Protective effects of vitamin E on chemotherapy-induced peripheral neuropathy: a meta-analysis of randomized controlled trials.
OBJECTIVE
This study aimed to investigate the neuroprotective effects of vitamin E for preventing chemotherapy-induced peripheral neuropathy (CIPN).


METHODS
A comprehensive search from 1973 through July 2011 identified randomized controlled trials (RCTs) that reported the preventive effects of vitamin E on CIPN. The relative risk (RR) of CIPN with vitamin E supplementation, compared with placebo, was assessed with the Bayesian random effect model and expressed as RR with a 95 % credible-interval (CrI). Bayesian outcome probabilities were calculated as the probability (P) of RR < 1.


RESULTS
Five RCTs, involving 319 patients, were identified. Upon pooling these RCTs, vitamin E supplementation (300 - 600 mg/day) had a significant effect on CIPN prevention (RR 0.43; 95 % CrI 0.10 - 1.00, P = 97.5 %). Subgroup analysis by chemotherapeutic agent type was only available for cisplatin and showed that vitamin E supplementation significantly reduced the incidence of CIPN (RR 0.26; 95 % CrI 0.06 - 0.89, P = 98.1 %). Furthermore, there were no adverse effects caused by vitamin E supplementation in any of the RCTs.


CONCLUSIONS
Available data included in this meta-analysis show that vitamin E supplementation might significantly prevent CIPN. Currently, however, the data are insufficient to confidently conclude the true value. Large-scale, rigorously designed RCTs are needed to confirm the role of vitamin E supplementation in CIPN prevention.
Department of Clinical Pharmacy, College of Pharmacy, Seoul National University, South Korea.
Seenae
S
Eum
Department of Clinical Pharmacy, College of Pharmacy, Seoul National University, South Korea.
Hye-Duck
HD
Choi
College of Pharmacy, Yonsei University, Gyeonggi-do, South Korea.
Min-Jung
MJ
Chang
Department of Family Medicine, Seoul National University Hospital, South Korea.
Ho-Chun
HC
Choi
Department of Family Medicine, Seoul National University Hospital, South Korea.
Young-Jin
YJ
Ko
Department of Family Medicine, Seoul National University Hospital, South Korea.
Jeong-Soo
JS
Ahn
Department of Clinical Pharmacy, College of Pharmacy, Seoul National University, South Korea.
Wan-Gyoon
WG
Shin
College of Pharmacy, Institute of Pharmaceutical Science and Technology, Hanyang University, Gyeonggi-do, South Korea.
Ju-Yeun
JY
Lee
D000970:Antineoplastic Agents / Q000009:adverse effects*; D000975:Antioxidants / Q000008:administration & dosage*; D001499:Bayes Theorem; D019587:Dietary Supplements; D006801:Humans; D010523:Peripheral Nervous System Diseases / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D014810:Vitamin E / Q000008:administration & dosage*
D000970:Antineoplastic Agents; D000975:Antioxidants; D014810:Vitamin E
chemotherapy; peripheral neuropathy; vitamin E