Metformin effect or just coincidence?

For the diabetics, do note that LDL is the most important thing to control and the new 2018 guidelines are for LDL to be below 70 for diabetics. My endo put me on Atorvastatin, which lowered my LDL from about 70-130 to now 35-65

hogo2000 said...
Grinnell86, i went on metformin 1700 mg/day and atorvastatin in March 10mg. lipids improved and today the psa dropped from .05 to .04. But isn't the metformin just masking the true PSA? It might make a difference for me as I approach SRT. Should I be waiting 10-13 days (the studies show it remains in plasma for up to 13 days) and retest to find out my "true" value, or just accept this as my fully-dosed metformin/statin adjusted psa and go from here. I don't want to be lulled into not acting with SRT.

Have call into Paul Nguyen at Dana Farber. Thoughts?

Hogo,
Some folks think that Metformin helps with the fight against PC, other cancers and a bunch of other issues. I do not know if this has ever been proved, but I wouldn't be surprised if it does.

However, I'm pretty sure it is proven that Metformin improves insulin sensitivity, thus leading to lower blood insulin levels as well as lower blood sugar levels. Insulin resistance(opposite of sensitivity) and higher blood insulin levels are heavily implicated in poorer outcomes for numerous cancers, including 3 to 8 times worse for PC.

So, it is at least reasonably possible that Metformin is not just masking your PSA, but actually improving your PC status, meaning fewer PSA producing PC cells left alive. It is def possible. Any dietary approach that lowers blood sugar/insulin will probably help as much or more than Metformin.

We were told by some authorities that T2 diabetes was actually protective against PC. Which was the ONLY cancer that diabetes was not actually harmful for. So we were told that PC was different from all other cancers, and what helped with them might make PC worse(even though all responded to surgery, RT and often ADT. But I have long called BS on that, and studies showing that greater blood insulin = worse PC ( and all other cancer) outcome back me up. I always said it was not the T2D that was protective, it was the TREATMENT for T2D, which during the early stages lowered blood insulin( i.e. Metformin and improved diet). And this lowering of blood sugar and insulin often started 10-30 years before PC is normally diagnosed. Hence, less insulin to promote growth of PC cells, over decades when the PC might be growing.

Therefore, I would not be overly concerned about your Metformin. If anything, be concerned about the amount of carbohydrates in your diet, which cause you to need Metformin in the first place. Good luck!

Post Edited (BillyBob@388) : 5/1/2019 10:23:10 PM (GMT-6)

Thanks everyone. Asked my PCP to put me on metformin/lipitor for off-label reasons to slow down PSA increase. Felt helpless seeing PSA increase and not yet time to pull trigger according to two top boston RO's. So...at the very least i am doing something to make my overall health better.

Here is an article, one of many, that talks about metformin/psa decrease. Insulin response absolutely is part of it but some concern about the drop affecting treatment management without proof of improvement in cancer control. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5758272/ Here is another article from about the symbiotic impact of the two drugs. https://www.urotoday.com/conference-highlights/asco-gu-2018/asco-gu-2018-prostate-cancer/101788-asco-gu-2018-individual-and-joint-effect-of-postdiagnostic-metformin-and-statin-use-on-prostate-cancer-mortality-among-patients-with-high-risk-prostate-cancer.html

My RO who i've been consulting with and am lucky enough to have in bullpen if needed said..."just use this number, don't worry about a masking effect. If you want to treat at .08 or .09 instead of .1..." and retest in 3-4 months...I'll take that...along with the lipitor and metformin.https://https://https://

Grinnell86 said...
I have been off metformin since December. I get my blood drawn in 2 weeks. I’ll give an update on all the numbers at that time.

Paul

How did you get off Metformin? Diet change?

G86,
Good for you. Usually, dropping 40 lbs will get er done, looks like it worked again!

Wow. I’m glad this thread came up. And yet it begs the question....are there valid studies showing benefit of Metformin for PCa? And if so, why wouldn’t it be approved for PCa rather than being an off label treatment.

I just looked at the Silverscript formulary and metformin (glocophage) is only listed under anti-diabetes. Reimbursement would probably depend on the coding the doctor provides and any appeal that might be made should the reimbursement be denied.

Here is a ASCO article about lipitor and metformin. https://www.urotoday.com/conference-highlights/asco-gu-2018/asco-gu-2018-prostate-cancer/101788-asco-gu-2018-individual-and-joint-effect-of-postdiagnostic-metformin-and-statin-use-on-prostate-cancer-mortality-among-patients-with-high-risk-prostate-cancer.html

There is also a clinical trial on the use of metformin to radiosensitize PCA cells prior to SRT. I asked my PCP to put me on both just to...do something....I am neither diabetic nor do I have high cholesterol. (in fact it's very low now....

The question I have...is the metformin slowing or killing cells or is it masking the PSA. [

Yeeha! I am convinced now that metformin is an aid to prostate cancer. Down from .079 to .059 after 6 months back on metformin. I am a believer. I did 500 mg twice/ day being non-diabetic. My new GP is very progressive (and she is also very good looking) and was very open to my suggestions that metformin helps suppress prostate cancer.