Histopathological characteristics predictive for growth of squamous cell carcinomas of the head and neck heterotransplanted to nude mice.

Human tumours heterotransplanted to nude mice vary both with respect to take rate and the rate of tumour line establishment, according to their histological type and between primary and recurrent tumours. The acceptance rate of squamous cell carcinomas of the head and neck is also thought to vary, according to their degree of differentiation and their site of origin. This provided the basis of the present analysis of different tumour characteristics predicting growth of squamous cell carcinomas of the head and neck. Eighty-five attempted heterotransplantations were analysed with respect to T-stage, site of origin, degree of differentiation, and a histopathological malignancy grading score based upon four tumour variables and four tumour-host variables. Of the 85 attempted transplantations, first passage was successful in 24 cases (28%), of which sixteen (19% of 85) resulted in established tumour lines. The frequency of established tumour lines was higher among T4 and poorly differentiated tumours (33% and 22%, respectively), than among less advanced or more differentiated tumours. Tumour size was a more crucial factor than degree of differentiation, and tumours of the oral cavity grew less readily than those from other sites. The take rate was strongly correlated to malignancy grading scores, increasing as they increased. The most predictive information was provided by tumour-host variables, of which vascular invasion and lack of lymphocytic response were the most important in this respect.