval of targeted therapies and to the development of molecular tests to select patients that will respond to treatments. KRAS status has emerged as a negative predictor of clinical benefit from anti-EGFR antibodies in colorectal cancer, and anti-EGFR antibodies use was limited to KRAS wild type tumors. In order to ensure wide access to tumor molecular profiling, the French National Cancer Institute (INCa) has set up a national network of 28 regional molecular genetics centers. Concurrently, a nationwide external quality assessment for KRAS testing (MOKAECM) was granted to analyze reproducibility and costs. METHODS: 96 cell-line DNAs and 24 DNA samples from paraffin embedded tumor tissues were sent to 40 French laboratories. A total of 5448 KRAS results were collected and analyzed and a micro-costing study was performed on sites for 5 common methods by an independent team of health economists. RESULTS: This work provided a baseline picture of the accuracy and reliability of KRAS analysis in routine testing conditions at a nationwide level. Inter-laboratory Kappa values were >0.8 for KRAS results despite differences detection methods and the use of in-house technologies. Specificity was excellent with only one false positive in 1128 FFPE data, and sensitivity was higher for targeted techniques as compared to Sanger sequencing based methods that were dependent upon local expertise. Estimated reagent costs per patient ranged from 5.5 to 19.0. CONCLUSION: The INCa has set-up a network of public laboratories dedicated to molecular oncology tests. Our results showed almost perfect agreements in KRAS testing at a nationwide level despite different testing methods ensuring a cost-effective equal access to personalized colorectal cancer treatment.
Assuntos
Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/economia , Testes Genéticos/economia , Proteínas Proto-Oncogênicas/economia , Proteínas Proto-Oncogênicas/genética , Proteínas ras/economia , Proteínas ras/genética , Anticorpos Monoclonais/uso terapêutico , Biópsia , Linhagem Celular Tumoral , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Fixadores , França , Testes Genéticos/métodos , Humanos , Metástase Neoplásica , Proteínas Proto-Oncogênicas/análise , Proteínas Proto-Oncogênicas p21(ras) , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Análise de Sequência de DNA/economia , Análise de Sequência de DNA/métodos , Inclusão do Tecido , Proteínas ras/análiseRESUMO
PURPOSE: The aim was to investigate whether germline polymorphisms within candidate genes known or suspected to be involved in fluorouracil (FU), oxaliplatin, and irinotecan pathways were associated with toxicity and clinical outcome in patients with metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: Blood samples from 349 patients included in the Fédération Francophone de Cancérologie Digestive 2000-05 randomized trial, which compared FU plus leucovorin (LV5FU2) followed by FU, leucovorin, and oxaliplatin (FOLFOX) followed by FU, leucovorin, and irinotecan (FOLFIRI; sequential arm) with FOLFOX followed by FOLFIRI (combination arm) in terms of progression-free survival (PFS) and overall survival, were collected. Twenty polymorphisms within the DPD, TS, MTHFR, ERCC1, ERCC2, GSTP1, GSTM1, GSTT1, and UGT1A1 genes were genotyped. RESULTS: The ERCC2-K751QC allele was independently associated with an increased risk of FOLFOX-induced grade 3 or 4 hematologic toxicity (P = .01). In the sequential arm, TS-5'UTR3RG and GSTT1 alleles were independently associated with response to LV5FU2 (P = .009) and FOLFOX (P = .01), respectively. The effect of oxaliplatin on tumor response increased with the number of MTHFR-1298C alleles (test for trend, P = .008). The PFS benefit from first-line FOLFOX was restricted to patients with 2R/2R (hazard ratio [HR] = 0.39; 95% CI, 0.23 to 0.68) or 2R/3R (HR = 0.59; 95% CI, 0.42 to 0.82) TS-5'UTR genotypes, respectively. Conversely, patients with the TS-5'UTR 3R/3R genotype did not seem to benefit from the adjunction of oxaliplatin (HR = 0.96; 95% CI, 0.66 to 1.40; trend between the three HRs, P = .006). CONCLUSION: A pharmacogenetic approach may be a useful strategy for personalizing and optimizing chemotherapy in mCRC patients and deserves confirmation in additional prospective studies.