For a cancer patient, a high red blood cell count can mean that the cancer has spread to the kidneys, resulting in renal cell carcinoma, explains Healthline. However, it can also indicate that an individual is merely dehydrated or taking certain drugs that can raise red blood cell counts.
For a cancer patient, a red blood cell count can be as innocuous as dehydration, but it can also point to dangerous secondary health problems such as heart or lung disease, as Mayo Clinic explains. High red blood cell levels can be caused by chronic obstructive pulmonary disease, which occurs in the lungs. This happens once the lungs become permanently damaged, a condition that can occur due to lung cancer or emphysema. Pulmonary fibrosis is another lung disease that raises red blood cell levels and can result from cancer radiation treatments or chemotherapy drugs.
Kidney cancer causes red blood cell levels to rise, according to Mayo Clinic. For a cancer patient, this can mean that the cancer is in any of the four stages. The earlier it is caught, the more likely that the tumor can be removed. By stage III, the cancer has metastasized or spread outside of the kidney.