[Histological changes after chemotherapy of soft tissue sarcomas in the adult]

The variations of histologic patterns inside the primary tumor have been studied in 15 patients with locally advanced soft tissue sarcomas who were given induction (neo adjuvant) chemotherapy. Increase of tumor necrosis and decrease of tumor cellularity were the predominant aspects identified. The mitosis count tend to be lower, while the nuclear atypies and the number of giant malignant cells tend to increase. In 2 cases, a better tumor differentiation, attributable to the induction chemotherapy was noted. In 10/15 cases, it was concluded to a tumoricidal effect of the chemotherapy. According to tumor grade, 6 among 10 patients with grade III tumor presented a histological response (greater than 50 p. cent of tumor destruction) while none among 5 lesions of grade I or II exhibited a response of such a level. So, the histological study allows an evaluation of the response to chemotherapy which usefully completes the clinical appreciation, and that may be useful for the selection of postoperative adjuvant treatment, as it is in osteosarcomas.