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T. Colin Campbell Center for Nutrition Studies
Food or Medicine? Preventing & Treating Breast & Prostate Cancer

Cancer – the word actually comes from the Greek word karkinos, a word used to describe carcinoma tumors by the famous physician Hippocrates (460-370 B.C.).[1] Cancer is arguably the most terrifying diagnosis anyone can receive from his or her physician. It’s also the second leading cause of death in the United States and around the world behind cardiovascular diseases.[1][2] Most people fear cancer more than any other disease.

Cancer doesn’t have to happen though, at least not in most scenarios. We know for a fact from the work of nutritional scientist T. Colin Campbell, PhD that cancer is largely preventable, as discussed in his book The China Study.[3] With few exceptions, cancer is due to the rich Western diet, not our genes contends Campbell.

So why is it that everyone automatically turns to surgery, chemotherapy, and radiation to fight cancer when food is the primary enemy? More often than not, there are almost no questions asked by patients to their doctors when given only these forms of conventional treatments to cure their cancer. Shouldn’t we be thinking outside the box of modern medicine when it comes to cancer, especially given all the horrendous side effects and meager results of many twenty-first century treatments? Or, at the very least, shouldn’t we be implementing a major diet and lifestyle change in conjunction with modern medical interventions when facing cancer?

These are the billion dollar questions—literally—as the U.S. is projected to spend $173 billion annually in treating cancer by the year 2020![4]

I certainly don’t have the answers to every situation involving cancer (no one does), but I will do my best in this article to give you some food for thought when it comes to treating cancer.

[Note – For the record, I’m a clinical hospital pharmacist, educated and surrounded by the best that medicine has to offer. I see the slicing and dicing, the bombardment of radiation, and the administering of chemotherapy all the time in my line of work. I thought to myself there had to be more options for those facing this life-and-death disease called cancer. Did my education and training leave me missing something critical? What I’ve learned is that there is no perfect solution, not every individual is created equal, and not all cancers are deemed equivalent. It’s important to do your homework if facing this deadly disease.]

Food vs. Medicine for the Treatment of Cancer

Food vs. Medicine for the Treatment of Cancer

Breast, prostate, and colon cancer are three of the most common cancers in America. While the data runs deep when it comes to modern medical treatments (surgery, radiation, chemotherapy, etc.) used for these cancers, the high-quality research to solidify the effectiveness of a whole food, plant-based diet (WFPB) as superior to these options is largely missing.

In fact, to my knowledge, only prostate cancer has controlled interventional studies (the gold standard in determining evidenced-based medical practices) to evaluate whether or not a WFPB diet should be the standard of treatment for any type of cancer. Even at that, these interventional studies measured blood markers as the end result and not morbidity and mortality (disability and death) due to prostate cancer. This is the equivalent of measuring the drop in a person’s cholesterol level after taking a statin drug without worrying about the rate of heart attacks and deaths had the statins not been taken. The latter is more important in the grand scheme of things. People care about becoming disabled and dying more than they care about their cholesterol level.

Nevertheless, the available studies on nutrition and cancer are still valuable on their own, but it would be nice to someday have studies using a WFPB diet as the solo treatment option in treating different types of cancer versus modern medical therapy.

Prostate Cancer – Treatment With Drugs, Surgery, & Radiation

It’s estimated that approximately 2.7 million men were living with prostate cancer in the United States in 2011.[5] At the time of diagnosis, it’s reported that 81% of these men had localized prostate cancer (confined only to the prostate gland), 12% had cancer that had spread to the lymph nodes, 4% had metastasized cancer to other organs in the body, and 3% were unstaged.

Common treatment options include watchful waiting, surgery, radiation, hormone therapy, and chemotherapy. Diet treatment alone is considered unconventional and not practiced by most physicians. I will mostly discuss available data regarding therapy in lower risk patients (i.e. localized prostate cancer) since most men fall into this category.

A 2010 article in the Annals of Oncology examined several treatment options for low-risk prostate cancer in men, including active surveillance (watchful waiting), radical prostatectomy (removal of prostate gland by surgery), and radiation therapy.[6] The authors stated, “Ten-year prostate cancer specific survival approaches 100% for each management option, including active surveillance for selected patient groups.” In other words, all forms of treatments led to the same results, even doing nothing (i.e. watchful waiting).

The study went on to say that for the intermediate-risk group “the actuarial risk of death from prostate cancer at 12 years was 12.5% for surgery compared to 17.9% for watchful waiting. Put it another way, the number needed to treat (NNT) to avoid one death from prostate cancer was 18.5. This means that on average a little over 18 men had to be treated in order for one man to avoid death due to prostate cancer. This beneficial impact of surgery on prostate cancer mortality was restricted to men age 65 or younger. Radical prostatectomy increased the rate of erectile dysfunction (ED) by 35%, and urinary leakage (incontinence) by 28%, in comparison with watchful waiting.”

To clarify the above results, men getting the surgery experienced an absolute risk reduction in avoiding death after a 12-year period by 5.4% over men who did nothing. With this small increase in risk reduction, approximately a fourth to a third of the men experienced the unwanted and permanent side effects of ED and/or urinary incontinence.

Another common treatment for prostate cancer is hormone therapy, otherwise known as androgen deprivation therapy (ADT), whereby a medication like Zoladex (goserelin) or Lupron (leuprolide) is given to lower testosterone levels in the body. These medications are also considered chemotherapy or antineoplastic agents. In theory, lowering testosterone makes sense because elevated testosterone levels in men typically go hand-in-hand with prostate cancer risk. However, it depends on your risk group whether or not these agents are indicated in prostate cancer.

An article in JAMA in 2008 looked at using ADT in 19,271 men with localized prostate cancer. Researchers found the 10-year survival rate in men treated with the medication was actually worse than the rate for those practicing watchful waiting.[7] ADT is only recommended in men with advanced or high-risk disease, such as those where the cancer has spread to the lymph nodes or beyond.[8]

ADT therapy is also not without its side effects. Among potential adverse effects are changes in serum lipid profiles, increased risk of insulin resistance, and increased risk of coronary artery disease.[8] In addition, 27%-49% of men will develop erectile dysfunction while on these medications.[9] It is clear that if you are a male candidate for ADT therapy, you should consider these risks, along with any potential benefits, in your decision making process as you talk to your doctor about your prostate cancer.

Prostate Cancer – Treatment With a WFPB Diet

Dean Ornish, MD, first published his studies on halting and potentially reversing prostate cancer with a WFPB diet in 2005 in the Journal of Urology.[10] In this study, Ornish took 93 male patients with biopsy proven, low-grade prostate cancer and randomized them into an experimental group (WFPB diet) of 44 men and a control group (Western diet) of 49 men. The WFPB diet consisted of fruits, vegetables, legumes, whole grains, and nuts/seeds. No animal foods were allowed in the WFPB group. A blood marker called a prostate specific antigen (PSA) level was taken at baseline and 1 year.

None of the men in the WFPB group required any further conventional medical treatment for their prostate cancer.

(PSA levels of below 4 ng/ml are considered normal, signifying no prostate cancer in men. However, the PSA test has been questioned for its accuracy. It is estimated that the risk of overdiagnosis in prostate cancer in men is between 5% and 44.9% for those aged 50-69 using the PSA test.[11] Nevertheless, the PSA test is still one of the best noninvasive indicators we have in diagnosing prostate cancer. The higher the PSA level, the higher the risk of prostate cancer. PSA levels between 4-10 ng/ml typically indicate low-grade prostate cancers. Biopsy of the prostate is ordered if PSA levels are elevated and then used to prove a diagnosis of prostate cancer.)

Returning to Ornish’s study, patient results at baseline and 1 year for PSA levels are shown here for both dietary groups:

  • Control group baseline PSA level – 6.36 ng/ml
  • Control group 1-year PSA level – 6.74 ng/ml (increase of 6%)
  • Experimental group baseline PSA level – 6.23 ng/ml
  • Experimental group 1-year PSA level – 5.98 ng/ml (decrease of 4%)

The prostate cancer in the WFPB experimental group reversed course, while those on their regular diets saw a worsening of their disease. In addition, none of the men in the WFPB group required any further conventional medical treatment for their prostate cancer. However, six men in the control group underwent further treatment due to rising PSA levels.

Side effects of the WFPB diet were all positive and included a drop in total and LDL cholesterol levels, along with an average 10 lb weight loss in the men. No erectile dysfunction or urinary incontinence was reported with the switch to a healthy plant-based diet.

These results were confirmed in another study published in 2006 by Saxe et al.[12] Researchers found either a reduction in PSA levels or a decrease in the rate of PSA rise in men who adopted a plant-based diet over a 6-month period.

Breast Cancer – Treatment With Drug Therapy

An estimated 2.9 million women were living with breast cancer in 2011.[5] At the time of diagnosis it’s reported that 61% of women had localized breast cancer (confined only to the breast tissue), 32% had cancer that had spread to the lymph nodes, 5% had metastasized cancer, and 2% of cases were unstaged.

While I am focusing on treatment options for breast cancer in this article, diagnosing the disease is a story in and of itself. Please see my article here for more information on annual mammogram screenings and how beneficial they may or may not be for women – The Business of Breast Cancer Awareness Month (And How To Prevent Breast Cancer In The First Place).

Two of the most common treatments for breast cancer include chemotherapy—specifically, anthracycline (Adriamycin) and taxane (Taxol) agents—and hormone therapy with a medication like tamoxifen (exerts an anti-estrogen effect on breast tissue). Tamoxifen typically follows chemotherapy for a period of 5 years.

Below are the success rates of Taxane and Anthracycline agents for 5- and 10-year breast cancer recurrence rates and survival rates in the treatment of breast cancer. These are typically what breast cancer victims are concerned with the most—death and/or a return of their breast cancer. Statistics are reported in absolute risk reduction terms.[13][14]

Taxane + Anthracycline vs. Anthracycline Agent Alone

  • 5% of women benefited by avoiding breast cancer recurrence at 5 years by undergoing the combination chemotherapy regimen versus an Anthracycline agent alone.
  • 3% of women benefited by avoiding death at 5 years by undergoing the combination chemotherapy regimen versus an Anthracycline agent alone.

Anthracycline Agent Alone vs. No Chemotherapy

  • 8.5% of women benefited by avoiding breast cancer recurrence at 5 years by undergoing Anthracycline-based chemotherapy versus doing nothing.
  • 8% of women benefited by avoiding breast cancer recurrence at 10 years by undergoing Anthracycline-based chemotherapy versus doing nothing.
  • 5.1% of women benefited by avoiding death at 5 years by undergoing Anthracycline-based chemotherapy versus doing nothing.
  • 5% of women benefited by avoiding death at 10 years by undergoing Anthracycline-based chemotherapy versus doing nothing.

For tamoxifen therapy the 5-year success rates are listed below for hormone-receptor positive cases of breast cancer in women. In hormone-receptor negative breast cancer cases, tamoxifen has little or no effect on recurrence and death rates. Once again, results are reported in terms of absolute risk reduction.[15]

Tamoxifen vs. No Treatment

  • 12.3% benefited by avoiding breast cancer recurrence at 5 years by taking tamoxifen versus no treatment.
  • 14.2% benefited by avoiding breast cancer recurrence at 10 years by taking tamoxifen versus no treatment.
  • 3.3% benefited by avoiding death at 5 years by taking tamoxifen versus no treatment.
  • 7.2% benefited by avoiding death at 10 years by taking tamoxifen versus no treatment.

Now that you’ve seen the benefits of taking the above drugs, let’s take a look at potential risks of experiencing side effects of these medications.[16][17][18]

Taxanes (Taxol)
Neutropenia (78-100%)
Alopecia (55-96%)
Anemia (47-96%)
Arthralgia/myalgia (93%)
Diarrhea (90%)
Leukopenia (90%)
Nausea/vomiting (9-88%)
Opportunistic infections (76%)
Peripheral neuropathy (42-79%)
Thrombocytopenia (4-68%)
Mucositis (5-45%)
Hypersensitivity (2-45%)
Renal impairment (34%)
Hypotension (17%)
Bradycardia (3%)

Anthracyclines (Doxorubicin)
Neutropenia (52%)
Anemia (52%)
Leukopenia (42%)
Pruritus (37%)
Nausea (37%)
Stomatitis (37%)
Fatigue (33%)
CHF (30%)
Thrombocytopenia (24%)
Vomiting (22%)
Rash (21%)
Alopecia (15%)
Anorexia (12%)
Constipation (12%)
Diarrhea (10%)
Cardiomyopathy (0.5-9%)

Tamoxifen
Hot flashes (64%)
Vaginal discharge (30%)
Amenorrhea (16%)
Menstrual changes (13%)
Oligomenorrhea (9%)
Cataracts (8%)
Bone pain (6%)
Nausea (5%)
Cough (4%)
Edema (4%)
Fatigue (4%)
Musculoskeletal pain (3%)
Ovarian cyst (3%)
Depression (2%)
Abdominal cramps (1%)
Anorexia (1%)

Breast Cancer & Diet

As mentioned earlier in this article, I am unaware of any controlled interventional studies of using a 100% WFPB diet in the treatment of breast cancer in which breast cancer recurrence and mortality data was reported. This, again, would be the gold standard in terms of evidence providing the highest quality of data that can be obtained.

However, John McDougall, MD, did conduct a controlled interventional study in 1984 using a low-fat, starch-centered, plant-based diet on a small group of postmenopausal women who had previously been diagnosed with breast cancer. McDougall found that specific markers (obesity, high cholesterol levels, high estrogen levels, and high prolactin levels) commonly associated with a poorer prognosis in breast cancer were all reduced after a 3-month period on his 100% starch-centered, plant-based diet.[19] While this information is valuable, we are still in need of long-term data on recurrence and mortality data in breast cancer with a WFPB diet.

Having said that, there are several population-based and prospective cohort studies that have observed a correlation of the effect of various diets on breast cancer.

Numerous studies show that a high-fat, Western diet is associated with higher incidences of breast cancer.[20][21] These studies show a definite link between unhealthy dietary patterns containing foods higher in fats (processed foods, meat, dairy, and animal fat) and breast cancer. Data like these should sound alarm bells for any woman wanting to avoid breast cancer. It is certainly a case of “better safe than sorry” when it comes to considering cutting out foods like beef, chicken, pork, fish, dairy, eggs, and processed foods from one’s diet in hopes of avoiding breast cancer.

Even though controlled interventional trials are virtually nonexistent for a low-fat, WFPB diet on breast cancer risk, there are a few randomized, controlled interventional trials analyzing a low-fat diet and breast cancer recurrence risk and death rates among breast cancer sufferers. A meta-analysis published in 2014 looked at two such studies.22 The two studies tested a low-fat (approximately 20-22% calories from fat) diet that included both plant and animal foods. This is a far cry from the 8% fat calories in the diet that McDougall tested in 1984. Nevertheless, in these studies there was a 23% reduction (statistically significant) on average in breast cancer recurrence rates and a 17% reduction (non-statistically significant) on average in all-cause mortality in breast cancer patients.

Another prospective cohort study published in 2013 followed 91,779 women who had never been diagnosed with breast cancer over a period of 14 years.[23] The investigators analyzed dietary intake patterns and breast cancer occurrence rates. The plant-based pattern (high consumption of fruits and vegetables) was associated with a reduction in breast cancer risk, while the salad and wine pattern (high consumption of salad, low-fat dressing, fish, wine, coffee, and tea) was associated with an increase in breast cancer risk. While all dietary patterns analyzed included both plant and animal foods in their respective groups, each particular pattern consisted of significantly higher amount of the foods listed in parentheses. While this is not the perfectly designed study to test direct cause-and-effect of a WFPB diet on breast cancer, it does provide yet another valuable lesson in showing us how whole, unrefined plant foods are protective against this awful disease.

Summary & Final Thoughts

Cancer is a frightening disease. The suffering that cancer patients endure during the course of their disease often incites fear not only in those suffering from the cancer, but also in those of us looking in from the outside. While no cancer is created equal, we have certainly made great strides in understanding the disease better. However, we have a long way to go in finding the ever-elusive “cure.”

Conventional treatments such as chemotherapy, radiation, and surgery have their own challenges in treating this disease, especially in terms of side effects. I’ve always maintained that our best bet is to prevent cancer in the first place by adopting healthy diet and lifestyle habits in order to avoid the medical events that follow. We can use these same prevention strategies in the treatment of cancer too, and we should. Prostate cancer is a shining example of this.

A health-promoting, cancer-fighting WFPB diet should be implemented in all patients with cancer regardless of whether or not that patient chooses to undergo conventional treatment options. There are no additional risks by doing so and only potential upsides in the form of reduced risks of several types of cancer.[24]

If you find yourself facing cancer, whatever you do, make sure to perform your due diligence in exploring all your treatment options in fighting this deadly disease. After all, knowledge is power and you’re going to need all the knowledge in the world to help you get through a disease like cancer.

Best of luck to you in your cancer-fighting journey! May life bless you with an abundance of health and happiness.

References

  1. Sudhakar A. History of cancer, ancient and modern treatment methods. J Cancer Sci Ther. 2009 Dec 1;1(2):1-4.
  2. Centers for Disease Control and Prevention (CDC). Leading causes of death. 2013. Available: http://www.cdc.gov/nchs/fastats/leading-causes-of-death.htm. Accessed 27 Feb 2015.
  3. Campbell TC, Campbell II TM. The China Study. Dallas, TX: Benbella Books, Inc. 2006.
  4. Mariotto AB, Yabroff KR, Shao Y, et al. Projections of the cost of cancer care in the United States: 2010-2020. J Natl Cancer Inst. 2011 Jan 19;103(2):117-28.
  5. Howlader N, Noone AM, Krapcho M, et al. SEER Cancer Statistics Review, 1975-2011, National Cancer Institute. Bethesda, MD, http://seer.cancer.gov/csr/1975_2011/, based on November 2013 SEER data submission, posted to the SEER website, April 2014.
  6. Horwich A, Parker C, Bangma C, et al. Prostate cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow-up. Annals of Oncology. 2010 May;21(5):129-133.
  7. Lu-Yao GL, Albertsen PC, Moore DF, et al. Survival following primary androgen deprivation therapy among men with localized prostate cancer. JAMA. 2008 Jul 9;300(2):173-181.
  8. Wilson S. Update on the management of prostate cancer with goserelin acetate: patient perspectives. Can Manag and Research. 2009;1:99-105.
  9. Treatments for Localized Prostate Cancer: Systematic Review to Update the 2002 U.S. Preventive Services Task Force Recommendation. 2011 Oct. (Evidence Syntheses, No. 91.)
  10. Ornish D, Weidner G, Fair WR, et al. Intensive lifestyle changes may affect the progression of prostate cancer. J Urol. 2005 Sep;174(3):1065-9.
  11. Louie KS, Seigneurin A, Cathcart P, et al. Do prostate cancer risk models improve the predictive accuracy of PSA screening? A meta-analysis. Ann Oncol. 2014 Nov 17.
  12. Saxe GA, Major JM, Nguyen JY, et al. Potential attenuation of disease progression in recurrent prostate cancer with plant-based diet and stress reduction. Integr Cancer Ther. 2006 Sep;5(3):206-13.
  13. De Laurentiis M, Cancello G, D’Agostino D, et al. Taxane-based combinations as adjuvant chemotherapy of early breast cancer: a meta-analysis of randomized trials. J Clin Oncol. 2008 Jan 1;26(1):44-53.
  14. Early Breast Cancer Trialists’ Collaborative Group (EBCTCG), Peto R, Davies C, et al. Comparisons between different polychemotherapy regimens for early breast cancer: meta-analyses of long-term outcome among 100,000 women in 123 randomised trials. Lancet. 2012 Feb 4;379(9814):432-44.
  15. Early Breast Cancer Trialists’ Collaborative Group (EBCTCG), Davies C, Godwin J, et al. Relevance of breast cancer hormone receptors and other factors to the efficacy of adjuvant tamoxifen: patient-level meta-analysis of randomised trials. Lancet. 2011 Aug 27;378(9793):771-84.
  16. Medscape Drugs & Diseases. Paclitaxel Adverse Effects. Available: http://www.reference.medscape.com/drug/taxol-paclitaxel-342187#4. Accessed 2 March 2015.
  17. Medscape Drugs & Diseases. Doxorubicin Adverse Effects. Available: http://reference.medscape.com/drug/doxorubicin-342120#4. Accessed 2 March 2015.
  18. Medscape Drugs & Diseases. Paclitaxel Adverse Effects. Available: http://reference.medscape.com/drug/nolvadex-soltamox-tamoxifen-342183#4. Accessed 2 March 2015.
  19. McDougall JA. Preliminary study of diet as an adjunct therapy for breast cancer. Breast. 1984;10:18-21.
  20. Kruk J, Marchlewicz M. Dietary fat and physical activity in relation to breast cancer among Polish women. Asian Pac J Cancer Prev. 2013;14(4):2495-502.
  21. Thiébaut AC, Kipnis V, Chang SC, et al. Dietary fat and postmenopausal invasive breast cancer in the National Institutes of Health-AARP Diet and Health Study cohort. J Natl Cancer Inst. 2007 Mar 21;99(6):451-62.
  22. Xing MY, Xu SZ, Shen P. Effect of low-fat diet on breast cancer survival: a meta-analysis. Asian Pac J Cancer Prev. 2014;15(3):1141-4.
  23. Link LB, Canchola AJ, Bernstein L, et al. Dietary patterns and breast cancer risk in the California Teachers Study cohort. Am J Clin Nutr 2013;98:1524-32.
  24. Lanou AJ, Svenson B. Reduced cancer risk in vegetarians: an analysis of recent reports. Cancer Manag Res. 2010 Dec 20;3:1-8.

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