[Vitamin A in tumor therapy: significance of clinical and pre-clinical findings for radiologic oncology]

Abstract

Purpose: Retinoids are a class of compounds structurally related to vitamin A which have been found to be active agents experimentally as well as clinically in the prevention and treatment of tumors. The data available suggest to study whether they might improve treatment results if combined with irradiation.

Methods: The clinical results in the prevention and treatment of cancer with retinoids are reviewed. In the context of experimental studies evaluating the antiproliferative effects of retinoids, cytokines and radiation alone or in combination our own experimental investigations analyzing a combination of all-trans-retinoic acid, interferon-alpha (IFN-alpha) and ionizing radiation in squamous cell carcinoma cell lines are described.

Results: There is a solid body of experimental and clinical data to combine retinoids with cytokines (e.g.IFN-alpha). Since it is known that vitamin A alters the radiation response in experimental tumors our analyses further support the combination of retinoids and IFN-alpha with ionizing radiation.

Conclusions: We emphasize further clinical investigations evaluating the combined treatment with retinoids/IFN-alpha and ionizing radiation in squamous cell carcinomas such as head and neck tumors and cervical cancer.