Pre-operative kinetic parameter determination of colorectal adenocarcinomas. Prognostic significance

Background The aim of this study was to test the prognostic value of pre-op erative assessment of tumour kinetics in colorectal adenocarcinoma. Methods The study of tumour kinetics was performed using an in vivo injecti on of bromodeoxyuridine. Endoscopic biopsies were obtained from the tumour and analysed using flow cytometry. This procedure enables calculation of th e in vivo S-phase fraction labelling index (LI), the duration of S-phase (T -s) and the potential tumour doubling time (T-pot). Disease-free survival c urves were calculated by a Kaplan - Meier method. The statistical significa nce between curves was tested by the log rank test. A multivariate analysis was performed using the Cox's proportional hazards model to determine the effect of pathological staging (lymph node involvement), ploidy and kinetic parameters. Results Thirty-eight colorectal carcinomas were studied without prior chemo therapy or radiation therapy. In univariate analysis, lymph node involvemen t, labelling index > 10% and T-pot < 5 days were associated with poor progn osis, with P = 0.0006, 0.049 and 0.029 respectively; no significant differe nces were found in T-s (P = 0.214), and ploidy (P= 0.095). In multivariate analysis, lymph node involvement, ploidy and T-pot were found to be indepen dent factors of colorectal cancer prognosis (P = 0.028, 0.032 and 0.035 res pectively) in all tumours, T-pot was considered a independent prognostic fa ctor in diploid tumours (P = 0.047) but not in aneuploid tumours (P = 0.345 ). Conclusions These results suggest that kinetic parameters determined by pre -operative biopsies of colorectal adenocarcinoma represent a prognosis fact or, independent of pathological staging, particularly in diploid tumours. f ur I Gastroenterol Hepatol 12:275 - 280 (C) 2000 Lippincott Williams & Wilk ins.