Understanding Blood Cancer

Blood cancer refers to a group of cancers that affect the blood, bone marrow or lymphatic system. These cancers interfere with the body's ability to produce normal blood cells and maintain a healthy immune system. Unlike solid tumours, blood cancers often involve abnormal cells circulating in the bloodstream or accumulating in the bone marrow, lymph nodes or other organs.

At the National Cancer Centre Singapore (NCCS), specialists use detailed blood tests, imaging, bone marrow examination and molecular testing to diagnose and manage blood cancers. This page provides an overview of what blood cancer is, the different types, how it is diagnosed and treated, and the support available to patients throughout their care.

What Is Blood Cancer

Blood cancer develops when abnormal blood cells grow and multiply in an uncontrolled manner. These cells arise from the bone marrow, where blood cells are normally produced. In a healthy person, the bone marrow makes:

• Red blood cells that carry oxygen
• White blood cells that fight infections
• Platelets that help prevent bleeding

In blood cancer, this process becomes disrupted. Abnormal blood cells may be produced in large numbers, fail to mature properly or survive longer than they should. Over time, these abnormal cells can crowd out healthy blood cells in the bone marrow and bloodstream. As a result, the body may struggle to deliver oxygen efficiently, defend against infections or control bleeding.

Unlike many other cancers, blood cancers do not always form a single solid tumour. Instead, cancerous cells may circulate in the blood or collect in the bone marrow, lymph nodes, spleen or other organs.

Types of Blood Cancer

Blood cancers are broadly grouped based on the type of blood cell involved and where the cancer originates. The main categories are leukaemia, lymphoma and multiple myeloma.

Leukaemia

Leukaemia is a cancer of the blood and bone marrow. It involves the overproduction of abnormal white blood cells, which interfere with normal blood cell formation.

Leukaemia may be:

• Acute — develops quickly and requires prompt treatment
• Chronic — progresses more slowly and may be monitored before treatment is needed

Examples include acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), chronic lymphocytic leukaemia (CLL) and chronic myeloid leukaemia (CML).

Lymphoma

Lymphoma affects the lymphatic system, which is part of the body's immune defense. It usually presents as enlarged lymph nodes but may also involve the bone marrow, spleen or other organs.

There are two main types:

• Hodgkin lymphoma
• Non-Hodgkin lymphoma, which includes many subtypes that vary in behaviour and treatment approach

Some lymphomas grow slowly and may not need immediate treatment, while others require prompt therapy.

Multiple Myeloma

Multiple myeloma is a cancer of plasma cells, a type of white blood cell found in the bone marrow. Abnormal plasma cells can weaken bones, impair kidney function and reduce the production of healthy blood cells.

Symptoms of Blood Cancer

Symptoms vary depending on the type and stage of blood cancer. In some cases, early blood cancer causes few or no symptoms and may be detected through routine blood tests.

Possible symptoms include:

• Persistent fatigue or weakness
• Frequent infections or slow recovery from illness
• Unexplained bruising or bleeding
• Fever or night sweats
• Unintentional weight loss
• Bone pain or back pain
• Enlarged lymph nodes, liver or spleen

These symptoms can also be caused by many non-cancerous conditions. However, persistent or unexplained symptoms should be assessed by a doctor to determine whether further investigation is needed.

Causes and Risk Factors for Blood Cancer

The exact cause of most blood cancers is not fully understood. They develop when genetic changes occur in blood-forming cells, leading to abnormal growth and survival.

Non-modifiable Risk Factors

• Increasing age
• Inherited genetic conditions
• Previous exposure to chemotherapy or radiotherapy

Modifiable or Environmental Factors

• Exposure to certain chemicals, such as benzene
• Smoking
• Chronic immune suppression

Having risk factors does not mean you will develop blood cancer. Many people diagnosed have no identifiable risk factors.

How Blood Cancer Is Diagnosed

Diagnosis involves a combination of laboratory tests, imaging and tissue sampling.

Blood Tests

Blood tests may show:

• Abnormal levels of white blood cells, red blood cells or platelets
• Abnormal proteins produced by cancerous cells

These tests often prompt further investigation.

Bone Marrow Examination

A bone marrow biopsy is commonly required to confirm a diagnosis. A small sample of bone marrow is taken, usually from the hip bone, and examined under a microscope. This test helps determine:

• The exact type of blood cancer
• The proportion of abnormal cells
• Key genetic or molecular features

Imaging Tests

Imaging such as CT, MRI or PET scans may be used to:

• Assess lymph node involvement
• Evaluate organ enlargement
• Determine disease spread

Molecular and Genetic Testing

Advanced testing examines specific genetic or molecular changes within cancer cells. These results help guide treatment decisions and may identify eligibility for targeted therapies.

Staging and Classification

Blood cancers are staged differently from solid tumours because they often involve the blood, bone marrow and lymphatic system rather than forming a single, localised mass. As part of the staging process, doctors assess:

• The number of abnormal cells in the blood or bone marrow
• How much normal blood cell production is affected
• Whether lymph nodes, liver, spleen or other organs are involved
• Genetic or molecular features of the cancer

Staging and classification help guide treatment and estimate prognosis.

Treatment for Blood Cancer

Treatment is personalised based on:

• Type of blood cancer
• Disease stage and behaviour
• Genetic features
• The patient's overall health and preferences

At NCCS, care is provided by multidisciplinary teams including haematologists, medical oncologists, radiation oncologists, transplant specialists, nurses and allied health professionals.

Chemotherapy

Chemotherapy uses medicines to destroy rapidly dividing cancer cells. It may be given alone or in combination with other treatments.

Targeted Therapy

Targeted therapies act on specific molecules or pathways involved in cancer growth. These treatments may be associated with fewer side effects than traditional chemotherapy and are used when tumour testing shows they are likely to be effective.

Immunotherapy

Immunotherapy helps the immune system recognise and attack cancer cells. It is used in selected blood cancers and depends on specific disease characteristics.

Radiation Therapy

Radiation therapy may be used to treat localised disease, relieve symptoms or prepare patients for stem cell transplantation.

Stem Cell Transplantation

In certain blood cancers, a stem cell transplant may be recommended to replace diseased bone marrow with healthy blood-forming cells. This approach is used selectively and involves careful assessment and preparation.

What Treatment Aims to Achieve

Treatment goals vary depending on the type and stage of blood cancer and may include:

• Achieving remission
• Controlling disease progression
• Relieving symptoms
• Improving quality of life

Some blood cancers are highly curable, while others are managed as long-term conditions with periods of treatment and monitoring.

Supportive Care and Living With Blood Cancer

Supportive care begins at diagnosis and focuses on managing symptoms, preventing complications and supporting emotional wellbeing.

Support may include:

• Infection prevention and management
• Blood transfusions when needed
• Nutritional advice
• Rehabilitation services
• Psychological and social support

Patients are encouraged to discuss any physical or emotional concerns with their care team.

Follow-Up and Monitoring

After treatment, regular follow-up is essential. Appointments may include:

• Blood tests
• Imaging studies
• Physical examinations

Ongoing monitoring helps detect relapse early, manage long-term effects of treatment and support recovery.

Guidance and Support at NCCS

Being diagnosed with blood cancer can feel overwhelming. At NCCS, patients receive coordinated, multidisciplinary care focused on both medical treatment and overall wellbeing. Clear communication, education and support help patients and families navigate each stage of diagnosis, treatment and follow-up with confidence.

Patients are encouraged to ask questions, seek clarification and take an active role in decisions about their care.

For more information about blood cancer or to discuss your individual treatment plan, please speak with your NCCS care team or visit www.nccs.com.sg.

Commonly Asked Questions

1. Can blood cancer go into remission, and what does remission mean for long-term care?
   Yes. Many blood cancers can go into remission, which means that signs of active disease are reduced or no longer detectable with standard tests. Remission does not always mean the cancer is cured, and ongoing follow-up is important. Your care team will continue to monitor your health through regular reviews to detect any changes early and manage long-term effects of treatment.
   
   
2. Will blood cancer or its treatment affect my immune system in the long term?
   Some blood cancers and their treatments can weaken the immune system, either temporarily or for longer periods. The extent varies depending on the type of blood cancer and treatment received. Your doctors will monitor your immune function and may recommend vaccinations, preventive measures or medications to reduce infection risk when needed.
   
   
3. Are there lifestyle changes I should make during or after treatment for blood cancer?
   Many patients benefit from maintaining a balanced diet, staying physically active within their limits and getting adequate rest. Some treatments may require temporary adjustments to daily routines. Your care team can provide personalised guidance on nutrition, activity levels and infection prevention to support recovery and overall wellbeing.
   
   
4. How often will I need blood tests or scans after treatment ends?
   Follow-up schedules differ depending on the type of blood cancer, stage and treatment response. Some patients require more frequent blood tests initially, with appointments becoming less frequent over time if recovery is stable. Regular monitoring helps detect relapse, manage side effects and support long-term health.
   
   
5. Should my family members be tested if I am diagnosed with blood cancer?
   Most blood cancers are not inherited. However, in selected situations, such as early age at diagnosis or certain rare subtypes, genetic assessment may be discussed. Your doctor can advise whether family members need further evaluation based on your individual diagnosis and family history.