Short-term in vitro chemosensitivity testing of tumours of the ovary, cervix and uterus. Measurement of DNA metabolism by 3H thymidine incorporation.

A 3-hour biochemical assay was chosen in the present prospective study to determine the in vitro chemosensitivity of tumours of the ovary, cervix and uterus. The basis of the assay was to determine the ability of a panel of cytotoxic drugs to inhibit the proliferative activity of tumour cells in culture, using 3H thymidine as a precursor of DNA synthesis. We found variability in the in vitro responses of individual tumours to the 4 drugs (cisplatin, adriamycin, melphalan, methotrexate). In ovarian cancer, cisplatin and adriamycin produced the best inhibitory effects; serous cystadenocarcinomas were most frequently inhibited by cisplatin, whilst undifferentiated carcinomas were more affected by adriamycin. Only 14% of tumours were sensitive to all 4 drugs. We found a good correlation between in vitro results and in vivo response in the medium term. For cisplatin, the predictive accuracy was 85% for 'sensitive' tumours and 72% for 'resistant' tumours. These findings should increase our confidence in the test as a new aid to planning of chemotherapeutic strategies.