Cytotoxic drug sensitivity of squamous cell carcinoma as predicted by an in vitro testing model.

An in vitro technique for testing the chemosensitivity of squamous cell carcinoma from the head and neck is described. Single-cell suspensions and tumor slices obtained from human xenografts were used. The sensitivity to cisplatin and bleomycin was quantified using the incorporation of (3H) thymidine as a parameter. The in vitro assays were compared with in vivo tests in mice. No reliable data could be obtained with cell suspensions of these tumors due to a rapid decrease in cell viability during incubation, while tumor slices revealed a stable control level of (3H) thymidine incorporation for up to 30 hours. In 6 out of 7 cases close agreement was found between the effect of the cytotoxic drug on the tissue slices and on the same tumors in nude mice.