Anemia is extremely common with cancer. Anemia is defined as a decrease in hemoglobin concentration, red blood cell count or a decrease in red blood cell pressure.
1. Mild anemia: 100 g/L ≤ hemoglobin ≤ 119 g/L
2. Moderate anemia: 80 g/L ≤ hemoglobin ≤ 99 g/L
3. Severe anemia: hemoglobin < 80 g/L.
Almost more than 100% of cancer patients will encounter anemia in their lifetime. There are three most common causes: bleeding (common in gastrointestinal tumors), insufficient hematopoiesis (cancer bone marrow infiltration or bone marrow suppression after treatment), and hemolysis.
Anemia has a direct impact on the prognosis and survival of tumor patients. It is very important to deal with cancer anemia and maintain a higher level of hemoglobin, especially for patients during treatment.
A. Look at the routine blood test and determine which of the following is the initial one?
1. Complete blood cell reduction. Platelet and white blood cell counts are reduced along with hemoglobin and hematocrit. The decrease in complete blood cell count is often seen in bone marrow metastasis of tumor or bone marrow suppression after radiotherapy.
2. Small MCV anemia. Iron deficiency is the most common cause of anemia. Small MCV anemia is diagnosed by peripheral blood smears and laboratory tests such as serum iron, total iron binding capacity, transferrin, ferritin, and hemoglobin electrophoresis.
3. Normal MCV anemia. Many anemias have normal MCV. Gastrointestinal blood loss often presents with normal MCV-type anemia. Chronic disease anemia is probably the most common orthocytic anemia.
4. Large MCV anemia. Many anemias are macrocytic, and only a few are megaloblastic. Common causes are folic acid and vitamin B1 deficiency. Deficiencies of both can manifest on peripheral blood films as excessive neutrophil lobulation or as nucleated red blood cells seen. Other diseases associated with macrocytic anemia are myelodysplastic syndromes, aplastic anemia, chemotherapy (anti-metabolic drugs), hypothyroidism, and other chronic diseases. Characteristically, an increase in MCV is also seen in the presence of a significant increase in reticulocytes.
II. Summarize clinical data and analyze to determine the specific cause of anemia
Understand the patient’s tumor stage, pathological type, and recent treatment.
1. Key points of physical examination
(1) Vital signs: Confirm whether the patient has postural hypotension. Observe whether the systolic blood pressure decreases by 10 mmHg and/or the heart rate increases by 20 beats/min after the patient is transferred from the prone position to the upright position for 1 minute. Postural changes suggesting the presence of acute blood loss or symptomatic anemia.
(2) Skin: capillary dilatation, hepatic palpitations and jaundice may suggest liver disease, and hemorrhagic manifestations and whole blood cytopenia suggest hematopoietic malignancy.
(3) Characteristic manifestations: linguitis is usually seen in iron and vitamin A deficiency.
(4) Abdomen: check for hepatosplenomegaly. (b) Cirrhosis, in patients with hepatosplenomegaly, with allogeneic cytopenia.
(5) Fecal occult blood test: for the presence of acute or chronic gastrointestinal blood loss.
2. Laboratory tests
(1) Peripheral blood smear: observation of peripheral blood film is crucial, noting the size and morphology of red blood cells. Nucleated erythrocytes, reticulocytes, broken erythrocytes, sickle cells, and target-shaped erythrocytes help in the diagnosis. Examine leukocyte morphology for excessive neutrophil lobulation or immature naïve cells.
(2) Reticulocyte count: the most important laboratory test after observation of peripheral blood films. An increased reticulocyte count suggests an appropriate response to anemia or a shortened erythrocyte life span due to blood loss or hemolysis. Whereas a decreased reticulocyte count is suggestive of a nutritional deficiency, immunosuppression, myelofibrosis or bone marrow suppression.
(3) Iron, total iron binding capacity (TIBC) or transferrin measurement: Usually, ferritin levels are measured if the patient is microcytic anemic. This will aid in the diagnosis of iron deficiency anemia.
(4) Vitamin B12 and folic acid: levels of vitamin B12 and folic acid are measured in all patients suspected of being vitamin B12 and folic acid deficient prior to transfusion. If the folate deficiency is secondary to malnutrition, serum folate levels can turn normal after one to two balanced diets. If the patient is still folate deficient after eating, it is necessary to consider checking the folate level in the red blood cells.
3. Pathologic evaluation
Unless there is a very direct or clear cause of anemia, all patients with anemia are indicated for bone marrow aspiration and biopsy. Even in patients with suspected iron deficiency anemia, decreased bone marrow iron stores support the diagnosis of iron deficiency.
Symptomatic management
1. Emergency blood transfusion is needed in case of large blood loss or hemodynamic instability
(1) If the patient is hemodynamically unstable or has angina pectoris, emergency blood transfusion is required.
(2) If there is acute massive bleeding, the patient should be ensured to have sufficient fluid intake, and blood volume should be restored rapidly and red blood cells should be transfused to correct anemia.
2. Anemia without hemodynamic instability or other complications
If the patient does not have hemodynamic abnormalities, the examination will be performed as usual. In many cases, the etiology of the anemia is not obvious. Moreover, the results of laboratory tests do not always have diagnostic value. A bone marrow biopsy is indicated if the patient’s history is unclear and the results of the physical examination and laboratory tests are ambiguous, with no obvious basis for underlying infection, malignancy or inflammatory disease.
3. Iron deficiency anemia
Iron deficiency anemia often occurs in patients with tumors. It is usually due to chronic blood loss, insufficient iron intake in food, and iron malabsorption. It must be remembered that excessive menstrual flow in young and middle-aged female oncology patients is also the most common cause of iron deficiency. Most patients can tolerate oral iron supplements such as ferrous sulfate 325 mg taken three times daily between meals. After the complete blood count is normalized, iron therapy still needs to be continued for 3-6 months to replenish the stored iron in the body. In order to increase the tolerance of iron, it can be gradually increased from 1 time to 2 or 3 times a day.
4. Folic acid deficiency
Common causes include inadequate intake (chronic alcoholism), malabsorption or increased demand, which requires folic acid supplementation of 1 mg per day.
5. Vitamin B12 deficiency
The most common cause is absorption disorders, and insufficient intake is less common. The most common cause is insufficient production of internal factors due to autoimmune factors, such as gastrectomy or ileostomy.
6. Hemolytic anemia
In the presence of elevated reticulocytes without significant blood loss, the possibility of erythrocyte destruction should be considered. Immune-mediated hemolysis (e.g., with chronic lymphocytic leukemia, non-Hodgkin’s lymphoma, or a history of autoimmune hemolytic anemia) can be diagnosed by the Coombs test. when the Coombs test is negative, consider other pathways of hemolysis, such as chemical or physical factors (after the use of arsenic agents), disseminated intravascular coagulation (DIC), etc.
7. Tumor progression-associated anemia
Most commonly, anemia occurs during the progression of malignant tumors. Excluding the above causes, or if the above treatments are ineffective, tumor-associated anemia is considered, and the basic treatment is as follows.
(1) Treat the malignant tumor. Anemia not related to treatment, considered to be caused by chronic consumption associated with the progression of malignant tumor, effective control of tumor and stopping its progression can improve the anemia status.
(2) Erythropoietin. Erythropoietin injections are generally well tolerated and have reliable efficacy in improving pernicious anemia. Some uncommon side effects include: hypertension (increased blood pressure), iron deficiency, occasional mild allergy, edema, and occasional exacerbation of diarrhea.