Combined analysis of MIB-1 and thyroid transcription factor-1 predicts survival in non-small cell lung carcinomas

The prognostic value of combined immunohistochemical analysis for the thyroid transcription factor-1 (TTF-1) and the proliferation marker MIB-1 was assessed in a consecutive series of non-small cell lung carcinomas (NSCLC). Tumor immunoreactivity for TTF-1 and MIB-1 was classified in three groups (−,+,++) and in two groups (−,+), respectively. Comparison across groups for TTF-1 reactivity showed significantly different survival curves (P=0.04). In particular, the best prognosis was associated with a TTF-1 negative pattern, whereas the TTF-1 ‘++’ cases showed the worst prognosis. A trend towards better prognosis was observed for MIB-1 negative cases (P=0.09). Multivariate analysis confirmed independent prognostic significance of TTF-1 (P=0.002), MIB-1 (P=0.01) and pStage (P=0.04). Accordingly, analysing TTF-1 and MIB-1 together, a better prediction of survival was obtained (P=0.02), with the poorest prognosis for the ‘TTF-1++/MIB-1+’ cases.