Analysis of the effect of prior therapy on progenitor cell yield: use of a chemotherapy scoring system

A quantitative analysis of peripheral blood stem cell (PBSC) yield, measuring absolute numbers of CD34(+) cellsx10(6)/kg and CFU-Cx10(4)/kg was performed in 74 consecutive patients. The interval or 'gap' from the end of previous chemotherapy to the dale of priming was recorded in weeks. Geometric mean CD34 and CFU-C values were significantly higher in patients with a score of less than or equal to 60 compared to those with score > 60 (P = 0.003 and 0.02, respectively) and a significant difference in CD34 Values was also found when scores of less than or equal to 38 were compared with scores > 38 (P = 0.003), with the difference in CFU-C values approaching significance (P=0.08). Patients exposed to toxicity factor 4 drugs had significant lowering of both CD34 and CFU-C Values (P<0.001 and P=0.038) and this emerged as the only independent factor when analysed using linear regression. No significant difference in the geometric mean CD34 or CFU-C values of patients was found in any of the gap categories analysed. Prior exposure to toxicity factor 4 drugs had a significant adverse effect on stem cell yield and should be avoided or minimized prior to stem cell harvesting.