Hematology is the medical discipline that studies blood diseases and cancers originating from bone marrow and deals with their treatments.
What are Blood Diseases?
It is necessary to broadly comprehend functions and structure of blood in order to understand answer to this question. In a healthy adult, the volume of blood is approximately 4 to 5 liters. Blood is a body fluid that transports substances required for nutrition and self regeneration, enables communication by and between organs through certain substances (hormone), fights and defeats foreign bodies and microbes and carries hazardous metabolic waste substances certain organs, such as lungs and kidneys, to excrete thereof.
Blood contains minerals, nutrients, hormones, and proteins that are required for cell proliferation and self-regeneration as well as other proteins that keep blood in liquid phase under normal circumstances, but produce clots in case of an injury along with blood cells and toxic metabolic waste products of organs. There are three types of cells in blood: red blood cells (erythrocytes), white blood cells (leukocyte) and platelets, which function to transfer oxygen and carbon dioxide to/from cells, defend the body against microbes and hazardous agents and enables coagulation in case of bleeding, respectively. Hemoglobin is the molecule that helps transport of oxygen and carbon dioxide by red blood cells. Blood cells are produced by stem cells in the bone marrow and they are broken down and destructed after a certain period. Since these cells are continuously produced by bone marrow, the number of blood cells is kept constant within certain limits. Lymph nodes, thymus and spleen collaborate with the white blood cells in order to protect the body against microbes and harmful agents (immune system). Lymph nodes are small organs that recruit a certain member of white blood cells, called lymphocytes, to fight microbes. Thymus gland also has a similar duty.
Major group of diseases the hematology department deals with are summarized below:
1. Abnormal production of blood cells or hemoglobin in bone marrow (various types of anemia, leukopenia and thrombocytopenia)
2. Destruction of blood cells earlier than usual life span (hemolytic anemia, ITP, etc.)
3. Dysfunctions of blood cells (sickle cell anemia, various dysfunctions, etc.)
4. Impaired blood clotting (hemophilia, von Willebrand disease, etc.)
5. Unnecessary coagulation of blood in the vascular system (thrombosis, pulmonary thromboembolism, thrombophlebitis, etc.)
6. Cancerous transformation of bone marrow cells and lymph node cells (leukemia, lymphomas, myeloma, etc.)
What are Symptoms of Blood Diseases?
Primary symptoms of blood diseases are fatigue, pallor, poor exercise capacity, infections at frequent intervals, persistent fever, bleeding for no reason or due to mild trauma, long-lasting bleeding in case of injuries, gradually growing painless lumps (nodes) on neck, armpits or groin and sudden-onset painful edema (swelling) in whole leg or below the knee level.
What are Principal Methods Used for Establishing Diagnosis of Blood Diseases?
It may be necessary to employ a wide range of tests to establish diagnosis of blood diseases: The most commonly required tests are complete blood count (analyzing various components, including hemoglobin, and indices of blood), analysis of hemoglobin subtypes with electrophoresis, peripheral blood smear (examining blood under microscope to look for abnormalities), bone marrow analysis (bone marrow aspiration and biopsy), analyzing iron, vitamin B12 and folic acid levels, which are required to produce blood cells, blood coagulation assays, tests that look for functions and life span of blood cells, analysis of proteins produced by immune system, and chromosomal and genetic analysis of blood cells and bone marrow cells that produce the former one as well as radiology studies.
Which Cancers Can Be Diagnosed with a PET-CT Scan?
This most recent and advanced imaging modality helps staging, evaluating response to treatment and detecting the risk for recurrence early in many types of cancers, especially including lymphoma and multiple myeloma.
Advantages of PET-CT
It saves the patient from unnecessary treatments and surgical procedures, as it visualizes spread of cancer far more precisely than other imaging modalities.
It reduces the number of surgical interventions, as the biopsy or excision site is very clearly detected, because the active disease areas are imaged.
Since it shows the changes in metabolic activity of the disease at early phase of the treatment period, it provides the physician with valuable data about outcomes.
It helps physicians detect ineffective treatments and accordingly saves time, which is crucial for treatment of the patient.
How Are Anti-Cancer Medications Selected?
The medications are selected by physicians depending on type of tumor, extent of metastasis or spread, age of patient and other co-existing diseases (high blood pressure, heart disease, diabetes mellitus and renal disease). Doses and administration frequency of the selected medications are also decided by hematologists.
How About Frequency and Duration of Chemotherapy?
Duration of chemotherapy and frequency of doses depend on the disease and overall health of patient. The hematologist who supervises the patient can modify duration and frequency of treatment according to the outcome and side effects. Various routes can be used to administer chemotherapeutic agents.
Intravenous (the most common method)
Oral
Into body cavities
Bone marrow
What are Side Effects of Chemotherapy and How Long Do They Persist?
Complete Blood Count: This test measures count of white blood cells, which are produced by bone marrow to fight germs, amount of hemoglobin, which transports oxygen, and count of platelets, which stops bleeding by coagulating the blood. Chemotherapy is not given, if count of cells determined through complete blood count is not within pre-determined ranges. In some cases, treatment may be postponed. Biochemical blood tests: Biochemical tests are a group of blood assays, such as urea, creatinine, glucose and liver enzymes, that look for if an organ functions properly.
Patient's life changes and the disease becomes the only thing in patient's mind, when a diagnosis is established and verified or metastasis is detected. Patients become reluctant to do anything and start to feel unhappy. These emotions pave the way for certain mental disorders in cancer patients.
Adjustment disorders and depression are the most common psychiatric disorders in cancer patients.
Who Should Carry Out Treatment of Blood Diseases?
Diagnosis and treatment of blood diseases require cooperation of numerous medical disciplines. A surgeon, a radiation Oncologist for radiotherapy and a hematologist, who can deal with chemotherapy and supportive medical treatment, must be included in the care team. Support must be requested from other departments, whenever necessary.
