ONC: Head and Neck Cancer: Radiation 2007
Click here to see the explanation of recommendation ratings (Strong, Fair, Weak, Consensus, Insufficient Evidence) and labels (Imperative or Conditional). To see more detail on the evidence from which the following recommendations were drawn, use the hyperlinks in the Supporting Evidence Section below.
ONC: Use of Antioxidant Vitamin E Oral Supplement
Use of vitamin E oral supplements to enhance efficacy, improve tolerance and reduce late-effects of radiation therapy for patients with head/neck cancer is not recommended. While limited evidence supports the use of vitamin E oral supplements to reduce late effects (osteoradionecrosis), there is strong research reporting an increased risk for second primary cancers and decreased survival rate with use of vitamin E in doses greater than or equal to 400 IU (268mg).
Risks/Harms of Implementing This Recommendation
No potential risks or harms are associated with the application of this recommendation.
Conditions of Application
No conditions limit the application of this recommendation.
Potential Costs Associated with Application
No obvious costs are associated with the application of this recommendation.
A positive quality RCT (Bairati et al, 2005) of older, stage I and II head and neck cancer patients receiving radiation therapy who continuously supplemented with 400IU per day of a-tocopherol (oral vitamin E) for three years resulted in negative outcomes. The study indicated use of the supplement may be associated with an increased occurance of second primary cancers and decreased duration of cancer-free survival in this population.
A neutral quality before and after time series study (Delanian et al, 2005) with a small, convenience sample found that a combination of pentoxifylline (800mg per day) and vitamin E (1, 000IU per day) boosted with clodronate (1, 600mg per day, 5 days/week) in only the most serious cases, induced mucosal and bone healing in patients with osteoradionecrosis. All patients improved at 6 months, and the investigators were not blinded.
Recommendation Strength Rationale
Based on one positive quality RCT, and one neutral quality before and after time series studies, conclusion statements are Grade II and Grade III.
- Risks/Harms of Implementing This Recommendation
The recommendations were created from the evidence analysis on the following questions. To see detail of the evidence analysis, click the blue hyperlinks below (recommendations rated consensus will not have supporting evidence linked).
Is there a relationship between supplementation of antioxidant vitamin E and the efficacy of radiotherapy treatment in patients with head and neck cancer?
Is there a relationship between supplementation of antioxidant vitamin E, which may interact with radiation therapy treatment, tolerance of radiation therapy treatment and late-effects of radiation therapy treatment in patients with osteoradionecrosis resulting from head and neck cancer treatment?
Bairati I, Meyer F, Gelinas M, Fortin A, Nabid A, Brochet F, Mercier JP, Tetu B, Harel F, Masse B, Vigneault E, Vass S, del Vecchio P, Roy J., A randomized trial of antioxidant vitamins to prevent second primary cancers in head and neck cancer patients. Journal of the National Cancer Institute 2005; 97(7):481-488.
Delanian S, Porcher R, Rudant J, Lefaix J-L. Kinetics of response to long-term treatment combining pentoxifyllin and tocoperol in patients with superficial radiation-induced fibrosis. Journal of Clinical Oncology 2005; 23:8570-8579.