The potential relevance of epidermal growth factor receptor (EGFR) mutations to non-small-cell lung cancer treatment has recently been identified. We have examined the presence of EGFR mutations in Japanese and Spanish gefitinib-treated non-small-cell lung cancer patients. A total of 34 gefitinib-treated patients were screened, 18 from Japan and 16 from Spain.
View Article and Find Full Text PDFBackground: Platinum-based doublets are the standard chemotherapy for advanced non-small-cell lung cancer (NSCLC). Excision-repair cross-complementing 1 (ERCC1), xeroderma pigmentosum group D (XPD) and ribonucleotide reductase subunit M1 (RRM1) are essential to the repair of cisplatin DNA adducts. Multidrug resistance 1 (MDR1) has been related to antimicrotubule resistance.
View Article and Find Full Text PDFSingle nucleotide polymorphisms (SNPs) in the metabolic pathways of S-adenosylmethionine have been related to global hypomethylation and a lower number of hypermethylated CpG islands of tumor suppressor genes. Hypermethylation of checkpoint and DNA repair genes has been shown to be indicative of chemosensitivity. In the present study, we have examined the SNP of methylenetetrahydrofolate reductase (MTHFR) C677T, which affects DNA methylation patterns and is linked to elevated plasma homocysteine levels in 208 patients with gemcitabine/cisplatin-treated stage IV non-small-cell lung cancer (NSCLC).
View Article and Find Full Text PDFPurpose: Genetic analysis has shown that cell-free circulating DNA in plasma or serum of cancer patients shares similar genetic alterations to those described in the corresponding tumor. One of the most important alterations involved in carcinogenesis is aberrant promoter methylation. The interest in this field has grown due to the implementation of the methylation-specific PCR (MSP) assay.
View Article and Find Full Text PDFOnly about one third of non-small-cell lung cancer (NSCLC) patients respond to cisplatin-based chemotherapy. Cisplatin DNA adducts are commonly repaired through the nucleotide excision repair pathway. The study of rare inherited disorders such as xeroderma pigmentosum and Cockayne syndrome has disclosed that XP genes, including XPD, play an essential role in DNA repair, both in the global genomic repair and in the transcription-coupled repair pathways.
View Article and Find Full Text PDFBackground: In spite of the growing list of genetic abnormalities identified as being involved in DNA repair pathways that alter chemosensitivity in non-small-cell lung cancer (NSCLC) patients, translational assays have not yet been developed for use in individualized chemotherapy.
Methods: In metastatic NSCLC, no single cisplatin-based chemotherapy regimen has been shown to be superior to any other. Although these studies show a small survival tail at 3 years, the majority of patients had a median survival of 8 to 10 months.
Gene methylation and K-ras mutations were examined in tumor and paired serum DNA of 50 resected non-small-cell lung cancer patients. RASSF1A, death associated protein kinase and target of methylation-induced silencing were methylated in 17/50 (34%), 23/50 (45%) and 18/50 (35%) tumors, respectively, and in 17/50 (34%), 20/50 (40%) and 17/50 (34%) sera, respectively. Methylation in tumor and serum were closely correlated (P=0.
View Article and Find Full Text PDFPurpose: In glioblastoma multiforme (GBM), the cytotoxic effect of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and temozolamide is dependent on O(6) alkylation, which correlates inversely with expression of the DNA repair enzyme O(6)-methyl-guanine-DNA methyltransferase (MGMT). Thus, MGMT assessment can be useful in predicting response in GBM, but the scarcity of neoplastic cells limits the practicality of MGMT assessment in these tumors. Although GBM grows within the skull, we investigated the concordance of methylation in glioma tissue, and paired serum DNA and the potential correlation with response and time to progression.
View Article and Find Full Text PDFIn this review, we deal with six groups of cytotoxic drugs commonly used in the treatment of non-small cell lung cancer (NSCLC). Although there are many reviews of thymidylate synthase (TS) and antifolate inhibitors, in this article, we have tried to highlight aspects that are more important for medical oncologists to consider when treating NSCLC patients. There is compelling evidence that TS gene transcripts and TS polymorphisms could be used to decide which patients can best benefit from adjuvant chemotherapy approaches, especially in colorectal cancer, and not less importantly, to tailor chemotherapy in metastatic NSCLC when using drugs akin to fluorouracil, such as pemetrexed.
View Article and Find Full Text PDF