RESUMO
Multiple myeloma is the most frequent indication for high-dose melphalan (HDM) chemotherapy with autologous stem cell transplantation (ASCT). Gastrointestinal symptoms represent the most significant nonhematological toxicity of HDM. However, specific, especially genetic, predictors of their incidence or clinical severity are lacking. The amino acid transporters LAT1 and LAT2 encoded by the SLC7A5 and SLC7A8 genes, respectively, are the principal mediators of melphalan uptake into cells. To determine whether genetic variability at these loci contributed to interindividual differences in the development of gastrointestinal complications of HDM, we analyzed single nucleotide polymorphisms (SNPs) in these genes in 135 patients with multiple myeloma treated with HDM and ASCT and correlated these with the need for total parenteral nutrition (TPN). Seven SNPs in SLC7A5 and 20 in SLC7A8 were genotyped. Multiple analyses indicated that 1 SNP in the first intron of SLC7A5, rs4240803, was significantly associated with TPN use (odds ratio = .45, 95% confidence interval, .25 to .79; P = .007). Further, every haplotype that correlated with TPN requirement included this SNP. These results suggest that variability in melphalan transport affects mucosal injury after HDM. This finding could help in individualizing the dose of this effective and widely used chemotherapeutic agent for multiple myeloma.
Assuntos
Antineoplásicos/efeitos adversos , Gastroenteropatias/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transportador 1 de Aminoácidos Neutros Grandes/genética , Melfalan/efeitos adversos , Mieloma Múltiplo/terapia , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Estudos de Casos e Controles , Terapia Combinada , Feminino , Gastroenteropatias/genética , Predisposição Genética para Doença , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Transportador 1 de Aminoácidos Neutros Grandes/metabolismo , Masculino , Melfalan/administração & dosagem , Melfalan/farmacocinética , Pessoa de Meia-Idade , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Mieloma Múltiplo/metabolismo , Polimorfismo de Nucleotídeo Único , Transplante AutólogoRESUMO
BACKGROUND: Although approximately 80% of hepatocellular carcinoma (HCC) cases occur in developing countries, the incidence of HCC in Western countries is on the rise due to the impact of hepatitis C. Challenges in developing effective therapies include the inherent chemoresistance of HCC, the pharmacologic challenges presented by a diseased liver, the presentation of most patients at advanced stages, and the difficulty in adequately measuring radiological response. While responses to traditional chemotherapeutic agents have been documented, significant survival benefit is debatable. METHODS: The authors review the results of published clinical trials of systemic therapy and immunotherapy that have impacted the present treatment of HCC. RESULTS: With recent progress in the elucidation of HCC molecular pathways, targeted agents show promise. The multikinase inhibitor sorafenib has provided survival benefit in patients with advanced HCC and well-preserved liver function. Sunitinib, bevacizumab, epidermal growth factor receptor inhibitors, and mammalian target of rapamycin (mTOR) inhibitors have shown activity in small patient cohorts. Immunotherapy appears to be a promising approach that can result in the regression of bulky, invasive cancer in some patients. CONCLUSIONS: New agents with a variety of mechanisms of activity offer promising therapeutic options for patients with advanced HCC.