Hydroxyurea modulates 5-fluorouracil antineoplastic activity in advanced head and neck carcinoma pretreated with chemotherapy.

After informed consent 21 patients with advanced head and neck cancer resistant to folinic acid/5-fluorouracil (FA/5FU + cisplatin) were treated with weekly FA/5FU plus low dose hydroxyurea (HU) to evaluate if HU could further modulate 5FU antineoplastic activity. Five patients achieved a partial response (23.8%) which was short-lived (mean duration 6.5 months). Three patients (14%) had stable disease and 13 (62%) progressed. Among responders, four patients had epidermoidal carcinoma and one had clear cell carcinoma. Treatment was well tolerated and 5FU-related toxicity was not apparently worsened by the addition of HU. The most frequent toxicities were nausea/vomiting (81%), diarrhea (52%) and leukopenia (57%). Grade 3 nausea/vomiting and leukopenia were recorded in only 19 and 9% of cases, respectively. One patient had grade 1 cutaneous toxicity and a second patient showed a hand-foot syndrome. These results suggest that HU may further positively modulate 5FU antineoplastic activity.