CHEMOTHERAPY OF CHORIOCARCINOMA AND RELATED TROPHOBLASTIC TUMORS IN WOMEN

Medical presentations of choriocarcinoma

Choriocarcinoma commonly presents with symptoms resulting from metastases in the lungs, central nervous system, or alimentary tract. This tumour may occur without any gynaecological symptoms and when pelvic examination and uterine curettage show no abnormality. Several years may elapse between the antecedent pregnancy and presentation with metastatic disease. The ability to eradicate these tumours with present chemotherapeutic methods depends on detecting their presence as soon as possible after the antecedent pregnancy.Wider recognition of the varied manifestations of metastatic choriocarcinoma and greater use of tests for chorionic gonadotrophin should result in earlier diagnosis and an improved prognosis in these patients. In particular, such tests should be made in patients with unexplained intracranial haemorrhage, progressive dyspnoea, and gastrointestinal haemorrhage.

Treatment of leukemia with large doses of methotrexate and folinic acid: clinical-biochemical correlates

Patients with acute leukemia were given repeated cycles consisting of infusions of methotrexate followed by "rescue" with folinic acid. Peripheral blood leukemic cells were harvested from patients before cyclical treatment, and the rates of incorporation of thymidine and of deoxyuridine into deoxyribonucleic acid (DNA) were measuared in vitro. There was no relationship between the pretreatment incorporation of either deoxynucleoside into DNA and the clinical response to therapy. Methotrexate suppressed deoxyuridine incorporation into DNA by the leukemic blasts in vitro, but the patients whose cells were most sensitive to this effect did not necessarily go into remission when treated. Leukemic cells were sampled during methotrexate infusions and the deoxynucleoside incorporation rates were determined. Thymidine incorporation into DNA was variably affected. If, by the end of the first infusion, it remained elevated, remission rarely followed, whereas if it was below the pretreatment value, remission was much more likely. In all cases, deoxyuridine incorporation was suppressed during the infusion. The greatest suppression occurred in patients who went on to remission, but the suppression did not correlate with that expected from pretreatment in vitro tests unless due weight was given to the concomitant effects of the methotrexate therapy on thymidine incorporation. Leukemic blasts surviving successive cycles of therapy became progressively more resistant to the suppressing effects of methotrexate in vitro. This resistance became especially marked in the blasts of patients who did not go into remission. During methotrexate infusions, inhibition of leukemic cell dihydrofolate reductase activity was greatest in blasts of patients whose disease subsequently remitted.

Experimental Cancer Chemotherapy in Animate and Humans

In cancer chemotherapy, experiments on transplanted animal tumors usually provide the basis for clinical (human) studies. In general, the correlation in drug response between animal and human tumors can be classified as poor. However, in properly selected settings, animal tumors can be used as reliable predicting systems. Drugs which passed the «animal tumor» stage go to clinical trials. An outline of these experiments is given and their crucial importance is emphasized. Skilfully designed clinical experiments are needed if the adequate exploitation of drugs in practical cancer chemotherapy is to be achieved.