DOUBLE-CYCLE HIGH-DOSE CHEMOTHERAPY WITH PERIPHERAL-BLOOD STEM-CELLS AND HEMATOPOIETIC GROWTH-FACTOR SUPPORT IN PATIENTS WITH ADVANCED SOLID TUMOR - A PILOT-STUDY BY THE HONG-KONG BIOTHERAPY GROUP

Background. High-dose chemotherapy with autologous bone marrow transpl antation has been useful in some patients with advanced breast, lympho ma, or germ cell tumors. Double-cycle high-dose chemotherapy may be ab le to deliver an even higher total dose within a given time period. It is important to determine whether peripheral blood stem cells and hem atopoietic growth factors can diminish the hematopoietic toxicity of s uch a treatment. Methods. From November 1989 to May 1991, 14 patients were enrolled in two cycles of high-dose chemotherapy consisting of cy clophosphamide, 4.5 g/m2; cisplatin, 150 mg/m2; and etoposide, 900 mg/ m2 in each cycle. The first five patients received peripheral blood st em cells harvested from 8-10 leukaphereses during steady state. The ne xt nine patients, besides receiving peripheral blood stem cells mobili zed by growth factors, also received either granulocyte-macrophage col ony-stimulating factor (GM-CSF) at 250 mug/m2/day by two subcutaneous (s.c.) injections given 12 hours apart from day 6 until neutrophil rec overy or granulocyte colony-stimulating factor (G-CSF) at 200 mug/m2 a s daily s.c. injections. Results. For the first five patients, there w as a median of 14 days from the first day of absolute marrow suppressi on to neutrophil count exceeding 500/mul and a median of 15 days for a platelet count exceeding 20,000/mul. For the next nine patients, with the use of either G-CSF or GM-CSF, there was a median of 8 days for a neutrophil count exceeding 500/mul and and a median of 11 days for a platelet count exceeding 20,000/mul. Conclusion. With the use of perip heral stem cells and growth factors, high-dose chemotherapy could be g iven safely every 30 days with acceptable toxicity. A high complete re sponse rate was seen in patients with nasopharyngeal carcinoma and in patients with small cell and non-small cell lung cancer who either had not received previous chemotherapy or who had responded to previous c hemotherapy.