Breast cancer is sneaky. A new study discovers a trick that breast cancers use to get around some of our best drugs. If you know about this trick you’ll be able to take action to put a stop to it.
The Background:
Two-thirds of all breast cancers are stimulated to grow by the hormone estrogen (also known as “estrogen receptor positive” or “ER-positive” breast cancer).
See the image on the right:
Inside the cell, on the surface of the nucleus, there are receptors called “estrogen receptors” (ER’s) which have one main job to do- wait for the hormone estrogen to come along, land in the receptor and activate it. Once activated by estrogen, the receptor sends a signal to the DNA inside the nucleus to tell the cell to grow and divide.
In hopes of stopping or slowing these cancers down (in individuals with ER-positive breast cancer), oncologists prescribe drugs that can either lower the amount of estrogen in the body (i.e. aromatase inhibitors) or block estrogen from landing in the estrogen receptor (i.e. Tamoxifen).
A New Discovery: Breast Cancer Likes Cholesterol
These drugs work very in many patients however just this month a new discovery found a sneaky bypass route used by ER-positive breast cancer cells that enables them to be stimulated to grow and divide even when there is little to no estrogen available to activate their ER’s.
Researchers from two different institutions (University of Texas Southwestern and Duke) reported that a metabolite of cholesterol, 27-hydroxycholesterol (or 27HC), is a potent stimulator of the ER.
Cholesterol is converted into 27HC in the liver by the enzyme (CYP27A1). 27HC is typically broken down by a different liver enzyme (CYP7B1). It turns out that that patients who have very aggressive breast cancers with poor prognoses make much less of this enzyme, so they accumulate higher levels of 27HC.
What Does All This Mean For My Patients?
If you have ER-positive breast cancer you should do everything you can to not only reduce your estrogen levels, but now based on this research you should also take steps to reduce your cholesterol levels (total and LDL).
What levels do we want to achieve for our cholesterol and lipids?
Unfortunately we don’t yet have studies to guide us on this for ER-positive breast cancer patients, so suggest using levels recommended for maintaining optimal cardiovascular health:
- Total cholesterol (160-180 mg/dL)
- LDL (50-99 mg/dL)…this is also know as our ‘bad‘ cholesterol
- HDL (50-60 mg/dL or greater)…this is also known as our ‘good‘ cholesterol
- Triglycerides (less than 80 mg/dL)
Low fat diets are the key to achieving optimal cholesterol and lipid levels, right?
No. A common misconception that I hear all the time (including from many doctors) is that cholesterol comes mainly from the food we eat and if you eat a low fat diet you will not have elevated cholesterol levels. This myth has been busted.
In fact, we produce about 1,000 mg of cholesterol in our body each day, whereas we consume only 200-300 mg per day in the standard U.S. diet. This means we need to do a lot more than just watch what we eat.
There are many things we can do to lower cholesterol and lipid levels:
- Exercise (Studies show exercise lowers ‘bad’ LDL and raises ‘good’ HDL cholesterol levels. Get at least 30-minutes of moderate intensity exercise 5-days per week and at least 2-sessions of weight or resistance training)
- Get off your bottom (buy a pedometer and make a goal of walking at least 10,000 steps every day)
- Eat an anticancer, anti-inflammatory diet (i.e. the Mediterranean diet)Maintain a healthy waist-to-height ratio (make sure your waist measures less than 50% of your height; this measurement is even more important than how much you weigh or your body mass index as it correlates better with the amount of abdominal fat you have- the most inflammatory and dangerous fat inn your body)
- The best diets are predominantly plant based, contain lots of fiber and healthy omega-3 fats, but are low in cholesterol, saturated fat, omega-6 fats, simple carbohydrates and processed foods.
- You can still eat animal meat and products, but do so sparingly
- Fish are a great source of protein, but choose less toxic varieties and avoid commercial-farm raised fish that are often fed corn and soy meal, antibiotics and growth hormones
- Eat nuts: studies show that eating a handful of nuts each day can increase ‘good’ HDL cholesterol levels (just don’t go crazy and eat too many handfuls each day as they are fattening)
- Completely avoid all trans fats: studies show trans fats raise ‘bad’ LDL cholesterol levels and lower ‘good’ HDL levels
- Drink green tea: studies show green tea lowers ‘bad’ LDL cholesterol levels
- Don’t smoke (studies show that tobacco lowers your ‘good’ HDL cholesterol and raises you ‘bad’ LDL levels)
- Get adequate sleep (studies show higher cholesterol levels in those who get less than 8 hours of sleep each night)
- Lower your stress levels (Chronic stress is associated with higher cholesterol levels. I strongly encourage my patients to meditate or practice breathing exercises for 30-minutes each day. If you want to turbocharge your meditation sessions, try listening to “binaural beat meditation” soundtracks.)
- There are many different medications that lower cholesterol. There can be serious side effects associated with these medications so you will need to weigh these against the potential benefits. Here are the main categories of cholesterol lowering medications:
- Statins (these drugs block the production of cholesterol in the liver and are the first line of treatment for most people with high cholesterol). Studies have even shown that breast cancer survivors taking a statin have a 10% lower risk of recurrence than those not taking a statin.
- Make sure you take a bioactive form (Ubiquinol) of Coenzyme Q10 (CoQ10) as this important antioxidant gets depleted when you take a statin
- Niacin
- Bile-acid resins
- Fibric acid derivatives
- Cholesterol absorption inhibitors
- Statins (these drugs block the production of cholesterol in the liver and are the first line of treatment for most people with high cholesterol). Studies have even shown that breast cancer survivors taking a statin have a 10% lower risk of recurrence than those not taking a statin.
- Here is a list of non-prescription supplements that may be able to reduce cholesterol levels (from Life Extension). Always discuss your use of supplements with your doctors:
- Inhibiting Cholesterol Synthesis:
- Pantethine: 400 – 1200 mg daily
- Red Yeast Rice: 600 – 1200 mg daily
- Garlic; standardized extract: 1500 – 3000 mg daily
- Amla (Indian gooseberry); standardized extract: 500 – 1000 mg daily
- Inhibiting Absorption of Dietary Cholesterol:
- Dietary Fiber: 25 – 30 grams daily
- Prebiotics: 5000 – 10 000 mg daily
- Plant Sterols: 600 – 1200 mg daily
- Soy isoflavones: 54 – 108 mg daily
- Enhancing Cholesterol Elimination:
- Artichoke Leaf; standardized extract: 500 – 1000 mg daily
- Inhibiting Cholesterol Synthesis:
The Bottom Line:
Who knew the estrogen receptor was so sneaky? Now that you know you can take action.
If you have estrogen receptor-postive (ER-positive) breast cancer you need to do everything you can to both lower your estrogen levels and your cholesterol levels. Fortunately, many of the same things that reduce systemic estrogen also reduce cholesterol levels (i.e. exercise, healthful diet, obtaining an optimal waist to height ratio, etc).
Should you take cholesterol lowering medications (i.e. statins)? Although these drugs have side effects, I would discuss with your oncologist the possibility of using them- especially if the estrogen blocking or anti-estrogen drugs you are taking are no longer effective and the other measures I’ve mentioned above aren’t working.
