Fresh explant culture of human tumours in vitro and the assessment of sensitivity to cytotoxic chemotherapy.

Ninety-seven fresh explants of human tumours have been cultured in vitro in an attempt to predict their sensitivity to subsequent cytotoxic chemotherapy. Only 3/26 solid ovarian tumours were cultured successfully although 12 of the 23 which failed to grow proved later to have benign histology. Of 10 solid tumours from other sites, only 2/4 renal tumours and one melanoma were successfully grown and tested in vitro. A higher success rate was achieved in culturing carcinoma cells of ovarian (10/22) and breast (10/22) origin from ascitic and pleural fluids. Using increase in cell number after 7 days' growth in vitro as the biological end-point, concentrations of cytotoxic drugs which are achievable in patients produced significant effects on some tumour explants. Detailed studies of serial subcultures in vitro from an ovarian tumour showed that large changes in chemosensitivity occur within about 2 passages, in vitro, so that sensitivity testing can only be carried out using fresh explants or their first subcultures if any possible correlation between in vitro cytotoxicity and in situ response is to be studied. Clinical effectiveness and in vitro chemosensitivity are compared for a limited number of patients with ovarian and breast carcinomata for whom follow-up information was available; no useful correlation was found.