[Analysis of clinical responses in comparison with the results of the chemosensitivity test by subrenal capsule assay].

We attempted to examine the practicality and the usefulness of 6-day subrenal capsule assay (SRCA) as a predictive chemosensitivity test. The success rate of this assay was 81% in 150 cases of various cancers. The drug sensitivity was evaluated by the inhibition rate of tumor growth (TGIR) on day 6 after drug treatment without immunosuppression of mice. We analyzed the clinical response in comparison with the results of SRCA in 38 cases in which transplanted tumor showed over 1.0 tumor growth rate (TGR). The average TGIR in these cases attained CR, PR, MR, NC and PD clinically were 60, 60, 49, 53 and 40%, respectively. The TGIR of CR and PR cases were significantly greater than that of PD cases (p less than 0.05). These results in SRCA correspond to clinically observed responses, using a greater than or equal to 45% inhibition in TGIR to define 'sensitivity'. Of 26 patients sensitive in SRCA, 18 patients (69%) showed true positive and 75% of patients (12 cases) resistant in the assay also failed to respond clinically (true negative). In the cases with less than 1.0 in TGR, a correlation between clinical responses and TGIR was not found. Based on these results, 6-day SRCA without immunosuppresive procedures can be utilized as a predictive chemosensitivity test for cancers which can grow over 1.0 in TGR in this assay system.