Getting the Most Out of Tamoxifen

By Keith Block, MD

Many women with breast cancer are aware of a recent long-term British study showing that taking the generic drug tamoxifen for five years resulted in a significantly lower risk of their cancer returning when compared to only taking the drug for two years.  In this clinical trial, nearly 3,500 breast cancer patients were studied for over 10 years.  The findings, published in the 1 May 2011 Journal of Clinical Oncology, showed that breast cancer returned in around 40% of those who took tamoxifen for five years, compared to 46% among those who took it for two years.

In other words, for every 100 patients who completed a full five-year course of tamoxifen, six fewer women had a recurrence, compared to those who only took the drug for two years.  In addition, the five-year course of tamoxifen resulted in a lower risk of developing or dying from heart disease.  For example, among women aged between 50 and 59 at diagnosis, 35% fewer women developing a heart condition and nearly 60% fewer deaths as a consequence.

Back in the 1970s, tamoxifen was designated as the first drug to block the effects of estrogen.  This is important, since about 75 percent of all breast cancers are estrogen-receptor positive, meaning their growth is largely driven by estrogen (among other hormones).  Even though women diagnosed with early-stage breast cancer are typically advised to take tamoxifen for five years, many stop after two or three years—usually due to concerns about side effects and treatment resistance.

Also, a new generation of drugs known as aromatase inhibitors (AIs) has now been developed, and these drugs appear to be even more effective in lowering breast cancer recurrences than tamoxifen.  On the other hand, AIs have more toxic effects—promoting heart disease and bone thinning, for example—and this may account for their lack of overall survival benefit when compared to tamoxifen, as reported in the 22 August 2011 Journal of the National Cancer Institute. 

For this reason, many cancer experts believe it is best to at least start with tamoxifen and then switch to AIs in order to limit longer AI exposure and thus increased risk of side effects while further helping to sustain a remission.  And for women already at high risk of developing heart disease and osteoporosis, taking the full 5-year course of tamoxifen may be a better option.

The problem with tamoxifen, though, is that it too has side effects—namely raising the risk of developing uterine cancer, blood clots, and cataracts.  However, these appear to be rarer problems and most of my colleagues tend to agree that the benefits outweigh the risks. Also, even though tamoxifen blocks estrogen in the breast, it acts like estrogen in your other tissues, which would help explain why it protects bones from osteoporosis and lowers bad cholesterol, hence protecting against heart disease.

So, if you’re going to take tamoxifen, my first piece of advice is to maintain a strong anti-cancer diet—one loaded with cruciferous vegetables, legumes, fruits, and whole grains.  Such an antioxidant-rich diet lowers your risk of not only uterine cancer, but also blood clots and cataracts.  It is also important to mention that one of the problems with the long-term use of tamoxifen is that cancer cells may develop resistance to the drug.  This means that some cancer cells will likely not be eliminated, increasing the risk of the cancer recurring.  There are specific nutraceuticals that have shown the potential to help reduce this resistance.  However, for this type of program, I strongly recommend one consult with a healthcare practitioner knowledgeable and experienced in the use of nutraceuticals for cancer patients.

Green tea and melatonin are among the best-studied agents in this regard.  A UCLA study concluded that “the combination of green tea and tamoxifen is more potent than either agent alone in suppressing breast cancer growth,” as reported in the December 2006 issue of Carcinogenesis.  And a 1995 clinical trial found that taking high-dose melatonin (20 mg) with tamoxifen led to significant tumor shrinkage in metastatic breast cancer patients who had not responded to tamoxifen alone.

Other supplements that have been shown to synergize with tamoxifen include selenium, panax ginseng, fish oil and borage oil.  This means that using these supplements in conjunction with the green tea, melatonin, and an anti-cancer diet, can be very helpful in maximizing the benefits of tamoxifen itself.  If you’re going to invest five years into taking a particular drug, it only makes sense to think in terms of a diet and supplement strategy that will give you the best results.    

For more information on The Block Center for Integrative Cancer Treatment, call (847) 230-9107 or visit BlockMD.com. 

Comments

[Michelle]

Thank you for posting this. I was just questioning my taking Tamoxifen and Green Tea, based on an article in the latest CURE magazine. In there they are showing Green Tea may increase the oral bioavailability of Tamoxfien, increasing the potential for interactions ( source: Memorial Sloan-Kettering Cancer Center).

[Noah Berkowitz]

My sister had asked me about that TAMOXIFEN, I am just new for the word so I search and glad that I found your so informative post. "tamoxifen was designated as the first drug to block the effects of estrogen", great. I am going to say it to my sister or may be sharing this link to her.

[Chris]

I found resdearch information were is mentioned that flaxseed and flaxseedoil have a simular effect as tamoxifen: why disbalancing my body if there is a healthier alternative??.
Reading the information above the questions rises wich benefit is better: a healthy lifestyle and cancer diet , green tea and usefull supplements completed with a the right doses of flaxseed/oil.

[Kari Wilson]

Thank you for this information. If we could only get further along in finding more friendly ways to combat the cancer cells. It seems like we are always so close but we just never quite get there. I wish the best for anyone who is currently going through this struggle.