Postmenopausal Women Taking Metformin For Diabetes Are At Lower Risk For Breast Cancer

Posted on

Estrogen Treatment is not a risk for breast cancer even though many women and their doctors have believed this mis-information for years. New studies in Europe, conclude what has already been proven in the US.

I have always wondered how Estrogen Replacement got the rap for causing post -menopausal breast cancer, when in my 29 years of practice in GYN, women who took estrogen did not have a higher rate of getting breast cancer, in fact, in my practice they had a lower incidence!  Recently, I read a journal article from a science journal that lists the risks of developing a new breast cancer (BC), that does not include the risk of taking ERT, estrogen replacement therapy. Daily Science April 2016 reveals a new idea concerning breast cancer: that women with diabetes have a 50% higher chance of getting breast cancer, and that there is a cheap and old drug that can lower that group’s risk of all cancers!

Risk of  Type 2 Diabetes = Risk for Breast Cancer

This is amazing, but predictable, if you consider the factors that increase AODM, Adult Onset Diabetes, in women are the same as the risk factors for Breast Cancer: obesity, abundant belly fat, loss of testosterone, high sugar intake, increased alcohol intake, lack of exercise and menopause.  Most of these behavioral habits can be remedied without even a pill, but as individuals, behavior change is the most difficult treatment regimen to follow. Because of that, we often fail to follow up on preventive measures, and wind up with AODM and Breast Cancer. Unfortunately, blaming estrogen is just easier, but avoiding estrogen will not take you where you want to go, if avoiding Breast Cancer is your goal!

Diabetes increases the risk and severity of all Cancers

The results of the study we are quoting from is from the International Journal of Cancer. They found that “women with AODM had a 45% greater risk of death from invasive cancer, when compared with women without diabetes”.  This is secondary to the fact that high blood sugar levels feed cancer’s growth! Then they compared women without diabetes and women with diabetes in regards to being diagnosed with invasive cancer, and they found that, “women with diabetes had a 13% higher risk of developing invasive cancer. These women also face increased risk that ranges from 20% to nearly double the chances of being diagnosed with the following cancers: colon, liver, pancreas, endometrial and non-Hodgkin lymphoma. “  Wow, that is startling! Why is that not on the headline of every newspaper in the US?

The Good News:

So here is the “blue sky” in all this depressing information.  Women with diabetes who took a generic, medication called metformin, had a much lower risk of cancer, and there was an increased survival rate for those who were “diagnosed with ovarian, colorectal and breast cancer”.

How to change your future:

Let’s put this information into a productive plan for those of you who have diabetes in your family or who crave sweets, or have gained belly fat from menopause, or who already have Type II Diabetes:


Behavioral methods to avoid diabetes:

  • Exercise at least 30 minutes daily
  • Eat at regular intervals(3-6 times a day)
  • Don’t eat large amounts at one time
  • Limit sugar and carbs to less than 25 gms per meal
  • Limit alcohol to weekends or 3 nights a week (no diabetes yet)
  • No alcohol (for diabetics)


Hormonal methods to avoid diabetes and cancer:

  • Replace testosterone in a non-oral form (-pellets are the best)
  • At menopause replace estradiol in non-oral form-also pellets are perfect for this!
  • Balance any hormones to pre-menopausal levels

If you have diabetes or are gaining weight, ask your doctor for Metformin XR daily and be compliant taking 500ER 2 times a day or more to prevent and treat diabetes., and therefore to prevent cancers, or make a cancer less invasive.

  • Metformin (RX) 500 ER 500-1500/day

How this relates to real life:

My experience is that the few women who do get breast cancer while on estradiol and testosterone pellets for more than two years, get very low grade, treatable cancers that do not take their life.  However, this is not just due to E/T in my practice, because I look for and treat all insulin resistance and adult onset diabetes aggressively and always with Metformin, diet and exercise or a more aggressive drug, Victoza, plus the other behavioral changes.  Preventing diabetes has always been on the forefront of my treatment plan for my patients and is becoming more and more important as the studies come in about extending the quality and health of aging women.  

You do your part with behavioral changes and I will diagnose, treat, and advise with E/T pellets and Metformin!


This Health cast was written and presented by Dr. Kathy Maupin, M.D., Bio-identical Hormone Replacement Expert and Author, with Brett Newcomb, MA., LPC., Family Counselor, Presenter and Author.  

Related Post: