Adult acute lymphoblastic leukaemia: is cell proliferation related to other clinical and biological features?

Flow cytometry with propidium iodide and fluorescein isothiocyanate was used to study 46 cases of adult acute lymphoid leukaemia (ALL) before any form of chemotherapy. Cell proliferation was related to the other clinical and biological characteristics and its prognostic significance was evaluated. The following cell-cycle variables were determined: S, G2 + M, and the Low Protein Content fraction of G1 (LPC fraction). The L3 group, corresponding to B-ALL, had significantly higher proliferation than L1 and L2 (P less than 0.01). The proliferation rate was not significantly higher for T-ALL than for the other phenotypes. Complete remission was successfully induced significantly more often in cases with the LPC fraction under 50% (P less than 0.05). Failure was mainly related to resistance to chemotherapy. Of the four patients who died during aplasia, three had an LPC fraction below 25%. Duration of complete remission and survival were significantly shorter for L3 which is the most proliferative ALL (P less than 0.01). Survival was also found to be longer (P less than 0.05) when G2 + M was between 3.8% and 5.1%. This finding and the negative correlation between S and G2 + M (P less than 0.01) are discussed.