Supplements and Conventional Cancer Treatment: An Exploration of Potential Synergies

By Keith I. Block, MD

For over 20 years, my research staff and I have been investigating the potential therapeutic relevance of using herbs and supplements in conjunction with chemotherapy and radiotherapy.  In addition, my 30+ years of clinical experience – as well as the relevant, available data – have led me to believe that an individualized supplement regimen can be of significant value to cancer patients when used as a part of a comprehensive, integrative treatment regimen (I review a number of these applications in Life Over Cancer).  This blog will take a look at a few of these applications.

I refer to agents that may favorably enhance tolerance and overall efficacy of conventional treatments as “treatment couplers.”  These natural agents can have one or more of the following effects: (1) increase the vulnerability of cancer cells to conventional treatments: (2) reduce the cancer cells’ resistance to these treatments; and (3) help reduce treatment-related toxicities or adverse side effects.  What follows are some brief examples of treatment couplers I have found useful in my own clinical practice.

Silibinin (from Milk Thistle).  This compound has shown various synergies with chemotherapy.  For example, a 2004 study published in Oncology Reports showed that the combination of chemotherapy and silibinin, a flavonoid from milk thistle, dramatically increased the killing of both estrogen-dependent and -independent breast cancer cells.  This synergy with silibinin was most pronounced for the drugs doxorubicin and carboplatin.  Similar benefits have been seen when the milk thistle component was included with cisplatin and carboplatin against various tumor types.  A September 2010 report in Cancer Metastasis Reviews concluded that silibinin could be helpful in preventing aggressive metastases.

Selenium.  A report in the December 2010 issue of Molecular Cancer suggests various ways by which selenium may improve chemotherapy outcomes.  Recent research out of Drew University of Medicine and Science in Los Angeles suggests that selenium supplementation enhances the chemotherapeutic impact of both taxol and doxorubicin—beyond the effects seen when only the chemotherapeutic drugs are used.  The studies found significant benefits of this combination in cancers of the breast, lung, liver, prostate, and intestines.

Vitamin D.  Vitamin D appears to enhance or potentate the anticancer effects of doxorubicin, taxol, cisplatin and possibly other chemotherapy drugs.  Much of the research has begun to focus on vitamin D analogs, look-alike synthetic forms of the vitamin that can be taken in higher doses and do not cause the loss of bone calcium linked with megadoses of vitamin D.  Vitamin D also bolstered the killing effects of radiation treatments against breast cancer cells.

Indole-3-carbinol and DIM.  Indole-3-carbinol is a natural compound found in broccoli, kale, brussel sprouts, and other members of the cabbage family.  Together with its metabolite, DIM (diindolylmethane), indole-3-carbinol may help kill ovarian cancer cells when combined with cisplatin, according to a report to the Society of Gynecologic Oncologists.  Remarkably, adding taxol to cisplatin increased the killing of ovarian cancer cells to 70%, but when DIM was combined with cisplatin, this rate jumped to 100%!  There is also evidence that indole-3-carbinol and tamoxifen cooperate in the killing of breast cancer cells.

Quercetin.  Quercetin, one of the most common plant flavonoids found abundantly in bright-colored fruits and vegetables, appears to potentiate the effects of doxorubicin against multi-drug resistant breast cancer cells.  A likely mechanism may involve blocking the p-glycoprotein, the “gatekeeper” protein that normally enables the cancer cell to pump out toxic chemotherapy agents, thereby avoiding their deadly accumulation within the cancer cell.

Curcumin.  Another power flavonoid in the cancer arena is curcumin, the active ingredient in the East Indian spice called turmeric.  For many years now, cancer researchers have regarded curcumin as a chemotherapy agent.  Numerous synergisms between curcumin and chemotherapy have been proposed, the most recent having been published in the 14 April 2011 issue of Molecular Pharmacology.  It turns out that curcumin reduces or blocks resistance to chemotherapy by inhibiting a protein called NF-kappa.  Another possible mechanism for curcumin may involve activating the p53 gene, which causes cancer cells to self-destruct when exposed to chemotherapy.

Omega-3s.  Chemoresistance may also be overcome by supplementation with fish oil or other omega-3 sources.  At least three mechanisms may be at work here: (1) cancer cell membranes become more fluid and thus more permeable to chemotherapy; (2) inhibition of NF-kappa, (a protein, which I mentioned above); and (3) oxidized omega-3 fats accumulate in cell membranes and within cancer cells, reducing their vitality and eventually causing their death.  Recent studies in France have shown that fish oil reduces chemoresistance to a variety of chemotherapy agents in vivo in both human and animal studies of breast cancer.

These are just a few of the ways we may be able to use specific nutrients and botanicals to enhance a patient’s response to chemotherapy.  The research I’ve cited above may help explain – at least in part – the doubling in survival we observed in advanced breast cancer patients who underwent our integrative chemotherapy program, as reported in the August 2009 issue of The Breast Journal.  In that clinical study of ninety consecutive patients with metastatic breast cancer, every single patient received high-potency fish oil, along with certain other core supplements that we believe can help bolster the efficacy of chemotherapy, reduce the side effects of treatment, and/or reduce resistance to chemotherapy.  Of course, supplementation was only one part of an individualized and comprehensive integrative program that was tailored to each patient’s unique needs.

As I’ve mentioned in previous blog articles, it is extremely important to let your healthcare practitioner know about all of the vitamins and supplements you are taking, as some may interact unfavorably with certain drugs.  In addition, doses as well as specific supplements may vary significantly from patient to patient.  Your physician can determine any deficiencies and adequate/optimal need.

Also, please remember that not all supplements are created equal.  Quality will vary not only from brand to brand, but if a company manufactures multiple supplements, not all of them may pass independent testing.  Here are a few reliable Internet resources that we are familiar with that perform independent testing and/or provide research reviews and clinical data on herbs and supplements (some require a subscription for access to all of their information):

www.consumerlab.com
www.naturaldatabase.org
www.herbalgram.org
www.herbmed.org

Note:  In the next blog, I will provide some examples of the various ways in which supplements can be used to reduce chemotherapy-related toxicities.

For more information on The Block Center for Integrative Cancer Treatment, visit BlockMD.com.

Comments

[Supplement43]

Nutritional supplements can also be confusing, because depending on who you talk to, you can very different opinions. Many people have extreme and biased views of nutritional supplements, people on one side saying everyone has to many different people take dietary supplements and on the other side saying all supplements are worthless. As with most problems, the truth is somewhere in the middle. There is certainly some great food, but many products are essentially worthless, and others have some positive effects, but are not worth the price you pay for them.