Most patients take vitamins-does this interfere with killing cancer cells?

Even under the best conditions patients want to do everything possible to protect themselves from radiotherapy side effects. Many patients who undergo cancer treatments take vitamins and supplements. Until recently, oncologists seldom asked patients about this.

Doctors still have almost no evidence on which to advice cancer patients about common supplements. But a previous, laboratory study by radiation oncologists at Rush-Presbyterian-St. Luke’s Medical Center found that “Cancer patients who take vitamin E are probably not hindering the desired effects of radiation.”

Dr. Keith Bruninga, gastroenterologist at Rush-Presbyterian-St. Luke’s has now looked to see how much protection vitamins E and C actually offer patients irradiated for prostate, cervical or endometrial cancer. The effect of the vitamins in the treatment of chronic radiation proctitis had not been studied before, Dr. Bruninga said.

In normal bowel and rectal tissues exposed to radiation for cancer in the pelvis, oxygen radicals form and patients experience the symptoms of proctitis, he said. The condition starts with swollen, inflamed tissue, and it increases with dose. The symptoms, which may include diarrhea, pain, bleeding and incontinence, usually clear up within a few weeks of the last radiation treatment.

However, the symptoms do not clear up in 10-20 percent of patients. Some patients develop symptoms months or years after the initial radiation exposure.

“Our study showed that we can harness the potent antioxidant properties of the vitamins to repair cell damage and bring relief to many people who suffer from the persistent, lifestyle-altering symptoms of chronic radiation proctitis,” Dr. Bruninga says in a paper published in the April issue of The American Journal of Gastroenterology.

Oxygen free radicals form from cells that have been injured. Oxygen free radicals are highly active molecules that react with cells by changing or damaging their structure. The formation of the oxygen free radicals increases the amount of injury to the cells and results in a chronic condition as blood flow to the cells is decreased.

Vitamin E is a potent antioxidant that can react with damaging oxygen free radicals. Vitamin C in combination with E increases the effects of vitamin E. The researchers believe that the antioxidant treatment regimen using the vitamins counteracts and can prevent oxygen free radical injury and increase blood flow to the injured cells of patients with chronic radiation proctitis.

Patients in the study, ten men and ten women with chronic radiation proctitis, took one 400 IU vitamin E tablet along with one 500 mg vitamin C tablet three times each day for eight consecutive weeks. Patients purchased the vitamins themselves at the store of their choice.

Each patient in the study rated their symptoms in terms of severity and frequency before and after treatment with the vitamins using a questionnaire developed by the researchers.

The impact of the symptoms on the lifestyle of the patients was also assessed using a questionnaire. Ten of the patients were assessed again after one year to determine if their initial responses were sustained.

The assessments showed a significant improvement in bleeding, diarrhea and urgency after taking the vitamins. Patients with rectal pain did not improve significantly. Thirteen patients reported an improvement in their lifestyle including seven whom reported a complete return to normal.

All of the ten patients who were assessed after one year reported a sustained improvement in their symptoms while continuing to take the vitamins.

The Rush physicians believe that the actual incidence of the ailment is greater than the estimated 10-20 percent of radiation patients. They feel that many patients, relieved and grateful that their cancers are remission, are embarrassed to tell their physicians about the symptoms of radiation proctitis.

Currently, the Rush physicians are seeking additional individuals with chronic radiation proctitis to conduct a larger, double-blinded study of the effectiveness of antioxidants in the treatment of the illness.

“If our continued research shows that the antioxidant regimen is successful in treatment of this illness, we plan to investigate its use to prevent chronic radiation proctitis,” said Dr. Bruninga.

Results of the study appear in April 2002 issue of The American Journal of Gastroenterology.
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VIT C RADIATION

VIT E RADIATION