A comparative study of proliferation-associated parameters in B-cell non-Hodgkin lymphoma.

The prognostic value of three proliferation-associated parameters, the frequency of cells in S-phase, mitotic index (MI) and serum deoxythymidine kinase levels (S-TK), was examined in 106 primary cases of B-cell non-Hodgkin lymphomas (NHL), 76 'low grade' NHL and 30 'high grade' NHL and compared with morphology and clinical variables. All three proliferation factors displayed large differences in the mean values of the two groups 'low grade' and 'high grade' NHL, and all revealed significant prognostic information. In 'low grade' NHL, the information decreased with follow-up time. A correlation (r = 0.7) was noted between S-phase values and MI but not between S-TK and the two others. In the entire patient material and in the two prognostic groups defined by morphology, S-TK gave the best prognostic information. MI gave better prognostic information than S-phase values in the whole material and in 'low grade' NHL, whereas the reverse appeared to be true for 'high grade' NHL. In the multivariate analyses, no other parameter apart from S-TK provided any further prognostic importance in the cases of 'high grade' NHL, whereas in that of 'low grade' NHL, MI, stage, age and histology had independent importance.