What is blood cancer?

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Written by Alexis Dobranowski

Dr. Rena Buckstein, head of Sunnybrook’s hematology site group at Odette Cancer Centre, answers a few questions about blood cancers and conditions – called “complex malignant hematology”.

What is complex malignant hematology (CMH)?

Complex malignant hematology includes a variety of disorders and cancers of the blood. These conditions start in the bone marrow or in the cells of the immune system.

What are the types of blood cancers?

Complex malignant hematology is divided into two main types: lymphoid and myeloid.

Lymphoid cancers affect the lymphocytes – part of the immune system. It may originate in the bone marrow or the lymph nodes.

Myeloid cancers start in the bone marrow. Bone marrow is a spongy tissue inside some of our bones that contains stem cells. Stem cells are immature cells that can develop into blood cells.

The conditions are further classified as “acute” or “chronic”. Acute conditions mean that the cancer cells are splitting and growing quickly, and affecting the immature cells. Chronic conditions mean the cells are reproducing more slowly, and typically involve more mature cells. Sometimes chronic conditions can transform into acute conditions.

Acute conditions may be life threatening left untreated and generally require the treatments to start within 1 week.

To better understand blood cancers, it is helpful to visualize how they are classified. While not an exhaustive list, the starred conditions would fall under the jurisdiction of Complex Malignant Hematology.

The goal of therapy in most CMH conditions is cure.

Lymphoid Conditions

Acute lymphoblastic leukaemia (ALL)*
Lymphoblastic lymphoma (LL)*

Hodgkin’s lymphoma
Non-Hodgkin’s lymphoma – many types, including:

  • Burkitts lymphomas*
  • High grade B-cell lymphomas double hit*
  • Primary CNS Lymphomas*

Myeloid Conditions

Acute Myeloid Leukemia (AML)*
Granulocytic sarcoma*

Myelodysplastic syndromes (MDS)
Myeloproliferative neoplasms (MPN)
Aplastic Anemia (AA)*
Paroxysmal Nocturnal Hemoglobinuria (PNH)*

What are the symptoms of blood cancers?

The symptoms of blood cancers or conditions can be different because of all the different types of condition.

Some of common symptoms of blood cancer, according to the Canadian Cancer Society, are:

  • Unexplained weight loss
  • Fatigue
  • Shortness of breath
  • Easy bruisability or bleeding
  • Enlarged lymph nodes in the neck, underarm, groin or above the collarbone
  • Swollen stomach or abdominal discomfort
  • Frequent and repeated infections
  • Fever/night sweats

Why do these conditions require such specialized care?

As a general rule, these conditions require management in specialized cancer centres. Many people require chemotherapy and or immunotherapy, and some may only be cured by a bone marrow transplant. The transplant can come either from ones own stem cells (autologous) or from an external donor’s (allogeneic). These treatments essentially wipe out the immune system, putting patients at risk for infection and at higher risk for needing blood transfusions. So, a very specialized care team and treatment space is needed to deliver the best and safest care.

More resources: 

Lymphoma Canada

Leukemia and Lymphoma Society of Canada

Learn more about Sunnybrook’s facility for treating complex malignant hematology.

This post was reviewed and updated Sept. 15, 2021.

About the author

Alexis Dobranowski

Alexis Dobranowski is a Communications Advisor at Sunnybrook.