Background: The administration of granulocyte-monocyte colony stimulating factor (GM-CSF) should allow an increase in the doses of chemotherapy for patients with advanced cancers of the head and neck.
Patients and methods: Eleven patients with histologically proven relapsed squamous cell carcinoma of the head and neck entered this Phase I study based on the combination of cisplatin (20 mg/m2/day for 5 days), escalating doses of 5-fluorouracil, both given by intravenous injection from day 1 to 5, and GM-CSF, 5 micrograms/kg from day 8 to day 19.
Results: The maximum tolerated 5-fluorouracil dosage was 300 mg/m2 i.v. bolus for 5 consecutive days q. 3 weeks. Thrombocytopenia was the limiting factor to further increase of 5-fluorouracil dosage. Moderate to severe stomatitis were quite rare despite the increased dose of the antimetabolite. GM-CSF was well tolerated: no significant local or systemic side effects attributable to this drug were recorded.
Conclusions: Adding GM-CSF to the combination of cisplatin and 5-fluorouracil allowed to increase 5-fluorouracil dose up to 50% over the conventional dosage. Further increase of the dose was precluded by the development of severe thrombocytopenia.