RESUMO
BACKGROUND: This study explored the impact of genetic polymorphisms in cytochrome P450 (CYP) enzymes and transporters on the plasma trough concentration of imatinib mesylate (IM) and clinical response in chronic myeloid leukemia (CML). PATIENTS AND METHODS: In total, 82 patients with CML who had been administered 400 mg IM daily for over 6 months were genotyped for 11 single-nucleotide polymorphisms in nine genes (CYP3A4, CYP3A5, CYP2C9, CYP2C19, CYP2D6, ABCB1, SLC22A1, SLC22A2 and ABCG2) using blood samples. The trough imatinib concentration and clinical responses were assessed 6 months after the initiation of IM therapy. RESULTS: The CC, CA and AA genotypes in ABCG2 421C>A gave significantly different frequencies for the major molecular response (MMR) (P = 0.02). However, no significant differences were found between the genotypes of the CYP enzymes and transporters identified in this study and the imatinib plasma trough concentrations and clinical response frequencies, except for the correlation of ABCG2 with MMR. CONCLUSIONS: The results of the present study may indicate that the ABCG 421C>A genetic polymorphism influences the MMR of imatinib in patients with CML.
Assuntos
Antineoplásicos/farmacocinética , Benzamidas/farmacocinética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Piperazinas/farmacocinética , Polimorfismo de Nucleotídeo Único , Pirimidinas/farmacocinética , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Adolescente , Adulto , Idoso , Hidrocarboneto de Aril Hidroxilases/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas de Transporte de Cátions Orgânicos/genética , Transportador 2 de Cátion Orgânico , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVE: This study was performed to assess the efficacy and safety profile of combination treatment with S-1 and cisplatin in patients with locally advanced squamous cell carcinoma of the head and neck. DESIGN: Eligibility criteria comprised: histologically confirmed squamous cell carcinoma of the head and neck; stage three or four disease with no evidence of distant metastasis; evaluable lesions; adequate organ function; age 20-80 years; and a performance status of two or less. Cisplatin was infused over one hour on day one (75 mg/m2) and S-1 was administered orally for 14 consecutive days (days two to 15). The dosages of S-1 were calculated according to the patients' body surface area: 50 mg twice a day (body surface area 1.5 m2). Each course was repeated every three weeks. After two courses, tumour response was evaluated by computed tomography and laryngoscopy. If a response was evident (either complete or partial), the patient received one more course of chemotherapy, before undergoing radical treatment such as radiotherapy or surgery. RESULTS: All 30 patients were assessable for toxicity, and 29 patients for treatment response. The overall response was 89.7 per cent (complete response: nine; partial response: 17). The two-year estimated overall survival rate was 79.2 per cent. Adverse reactions occurred 128 times during 81 courses in the 30 cases. The most common grade three to four adverse event was neutropenia, which occurred in eight patients. Cases of non-haematological grade three or four toxicity included nausea and vomiting in four patients, stomatitis in two and diarrhoea in one. CONCLUSION: S-1 plus cisplatin combination chemotherapy is effective against locally advanced squamous cell carcinoma of the head and neck, with only mild toxicity.
