Patients and Carers

This page is intended for patients and their carers who wish to learn more about blood cancers.

Blood Cancers: Understanding, Treatment, and Innovations – What You Need to Know

What Are Blood Cancers?

Blood cancers, also called hematologic cancers or hematological malignancies, develop from abnormal blood cells. Blood cells include red blood cells, white blood cells, and platelets, essential for oxygen transport, immunity, and clotting.

The most common types of blood cancers are:

  • Leukemia (acute and chronic forms), affecting bone marrow cells that produce white blood cells.
  • Multiple myeloma, impacting plasma cells (a type of white blood cell).
  • Lymphoma, targeting lymphocytes (white blood cells), including Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL).

For detailed information on blood cancers, visit The Leukemia & Lymphoma Society®’s website and the Anthony Nolan Foundation.

Today, multiple treatment options are available to fight blood cancers, also known as hematologic malignancies. The choice of therapy depends on the type of cancer, its stage, and the patient’s overall health condition. Common treatment approaches include: chemotherapy, targeted therapy, radiation therapy,  and in some cases, bone marrow or hematopoietic stem cell transplantation.

Recent advances in cancer immunotherapy have opened promising new pathways. Immunotherapy works by activating the patient’s own immune system to recognize and destroy cancer cells more effectively.

Bone Marrow Transplantation for Blood Cancers

Hematopoietic stem cells, found in the bone marrow or collected from the peripheral blood of a healthy donor, are the precursor cells that give rise to all types of blood cells. Bone marrow is a spongy tissue located inside certain bones and is essential for the production of red blood cells, white blood cells, and platelets.

A bone marrow transplant—also known as a hematopoietic stem cell transplant (HSCT)—aims to rebuild a patient’s blood and immune system, particularly after intensive treatments like chemotherapy or radiation therapy. The goal is to replace the damaged or diseased bone marrow with healthy stem cells from a donor. Once transplanted, these healthy stem cells can differentiate and regenerate fully functional blood cells.

There are different types of stem cell transplants based on the source of the cells:

  • Autologous transplant: The patient’s own stem cells are used.
  • Allogeneic transplant: Stem cells come from a compatible donor.

While stem cell transplantation can be a life-saving procedure, it also involves significant risks and potential complications, which should be carefully discussed with the medical team. A major concern is the weakened immune system following the transplant, which increases vulnerability to infections. One of the most serious complications is graft-versus-host disease (GvHD), where the donor’s immune cells attack the recipient’s tissues which require careful management by healthcare teams.

Who Can Be a Stem Cell Donor?

The donor must be in good health and highly compatible with the recipient. Compatibility is assessed through HLA typing (Human Leukocyte Antigen), which analyzes specific proteins on the surface of cells that play a key role in the risk of transplant rejection.

The search for a compatible donor typically begins within the patient’s siblings, where there is a 1 in 4 chance of finding a genetic match. If no suitable family donor is found, unrelated volunteer donors listed in international registries may be considered.

Want to know more: Cancer Research UK – who can donate stem cells or bone marrow?

Graft-versus-Host Disease (GvHD)

Graft-versus-Host Disease (GvHD) is a serious complication that can occur after an allogeneic stem cell transplant, a common treatment for blood cancers such as leukemia, lymphoma, and myeloma. GvHD happens when the donated hematopoietic stem cells view the recipient’s body as foreign and start attacking healthy tissues and organs.

There are two main forms of GvHD: acute GvHD (aGvHD), that occurs within the first 100 days post-transplant, and chronic GvHD (cGvHD), that develops after 100 days or more. Both types can significantly impact survival rates and quality of life after stem cell transplantation. The symptoms of each form also vary significantly.

Chronic GvHD

Chronic GvHD, which develops more than 100 days post-transplant, affects multiple organs and systems and often includes:

  • Skin symptoms: Dryness, rash, itching, peeling, hardening, or darkening of the skin
  • Eye dryness and burning sensation
  • Oral dryness, with or without mouth ulcers
  • Gastrointestinal issues: Diarrhea, appetite loss, cramps, vomiting, weight loss
  • Muscle and joint pain
  • Frequent infections
  • Respiratory difficulty

Acute GvHD (aGvHD)

Acute GvHD mainly affects three organs: skin, liver, and the gastrointestinal tract.

Skin rash is the most common manifestation of acute GvHD. It can be mild and localized, but may also spread to the entire body.

Acute GvHD becomes more severe when it affects the gastrointestinal tract or the liver. A yellowish skin tone (jaundice) is the main symptom indicating liver involvement. Gastrointestinal involvement is often associated with serious complications such as severe diarrhea, abdominal pain, intestinal bleeding, and even death.

Grading of Acute GvHD is based on symptom severity:

  • Grade I: Mild symptoms (only skin involved)
  • Grade II: Moderate symptoms
  • Grade III: Severe symptoms
  • Grade IV: Life-threatening symptoms

GvHD Treatment

Managing a Life-Threatening Complication

When the first signs of GvHD appear after an allogeneic stem cell transplant, corticosteroids are usually the first line of treatment. These medications help control inflammation and reduce immune attacks.

Immunotherapy may be considered in some cases, but treatment options remain limited and often show variable results.

Despite available treatments, there remains a high unmet medical need for patients with GvHD. This has led researchers to explore innovative therapies—one promising area being the gut microbiome.

Gut microbiome and Blood cancers: Improving Outcomes for Patients

The gut microbiome—a complex community of billions of microorganisms living in our intestines—plays a crucial role in overall health. It is unique to each individual and affects not just digestion, but also immune function and the effectiveness of certain cancer treatments.
Click here for more information about gut microbiome.

Source : INSERM https://www.inserm.fr/dossier/microbiote-intestinal-flore-intestinale/

Microbiome and Post-Transplant Complications

What’s the Link?

Intensive chemotherapy and antibiotic use can seriously disrupt the gut microbiome, leading to a condition called dysbiosis (microbial imbalance). Emerging data suggests a link between gut dysbiosis and GvHD, as well as overall survival in transplant patients.

Recent studies show that high bacterial richness (total number of bacterial species) and high bacterial diversity (variety of different bacterial species) are associated with better survival rates and fewer complications in patients who undergo allogeneic HSCT (Source Peled et al., 2020 — “Microbiota as predictor of mortality in allogeneic hematopoietic-cell transplantation” – New England Journal of Medicine).

For additional information, please visit Anthony Nolan Blog – Bacteria in Stem Cell Transplant

Gut Microbiome Restoration

An Innovative Approach

In light of recent findings and in addition to current GvHD treatments, an innovative therapeutic strategy is emerging: restoring the gut microbiome using microbiota-based medications to reestablish a healthy microbial balance. Although this approach is still in the clinical trial phase for hematologic cancers, it shows promising potential in enhancing the effectiveness of anti-cancer therapies and boosting the immune response after stem cell transplantation.

Current clinical studies suggest that gut microbiome restoration could:

  • Enhance the efficacy of cancer treatments
  • Reduce side effects related to allogeneic stem cell transplantation
  • Improve quality of life and overall survival (OS) for patients