Cancer cells have such a hunger for iron that it's been termed an "iron addiction".
Transferrin is the protein that transports iron for delivery to cells.
Cancer cells have massively more transferrin receptors than normal cells, in some cases 100x more or even greater. This is illustrated in the images below.
The amount of iron carried by transferrin varies - that's the significance of the common lab test transferrin saturation. It has low saturation in iron-poor conditions, and high saturation in iron-loaded conditions.
You can decrease the saturation - the most efficient way is by donating blood.
This means that cancer cells, even with their many transferrin receptors, have more difficulty getting enough iron to grow.
A randomized controlled trial has already demonstrated that phlebotomy (bloodletting, equivalent to blood donation) lowers cancer incidence (35% over 4.5 years) and cancer mortality by 60%.
Iron is an underrated factor in aging, as well as an underrated factor in cancer.
ALT PMID: 30034931