Changes in peripheral blood composition following single and repeated courses of intermittent cancer chemotherapy.

In fifteen patients treated for lung cancer with a combination of vincristine (VCR) (2 x 0.325 mg/kg), amethopterin (MTX) (3 x 0.4 mg/kg) and cyclophosphamide (CY) (30-50 mg/kg) at monthly intervals the peripheral blood parameters were determined every 2-4 days. The values of these parameters including neutrophils, lymphocytes, platelets, erythrocytes and reticulocytes decreased uniformly reaching the lowest level about the 11th day post each course of chemotherapy. Subsequently, by the 17th day, the values of all these parameters except the red cell count returned to the pretreatment levels. The only parameter whose nadir value was associated with known risk to the health was the absolute neutrophil count. The period of dangerous decrease of this count began on the 6th day and ended approximately on the 17th day after cyclophosphamide infusion. Repeated courses had no additive toxicity since the time interval between courses allowed for hematopoietic recovery. However, the gradual decrease in the red cell count was observed during intermittent chemotherapy.

Modified megathrombocyte index in the diagnosis of thrombopoiesis injury produced by cancer chemotherapy.

The border-line separating the normal platelet from the megathrombocyte was lowered from 2.5 microns, classically used, to 2 microns. This modification allowed more precise definition of normal frequency of megathrombocytes among platelets (megathrombocyte index--MI) which was 10-35%. The modified MI determination demonstrated the same kinetics of changes following the intensive cancer chemotherapy as the classical one and, moreover, enabled individual diagnosis of thrombopoiesis perturbation induced by chemotherapy which was not possible with the classical MI.

Critical evaluation of the usefulness of different reticulocyte parameters in monitoring the erythropoiesis reaction to cancer chemotherapy.

Eighteen patients with various solid tumors were treated with combination of vincristine and 30-50 mg/kg of cyclophosphamide. Prior therapy and in 1-3 day intervals these patients had determined in peripheral bloods: frequency of reticulocytes (%R), absolute reticulocyte count (ARC), corrected reticulocyte count (CRC), reticulocyte production index (RPI) and hematocrit (Ht). These studies have shown that the impairment of reticulocyte production is earlier diagnosed by RPI than ARC and CRC, and finally by %R. On the other hand, %R was the parameter which allowed for the earliest detection of the beginning of recovery post chemotherapy. It is concluded that the RPI is the parameter of choice for detecting the impairment of erythropoiesis during evaluation of new drugs and protocols of cancer chemotherapy.