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Query: UMLS:C0242379 (lung cancer)
 71,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemiological studies have indicated that reduced DNA repair capacity and increased DNA adduct levels are associated with increased risk of lung cancer. Nucleotide excision repair (NER) is the major pathway in humans for repairing DNA adducts induced by smoking-related carcinogens, such as benzo[a]pyrene diol epoxide. We hypothesized that genetically determined baseline expression level of genes involved in NER is associated with risk of lung cancer. In a pilot case-control study, we measured the relative expression levels of five NER genes [ERCC1, XPB/ERCC3, XPG/ERCC5, CSB/ERCC6 and XPC (ERCC, excision repair cross-complementing; CSB, Cockayne's syndrome complementary group B)] in phytohemagglutinin-stimulated peripheral lymphocytes obtained from 75 lung cancer patients and 95 controls using a newly developed multiplex RT-PCR assay. Cases and controls were matched on age, sex, ethnicity and tobacco use. The expression level of the beta-actin gene was used as an internal control for the relative quantitation. We observed a 12.2 and 12.5% decrease in the baseline expression levels of XPG/ERCC5 and CSB/ERCC6, respectively, in cases compared with controls. These differences were statistically significant (P < 0.01) when the median expression level in the controls was used as the cut-off point, the lung cancer patients were significantly more likely than the controls to have reduced expression levels of XPG/ERCC5 [odds ratio (OR), 2.32; 95% confidence interval (CI), 1.22-4.43] and CSB/ERCC6 (OR, 2.49; 95% CI, 1.28-4.84). There was also a dose-response relationship between reduced expression levels and increased lung cancer risk (trend test: P < 0.01). Our results suggest that individuals whose expression levels of XPG/ERCC5 and CSB/ERCC6 are reduced may be at higher risk of lung cancer.
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PMID:Reduced expression levels of nucleotide excision repair genes in lung cancer: a case-control analysis. 1091 Sep 54

A wealth of data indicates that certain genetic abnormalities can target specific cytotoxic drugs and intervene at an early step as a mechanism of resistance in the treatment of non-small-cell lung cancer. Therefore prescribing certain combinations of cytotoxic anticancer agents to a vast majority of these patients is futile. Genetic abnormalities have been found to be useful surrogate markers for response, particularly in colorectal cancer: thymidylate synthase mRNA and ERCC1 mRNA levels. In addition, beta-tubulin mutations may also confer paclitaxel resistance in patients. An important target to be explored for gemcitabine resistance is the assessment of a particular region in chromosome 11p15.5 wherein lies the ribonucleotide reductase gene that could affect gemcitabine metabolism. Shedding light on this genetic framework, several proposed customized chemotherapy studies could help validate the relevance of these markers.
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PMID:Novel approaches in the treatment of non-small-cell lung cancer. 1130 50

Non-small cell lung cancer (NSCLC) is a systemic illness. The majority of newly diagnosed patients depend on systemic chemotherapy to improve outcome. Among the new chemotherapeutic agents recently tested, paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) has shown convincing single-agent activity in advanced NSCLC. The two initial phase II studies using paclitaxel alone showed a 1-year survival rate of 40%, comparable to that seen with combination regimens. Paclitaxel/carboplatin is one of several standard regimens for patients with stage IIIB to IV disease. It is as effective as any other new agent/platinum combination studied to date; it is easy to administer and well tolerated. Identification of the molecular and genetic events involved in each step of tumor progression seems to be crucial both to understanding lung cancer and for the development of new pharmacologic compounds that target specific cellular processes affecting growth and proliferation. An innovative strategy is to combine established chemotherapy with these new compounds. Resistance to available chemotherapy drugs is the major obstacle to effective chemotherapy. Genetic abnormalities could play a role in outlining some patterns of chemoresistance. Acquired resistance to paclitaxel can be mediated by several mechanisms, including overexpression of p-glycoprotein, altered expression of beta-tubulin isotypes, intrinsic or acquired mutations in beta-tubulin, and expression of novel genes. Beta-tubulin mutations were recently identified in 33% of 49 NSCLC patients, none of whom had an objective response to paclitaxel treatment. Cisplatin resistance is associated with several molecular alterations, including overexpression of metallothionein and the mRNA level of the excision repair cross-complementing (ERCC1) gene. Early detection of circulating cancer cells in peripheral blood would enable more accurate lung cancer staging. Furthermore, sequential measurements of DNA concentration may be used to monitor the effects of therapy. Serum DNA can be used as a surrogate for detecting genetic abnormalities and as a potential guide for customizing treatment. We analyzed the presence of beta-tubulin mutations in serum DNA from NSCLC patients and from healthy individuals. Beta-tubulin mutations were detected in 42% of the 131 patients and in none of the control group. Several clinical studies are proposed to develop more customized approaches in lung cancer.
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PMID:Predicting response to paclitaxel/carboplatin-based therapy in non-small cell lung cancer. 1160 82

The results of cisplatin-based chemotherapy seem to have reached a plateau, and empirical approaches are targeting the inclusion of novel biological agents with different mechanisms of action, but their clinical benefit is still unknown. In preparing this review of cisplatin resistance, we posed two questions: Who are we writing for and why? We believe that medical oncologists should be involved in the reality of the growing list of genetic mechanisms of cancer and chemoresistance. Only by becoming familiar with these mechanisms will we be able to circumvent them. In this review, we provide some insight into DNA repair defects involved in non-small-cell lung cancer (NSCLC) and cisplatin effect. Some DNA repair genes, like ERCC1, have been shown to be crucial in predicting cisplatin resistance and can be used for tailoring cisplatin-based chemotherapy.
Lung Cancer 2002 Dec
PMID:DNA repair and cisplatin resistance in non-small-cell lung cancer. 1244 42

Detection of genomic differences predictive of drug response or resistance in individual patients may allow therapy to be customized to the characteristics of particular tumors. Preliminary findings are that non-small cell lung cancer patients overexpressing ERCC1 mRNA have lower response to cisplatin chemotherapy, while those overexpressing ribonucleotide reductase mRNA have limited benefit from gemcitabine. In addition, overexpression of beta-tubulin III and stathmin can influence the sensitivity to microtubule interacting drugs, like vinorelbine and paclitaxel. The introduction of biological agents which target highly specific intracellular pathways offers the promise of enhancing the efficacy of cytotoxic chemotherapy. Among many promising biological agents is the monoclonal antibody C225, which blocks the EGFR receptor. The addition of C225 appears to induce responses in a proportion of colon cancer patients refractory to 5-FU or irinotecan, supporting pre-clinical evidence of synergistic activity. It also appears from xenograft data that C225 enhances the sensitivity of tumors to radiation and docetaxel or the combination.
Lung Cancer 2002 Dec
PMID:Molecular markers and targeted therapy with novel agents: prospects in the treatment of non-small cell lung cancer. 1248 Jan 94

Common polymorphisms in DNA repair genes may alter protein function and an individual's capacity to repair damaged DNA; deficits in repair capacity may lead to genetic instability and carcinogenesis. To establish our overall understanding of possible in vivo relationships between DNA repair polymorphisms and the development of cancer, we performed a literature review of epidemiological studies that assessed associations between such polymorphisms and risk of cancer. Thirty studies of polymorphisms in OGG1, XRCC1, ERCC1, XPC, XPD, XPF, BRCA2, and XRCC3 were identified in the April 30, 2002 MEDLINE database (National Center for Biotechnology Information. PubMed Database: http://www.ncbi.nlm.nih.gov/entrez). These studies focused on adult glioma, bladder cancer, breast cancer, esophageal cancer, lung cancer, prostate cancer, skin cancer (melanoma and nonmelanoma), squamous cell carcinoma of the head and neck, and stomach cancer. We found that a small proportion of the published studies were large and population-based. Nonetheless, published data were consistent with associations between: (a) the OGG1 S326C variant and increased risk of various types of cancer; (b) the XRCC1 R194W variant and reduced risk of various types of cancer; and (c) the BRCA2 N372H variant and increased risk of breast cancer. Suggestive results were seen for polymorphisms in other genes; however, small sample sizes may have contributed to false-positive or false-negative findings. We conclude that large, well-designed studies of common polymorphisms in DNA repair genes are needed. Such studies may benefit from analysis of multiple genes or polymorphisms and from the consideration of relevant exposures that may influence the likelihood of cancer in the presence of reduced DNA repair capacity.
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PMID:Polymorphisms in DNA repair genes and associations with cancer risk. 1249 39

Cisplatin or carboplatin is commonly used with gemcitabine, docetaxel, paclitaxel, or vinorelbine as chemotherapy doublets in the treatment of advanced non-small-cell lung cancer (NSCLC). Several randomized trials have failed to identify major differences in survival between any of these doublets. This lack of evidence for improvement in survival with any chemotherapy regimen has created a tabula rasa where no more large randomized trials should be conducted without including a genetic analysis. Patients see survival as their major concern, and other considerations, such as cost and quality of life, are relegated to lower positions. Genetic alterations related to the transcription-coupled repair pathway of the nucleotide excision repair system (TC-NER) have revealed the subset of patients who are resistant to cisplatin. TC-NER involves genes that are deficient in rare inborn disorders such as Cockayne syndrome and xeroderma pigmentosum. For a long time, ERCC1 mRNA levels have been known to correlate with DNA repair capacity in various tissues. Levels of DNA cisplatin adducts in peripheral blood and buccal mucosa cells predict chemotherapy response, and high ERCC1 mRNA levels have been related to chemoresistance in ovarian cancer and in malignant lymphocytes from chronic lymphocytic leukemia. Moreover, in some instances, mRNA expression has been correlated with polymorphisms. Overexpression of ERCC1 correlates with poor survival in gemcitabine/cisplatin-treated NSCLC patients. An ongoing customized ERCC1-based chemotherapy trial has been designed based on this knowledge. Patients are randomized to the control arm of cisplatin/docetaxel or to the experimental arm, where docetaxel is combined with cisplatin or gemcitabine according to ERCC1 levels. To date, 86 patients have been included.
Lung Cancer 2003 Aug
PMID:Genetic testing for chemotherapy in non-small cell lung cancer. 1286 68

Only 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. XPD polymorphism and decreased expression of XP genes have both been linked to lower DNA repair capacity. ERCC1 overexpression has been associated with cisplatin resistance, and experimental evidence shows a close association between ERCC1 and XPD. In the present study, we have examined XPD polymorphisms at codons 751 and 312 in DNA isolated from peripheral blood in 39 patients with gemcitabine/cisplatin-treated locally advanced non-small-cell lung cancer Although no significant correlation was observed between XPD genotype and objective response, a trend toward better response was observed in patients with XPD polymorphism at codon 312. The map of the nucleotide excision repair pathway can be used to design translational research studies to identify and validate predictive markers of response to cisplatin, and the Spanish Lung Cancer Group has recently accrued 250 gemcitabine/cisplatin-treated NSCLC patients for a prospective assessment of XPD genotype
Clin Lung Cancer 2003 Jan
PMID:Assessment of nucleotide excision repair XPD polymorphisms in the peripheral blood of gemcitabine/cisplatin-treated advanced non-small-cell lung cancer patients. 1462 13

ERCC1 (excision repair cross-complementation group 1) and XPD (ERCC2, excision repair cross-complementation group 2) as genes have been known to be belonged to the nucleotide excision repair pathway and therefore related to DNA repair. Polymorphisms in these genes have been rarely evaluated in terms of predicting cancer patient survival. We investigated whether these polymorphisms have an effect on response to chemotherapy and survival in 109 patients with non-small-cell lung cancer treated with cisplatin combination chemotherapy. Polymorphisms of ERCC1 Asn118Asn (C --> T), XPD Lys751Gln (A --> C) and Asp312Asn (G --> A) were evaluated using a SNaPshot kit. As for chemotherapy response, treatment response did not show statistically significant differences between the wild genotypes and the variant genotypes for the ERCC1 and XPD gene. The median survival time of all patients was 376 days (95% CI, 291-488). As for survival rate according to the polymorphism of codon 118 in ERCC1, median survival time in patients showing C/C genotype was 486 days (95% CI, 333-x), which was significantly different from the 281 days (95% CI, 214-376) of patients with the variant genotype (T/T or C/T) (P = 0.0058). Using the Cox-proportional hazards model, the polymorphism of codon 118 in ERCC1, response to chemotherapy, weight loss and performance status effected overall survival significantly (P = 0.0001, 0.0001, 0.0028 and 0.0184, respectively). However, polymorphisms of codons 751 and 312 in the XPD gene did not affect patient survival (P = 0.4711 and 0.4542, respectively). Therefore, we suggest that the C/C genotype in codon 118 of ERCC1 is a surrogate marker for predicting better survival in non-small-cell lung cancer patients treated with cisplatin combination chemotherapy.
Lung Cancer 2004 Jun
PMID:Association between polymorphisms of ERCC1 and XPD and survival in non-small-cell lung cancer patients treated with cisplatin combination chemotherapy. 1514 May 44

The treatment of advanced non-small-cell lung cancer (NSCLC is based on the combination of platin and one of the following agents: taxanes, gemcitabine, vinorelbine or irinotecan. There are no significant differences in efficacy among these combinations suggesting that the maximum efficacy has been reached. In this review, we will consider the mechanisms of chemoresistance of the five groups of cytotoxic drugs commonly used in the treatment of advanced NSCLC as well as the clinical studies which have assessed the value of chemoresistance markers. Breast Cancer Related Protein (BRCP) expression has been related to irinotecan and cisplatin (CDDP) resistance. DNA repair capacity influences response to CDDP and ERCC1 gene stands out as a predictive marker of CDDP sensitivity. Preliminary studies indicate that high tubulin III and stathmin mRNA levels correlate with response to paclitaxel and vinorelbine and that high expression of class III tubulin by tumor cells assessed immunohistochemically in patients receiving a taxane-based regimen is associated with a poor response to chemotherapy, and a shorter progression-free survival. High expression levels of ribonucleotide reductase has also been related to response to gemcitabine. Uridine diphosphate glucuronosyltransferase isoform 1A1 (UGT1A1) genotype has been reported to be associated with time to progression and survival in patients treated with irinotecan. These data suggest that pharmacogenomic strategies may be used for developing customized chemotherapy in prospective studies. Adjuvant chemotherapy which had recently shown its usefulness in limited lung cancer represents another area of investigation for pharmacogenomic studies.
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PMID:Chemoresistance in non-small cell lung cancer. 1572 Feb 63


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