Comparison of chemosensitivity of transplantable non-small cell bronchial tumours of rats in syngeneic hosts and in nude rodents.

Four transplantable poorly to well differentiated bronchial carcinomas, originally induced in the lungs of WAG/Rij and BN rats, were used to study their responsiveness to cytostatic drugs when growing in syngeneic hosts or in nude mice or rats. Growth delay was the endpoint determined. The responsiveness to drugs was specific for each tumour line and between tumours it was heterogeneous. In general, the same tumour specific pattern of response was observed regardless whether tumours grew in syngeneic hosts or in nude mice or nude rats. These results indicate that the stroma of the host does not contribute significantly to the response of the tumour, but that the intrinsic sensitivity of the malignant cells is the prevailing factor.