Krebs von den Lungen-6 (KL-6) is a prognostic biomarker in patients with surgically resected nonsmall cell lung cancer

Int J Cancer. 2012 Jan 15;130(2):377-87. doi: 10.1002/ijc.26007. Epub 2011 Apr 27.


By immunizing mice with a lung adenocarcinoma cell line, we previously established a murine IgG1 monoclonal antibody that recognizes a sialylated sugar chain designated Krebs von den Lungen-6 (KL-6). KL-6 is a high-molecular-weight glycoprotein classified as a human MUC1 mucin. The aim of this study was to determine whether KL-6 expression in tumors correlates with circulating KL-6 levels and whether circulating KL-6 has any prognostic value in patients with surgically resected non-small cell lung cancer (NSCLC). Immunohistochemical analysis of KL-6 expression was performed on 103 NSCLC tissues, and its associations with serum KL-6 levels and survival were examined. We also evaluated whether KL-6 expression patterns and/or serum KL-6 levels could predict prognosis in these NSCLC patients. Immunohistochemical analysis of KL-6 in NSCLC tissues showed that a depolarized KL-6 expression pattern was associated with a high level of circulating KL-6 and a poor prognosis in NSCLC patients who underwent curative surgery. Furthermore, a high circulating KL-6 level was associated with both poorer progression-free survival (PFS) and overall survival (OS), and multivariate analyses confirmed its independent prognostic value for both PFS and OS (p = 0.041 and 0.023, respectively). Our data suggest that preoperative serum KL-6 level reflects KL-6 expression patterns in NSCLC tissue, and can serve as a useful prognostic biomarker in NSCLC patients who undergo curative surgery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Biomarkers, Tumor / blood*
  • Carcinoma, Non-Small-Cell Lung / blood*
  • Carcinoma, Non-Small-Cell Lung / surgery*
  • Female
  • Humans
  • Immunohistochemistry
  • Lung Neoplasms / blood*
  • Lung Neoplasms / surgery*
  • Male
  • Mice
  • Middle Aged
  • Mucin-1 / blood*
  • Prognosis
  • Treatment Outcome


  • Biomarkers, Tumor
  • MUC1 protein, human
  • Mucin-1