Comparisons of carboplatin and cisplatin as potentiators of 5-fluorouracil and radiotherapy in the mouse L1210 leukaemia model.

BACKGROUND

Carboplatin (CBDCA), an analogue of cisplatin (CDDP), has synergistic antitumour activity in combination with 5-fluorouracil (5-FU) and radiotherapy and is better tolerated than CDDP by patients. In an in vivo model, we evaluated the doses of CBDCA and CDDP required to obtain, in these combinations, equal curative effects.

MATERIALS AND METHODS

Groups of 6-week-old B6D2F1 mice were injected with L1210 leukaemia. The chemotherapy was administered 24 hours after L1210 inoculation, while the radiotherapy was performed 1 or 24 hours later. Treatment results were evaluated in terms of prolonged survival.

RESULTS

The same degree of potentiation was obtained at the dose ratio CBDCA/CDDP of 4 in association with 5-FU and 3 in combination 5-FU/radiotherapy, with a longer delay between CBDCA administration and radiotherapy.

CONCLUSION

CBDCA could be used as a potentiator of 5-FU and radiosensitizer at a daily dose of 20 mg/m2 in clinical therapy.