Formalin-fixed, paraffin-embedded tissue sections of resected tumors from 90 patients were immunohistochemically studied to assess the prognostic value of proliferating cell nuclear antigen (PCNA) expression in non-small cell lung cancer. The individual tumors were classified into groups of high, moderate or low proliferative grade, and 38 (42.2%) patients had a high grade of proliferation. No statistically significant correlations were observed between PCNA grade and TNM status, pathological stage, resectability, histological type, degree of histological differentiation. Only vascular invasion significantly correlated with proliferative grade (p < 0.05). Survival analysis showed that patients with low proliferative grade tumors survived significantly longer (a 5-year survival rate of 83.3%) than those with high proliferative grade tumors (39.4%, p < 0.005). Cox's multivariate analysis revealed that PCNA grade was a significant prognostic determinant of survival. These results suggest that PCNA expression provides an independent prognostic variable for patients with non-small cell lung cancer and that it may be useful to consider this factor in treatment planning.</p
