As a functional medicine doctor, I am always looking for biomarkers that provide prognostic value aside from PSA (Prostate-Specific Antigen). I think Hemoglobin A1c is one of them.
What is Hemoglobin A1c?
- Hemoglobin A1c (HgA1c) is a biomarker clinically tested for blood sugar abnormalities like diabetes. A level higher than 6.5% (along with blood glucose ≥126 mg/dL) might indicate an individual has diabetes.
How does Hemoglobin A1c work?
- Briefly, hemoglobin is a protein in red blood cells that carry oxygen to your whole body.
- You know hemoglobin very well as it is a standard blood test to determine if you are anemic.
- Red blood cells, including the hemoglobin, last about three months before dying off as the body makes more of these cells in the bone marrow.
- Glucose (sugar) attaches to hemoglobin protein in the red blood cell for the time those cells are around (about three months), so what the HgA1c test does is measures blood sugar for the last three months of the blood draw.
What is the Connection with Hemoglobin A1c and Cancer
HgA1c gives me an idea of sugar metabolism in the body, and the ability to metabolize sugar well is associated with many diseases, including cancer.
- In one study of close to 30,000 people studied, researchers noticed a non-diabetic range (6.0–6.4%) was associated with a 51% higher colorectal cancer risk.
- Another study showed that HbA1c levels from 6.0 to 6.9% had a 40% higher risk of all cancers than individuals with HbA1c levels less than 6.0%.
What is the relationship between Hemoglobin A1c and Prostate Cancer?
The relationship between HgA1c and prostate cancer is interesting – higher hemoglobin A1c typically equates to lower PSA, but here’s the kicker, lower PSA in this scenario can be a false negative. In other words, when HgA1c is high, but PSA is low, there can still be cancer in the prostate. But, that’s not all… a high Hemoglobin A1c but low PSA can still mean there’s likely aggressive cancer harboring in the prostate gland.
- One study showed HbA1c levels were higher in patients with high-grade prostate cancer.
- Another study showed that high preoperative hemoglobin A1c level, despite a diagnosis of diabetes, was associated with worse oncological outcomes, worse incontinence recovery, and harder (pun) to obtain an erection post-surgery.
Final Thoughts on Hemoglobin A1c and Prostate Cancer
As a patient, you may ask your urologist for a HgA1c test on your next blood draw, but they may not honor it. This is because urologists do not want to “treat abnormal lab numbers” they are not trained to treat – if your HgA1c is high, they are responsible for that increased value, and they likely would not want to carry that liability.
Hemoglobin A1c for prostate cancer stratification is not the end-all-be-all but it is one important non-invasive piece to the puzzle.