Tumour cell kinetics as prognostic factor in surgically-treated-non-small cell lung cancer

The proliferative rate of tumour cells were studied in 80 non-small cell lung cancers (NSCLC) treated surgically at the Centre of Oncology in Kraków, between 1990 and 1996. There were 56 squamous cell carcinoma (SqLC) and 24 non-SqLC (18 adenocarcinoma (AcLC), three large cell carcinomas (LcLC), three mixed tumours). The proliferative potential of the tumour cells was studied on the basis of percentage of cells in the S-phase (S-phase fraction, SPF), proliferative index (PI, number of cells in S+ G2/M phases), bromodeoxyuridine labelling index (BrdUrdLI), and predictive potential doubling time (pred Tpot). Significant differences in the proliferating rate between histological groups of tumours were shown by the BrdUrdLI. The 5-year survival time for patients with higher proliferating tumours (BrdUrdLI > 4.1%, optimal cutoff level) was significantly higher (median survival time of > 60 months) than those with lower proliferative potential (BrdUrdLI < or = 4.1%) (median survival time of 19 months, P = 0.0091). SqLC patients had significantly better 5-year survival (median survival time of 47.5 months) than those with non-SqLC (median survival time of 18.5 months). Cox multivariate analysis showed that only higher proliferation of the tumour cells (BrdUrdLI > 4.1%), and lower clinical stage (I and II) were favourable prognostic factors in respect to patients' survival.