Ralph W. Moss, Ph.D. Weekly CancerDecisions.com
Newsletter #326 02/03/08
NEW STUDY CLARIFIES ROLE OF ANTIOXIDANTS DURING RADIATION TREATMENT
An important paper on the interaction of antioxidants and radiation
therapy was recently published in the International Journal of Cancer.
Interestingly, despite the significance of its findings, this study has
received virtually zero attention from the scientific community or the
media.
As background, in April 2005, Isabelle Bairati, MD, PhD, and her
colleagues at the Hôtel-Dieu de Québec Research Centre and the
Université Laval completed a ten-year study on the interaction of
antioxidants and radiation therapy. This was hailed as the first
placebo-controlled, double-blind, randomized trial assessing the effect
of supplementation with antioxidant vitamins during radiation therapy.
The study concluded that supplements of synthetic beta-carotene (30 mg
per day) or alpha tocopherol (400 IU per day) had a harmful effect on
cancer patients. In particular, the authors claimed that the cancer
recurrence rate was 40 percent higher among patients who had been
randomly assigned to the supplementation arm of the trial. They
therefore called on patients and physicians to exert caution in using
antioxidants until new evidence could be provided by future trials.
Kedar Prasad, PhD, and other proponents of the concurrent use of
antioxidants during cancer treatment criticized the Bairati paper. They
were disappointed that Bairati and colleagues had used ordinary alpha
tocopherol as their choice of vitamin E when Prasad's previous work had
shown that it was not just alpha tocopherol but alpha tocopherol
succinate that had the anticancer efficacy. They also felt that natural
forms of the vitamin were more effective than synthetic, drug store-type
vitamins. But, by and large, the medical world accepted the Bairati
trial as definitive proof that antioxidants interfered with radiation
therapy. Word spread like wildfire in oncology circles, confirming a
long-held belief that antioxidants interfered with standard cancer
treatments such as radiation and chemotherapy. The take away message, as
stated in a Université Laval press release, was that "Supplements May
Speed Up Development of Cancer." Advocates of co mplementary and
alternative medicine (CAM) were confounded by this large and impressive
study.
But now the other shoe has dropped.
In December 2007, Dr. Bairati and her Québec colleagues published a
major modification of their previous conclusions. Further analysis
revealed, they said, that the danger of synthetic antioxidants was
limited to one particular sub-population: cigarette smokers -
specifically, those who continued to smoke during radiation treatment.
The authors analyzed the outcome in 540 patients who had been given
radiation for head and neck cancers.
During the follow-up period, 119 patients had a recurrence of their
disease and 179 died. Smokers were the group with the worst prognosis.
However, astonishingly, smoking in the period leading up to or following
radiation therapy did not modify the effects of the two supplements. It
was only smoking during the course of radiation therapy that led to a
statistically significant increase in the risk of a recurrence. It was a
large enough increase to skew the statistics for the group as a whole,
leading to the erroneous co nclusion that antioxidants interfered with
radiotherapy in the general patient population.
Statistically, increased risk is generally expressed as a "hazard ratio"
(abbreviated HR). In this study, current smokers had an HR of 2.41 for
recurrence, in other words more than double the chance of a recurrence
compared to the rest of the patient population. The HR for death from
any cause was a similar 2.26. But the hazard ratio for dying of their
initial head and neck cancer was a whopping 3.38 in patients who got
radiation, smoked and also received a single synthetic antioxidant.
"These results could best be explained by the hypothesis that the
combined exposures reduced the efficacy of radiation therapy," Bairati
and her colleagues now say. "Particular attention should be devoted to
prevent patients from both smoking and taking antioxidant supplements
during radiation therapy" (Meyer 2007).
According to the National Cancer Institute, 85 percent of head and neck
cancers are linked to tobacco use. (Alcohol use further exacerbates this
trend.) This has been widely known for years, and so it is shocking that
there are still people so hopelessly addicted to tobacco that they not
only continue to smoke after they've been diagnosed with head and neck
cancer but continue to smoke right through their radiation therapy. It
was in this subset of particularly unhealthy individuals that
antioxidants were associated with an increased risk of disease
progression. As Bairati and colleagues suggest, such individuals should
definitely not compound their problems by then taking a synthetic
antioxidant.
But the more important lesson for patients and practitioners is that
antioxidants do NOT generally interfere with the effects of radiation
therapy, as was previously suggested. They do NOT increase the risk of a
recurrence, of death from head and neck cancer, or of overall mortality
in the average patient. In this updated study, the harmful effect of
synthetic antioxidants was entirely limited to those relatively few
tobacco-addicted patients who continued to smoke during their radiation
therapy.
Thus, the major premise underpinning oncologists' condemnation of
antioxidants during radiation therapy has crumbled, although few seem to
have noticed so far.
ANTIOXIDANTS AND CANCER TREATMENT - A CHOICE OF REPORTS
In late 2005 the peer-reviewed journal CA (the American Cancer Society's
journal for clinicians working in the field of cancer) published a paper
strongly recommending against the use of antioxidants during cancer
treatment. In response to this paper we published a detailed report
titled Should Patients Undergoing Chemotherapy and Radiotherapy Be
Prescribed Antioxidants? This report analyzes the specific arguments
raised by D'Andrea and others against the use of antioxidants during
cancer therapy and finds that there is scant evidence to support the
widespread practice of forbidding antioxidants during cancer treatment.
Because this is a topic of such immediate importance to cancer patients,
we are now offering this report packaged with our newly published Do
Antioxidants Interfere With Radiation Treatment for Cancer? The combined
report, totaling 83 pages, gives an extensive overview of the entire
subject, including a detailed, point-by-point rebuttal of the specific
arguments put forward against the use of antioxidants during cancer
therapy.
"Do Antioxidants Interfere With Radiation Treatment for Cancer?"
received enthusiastic reviews from several prominent clinicians and
researchers:
"An excellent article that clearly brings into perspective the issues
raised."
-Kenneth A. Conklin, MD, PhD, University of California, Los Angeles
"Excellent and timely."
-Jeanne Drisko, MD, University of Kansas Medical Center
"Superb, very thorough, should convince anyone except those whose minds
are closed."
-Abram Hoffer, MD, PhD, FRCP (C)
"A comprehensive rebuttal that is also an excellent review of this
complex topic."
-Leanna Standish, ND, PhD, Bastyr University, Seattle
You can purchase the combined report - "Do Antioxidants Interfere With
Radiation Treatment for Cancer?" plus "Should Patients Undergoing
Radiation and Chemotherapy Take Antioxidants?" by going to:
https://webssl.cancerdecisions.com/list/optin.php?form_id=29
To purchase the single report "Do Antioxidants Interfere With Radiation
Treatment for Cancer?" please go to:
https://webssl.cancerdecisions.com/list/optin.php?form_id=28
MOSS REPORTS
We have Moss Reports on more than 200 different cancer diagnoses. You
can see the full list of reports, view a table of contents and read a
sample excerpt from one of the reports at our Web site,
www.cancerdecisions.com.
PHONE CONSULTATIONS - FINDING DIRECTION AND REGAINING A SENSE OF CONTROL
A phone consultation can be enormously helpful in drawing up an
effective treatment strategy and getting one's options clearly
prioritized, as these comments from recent phone consultation clients
illustrate:
“The phone consultation was very enlightening. Dr. Moss has a
compassionate way of communicating a message of hope and explaining
various avenues of inquiry that are easy to understand. He projects a
feeling of empowerment, that to date, has been lacking in my discussions
regarding my cancer” - S.M.
Clients who have purchased a Moss Report can schedule an appointment for
a phone consultation by calling 1-800-980-1234 (814-238-3367 from
outside the US) or by submitting a request via email to
Jacquie@cancerdecisions.com.
We look forward to helping you.
--Ralph W. Moss, Ph.D.
References:
Bairati I, Meyer F, Jobin E, et al. Antioxidant vitamins supplementation
and mortality: a randomized trial in head and neck cancer patients. Int
J Cancer. 2006;119:2221-4.
Bairati I, Meyer F, Gélinas M, et al. Randomized trial of antioxidant
vitamins to prevent acute adverse effects of radiation therapy in head
and neck cancer patients. J Clin Oncol. 2005;23:5805-5813.
Bairati I, Meyer F, Gélinas M, et al. A randomized trial of
antioxidant vitamins to prevent second primary cancers in head and neck
cancer patients. J Natl Cancer Inst. 2005;97:481-488.
Meyer F, Bairati I, Fortin A, et al. Interaction between antioxidant
vitamin supplementation and cigarette smoking during radiation therapy
in relation to long-term effects on recurrence and mortality: A
randomized trial among head and neck cancer patients. Int J Cancer. 2007
Dec 4;122(7):1679-168.
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