Abstract
In vitro studies that showed RA could cause growth arrest and differentiation of myelogenous leukemia and neuroblastoma led to clinical trials of retinoids in APL and neuroblastoma that increased survival for both of those diseases
In the case of APL, ATRA has been the drug of choice, and preclinical and clinical data support direct combinations of ATRA with cytotoxic chemotherapy.
For neuroblastoma, a phase I study defined a dose of 13-cis-RA, which was tolerable in patients after myeloablative therapy, and a phase III trial that showed postconsolidation therapy with 13-cis-RA improved EFS for patients with high-risk neuroblastoma. Preclinical studies in neuroblastoma indicate that ATRA or 13-cis-RA can antagonize cytotoxic chemotherapy and radiation, so use of 13-cis-RA in neuroblastoma is limited to maintenance after completion of cytotoxic chemotherapy and radiation.
A limitation on the antitumor benefit of ATRA in APL is the marked decrease in drug levels that occurs during therapy as a result of induction of drug metabolism, resulting in a shorter drug half-life and decreased plasma levels. Although early studies sought to overcome the pharmacologic limitations of ATRA therapy in APL, the demonstration that ATO is active against APL in RA-refractory patients has led to a focus on studies employing ATO.
Use of 13-cis-RA in neuroblastoma has avoided the decreased plasma levels seen with ATRA. It is likely that recurrent disease seen during or after 13-cis-RA therapy in neuroblastoma is due to tumor cell resistance to retinoid-mediated differentiation induction.
Studies in neuroblastoma cell lines resistant to 13-cis-RA and ATRA have shown that they can be sensitive, and in some cases collaterally hypersensitive, to the cytotoxic retinoid fenretinide. Fenretinide induces tumor cell cytotoxicity rather than differentiation, acts independently from RA receptors, and in initial phase I trials has been well tolerated. Clinical trials of fenretinide, alone and in combination with ceramide modulators, are in development.
See also:
- All-Trans-Retinoic Acid (ATRA - analogues and/or derivatives);
- The Di Bella Method (A Fixed Part - All-Trans Retinoic Acid, Analogues and/or Derivatives);
- Solution of retinoids in vitamin E in the Di Bella Method biological multitherapy;
- The Di Bella Method (A Fixed Part - Alpha tocopheryl acetate/Vitamin E);
- Vitamin D (analogues and/or derivatives) and cancer;
- The Di Bella Method (A Fixed Part - Dihydrotachysterol, Alfacalcidol, synthetic Vitamin D3);
- Neuroblastoma: Complete objective response to biological treatment;
- Oesophageal squamocellular carcinoma: a complete and objective response;
- Large B-cells Non-Hodgkin's Lymphoma, Stage IV-AE: a Case Report;
- Non-Hodgkin's Lymphoma, Stage III-B-E: a Case Report;
- Complete objective response to biological therapy of plurifocal breast carcinoma.