There are three main groups of blood cancer:

Overview

• Blood cancer is a group of cancers that affect the blood, bone marrow and lymphatic system.
• Blood cancer begins when something goes wrong in this process: the DNA inside developing blood cells becomes damaged, causing those cells to grow and multiply in an uncontrolled way
• Because blood cells travel throughout the whole body, blood cancers tend to behave differently from cancers that form solid lumps in a single organ
• They are often widespread at the time of diagnosis, which is why they are treated with medicines that work throughout the body rather than surgery alone

Types of blood cancer

There are three main groups of blood cancer:

• Leukaemia: Cancer of white blood cells, originating in the bone marrow; it can be acute (fast-growing, needs urgent treatment) or chronic (slower-growing)
• Lymphoma: Cancer of white blood cells called lymphocytes, which form part of the immune system; it mainly affects the lymph nodes (small glands found throughout the body)
• Myeloma (multiple myeloma): Cancer of plasma cells, a type of white blood cell that normally makes antibodies to fight infection; abnormal plasma cells accumulate in the bone marrow, crowding out healthy cells and producing abnormal proteins that can damage the kidneys and bones

How common is blood cancer?

• Blood cancers account for 6.6% of all cancer cases and 7.2% of all cancer-related deaths worldwide in 2022
• Globally, approximately 1.3 million new cases of blood cancer are diagnosed each year, with an estimated 700,000 deaths annually
• In India, leukaemia is the most commonly diagnosed childhood cancer, accounting for 41.3% of all childhood cancers

Causes

• Age: Blood cancer are more common in older adults; leukaemia is more common in children
• Previous cancer treatment: People who have previously had chemotherapy or radiation therapy for other cancers have a higher risk of developing blood cancer
• Genetic conditions: Down syndrome is associated with a significantly higher risk of leukaemia in children
• Weakened immune system: People with HIV/AIDS, those taking medicines to suppress the immune system (e.g. after an organ transplant) or those with autoimmune conditions have a higher risk of lymphomas
• Certain viral infections: Epstein-Barr virus (EBV, the virus causing glandular fever) is linked to lymphoma; Human T-cell lymphotropic virus (HTLV-1) is also linked to leukaemia
• Family history: Close relatives with blood cancers may slightly increase your own risk
• Smoking: Increases the risk of blood cancer
• Long-term exposure to certain chemicals: Benzene (found in some industrial workplaces and tobacco smoke) and pesticides are associated with a higher risk of leukaemia
• Prolonged high-dose radiation exposure: e.g. from atomic bomb survivors or certain occupational exposures
• Obesity: linked to a modestly increased risk of lymphomas and myeloma

Common symptoms

Because blood cells are involved in fighting infection, carrying oxygen and helping blood clot, blood cancer can cause a wide range of symptoms:

• Unusual and persistent tiredness or weakness (due to low red blood cells — anaemia)
• Frequent infections or infections that are more severe or take longer to clear (due to abnormal white blood cells that cannot fight infections properly)
• Unexplained bruising or bleeding more easily than usual (due to low platelets)
• Swollen, painless lumps in the neck, armpits or groin (enlarged lymph nodes — common in lymphoma)
• Unexplained weight loss
• Drenching night sweats
• Persistent fever without an obvious cause
• Shortness of breath or breathlessness
• Bone pain or backache, particularly common in myeloma, where abnormal cells can damage bones
• Itchy skin or a rash can occur with some lymphomas

Warning signs of a serious condition

• Rapidly increasing swelling of lymph nodes
• Severe breathlessness or chest pain: May indicate leukaemia affecting the lungs or mediastinum
• Confusion, headache or vision disturbance: May indicate spread to the brain or spinal fluid
• Very high fever with rigors (shaking chills): May indicate a serious infection in a patient with a weakened immune system
• Sudden severe bone pain or unexplained fracture: May indicate myeloma damaging bones

Diagnosis and Investigations

• Complete blood count (CBC / full blood count): Measures the number of red cells, white cells and platelets in the blood; abnormal levels of any of these can suggest blood cancer and are usually the first test ordered
• Blood film (peripheral smear): Sample of blood is examined under a microscope to look for abnormal or immature blood cells
• Blood chemistry tests: Investigates the levels of proteins, calcium, kidney function and other markers; abnormal proteins in the blood or urine can indicate myeloma
• Bone marrow biopsy and aspiration: The gold-standard test for leukaemia and myeloma; a small sample of bone marrow is taken from the hip bone under local anaesthetic and examined under a microscope to confirm whether cancer is present, what type it is and how serious it is
• Flow cytometry: Laboratory test that identifies specific surface markers on blood or bone marrow cells, helping to precisely classify the type and subtype of blood cancer
• Cytogenetic and molecular genetic tests: Look for specific chromosome changes or gene mutations that affect treatment decisions
• Lymph node biopsy: If lymphoma is suspected, a lymph node (or part of it) is removed and examined under a microscope
• CT, PET/CT or MRI scan: Imaging tests used mainly for lymphoma and myeloma to see how many lymph nodes or organs are affected, how far the cancer has spread and to plan treatment

Treatment options

Treatment for blood cancer depends on the type and subtype, how fast it is growing, the extent of disease, your age and your overall health

Chemotherapy

• Uses powerful drugs to destroy cancer cells or stop them from dividing; it remains the cornerstone of treatment for acute leukaemias and aggressive lymphomas
• Often given in cycles over several months, sometimes in combination with other treatments
• May be given by mouth (tablets) or through a vein (intravenously)

Targeted therapy

• Drugs designed to target specific molecules or genetic mutations in cancer cells, leaving healthy cells largely unaffected; usually with fewer side effects than traditional chemotherapy

Immunotherapy

• Uses or stimulates the body's own immune system to find and attack cancer cells

CAR T-cell therapy

• A newer form of immunotherapy where a patient's own white blood cells are removed, genetically re-engineered to attack cancer cells and then returned to the patient
• Used for certain relapsed or treatment-resistant leukaemias and lymphomas, with remarkable results in some patients

Stem cell (bone marrow) transplant

• Involves giving high-dose chemotherapy to destroy the diseased bone marrow, followed by an infusion of healthy stem cells from a donor (allogeneic transplant) or from the patient's own body (autologous transplant)
• Used in high-risk leukaemias, relapsed lymphomas and myeloma

Lifestyle and prevention

Recommended diet: Eat a balanced diet rich in fresh fruits, vegetables, whole grains and proteins (pulses, eggs, fish, lean meat); stay hydrated and avoid raw, undercooked or process foods

Exercise: Light to moderate physical activity (walking, gentle yoga) can help reduce fatigue, a very common side effect of blood cancer and its treatment

Long-term care

• Attend all follow-up appointments and take all prescribed medicines exactly as directed
• Avoid smoking as it increases the risk of blood cancer and can interfere with treatment
• Report any new symptoms promptly to your medical team
• Seek emotional support from specialists, counsellors and patient organisations

Myths and facts

Myth 1: Blood cancer is always inherited and runs in families

Fact: The vast majority of blood cancers are caused by DNA mutations that happen during a person's lifetime, they are not inherited or passed on to children. Only a very small proportion are linked to genetic conditions.

Myth 2: Blood cancer only affects children

Fact: While leukaemia is the most common childhood cancer, blood cancers affect people of all ages.

Myth 3: Blood cancer is always fatal

Fact: Outcomes vary greatly by type, subtype and stage. Many people live for years or decades with blood cancer with targeted therapy.

Myth 4: Swollen lymph nodes always mean lymphoma

Fact: Not always, swollen lymph nodes can also mean infection. You should report to your doctor for more detailed assessment.

Frequently Asked Questions (FAQs)