1. Department of Biochemistry and Molecular Biology, University of Granada School of Medicine, Granada, Spain.
2. Department of Thoracic Surgery, Virgen de las Nieves University Hospital, Granada, Spain.
3. Department of Statistics and Operative Research, University of Granada School of Medicine, Granada, Spain.
Novel biomarkers are required to improve prognostic predictions obtained with lung cancer staging systems. This study of 62 surgically-treated Non-Small Cell Lung Cancer (NSCLC) patients had two objectives: i) to compare the predictive value of T-stage classifications between the 6th and 7th editions of the Tumor, Node, and Metastasis staging system (TNM); and ii) to examine the association of Pkp1 and/or Krt15 gene expression with survival and outcomes. Multivariate and Kaplan-Meier survival analyses were performed, examining the relationship of survival with T-stage, recurrence, and TNM-stage (by each TNM edition) and with the single/combined expression of Pkp1 and/or Krt15 genes. Five-year survival rates only significantly differed as a function of T-stage in patients without recurrence when estimated using the 6th edition of the TNM classification and only in patients in pathologic TNM-stage IA using the 7th. Overall survival for patients with elevated expression of both genes was 13.5 months in those with adenocarcinoma and 34.6 months in those with squamous cell carcinoma. Overall survival was 30.4 months in patients with Pkp1 gene upregulation and 30.9 months in those with Krt15 gene upregulation. In conclusion, survival estimations as a function of T-staging differed between the 6th and 7th editions of TNM. Overall survival differed according to the expression of Pkp1 and/or Krt15 genes, although this relationship did not reach statistical significance.
Keywords: Survival, adenocarcinoma, squamous cell-carcinoma, non-small cell lung cancer, desmosomal plaque