• 7/19/2005
  • Isabelle Bairati et al.
  • Journal of Clinical Oncology, 10.1200/JCO.2005.05.514 This Article

Purpose:
Many cancer patients take antioxidant vitamin supplements with the hope of improving the outcome of conventional therapies and of reducing the adverse effects of these treatments. A randomized trial was conducted to determine whether supplementation with antioxidant vitamins could reduce the occurrence and severity of acute adverse effects of radiation therapy and improve quality of life without compromising treatment efficacy.

Patients and Methods:
We conducted a randomized, double-blind, placebo-controlled trial among 540 head and neck cancer patients treated with radiation therapy. Patients were randomly assigned into two arms. The supplementation with -tocopherol (400 IU/d) and -carotene (30 mg/d) or placebos was administered during radiation therapy and for 3 years thereafter. During the course of the trial, supplementation with -carotene was discontinued because of ethical concerns.

Results:
Patients randomly assigned in the supplement arm tended to have less severe acute adverse effects during radiation therapy (odds ratio [OR], 0.72; 95% CI, 0.52 to 1.02). The reduction was statistically significant when the supplementation combined -tocopherol and -carotene for adverse effects to the larynx (OR, 0.38; 95% CI, 0.21 to 0.71) and overall at any site (OR, 0.38; 95% CI, 0.20 to 0.74). Quality of life was not improved by the supplementation. The rate of local recurrence of the head and neck tumor tended to be higher in the supplement arm of the trial (hazard ratio, 1.37; 95% CI, 0.93 to 2.02).

Conclusion:
Supplementation with high doses of -tocopherol and -carotene during radiation therapy could reduce the severity of treatment adverse effects. However, this trial suggests that use of high doses of antioxidants as adjuvant therapy might compromise radiation treatment efficacy.

Authors:
Isabelle Bairati , François Meyer, Michel Gélinas , André Fortin , Abdenour Nabid , François Brochet , Jean-Philippe Mercier , Bernard Têtu , François Harel , Belkacem Abdous , Éric Vigneault , Sylvie Vass , Pierre del Vecchio , and Jean Roy

Authors’ affiliation:
From the Laval University Cancer Research Center; the Centre Hospitalier Universitaire de Québec; the Département de Médecine Sociale et Préventive, Université Laval, Quebec City; the Centre Hospitalier de l’Université de Montréal; the Hôpital Maisonneuve-Rosemont, Montreal; the Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke; and the Complexe Hospitalier de la Sagamie, Saguenay, Quebec, Canada