Ferritin Level in Anemic Patients Can Indicate Colon Cancer

The ferritin level of an anemic person's blood may help healthcare providers decide whether to order a colonoscopy to see if colon cancer is the problem.

One of the leading reasons to look for colon cancer is the presence of iron-deficiency anemia, since bleeding from such a cancer may cause loss of iron from the body. Ferritin is a measure of how much iron your body has stored for future use; low levels are considered diagnostic of iron deficiency. However, other conditions (such as inflammation) may increase ferritin and hamper recognition of iron deficiency.

A study by investigators at the Minneapolis Veteran's Administration (VA) Hospital (MN, USA) found that looking at the ferritin level in individuals with anemia may provide additional information on risk of colon cancer. For this retrospective study, they examined the data on 414 people (almost all older men) who had a colonoscopy because they had anemia, and 323 people who had no symptoms or anemia but had a colonoscopy as a routine screening for colon cancer. All subjects in the study had no abdominal symptoms and no documented intestinal bleeding. The mean age of those studied was 69 years old. All those with anemia also had measurement of ferritin shortly before the colonoscopy was performed. The authors studied four groups: those with no anemia, and those with anemia who had ferritin levels that were low (50 ng/ml or less), low normal (51-100 ng/ml), or not low (above 100 ng/ml).

As expected, those with iron deficiency (low ferritin) were significantly more likely to have a cancerous or pre-cancerous condition in the colon (called advanced colonic neoplasia). However, those with anemia and low normal ferritin were just as likely to have advanced colonic neoplasia. In contrast, those with anemia but without low or low normal ferritin were no more likely to have advanced colonic neoplasia than those who did not have anemia.

When age was factored in, indivdiuals with serum ferritin levels below 100 ng/ml were almost five times more likely to have colon cancer or high-risk types of polyps, observed the investigators. For men with unexplained anemia, they concluded that a ferritin level below100 ng/ml is a reason to promptly refer these patients for colonoscopy. The test helps determine if the anemia is related to colon cancer.


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Minneapolis VA Hospital