Prognostic significance of Ki67 labelling in resected non small cell lung cancer

One hundred and eleven tissue samples of primary non small cell lung cancer obtained from patients undergoing radical surgery for resectable disease were investigated for the presence and distribution of Ki67 related antigen using an immunohistochemical technique, as a marker of the proliferative activity of the tumour. No correlation was seen between Ki67 expression and clinico-pathological variables (sex, age, histology, grading and pTNM stage) but disease-free survival was significantly lower in patients with higher Ki67 score (> 25% positive cells) at diagnosis (P < 0.03). Growth fraction evaluated by Ki67 labelling may provide a complementary prognostic parameter in non small cell lung cancer.