Activity of Conventional Drugs in Head and Neck Cancer Xenografts

Abstract

Nude mice bearing human head and neck cancer xenografts were treated with 5 anticancer drugs that are active in patients with this type of tumour. Using maximum tolerated dose levels, bleomycin appeared to be the most active drug, with activity in 4/9 lines tested; a growth delay factor of more than 2 (GDF>2) was taken as criterion of activity. 5-Fluorouracil and cyclophosphamide gave only moderate responses (1 <GDF<2) in 4/7 and 4/6 of the lines, respectively. Methotrexate and cisplatin, tested in 11 and 10 lines, respectively, were minimally or not active in the lines investigated. The activity of cisplatin appeared to be dose dependent. In the past higher doses could be given, resulting in 5/6 responding lines. In 4 lines a direct comparison could be made between the two schedules: lines that did not respond to treatment with the present schedule did so in the past, when the higher total dose was used. The activity of methotrexate in the nude mouse is less than can be expected from clinical studies. The mechanism responsible for this lack of activity is discussed in relation to our recent results.