MORE ON ANTIOXIDANTS and CHEMO/RADIATION THERAPY
Let’s Check the RECENT Published Research
Re antioxidants and conventional cancer care: pretty controversial still despite lot sof current research. A few years ago, a PubMed search and found ZERO human studies on this topic, although some animal studies were suggesting possible benefit and no inhibition of the efficacy of the chemotherapy. At that time, there were strong theoretical reasons for concern about mixing anti-oxidants and chemotherapy or radiation therapy but now the research is more revealing:
Doing a PubMed search 6-09 “antioxidants cancer chemotherapy” produces a bit over 1,000 hits. Putting in the limits Human and Abstract and Clinical Trial reduces to 146 hits. However, very few were actual intervention trials.
What I found in the most recent 40:
1. There was no difference in objective mucositis scores with a mean score of 0.2 with vitamin E and 0.3 with placebo.
2. vitamin E effectively and safely protects patients with cancer from the occurrence of paclitaxel-induced peripheral nerve damage
3. oral N-acetylcysteine reduces the incidence of oxaliplatin-induced neuropathy in colon cancer patients
4. These results do not support the concern that antioxidants might protect cancer cells from the free radical damage induced by chemotherapy. Larger trials are needed to demonstrate whether high-dose multiple antioxidants in conjunction with chemotherapy increase the response rates and/or survival time in advanced lung cancer.
5. No significant differences were found between the two study groups with respect to these primary outcome measures. However, patients who achieved the highest plasma concentrations of the three antioxidant micronutrients had significantly less loss of high-tone hearing.
6. we conclude that there are beneficial effects caused by ingesting selenium, as a supportive element in chemotherapy.
7. Supplementation of patients receiving cisplatin chemotherapy with vitamin E decreases the incidence and severity of peripheral neurotoxicity.
None of these recent studies reported impairment or improvement in clinical efficacy of the chemotherapy and most suggested some benefit in terms of reduced ADRs.
So my impression at this time is that for selected chemotherapy drugs, some specific antioxidants appear to ameliorate their toxicity.
This is not a blanket statement of safety and efficacy of antioxidants, but also looks like there is no documentation of harm.
OPINION OF CONVENTIONAL CANCER TREATMENT TEAM:
The subject of supplemental antioxidants with radiation and chemotherapy has gotten a lot of press. The human evidence, however, is quite definite that antioxidants will interfere with radiation and ros (reactive oxygen species) based chemotherapies some but not all of the time. Bairati et al is a great example of this principle. Unfortunately there is no mechanism to predict when these interactions will occur and when they will not.
Since antioxidants are important nutrients for all humans, especially cancer survivors, we presumptively assume that an interaction can take place with patients receiving potentially vulnerable cancer treatments and then time the antioxidants based on the pharmacokinetics of both so that they do not interact.
With that said we will be certain to copy you on our progress notes with that detail once we’ve seen the patient. If you have any questions or concerns feel free to contact me at any time. I commend you for your care and concern for your patient. Let me know if there is anything else we can do to further support your care.