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.