Biological prognostic factors for early stage completely resected non-small cell lung cancer

The different and unpredictable outcomes in early-stage non-small cell lung cancer patients requires urgent research concerning the biological pathway of this neoplasm. Our study investigated the frequency of expression and the clinicopathologic and prognostic significance of a series of biological markers in stage I and II resected non-small cell lung cancer.

A total of 99 cases of pathologic stage I and II were analyzed. The mean follow-up of surviving patients was 41 months. The expressions of the following biological markers were tested: bcl-2, p53, Ki-67, angiogenesis, and tumor vessel invasion. Kaplan-Meier estimates of survival and time to recurrence were calculated for clinical variables and biological markers using Cox's model for multivariate analysis.

Tumoral vessel invasion was present in 22 (22%) pathologic samples, the angiogenesis mean value was 37 +/- 13, and median was 35; 13 (13%) patients showed positive immunostaining for bcl-2 oncoprotein. P53 oncoprotein expression was present in 48 patients (48.5%). All samples presented Ki-67 expression (mean value = 25.3 +/- 19.3, median = 20). The pathologic staging of the tumor was the most important independent prognostic factor for survival (P = 0.037) and for recurrence of disease (P = 0.040). Tumoral vessel invasion was the only marker with an independent predictive factor for survival and recurrence of disease in the group of patients without lymph node involvement (P = 0.02).

Our data do not support a relevant prognostic role for p53, bcl-2, or Ki-67 immunohistochemical markers in non-small cell cancer. Tumor vessel invasion was an independent predictive factor of poor outcome in the group of patients without lymph node involvement. Pathological stage was confirmed as the most important independent prognostic factor.