Is there a role for retinoids to treat minimal residual disease in neuroblastoma?

A variety of pre-clinical and clinical data point toward high drug levels o f retinoids being required to achieve optimal efficacy against neuroblastom a. The results of the Kohler trial reported in this issue demonstrate that low-dose 13-cis-RA does not have clinical efficacy against neuroblastoma in a setting of minimal residual disease. A comparison of the Kohler trial wi th the US CCG trial provides clinical evidence that high-dose levels of ret inoids are optimal for treating minimal residual disease in neuroblastoma. The comparison of high-dose and low-dose 13-cis-RA studies in neuroblastoma suggests the intriguing possibility that high dose, pulse schedules of oth er retinoids could be effective as therapeutic and chemopreventive agents i n diseases where low-dose, chronic retinoid administration was not effectiv e. Pre-clinical and perhaps clinical studies of the latter concept should b e considered. (C) 2000 Cancer Research Campaign.