Understanding blood cancer: What it is and how it’s diagnosed

September 16, 2024

healthcaretoday, National Cancer Society Malaysia, NCSM, blood cancer, lymphoma, leukemia, multiple myeloma, non-Hodgkin, Hodgkin lymphoma, Acute Lymphoblastic Leukemia, Acute Myeloid Leukemia, Chronic Lymphocytic Leukemia, Chronic Myeloid Leukemia, hemoglobin, anemia, bone marrow biopsies, stem cell, CAR-T therapy

Blood cancer is a devastating disease that affects a large number of people worldwide. In the UK alone, someone is diagnosed with blood cancer every 20 minutes. That adds up to a staggering 70 people per day and 25,000 people annually. However, thanks to groundbreaking discoveries in medical research and treatment, the landscape of blood cancer treatment has evolved significantly over the years. From the discovery of the circulatory system to the revolutionary CAR-T cell therapy, the trajectory of blood cancer treatment is a testament to human ingenuity and determination.

This article will delve into the different types of blood cancers, their diagnosis, treatment options, and how cutting-edge treatments like CAR-T therapy are changing the lives of patients around the world.

Understanding blood cancer: The big three
Dr Nur Adila Anuar (pix), Consultant Physician and Haematologist at KPJ Ampang Puteri Specialist Hospital, sheds light on the three major types of blood cancers during her presentation at the National Cancer Congress Malaysia. These include:

Lymphoma
Leukemia
Multiple myeloma

Of these, lymphoma is the most common, accounting for almost half of all blood cancer cases. It develops in the lymphocytes, a type of white blood cell, and can be further classified into non-Hodgkin and Hodgkin lymphoma. Non-Hodgkin lymphoma is the most prevalent of the two. On the other hand, leukemia—especially acute lymphoblastic leukemia (ALL)—is more common in children, while acute myeloid leukemia (AML) affects mostly adults. Lastly, multiple myeloma, once considered a disease of older adults, is now being diagnosed in patients as young as their 30s and 40s, presenting in a more aggressive form.

Leukemia: Acute and chronic forms
Leukemia is a type of blood cancer characterized by the abnormal proliferation of blood cells in the bone marrow. It is broadly divided into acute and chronic forms:

Acute leukemia:

Acute Lymphoblastic Leukemia (ALL)
Acute Myeloid Leukemia (AML)

Chronic leukemia:

Chronic Lymphocytic Leukemia (CLL)
Chronic Myeloid Leukemia (CML)

Dr Nur Adila explains, “The presentation of leukemia varies depending on which blood cells are affected. For instance, if the production of platelets is impaired, patients may experience symptoms like bruising, bleeding, and fatigue. If the production of hemoglobin is disrupted, anemia symptoms such as paleness and shortness of breath may arise.”

While the diagnostic process for leukemia has evolved over the years, the gold standard remains the bone marrow examination. “Although bone marrow biopsies may sound daunting, they are routinely done as outpatient procedures in most healthcare settings,” Dr Nur Adila reassures.

Management of leukemia: Tailored treatment
The treatment of leukemia is highly individualized, depending on factors such as the specific type of leukemia and the patient's overall health.

Acute Lymphoblastic Leukemia (ALL): Treated with chemotherapy, sometimes in combination with tyrosine kinase inhibitors (TKIs), and in some cases, stem cell transplantation.
Acute Myeloid Leukemia (AML): Managed with chemotherapy, FLT3 inhibitors, and possibly stem cell transplantation, especially in high-risk cases.
Chronic Lymphocytic Leukemia (CLL): Watchful waiting is often recommended until treatment becomes necessary, at which point targeted therapies are used.
Chronic Myeloid Leukemia (CML): Treated primarily with tyrosine kinase inhibitors, which have significantly improved patient survival rates.

Warning signs of lymphoma
The early detection of lymphoma, the most common form of blood cancer, can lead to better treatment outcomes. Key warning signs include:

Fever
Swelling of the face, neck, or lymph nodes (especially in the armpits or groin)
Excessive night sweating
Unexplained weight loss
Breathlessness
Persistent fatigue
Itchiness
Loss of appetite

In Malaysia, the incidence of non-Hodgkin’s lymphoma far exceeds that of Hodgkin’s lymphoma. A study conducted at a single center revealed that 84.7% of lymphoma cases were non-Hodgkin’s, with the majority being B-cell lymphoma.

Diagnosing and staging lymphoma
The Ann Arbor Staging System is widely used to classify both Hodgkin and non-Hodgkin lymphomas. The stages are as follows:

Stage 1: Involvement of a single lymph node region or a single extralymphatic site.
Stage 2: Involvement of two or more lymph node regions on the same side of the diaphragm.
Stage 3: Lymph node regions on both sides of the diaphragm are affected, possibly including the spleen.
Stage 4: Diffuse disease, involving organs like the liver, bone marrow, or lungs.

Diagnosis typically involves a biopsy of the affected lymph node, followed by additional tests to stratify the risk and guide treatment.

Multiple myeloma: A changing disease
Multiple myeloma is a malignancy of plasma cells, a type of white blood cell responsible for producing antibodies. Once considered a disease of the elderly, with a median diagnosis age of 60, younger patients are increasingly being diagnosed with this aggressive cancer. The disease is characterized by the overproduction of monoclonal paraproteins, leading to organ damage, compromised immunity, and other systemic effects.

Chronic myeloid leukemia: The role of the Philadelphia chromosome
Chronic myeloid leukemia (CML) is caused by the presence of the Philadelphia chromosome, which leads to the abnormal growth of myeloid cells. The disease progresses in three phases:

Chronic phase: Patients are often asymptomatic or have mild symptoms, with 10-15% blast cells.
Accelerated phase: New genetic abnormalities appear, leading to increased blasts (16-30%) and symptoms like splenomegaly and fatigue.
Blast crisis: The disease becomes aggressive, with more than 30% blasts in the bone marrow, often leading to life-threatening complications.

The introduction of tyrosine kinase inhibitors (TKIs) has revolutionized CML treatment, increasing survival rates to 92% and allowing many patients to lead normal lives.

Stem cell transplantation: A lifesaving procedure
Stem cell transplantation has evolved from experimental procedures in the 1950s to a standard treatment for various blood cancers today. There are two main types of stem cell transplants:

Autologous transplants: In which patients use their own stem cells, harvested and reinfused after intensive chemotherapy.
Allogeneic transplants: Where stem cells are sourced from a donor, often used when the patient’s own stem cells are deemed insufficient.

CAR-T therapy: The future of blood cancer treatment
The latest frontier in blood cancer treatment is Chimeric Antigen Receptor T-cell (CAR-T) therapy. This groundbreaking treatment involves modifying a patient's own T-cells to target and kill cancer cells more effectively. Here's how it works:

Apheresis: T-cells are collected from the patient.
Reprogramming: These cells are genetically modified to recognize specific cancer antigens.
Multiplication: The modified cells are multiplied in a lab until they reach the required numbers.
Infusion: The reprogrammed T-cells are reinfused into the patient.
Targeting cancer cells: These modified cells then seek out and destroy cancerous cells.

CAR-T therapy represents a major leap forward in personalized cancer treatment, offering a lifeline to patients with previously untreatable forms of blood cancer.

Blood cancer treatment has come a long way, from the rudimentary methods of the 20th century to the advanced, personalized therapies we see today. With innovations like CAR-T cell therapy and targeted treatments like tyrosine kinase inhibitors, patients are now living longer, healthier lives. The future of blood cancer treatment lies in continued research, early detection, and an emphasis on precision medicine.