Changes in plasma iron levels following Carboplatin administration.

Carboplatin-induced changes in plasma iron levels and the related erythropoiesis impairment were investigated in 32 neoplastic patients for a total of 64 courses of chemotherapy. Iron showed a significant increase over pretreatment levels starting from day 1 after carboplatin administration (p< 0.001). Return to pre-treatment levels was achieved on day 14. Hemoglobin decreased significantly on day 7 (p< 0.05) and further on days 14 and 21 (p< 0.001). In patients undergoing 3 consecutive cycles of chemotherapy, basal hemoglobin before the 2nd cycle was significantly lower than before the 1st (p< 0.05), whereas before the 3rd cycle the levels were similar to those before the 2nd. Hemoglobin time-course did not differ among the three cycles. No relationship was observed between maximum iron levels and hemoglobin at minimum levels, nor between pre-treatment hemoglobin levels and severity of chemotherapy-induced subacute anemia. These results suggest that neither pre-treatment hemoglobin nor the entity of iron increase are predictive of the need of blood transfusion. Moreover, the absence of correlation between iron increase and hemoglobin decrease suggests that the toxic block on erythroid maturation is not the only mechanism with which platinum compounds interfere with iron metabolism. It is possible that the bivalent platinum ion may displace competitively iron from its binding sites, either on proteins or on cells.