Assessment of methylation status of locoregional lymph nodes in lung cancer using EBUS-NA

Clin Exp Metastasis. 2015 Oct;32(7):637-46. doi: 10.1007/s10585-015-9733-2. Epub 2015 Jun 29.

Abstract

Hypermethylation of the promoter region of tumor suppressor genes is associated with carcinogenesis in lung cancer (LC). Endobronchial ultrasound with needle aspiration (EBUS-NA) is a semi-invasive method for obtaining cell blocks from lymph nodes, which can be used for epigenetic analyses. To establish the relationship between methylation status of p16, DAPK, RASSF1a, APC and CDH13 genes in lymph nodes sampled by EBUS-NA, tumor staging and prognosis. Methylation status of DAPK, p16, RASSF1a, APC and CDH13 genes was assessed in EBUS-NA cell blocks from LC patients and related to stage and survival. Eighty-five consecutive patients [mean age 67 (SD 8)] were included. Methylation of ≥1 gene was found in 43 malignant nodes (67 %). A higher prevalence of RASSF1a methylation was observed in small cell lung cancer patients [9/10 (90 %) vs. 15/53 (28 %); p < 0.001 χ(2) test]. Methylation of APC and/or p16 was related to advanced staging in non-small cell lung cancer (NSCLC) [15/29 (52 %) vs. 6/24 (25 %), p = 0.048, χ(2) test]. Patients with NSCLC showing methylation of APC and/or p16 had also lower 6-month survival (p = 0.019, log rank test), which persisted after adjustment for age and subtyping (HR = 6, 95 % CI [1.8-19.5], p = 0.003, Cox regression). Epigenetic analyses are feasible in EBUS-NA cell blocks and may identify methylation patterns associated with worse prognosis. Methylation of p16 and APC genes in NSCLC patients was associated with advanced staging and lower 6-month survival.

Keywords: EBUS-NA; Lung cancer; Lymph nodes; Methylation; NSCLC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Bronchoscopy
  • Carcinoma, Non-Small-Cell Lung / genetics*
  • Carcinoma, Non-Small-Cell Lung / mortality
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cross-Sectional Studies
  • DNA Methylation*
  • Endoscopic Ultrasound-Guided Fine Needle Aspiration / methods*
  • Female
  • Humans
  • Kaplan-Meier Estimate
  • Lung Neoplasms / genetics*
  • Lung Neoplasms / mortality
  • Lung Neoplasms / pathology
  • Lymphatic Metastasis / genetics
  • Lymphatic Metastasis / pathology
  • Male
  • Middle Aged
  • Polymerase Chain Reaction
  • Proportional Hazards Models
  • Small Cell Lung Carcinoma / genetics*
  • Small Cell Lung Carcinoma / mortality
  • Small Cell Lung Carcinoma / pathology