An analysis of spontaneous and chemotherapy-associated changes in skeletal osteosarcomas.

Microscopically assessed changes observed in large sections of osteosarcomas from patients who had undergone pre-operative chemotherapy (PCT) (n = 22), or no chemotherapy (n = 22), were examined either quantitatively, semiquantitatively, or qualitatively. Eight tumour characteristics were associated with the treatment mode by way of a stepwise logistic analysis. Minimal amount of viable tumour tissue (less than 10 per cent) and strong fibroblastic proliferation were each proved to be associated with PCT. These two variables in combination indicated a good response to PCT. The discrimination between PCT and non-PCT patients based on statistical analysis was superior to discrimination based on 'overall impression'.