Author of

• 11454

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  P2.01 - Poster Session 2 - Cancer Biology (ID 145)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Biology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11478

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    P2.01-024 - Quantitative determination of EGFR gene aberrant methylation in non small cell lung cancer (NSCLC): a comparative analysis in tumor tissue, normal lung tissue, peripheral blood, sputum and bronchial aspirate. Correlation with clinical variables. (ID 1942)

    09:30 - 09:30  |  Author(s): R.L. Valenzuela
    • Abstract

    Background
    To evaluate and compare quantitatively aberrant methylation in the promoter area of EGFR gene in patients (p) with in non small cell lung cancer (NSCLC) lung tumor tissue (TT), lung normal tissue (NT), blood (B), bronchial aspirate (BA) and sputum (S). Correlate these methylation patterns with clinical variables.

    Methods
    DNA was extracted from samples of B, S and BA from patients with NSCLC prior to surgery and resected TT and NT. Methylation patterns were analyzed by the bisulfite conversion and subsequent pyrosequencing (QIagen PyroMark System). We analyzed three CpG islands in the promoter region of EGFR gene.

    Results
    43p were included, median age 66 years (range 46-79), 35 men and 8 women. Histology: 26p adenocarcinoma, 14 squamous and 3 others. 2p had EGFR mutation. Smoking status: 4p never smokers, 21p former smokers, 18p smokers. Significant differences in methylation percentage (%Mth) were observed between TT and S in the following islands: CpG2 (11.8vs7.1, p = 0.008), CpG3 (10vs7.4, p = 0.037) and in overall promoter area (10.6vs7. 6, p = 0.034). The %Mth was higher in women vs men in TT CpG1 island (16.2vs24.9, p = 0.042) and TT CpG2 island (15.8vs26.5, p = 0.013). The %Mth was higher in squamous histology compared to adenocarcinoma in NT CpG2 island (22.6vs14.1, p = 0.017) and S CpG1 island (13.7vs8.2, p = 0.047). However, the %Mth was higher in the overall promoter area of adenocarcinoma respect to squamous histology (19.7vs12.8 TT, p = 0.042). The %Mth was higher in overall promoter area of NT respect Stage I vs II vs III (22.3 vs 13 vs 17.5, p = 0.03). The %Mth was higher in former smokers compared to current smokers and non smokers in NT CpG3 (22.8 vs 13 vs 14.1, p = 0.032). The %Mth in NT CpG3 was higher in never smokers and former smokers > 5 years, respect to current smokers and former smokers <5 years, (23.3 vs 15.8, p = 0.05).

    Conclusion
    EGFR aberrant hypermethylation was higher in tumor tissue respect to sputum, with no correlation with EGFR mutation. The %Mth in normal tissue was higher in never smoker and former smokers > 5 years patients. * This study was funded by the Carlos III Health Institute (PS09/00308), Spain

• 12386

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  P3.02 - Poster Session 3 - Novel Cancer Genes and Pathways (ID 149)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Biology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 12397

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    P3.02-011 - Quantitative determination of methylation patterns in FHIT and APC genes in non small cell lung cancer (NSCLC): a comparative analysis in tumor tissue, normal lung tissue, peripheral blood, sputum and bronchial aspirate. Correlation with clinical variables. (ID 2011)

    09:30 - 09:30  |  Author(s): R.L. Valenzuela
    • Abstract

    Background
    Quantifying and comparing the degree of methylation in the promoter region of APC gene and coding region of FHIT gene in patients (p) with non small cell lung cancer (NSCLC) in different samples. Correlate these methylation patterns with clinical variables.

    Methods
    DNA was extracted from peripheral blood simples (B), sputum (S) and bronchial aspirate (BA), obtained from patients with NSCLC prior to the completion of surgery, as well as resected lung tumor tissue (TT) and normal lung tissue (TN). Methylation patterns were analyzed by bisulfito conversion and subsequent pyrosequencing (QIagen PyroMark System).We analyzed 5 CpG islands in the promoter region of the APC gene and 5 CpG islands in the coding region of the FHIT gene.

    Results
    We analyzed 20p, with a median age of 64 years (range 48-70), 16 men and 4 women. Smoking status: 2p never smokers, 11p former smokers, 7p current smokers. Histology: 10p adenocarcinoma, 9p squamous, 1p large cell. Stage: I 8p, II 8p, III 4p. No statistically significant differences were observed between the samples studied to any of the islands analyzed. The degree of methylation in TT CpG1 was higher in smokers and former smokers <5 years, compared to never smokers and ex-smokers >5 years, mean 4 (0-10) vs 0, p=0.022. There was no other difference when analyzing the degree of methylation as a function of the variables age, sex, smoking status, cumulative tobacco consumption, histological type and clinical stage. Respect FHIT gene, no statistically significant differences were found between the tissues studied respect to any of the CpG islands analyzed and like wise, no differences were observed when analyzed for degree of methylation depending on the clinical variables studied.

    Conclusion
    The area of ​​the APC gen promoter and FHIT coding region analyzed showed a low degree of methylation, with no significant difference observed between the samples studied. The degree of methylation in the TT CpG1 island of the APC gene was higher in current smokers and former smokers <5 years. However, these findings have to be confirmed in a larger sample. *This study was funded by the Carlos III Health Institute (PS09/00308), Spain.