Loss of PTEN expression is not uncommon, but lacks prognostic value in stage I NSCLC.

The PTEN gene is a tumor-suppressor gene that is inactivated in several types of human tumors. The loss of PTEN expression has been supported as a prognostic marker. Using immunohistochemical analysis, we retrospectively analyzed PTEN expression in specimens from 53 patients with completely resected stage I non-small cell lung cancer (NSCLC) for whom clinical follow-up data were available. Seven of the 53 specimens showed a total lack of staining for PTEN. No statistically significant relationship could be found between PTEN expression and clinicopathological parameters. Although genetic alterations of the PTEN gene are rare in NSCLC, loss of PTEN protein is not an uncommon event in early-stage NSCLC (13.2%). Here, we also report that the level of PTEN protein expression is not an independent prognostic marker in early-stage NSCLC.