ALDH1 Expression and the Prognosis of Lung Cancer: A Systematic Review and Meta-Analysis

Heart Lung Circ. 2015 Aug;24(8):780-8. doi: 10.1016/j.hlc.2015.03.021. Epub 2015 Apr 3.


Purpose: Aldehyde dehydrogenase 1 (ALDH1) has been identified as a putative cancer stem cell (CSC) marker in lung cancer. However, the clinicopathological and prognostic value of this protein in lung cancer patients remains controversial. Thus, we performed a systematic review and meta-analysis of studies assessing the clinical and prognostic significance of ALDH1 expression in lung cancer.

Methods: An identification and review of publications assessing clinical or prognostic significance of ALDH1 expression in lung cancer until September 1, 2014 was undertaken. A meta-analysis was performed to clarify the association between ALDH1 expression and clinical outcomes.

Results: A total of 14 publications met the criteria and comprised 1926 cases. Analysis of these data showed that ALDH1 expression was not significantly associated with the patient age (OR = 0.82, 95% confidence interval [CI]: 0.45-1.50, P=0.52), tumour size (OR=0.68, 95% CI: 0.22-2.06, P=0.49), smoking status (OR=1.37, 95% CI: 0.85-2.22, P=0.19), or tumour grade (OR=1.65, 95% CI: 0.83-3.26, P=0.15). However, in the identified studies, ALDH1 expression was highly correlated with lymph node metastasis (OR=1.97, 95% CI: 1.16-3.34, P=0.01), tumour TNM staging (OR=1.68, 95% CI 1.28-2.22, P=0.0002), decreased overall survival (relative risk [RR]: 1.97,95% CI: 1.16-3.34, P =0.01) and decreased disease free survival (RR: 1.63, 95% CI: 1.01-2.64, P=0.05).

Conclusions: This meta-analysis shows ALDH1 expression in lung cancer is connected with decreased overall and disease free survival and thus marks a worse prognosis.

Keywords: Cancer stem cell; Disease-free survival; Meta-analysis; Overall survival; Prognosis.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Aldehyde Dehydrogenase 1 Family
  • Disease-Free Survival
  • Gene Expression Regulation, Enzymologic*
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Isoenzymes / biosynthesis*
  • Lung Neoplasms* / enzymology
  • Lung Neoplasms* / mortality
  • Lung Neoplasms* / pathology
  • Neoplasm Proteins / biosynthesis*
  • Neoplastic Stem Cells* / enzymology
  • Neoplastic Stem Cells* / pathology
  • Retinal Dehydrogenase / biosynthesis*
  • Survival Rate


  • Isoenzymes
  • Neoplasm Proteins
  • Aldehyde Dehydrogenase 1 Family
  • ALDH1A1 protein, human
  • Retinal Dehydrogenase