The MTS assay as an indicator of chemosensitivity/resistance in malignant gynaecological tumours

The aim of this study was to use the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) (MTS) assay to determine the response of 17 endometrial and 27 cervical tumours to cytotoxic drugs. Tumour samples were taken at surgery and cultured using the explant technique. Cells were incubated with chemotherapy drugs. The MTS cytotoxicity assay was carried out to ascertain the response to the drugs and correlated retrospectively to the clinical outcome. Tumours of similar stage and grade displayed heterogeneity in their responses to the drugs. A total of 88 of 90 tumours (97.8%), including data from an earlier study of 44 ovarian tumour samples yielded chemosensitivity data. A total of 45 specimens were evaluable for in vitro–in vivo correlations. In vitro sensitivity was associated with clinical response in 26 of 30 patients and in vitro resistance with progressive disease or death in 14 of 15 patients. A randomised prospective trial should be carried out to validate chemosensitivity/resistance testing.