Morphometric studies on treated and untreated heterotransplanted malignant tumours.

Short-term therapy effects on heterotransplanted tumours are important to know in order to study the action of anticancer treatment. They are, however, difficult to assess due to interference from such factors as edema, vascular swelling and necrosis. Non-invasive methods such as NMR can be of some use, but the applicability is limited since background noise from the host animal organism may confound measurements. We studied a series of Cisplatine-treated bladder carcinomas heterotransplanted to nude mice and their untreated controls in order to illustrate short-term chemotherapy effect. We applied simple unbiased morphometric methods on formalin-fixed and paraffin-embedded material in order to obtain an unbiased estimate of the volume of the whole tumour and the volume of vital tumour tissue on day 1 and day 3 after treatment, at which time no gross changes in tumour size were evident. Furthermore, we estimated the number of tumour cells in the tumours. The estimate was based on measurement of the mean nuclear volume and the nuclear volume fraction in combination with the measured volume of vital tissue in the tumour. The pronounced therapy effects seen in this experimental system may be of potential interest in monitoring effects at the clinic.