A phase III randomised trial of cisplatinum, methotrextate, cisplatinum + methotrexate and cisplatinum + 5-FU in end stage squamous carcinoma of the head and neck. Liverpool Head and Neck Oncology Group.

Superior localisation and imaging of radiolabelled monoclonal antibody E48 F(ab'), fragment in xenografts of human squamous cell carcinoma of the head and neck and of the vulva as compared to monoclonal antibody E48 IgG Summary Monoclonal antibody (MAb) E48 and its F(ab')2 fragment, radiolabelled with "'I, were tested for tumour localisation and imaging in nude mice bearing a squamous cell carcinoma xenograft line derived from a head and neck carcinoma (HNX-HN) or from a vulva carcinoma (VX-A431). MAb IgG or F(ab')2 fragments were injected in parallel and at day 1, 2, 3 and 6 or 7, mice were either scanned with a gamma camera or dissected for determination of isotope biodistribution. In HNX-HN bearing mice, E48 IgG as well as F(ab')2 showed highly specific localisation in tumour tissue. The mean tumour uptake (n = 4) expressed as the percentage of the injected dose per gram of tumour tissue (percentage ID/g) of IgG was 11.9% at day 1 and increased to 14.6% at day 6 whereas percentage ID/g of F(ab')2 was 7.2% at day 1 and decreased during subsequent days. Tumour to blood ratios (T/B) at day I were 1.2 for IgG and 13.6 for F(ab')2 and reached a maximum at day 6 with values of 6.4 and 54.2 respectively. In VX-A431 bearing mice, only E48 F(ab')2 showed preferential localisation in tumour tissue. At day 1, Percentage ID/g of IgG was 3.7 and T/B was 0.3, while percentage ID/g of F(ab')2 was 2.4 and T/B was 3.2. Percentage ID/g decreased after day I while T/B increased. In these experiments no preferential localisation of either isotype matched '251I-labelled control IgG or F(ab')2 was observed. In F(ab')2 injected HNX-HN bearing mice as well as VX-A431 bearing mice, tumours could be visualised at day 1 and 2 without any appreciable background activity. With MAb IgG this was also possible in HNX-HN bearing mice (but not in VX-A431 bearing mice) but only at day 3 and 6. These findings suggest that the superior tumour to non-tumour ratios render the E48 F(ab')2 fragment more qualified for specific targeting of radioisotopes to tumour xenografts in this experimental setting. Of all human neoplasms, squamous cell carcinoma (SCC) is one of the most common tumour types and represents the major histological type of neoplasm arising from head and neck, cervix, skin, and lung. The relative sensitivity of head and neck SCC for radiation therapy has led us to investigate …