title: Acute adverse effects of radiation therapy and local recurrence in relation to dietary and plasma beta carotene and alpha tocopherol in head and neck cancer patients.
abstract: There is a debate concerning the effects of antioxidant vitamins during radiation therapy: Can they reduce the adverse effects of therapy without reducing treatment efficacy? We examined whether dietary and plasma beta carotene and alpha tocopherol were related to severe acute adverse effects of radiation therapy and to cancer local recurrence. We conducted a prospective study of 540 head and neck cancer patients treated by radiation therapy. Dietary intakes of beta carotene and alpha tocopherol were measured by a validated food frequency questionnaire and plasma levels were determined. Acute adverse effects of radiation therapy and local recurrence were documented. A higher beta carotene dietary intake was associated with fewer severe acute adverse effects: odds ratio (OR) = 0.61 [95% confidence interval (CI) = 0.40-0.93]. There was a tendency for a similar effect for plasma beta carotene: OR = 0.73 (95% CI = 0.48-1.11). Participants with higher plasma beta carotene had a significantly lower rate of local recurrence (hazard ratio = 0.67; 95% CI = 0.45-0.99). Alpha tocopherol was not related to severe adverse effects or to cancer recurrence. This study suggests that a higher usual dietary beta carotene intake can reduce the occurrence of severe adverse effects of radiation therapy and decrease local cancer recurrence.
authors.affiliation: Laval University Cancer Research Center, Quebec, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Meyer
authors.forename: Isabelle
authors.initials: I
authors.lastname: Bairati
authors.forename: Edith
authors.initials: E
authors.lastname: Jobin
authors.forename: Michel
authors.initials: M
authors.lastname: Gélinas
authors.forename: André
authors.initials: A
authors.lastname: Fortin
authors.forename: Abdenour
authors.initials: A
authors.lastname: Nabid
authors.forename: Bernard
authors.initials: B
authors.lastname: Têtu
mesh_terms: D000975:Antioxidants / Q000378:metabolism / Q000627:therapeutic use; D016001:Confidence Intervals; D004032:Diet; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006258:Head and Neck Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000532:radiotherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy; D016017:Odds Ratio; D011446:Prospective Studies; D011832:Radiation Injuries / Q000517:prevention & control*; D011795:Surveys and Questionnaires; D024502:alpha-Tocopherol / Q000097:blood* / Q000627:therapeutic use*; D019207:beta Carotene / Q000097:blood* / Q000627:therapeutic use*
chemical_list: D000975:Antioxidants; D019207:beta Carotene; D024502:alpha-Tocopherol