Cancer patients who have undergone chemotherapy are exposed to peripheral neurotoxicity as a result, and several medications have been developed to prevent CICNT. The NMA sought to determine the relative efficacies of these medications by assessing 23 relevant studies whose papers had been published between 1995 and 2014.
The meta-analysis, undertaken by researchers at Jilin University, found that amifostine, a prescription drug, was more effective in fighting CICNT than supplements often used in post-chemotherapy treatment.
The NMA found that “subjects treated with glutathione, vitamin E, and amifostine showed a reduced risk of overall neurotoxicity”, but that “amifostine appears to be superior to glutathione in decreasing the risk of overall neurotoxicity”.
When it came to severe neurotoxicity, glutathione and amifostine were found to be most efficient in lowering its risk, with amifostine once again being superior to glutathione.
The NMA said that the “excellent performance of amifostine in treating CICNT may come from its ability to eliminate the harmful oxidants derived from the interaction of oxygen radicals and neurotoxicity-related DNA groups”, which it achieves by “competing with oxygen or oxygen radicals for the binding to DNA groups”.
Furthermore, the intracellular micro-environmental difference between normal and tumour cells also fosters amifostine’s absorption into and protection of normal cells.
Apart from amifostine, glutathione and vitamin E, calcium and magnesium infusion (Ca/Mg) is the most popular regimen for preventing and treating CICNT. However, its actual efficacy is still disputed.
While individual trials have suggested it is “an effective intervention for dealing with oxaplatlin-induced cumulative neurotoxicity in colon cancer and that it can also reduce the probability of all-grade neurotoxicity…without remarkably altering the validity of chemotherapy”, other studies have indicated it is not significantly more effective than the placebo.
The NMA named amifostine its top recommendation for preventing and treating both overall and severe neurotoxicity. Glutathione was its second choice for severe neurotoxicity, and vitamin E its second choice for overall neurotoxicity.
It concluded that due to limited data, the safety outcome of each therapy could not be compared and “therefore, there is still an urgent need for future research”.
Source: Frontiers in Neurology
Efficacy of Drug Interventions for Chemotherapy-Induced Chronic Peripheral Neurotoxicity: A Network Meta-analysis
Authors: Xiying Fu, et al.