The effect of methylprednisolone (MP) on the cell kinetic response to cyclophosphamide (CP) and Adriamycin (ADR) in C3H/HeL spontaneous mammary rumors and hematopoietic tissue was investigated. The [3H]deoxythymidine labeling index, the primer-dependent DNA polymerase labeling index (an estimate of tumor growth fraction), and the mitotic index were determined at various intervals after treatment. Treatment consisted of CP (200 mg/kg) on Day 0 plus ADR (2 mg/kg) on Day 1 with or without MP every 12 hr for 9 doses beginning on Day 2. In tumors treated with CP and ADR alone, changes in the kinetic parameters suggested proliferative recovery between Day 3 and 4 which coincided with bone marrow recovery. In tumors treated with CP, ADR, and MP, although the timing of the hematopoietic recovery was not affected by MP, the overshoot of the [3H]deoxythymidine labeling index on Days 3 and 4 was abolished. Proliferative recovery in the tumor was delayed until after cessation of MP treatments. Cell kinetic changes in the tumor after CP, ADR, and MP were used to design effective sequential chemotherapy which obviated the hematopoietic toxicity associated with sequential therapy designed from cell kinetic changes after CP and ADR alone.
|Original language||English (US)|
|Number of pages||4|
|State||Published - Oct 1 1979|
ASJC Scopus subject areas
- Cancer Research