Intravesical CDDP therapy compared with combined CDDP and external radiation in noninvasive bladder cancer. Monitored with quantitative fluorescence cytology

Combined treatment of radiation and cisdiamminedichloroplatinum (II): a review of experimental and clinical data

Cis-diamminedichloroplatinum (II) (c-DDP), a highly effective cytostatic drug, is increasingly used in combination with irradiation both in the laboratory and in patients. This review aims at a critical reassessment of the potential role of this drug as a "radiosensitizer." The opinion about c-DDP being an effective hypoxic cell radiosensitizer in bacteria was substantiated in some studies on mammalian cells in culture but not in others. More powerful mechanisms of radiation enhancement, which are not yet fully explored, may be depletion of endogenous thiols, inhibition of cellular repair processes, and proliferation inhibition. The effects of c-DDP in combination with irradiation in experimental tumors seem to vary between different investigators and between different tumor systems. Occasionally, supra-additive effects have been observed in some animal tumors. This stresses the need for testing this combination treatment in various tumor types, preferentially of human origin. In normal tissues, the effects are, to a large extent, explained by independent cell killing by each agent. A substantial number of clinical pilot studies have shown that the combination treatment is feasible, but the results of ongoing phase III trials will be needed to assess the potential therapeutic benefit of this combined treatment modality.

Early and late damage in the mouse rectum after irradiation and cis-diamminedichloroplatinum(II)

The effects of radiation and cis-diamminedichloroplatinum(II) (c-DDP) in the mouse rectum were assessed using two functional endpoints (anal discharge/diarrhoea and body weight changes), one lethal endpoint (obstructive rectal stenosis) and a microscopic endpoint (semiquantitative histological scoring). After irradiation, anal discharge, diarrhoea and lethal rectal stenosis were found to be the result of submucosal fibrosis with a secondary mucosal ulcer due to mechanical damage by the faeces. Weight loss at both early and late times after irradiation seemed to be related to epithelial cellular depletion. c-DDP, when given in combination with X-rays, did not enhance the incidence of late anal discharge, diarrhoea or rectal stenosis. Using an arbitrary semiquantitative scale for measuring the degree and extent of late rectal injury, c-DDP sometimes seemed to postpone the expression of radiation damage in the rectum. This effect, however, might also be the result only of interexperimental variation. An increase by c-DDP in the early body weight loss after irradiation was also observed which could be explained by an additive effect in the rectal epithelium.