This is prompted by the recent post by justfor [1].
I was at my integrative medicine doctor yesterday. He's my enabler for off-label meds. We go back to 2006.
When I took my most recent lab results (back then), he jumped all over the ferritin number. As I recall, it was in the upper-200s. He wanted it below 100, perhaps close to 50. The remedy was phlebotomy. "In most cases the serum ferritin will drop by about 30ng/mL with each full unit of blood removed."
I went through this a few times. Maybe 4 sessions each time before a re-test.
But why did ferritin bounce back? I have a low-iron diet, IMO. Where did the iron come from that elevated ferritin? Is ferritin even a good measure of iron stores? Does it correlate well with iron in PCa cells?
A low ferritin reading reliably supports the idea that a person's anemia is due to iron deficiency. Men on ADT who develop anemia, should not supplement with iron if ferritin is normal. (Many do.)
"However, ferritin levels may be artificially high in cases of anemia of chronic disease where ferritin is elevated in its capacity as an inflammatory acute phase protein and not as a marker for iron overload." [2]
"As ferritin is also an acute-phase reactant, it is often elevated in the course of disease. A normal C-reactive protein can be used to exclude elevated ferritin caused by acute phase reactions." [2]
Also: "The concentration of ferritin has been shown to increase in response to stresses such as anoxia; this implies that it is an acute phase protein." [2]
"Acute-phase proteins ... are a class of proteins whose plasma concentrations increase (positive acute-phase proteins) or decrease (negative acute-phase proteins) in response to inflammation." [3]
Anoxia (severe hypoxia - very low oxygen) isn't something we are likely to experience although castrate testosterone levels may lead to a severe loss of oxygen carrying hemoglobin. (Hypoxia certainly happens in PCa tumors that have outgrown their oxygen supply.)
I often wondered if ferritin could be empty of iron, but in this state, it is called apoferritin. "Ferritin has a high capacity as an iron store, incorporating some 4500 iron atoms" [3] Iron will bind to apoferritin, or ferritin of low iron content.
So, while ferritin is never empty, it might not be full.
It is not easy to measure iron status. There are a half-dozen or so "bioindicators" (not biomarkers) that have their pros & cons, & which, alone or in combination, may not reliably provide the iron status of an individual.
Having said that, what about ferritin in PCa studies?
In a 2004 U.S. study [5]:
"In contrast with other malignancies, men with PC had significantly lower mean concentrations of serum ferritin (156 microg/L) and TS (24.35%) than those without PC (ferritin, 245 microg/L; TS, 31.98%)" "TS" is transferrin saturation.
That is a big difference. Did the men have low-iron diets, or did the cancer suck the iron up? Or does PCa interfere with the small loss of iron in urine, etc?
In contrast, the bigger 2017 Chinese study cited by justfor [6] found higher ferritin levels in PCa cases than BPH cases. Why didn't they compare PCa to non-BPH? Because PSA alone can't be used to distinguish PCa from BPH. But it would be nice to know what normal mean ferritin was in healthy Chinese men. Mean PCa ferritin was 200 ng/mL versus 180 ng/mL for BPH.
Another 2017 Chinese study [7] reported that:
"The levels of ferritin were verifed to be signifcantly higher in the urine of PCa patients than in that of BPH patients and controls."
Wait a moment - higher blood levels & higher loss through urine. Where is the iron coming from, other than diet? Or is it leaching fron the liver or other tissue associated with iron stores?
In a 2018 German study [8], we learn that:
"Neither ferritin nor the other markers of iron status were significantly associated with colorectal, prostate or lung cancer risk."
Although: "An inverse association was observed between ferritin and total cancer mortality (HR: 0.70 ..."
So, until they sort this out, one should be cautious regarding the use of ferritin as a "bioindicator".
Incidentally, my last lab result in 2018, without the assistance of phlebotomy, was 95 mg/mL.
-Patrick
[1] healthunlocked.com/advanced...
[2] en.wikipedia.org/wiki/Ferritin
[3] ncbi.nlm.nih.gov/pmc/articl...
[4] en.wikipedia.org/wiki/Acute...
[5] ncbi.nlm.nih.gov/pmc/articl...
[6] ncbi.nlm.nih.gov/pmc/articl...
