Carstensen, H. and Tholander, B.

Chemosensitivity of ovarian carcinoma: In vitro/in vivo correlations using the dye exclusion assay of Weisenthal (meeting abstract). Division of Gynecologic Oncology, Uppsala University, Uppsala, Sweden

Proceedings: 3rd European Conference on Clinical Oncology, Stockholm: p. 206, 1985. (Cancerlit retrieval).

Aim: The reliability of the dye exclusion assay of Weisenthal for determining chemosensitivity of ovarian carcinoma was tested by correlating in vitro result with in vivo response. Material: Twenty-three patients have been tested. All have had prior chemotherapy. In 14 cases the assay was performed on solid tumor. Ascites was used in 6 cases and pleural effusions in 3 cases. Method: A cell suspension is prepared and dissociated cells are exposed to antineoplastic drugs for 1 hr (or continuously) and then cultured for 4 days in liquid medium. Cells are then stained with fast green dye and sedimented on to slides. Viable cells exclude fast green. Counterstaining with hematoxylin-eosin permits recognizing tumor cells. Cell kill is calculated. Four to six drugs were tested in each assay. Less than 30 per cent viable cells after drug-exposure was defined as in vitro sensitivity (positive,+). In vivo sensitivity (positive,+) was defined as CR or PR at second look, decreased ascites production or SD for more than 6 mo. In vivo resistance was defined as PD for at least 3 mo or increased ascites production. Result : Success rate of in vitro assay was 92 per cent. In two cases too few tumor cells were obtained. Twenty- two cases were evaluable for in vivo response. Retrospective correlations (in vitro/in vivo) in 12 cases showed 1 true positive (+/+) test, 3 false positive (+/-) tests 8, true negative (-/-) and no false negative (-/+) tests. Prospective correlations in 10 cases showed 5 true positive (+/+) tests, 1 false positive (+/-), 4 true negative (-/-) and no false negative (-/+) tests. Sensitivity of the assay was 100 percent. Predictive accuracy for a positive result was 60 per cent and for a negative result 100 percent. (Probability of a test result being correct). Specificity was 75 percent.

Editor's note: Hans Carstensen, M.D. was a Swedish gynecologic oncologist who, with his wife (a medical technologist), visited my laboratory at the Long Beach Veterans Administration Medical Center in the summer of 1983. He and his wife spent a week in our laboratory learning the assay methodology, and then returned to Sweden to establish a fresh human tumor culture laboratory, because, in the precise words of Dr. Carstensen, "chemotherapy in ovarian cancer is just not good enough." He was able to carry out the pilot study reported above, but tragically died of a sudden cardiovascular event before he was able to complete his work.