Does metformin prevent prostate cancer? Or increase risk? Or both?
Some inflammatory comments about metformin
I had a widow-maker heart attack 17 years ago. I beat the odds and survived it.
In 2010, was diagnosed with very low-risk (Gleason 6) prostate cancer.
In 2017, I was diagnosed with type-2 diabetes.
These events are not unrelated.
They are all inflammatory processes.
I have been lucky all the way. My luck is based on a usually decent diet and regular exercise.
I was put on metformin, a well-established and safe medication, when I was diagnosed with T2D, which helps lower blood sugar.
I have an average A1c of 6 but if I get serious about diet I can bring it down to 5.2 or lower and reverse my diabetes.
I keep swearing I will. Stay tuned on that.
I was prescribed 2,000 mg/day of metformin. My former internist said most of his patients end up on 2,000 because they are non-compliant. But I switched doctors, and my new one has been weaning me from some meds. I went off metformin and found my blood sugar stayed about the same. But for safety sake, I returned to 1,000 mg/day.
My urologist and metformin
When the diabetes was diagnosed, I told my urologist, Brian Helfand, MD, about it and also the metformin.
He said metformin is an interesting med.
He said noted it had been shown to lower PSAs. In fact, my PSA went down a bit. But some weight loss might have helped that.
Some major leaders in prostate health, such as Mark Moyad, MD, of the University of Michigan (Go Blue) routinely recommend metformin for the prostate along with aspirin for its heart benefits for some and statins for cholesterol control as a way to fend off the inflammatory risks even for men who have no prostate cancer issues.
BONUS round: Research has shown metformin may have other benefits. Everyday Health reports: “Metformin has established itself as the medication of choice when it comes to the first-line treatment of type 2 diabetes. In addition to lowering blood sugar, the medication may extend lives, lower heart risks, lower high blood pressure, and provide other health benefits.”
I’m gonna live forever?
Metformin also may influence metabolic and cellular processes associated with the development of age-related conditions, such as inflammation, oxidative damage, diminished autophagy, cell senescence, and apoptosis. Hence, metformin is of particular interest in clinical translational research in aging since it may influence fundamental aging factors that underlie multiple age-related conditions.
Good news for lab rats and maybe humans.
Bad news?
So now, some mixed news from Israel.
Researchers there have found that metformin exposure in the previous year may increase the risk for prostate cancer in patients.
But get this: Exposure in the previous 2 to 7 years may lower the risk, according to the study.
More here: https://bit.ly/3u3mDcm
Researchers conducted a population-based study of 145,617 men aged 21 to 90 years with newly diagnosed diabetes.
Of these men, 1,592 were diagnosed with prostate cancer.
Those who took metformin in the previous year had a 53% increased risk for a prostate cancer diagnosis per defined daily dose before adjusting for glucose control. Forty-two percent had an increased risk after adjusting for glucose control researchers reported in the American Journal of Epidemiology.
The Active Surveillor has asked a few doctors for second opinions.
Christopher Wallis, MD PhD FRCSC, assistant professor, Division of Urology, University of Toronto, said: “Most studies suggest a generally beneficial effect, if anything, from metformin on prostate cancer. The MAST (Metformin Active Surveillance Trial) is assessing this more formally but, if indicated for diabetes, metformin should be. [prescribed]..”
MAST is looking at these issues in a double-blind study of 408 patients at the University Health Network in Toronto. The results are due in 2024,
Wallis said, "Evidence for metformin in prostate cancer isn't strong enough to make treatment recommendations in my opinion. Treatment for diabetes should be driven by what is guideline appropriate for diabetes, as decided by the primary care physician/endocrinologist.”
Treatment for diabetes should be driven by what is guideline appropriate for diabetes, as decided by PCP/endocrine.
Meanwhile, ask your own doctor for advice on metformin.
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