Growth Kinetics of Plasma Cell Myeloma2

Publisher Website
Google Scholar
Abstract
The plasma cell labeling index(es) (LI) of 128 patients with multiple myeloma at various stages of disease was compared as a function of tumor mass load and length of treatment. No significant differences in Ll were noted for patients with various degrees of tumor reduction. Patients observed during the first 3 months of treatment had significantly higher Ll than did untreated patients and those studied after longer intervals. In vivo cell-cycle analysis of myeloma cells by the halving time of the grain-count method failed to establish the length of the cell cycle but defined the length of S+G2 phases as being longer than 60 hours. Similar studies conducted in vitro defined a shorter combined length of S+G,2 phase. In 2 patients in whom continuous infusion with [3H]thymidine was performed, the generation time was established as 8 days. Both patients had similar initial Ll (5.7 and 6.6) but different growth fractions (19 and 47%). The measured tumor mass doubling time was much longer than the calculated one, suggesting the presence of considerable intrinsic cell loss (83 and 47%). These observations were summarized by a hypothetical two-compartment model for the growth kinetics of multiple myeloma.