The proliferative rate of tumour cells were studied in 80 non-small ce
ll lung cancers (NSCLC) treated surgically at the Centre of Oncology i
n Krakow, between 1990 and 1996. There were 56 squamous cell carcinoma
(SqLC) and 24 non-SqLC (18 adenocarcinoma (AcLC), three large cell ca
rcinomas (LcLC), three mixed rumours). The proliferative potential of
the tumour cells was studied on the basis of percentage of cells in th
e S-phase (S-phase fraction, SPF), proliferative index (PI, number of
cells in S + G(2)/M phases), bromodeoxyuridine labelling index (BrdUrd
LI), and predictive potential doubling time (pred T-pot). Significant
differences in the proliferating rate between histological groups of t
umours were shown by the BrdUrdLI. The 5-year survival time for patien
ts 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 less than or e
qual to 4.1%) (median survival time of 19 months, P = 0.0091). SqLC pa
tients 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 proliferat
ion of the tumour cells (BrdUrdLI >4.1%), and lower clinical stage (I
and II) were favourable prognostic factors in respect to patients' sur
vival. (C) 1997 Elsevier Science Ireland Ltd.