The expression levels of procalcitonin-20 and E-cadherin in lung cancer and their correlations with prognosis

Lung cancer metastasis is correlated with prognosis. Epithelial E-cadherin (EC) inhibits tumor invasion, and EC deficiency facilitates tumor metastasis. Protocadherin-20 (PCDH20) plays important roles in intracellular signal transduction and inhibits the growth and clonal formation potency of non-small cell lung cancer (NSCLC). This study measured PCDH20 and EC expressions in lung cancer tissues to investigate their relationship with prognosis. A total of 68 NSCLC patients were recruited during the period January 2013 to June 2015. Immunohistochemical (IHC) staining was used to measure PCDH20 and EC protein expressions to analyze their correlations with the cohort's clinical/pathological features. The Kaplan-Meier approach plotted survival curves, and the Cox ratio risk model was employed to conduct a multi-variate survival analysis. NSCLC tissues had 20.59% and 44.12% positive rates of PCDH20 and EC expression respectively, which were significantly lower than in adjacent tissues (58.82% and 61.76%, p<0.05). Protein expressions were correlated with TNM stage and lymph node metastasis (p<0.05) but not with the pathology subtype or tumor size. A Kaplan-Meier curve revealed 12.0 months of median survival time in the PCDH20-negative groups, as compared to the PCDH20-positive rate (20.0 months). The EC-negative patients also showed a shorter median survival span than the EC-positive groups (14.0 months vs. 23.0 months, p<0.05). The Cox regression analysis identified the TNM stage, differentiation grade, PCDH20/EC protein expression, and lymph node metastasis as independent prognostic factors for NSCLC (p<0.05). PCDH20 and EC may play important roles in NSCLC progression and might work as reference points for prognostic evaluation.