Experience with GM-CSF in the treatment of solid tumors

The efficiency of GM-CSF to reduce myelosuppression after chemotherapy depends on the schedule of administration and the dose of chemotherapy. If conventional chemotherapy doses are given, a seven to ten day administration starting one day after the end of chemotherapy is able to reduce both degree and duration of leucopenia. A later onset is less effective, an earlier one aggravates leuco- and thrombocytopenia. The reduction of myelosuppression is accompanied by a reduction of infection rates and hospitalisation of patients due to these complications. If high-dose chemotherapy is given, GM-CSF does not markedly affect nadir values for leuco- and thrombocytes, but still shortens the duration of leucopenia. This effect is consistently seen after the initial cycles of chemotherapy, but seems to be less pronounced in later cycles. Thus, the growth factor administration allows a treatment intensification mainly by shortening of treatment intervals. Whether these modifications will improve the prognosis of patients with solid tumors is currently being investigated in small cell lung cancer in a German multicenter randomized trial.