RESUMO
This narrative review describes implementation, current status and perspectives of a pharmacogenomic (PGx) program at the Brazilian National Cancer Institute (INCA), targeting the cancer chemotherapeutic drugs - fluoropyrimidines, irinotecan and thiopurines. This initiative, designed as a research project, was supported by a grant from the Brazilian Ministry of Health. A dedicated task force developed standard operational procedures from recruitment of patients to creating PGx reports with dosing recommendations, which were successfully applied to test 100 gastrointestinal cancer INCA outpatients and 162 acute lymphoblastic leukemia pediatric patients from INCA and seven other hospitals. The program has been subsequently expanded to include gastrointestinal cancer patients from three additional cancer treatment centers. We anticipate implementation of routine pre-emptive PGx testing at INCA but acknowledge challenges associated with this transition, such as continuous financing support, availability of trained personnel, adoption of the PGx-informed prescription by the clinical staff and, ultimately, evidence of cost-effectiveness.
Assuntos
Antineoplásicos/uso terapêutico , Órgãos Governamentais/tendências , Neoplasias/tratamento farmacológico , Neoplasias/epidemiologia , Testes Farmacogenômicos/tendências , Antineoplásicos/economia , Brasil/epidemiologia , Análise Custo-Benefício/economia , Análise Custo-Benefício/tendências , Órgãos Governamentais/economia , Humanos , Neoplasias/economia , Testes Farmacogenômicos/economiaRESUMO
Radiation therapy is routinely prescribed for high-grade malignant gliomas. However, the efficacy of this therapeutic modality is often limited by the occurrence of radioresistance, reflected as a diminished susceptibility of the irradiated cells to undergo apoptosis. Heat-shock proteins (Hsps) synthesis can be increased by cellular insults, such as radiation-induced damage. Inducible Hsp70 has been suggested to have multiple roles in cytoprotection against apoptosis. Accordingly, high levels of Hsp70 prevent stress-induced apoptosis. In the present study, we investigated whether the content of Hsp70 is associated to glioblastoma cell radioresistance. To this end, the U-87MG, U-251MG and MO59J human glioblastoma cell lines were irradiated at 2, 5 and 10 Gy and their relative radioresistance and Hsp70 were determined. Following 5 Gy irradiation, in MO59J and U-251MG a significant decrease in colony formation was found, whereas the U-87MG was relatively radioresistant. Three hours after the irradiation (at 5 Gy) Hsp70 contents increased 110% in the U-87 MG cells, but did not significantly change in the U-251MG and MO59J cells. Thus, our results suggest that Hsp70 protection against radiation-induced apoptosis might underlie glioblastoma radioresistance.
Assuntos
Glioblastoma/radioterapia , Proteínas de Choque Térmico HSP70/metabolismo , Tolerância a Radiação/fisiologia , Apoptose , Ciclo Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Células Tumorais Cultivadas , Regulação para CimaRESUMO
O etoposide é um inibidor da topoisomerase II capaz de produzir respostas objetivas em cerca de 10% das pacientes com câncer de mama metastático após a falha a esquemas convencionais. A administração oral de doses fracionadas de etoposide produz um aumento significativo do tempo de exposição dos tecidos em níveis terapêuticos deste agente, aumentando o seu índice terapêutico. Neste artigo, são descritos os resultados de um ensaio clínico de fase II com etoposide oral em doses fracionadas diárias em 20 mulheres com câncer de mama metastático refratário a múltiplos esquemas quimioterápicos. Foram elegíveis pacientes entre 18-75 anos de idade, desempenho clínico entre 0-2 (ECOG), diagnóstico histopatológico de câncer de mama, doença metastática visceral, sem disfunção de órgãosvitais e sem envolvimento do Sistema Nervoso Central (SNC). A assinatura de um documento de consentimento pelapaciente, segundo as normas da CONEP e do Comitê de Ética da Instituição, era condição necessária para inclusão.O conteúdo da ampola de etoposide para uso endovenoso foi administrado por via oral na dose de 20mg/m2 a cadaoito horas, diluído em veículo ácido (suco de laranja ou uva), diariamente por 14 dias, seguido de sete dias deintervalo. A cada 21 dias, as pacientes foram reavaliadas quanto à toxicidade (critério do NCI-CTC) e, a cada doisciclos (42 dias), quanto à resposta tumoral (critério da RECIST). As pacientes foram tratadas até a progressão, toxicidade limitante ou desejo próprio de interromper o tratamento. Foram incluídas 20 pacientes no estudo, tendo sido analisado um total de 55 ciclos de tratamento, com uma mediana de dois ciclos por paciente (1-10). Os efeitosadversos mais observados foram: náusea (36%), vômitos (24%), mucosite (16%) e neutropenia (14%). Neutropenia febril ocorreu em apenas um caso (2%). Não foram documentadas respostas objetivas. Entretanto, 9 pacientes apresentaram doença estável (45%), algumas com duração prolongada (30+, 21+ e...
Etoposide is an inhibitor of the nuclear topoisomerase II enzyme, which produces objective tumor responses inabout 10% of patients with metastatic breast cancer failing to standard chemotherapy regimens. Fractionatedoral administration of etoposide causes significant increase in tissue drug exposure, leading to a better therapeuticindex. In this paper, the outcomes of a Phase II trial of fractionated oral daily doses of etoposide conducted in20 women with metastatic breast cancer, who progressed following multiple chemotherapy regimens, are described. Eligible patients were those between 18-75 years old, ECOG performance status between 0-2, confirmed histopathological diagnosis of breast cancer, presence of visceral involvement, no vital organs dysfunction and no CNS involvement. A written informed consent was required, in accordance with the local IRB and theMinistry of Health of Brazil. The content of an ampoule for IV use was administered orally, at the dose of 20mg/m2, every eight hours, diluted in a low pH fluid (orange or grape juice), daily for 14 consecutive days,followed by a 7-day rest. Patients were reviewed every 21 days for toxicity (NCI-CTC criteria), and every 42days for tumoral response (RECIST criteria). Patients were treated until tumor progression, dose-limiting toxicityor own desire to interrupt the treatment. Twenty patients were included in the trial, and a total of 55 treatment cycles administered with a median of two cycles per patient (1-10) was evaluated. The most common side-effects were nausea (36%), vomiting (24%), mucositis (16%) and neutropenia (14%). Febrile neutropenia was documented in one case (2%) only. No objective response was documented. However, nine patients showed stable disease (45%), in some cases with prolonged duration (30+, 21+ and 18 weeks). The median duration of stable disease was 15 weeks (9-30+). In summary, this daily fractionated regimen of oral etoposide was welltolerated, producing...