Argyriou, A.A., Chroni, E., Koutras, A., Ellul, J., Papapetropoulos, S., Katsoulas, G., . . . Kalofonos, H.P. (2005). Vitamin E for prophylaxis against chemotherapy-induced neuropathy: A randomized controlled trial. Neurology, 64, 26–31.

Patients were enrolled to test vitamin E as prophylaxis against chemotherapy-induced peripheral neuropathy.

Patients were randomly divided into groups assigned to receive chemotherapy treatment with (group I) or without vitamin E supplementation (group II). Group II served as control. Patients assigned to group I received alpha-tocopherol (i.e., vitamin E) orally at a dose of 300 mg per day twice daily during chemotherapy and as long as three months after chemotherapy was completed.

• The total sample consisted of 40 patients treated with six courses of cumulative cisplatin, paclitaxel, or their combination regimens for a nonmyeloid malignancy.
• The final sample size was 31.
• Exclusion criteria included a history of neuropathy, systemic diseases such as diabetes, lupus, HIV, alcohol abuse, and those who had received chemotherapy in the past.

The study had a pilot, randomized, controlled, open label with blind assessment design.

The clinical evaluation of neuropathy was based on a modified Neurologic Symptom Score (NSS) and Neurologic Disability Score (NDS). NSS selected symptoms such as weakness, numbness, or pain, scoring as present (1) or absent (0). Clinical signs (i.e., cranial nerves function; joint position, pin prick, and vibration sensation; muscle strength and deep tendon reflexes) were assessed using a modified version of NDS ranging from 0 (no deficit) to 4 (absence of function/severest deficit). Electrophysiologic examination included motor conduction of ulnar and peroneal nerves. Measures were taken at baseline and repeated after the third and sixth cycles as well as three months after cessation by the same neurologist.

Vitamin E supplementation significantly decreased the incidence of neurotoxicity, with 25% of patients receiving Vitamin E experiencing chemotherapy-induced peripheral neuropathy compared to 73.3% in the control group.

This pilot study with a small sample size and many variables assessed make achieving a statistically significant result by chance alone more likely.

Small sample size