[Contribution] ‘Anemia’ is the most common change after stomach cancer surgery

If your stomach is removed due to stomach cancer, you can't eat much at a time, your food intake is limited, and you experience dumping syndrome if you eat too quickly, among other uncomfortable symptoms.

In addition to these eating problems, many other physical changes occur, the most common and important of which is anemia.

If your stomach is removed due to stomach cancer, you can't eat much at a time, your food intake is limited, and you experience dumping syndrome if you eat too quickly, among other uncomfortable symptoms.

In addition to these eating problems, many other physical changes occur, the most common and important of which is anemia.

Anemia is a condition in which the number of red blood cells in the body is reduced, or the red-colored protein in red blood cells called hemoglobin is reduced. Hemoglobin binds to oxygen in the lungs, and red blood cells with this binding carry oxygen around the body. This is why anemia causes a decrease in red blood cells or hemoglobin, which leads to hypoxia, a condition in which the oxygen supply to various tissues is impaired.

In adults, anemia is diagnosed when the blood test is lower than 13 g/dL in men and 12 g/dL in women. Mild anemia may have no symptoms, but as it progresses, it can cause fatigue, weakness, decreased athletic performance, dizziness, and shortness of breath after a short walk.

If left untreated, it could result in heart palpitations and generalized edema. Overall pallor, bluish nails, and loss of luster may also follow.

Two leading causes of anemia associated with stomach cancer are iron deficiency anemia and vitamin B12 deficiency anemia. While iron deficiency anemia is more common, vitamin B12 deficiency anemia can be accompanied by several neurological symptoms, so both should be carefully monitored and treated.

30-40% of patients experience iron deficiency anemia after stomach cancer surgery

Iron is the main component of hemoglobin in red blood cells, and insufficient intake or poor absorption of iron can lead to iron deficiency anemia.

Patients who have undergone stomach cancer surgery eat fewer iron-rich foods than they did before surgery. They also absorb iron less well, making them more prone to anemia. Studies show that 30-40 percent of patients experience iron deficiency anemia after surgery.

The richest source of iron is meat. However, stomach cancer patients, many of whom are elderly, are often reluctant to eat meat due to digestive problems.

Add to that the new pathway that connects the stomach to the small intestine after gastrectomy, which bypasses the duodenum, the main absorber of iron, and you've got a recipe for iron deficiency anemia.

Total gastrectomy patients need vitamin B12 injections one year after surgery

Vitamin B12 is one of the vitamin Bs and plays an important role in the body's production of red blood cells. A deficiency can cause anemia.

Normally, vitamin B12 is absorbed in the small intestine by binding to a protein called intrinsic factor, secreted by the stomach's upper part. Therefore, a total gastrectomy, in which the entire stomach is removed, can disrupt the secretion of intrinsic factors, leading to problems with vitamin B12 absorption and subsequent anemia.

Vitamin B12 is regulated in very small amounts, and the body already has a large stockpile in the liver, so anemia does not occur easily. However, about a year after gastrectomy, the liver will use the vitamin B12 stores, so it must be replenished regularly with injections.

Anemia is easily diagnosed with a blood test and listening to your symptoms. The hemoglobin level will be lower than the normal range, or the serum ferritin level will be low. A test to measure the blood level of vitamin B12 will also be performed to diagnose hypovitaminosis B12. It's essential to look for signs of bleeding from somewhere, not a problem with iron or vitamin B12 absorption.

Iron and vitamin B12 are found in meat, fish, and eggs, so eating these foods regularly is essential. Vitamin C improves iron absorption, so eating plenty of vegetables and fruits is essential.

Depending on the severity of your anemia, if you need to supplement with iron, you should take an oral iron supplement for at least three months. If you have side effects or cannot tolerate these oral medications, injectable iron is a good option. Patients undergoing total gastrectomy should continue supplementing vitamin B12 by injection for one year after surgery.