First-Line Treatments for Blood Cancers
Chemotherapy as Initial Therapy
First-line treatments for blood cancers typically involve chemotherapy. Following this primary intervention, patients may undergo stem cell therapy as a final approach to combat the disease.
Concerns About Stem Cell Therapy
A recent article in Science Health highlights that the repercussions of stem cell therapy can be as severe as those of the cancer itself, affecting approximately 50% of patients.
Understanding Stem Cell Therapy
The Two-Step Process
Stem cell therapy consists of a two-step procedure. Initially, the patient’s blood cells are eradicated through chemotherapy, radiation therapy, or immunosuppression. This conditioning phase also targets any cancer cells that may have survived the first-line treatments. In the second step, the patient receives stem cells sourced from a donor’s bone marrow or peripheral blood.
Risks of Graft-Versus-Host Disease (GVHD)
While stem cell therapy can potentially offer a cure, it carries the risk of graft-versus-host disease (GVHD) in up to 50% of cases. GVHD is more prevalent among patients receiving peripheral blood transplants and can be fatal for 15% to 20% of these individuals.
Types of GVHD
GVHD can manifest in two forms: acute and chronic. Patients may experience either one, both, or neither. The likelihood and severity of GVHD symptoms tend to decrease when donor cells closely match the patient’s cells.
Acute GVHD Symptoms and Management
Acute GVHD may appear within 100 days post-transplant. The initial phase of stem cell therapy can inflict tissue damage, potentially allowing gut bacteria to enter the bloodstream. This situation activates the patient’s immune response, leading donor T cells to attack the patient’s tissues. Symptoms can include vomiting, diarrhea, skin rashes, nausea, and liver dysfunction. In about one-third of patients, immunosuppressive treatments can resolve acute GVHD relatively quickly; however, some may progress to chronic GVHD.
Chronic GVHD Mechanisms and Symptoms
Chronic GVHD’s biological mechanisms remain partially understood, but it is believed that immune cells from the donor, such as B cells and macrophages, contribute to tissue damage in the patient. Symptoms may include dry eyes, mouth sores, muscle weakness, fatigue, and joint issues.
Current Challenges in GVHD Treatment
Need for Effective Treatments
Despite the rising number of GVHD cases and advancements in understanding the condition, the development of effective treatments has not progressed at the same pace. Current standard treatments primarily involve corticosteroids and medications that lower IL-2 levels, an immune system chemical that promotes T-cell proliferation. However, these treatments can suppress the immune system, increasing the risk of infections.
Challenges in Drug Research
One obstacle in drug research is that a minimal graft-versus-host response is necessary for successful stem cell therapy, as donor cells must eliminate remaining cancer cells after the initial therapy. This challenge was discussed in the aforementioned Science Health article.
Potential Treatments and Biomarkers
Numerous treatments have been explored, yet results vary and often focus on either acute or chronic GVHD. Biomarkers indicating individuals at risk of severe GVHD have been identified, potentially aiding in the creation of personalized treatment strategies. Some drugs, initially approved for other diseases, show promise for GVHD; these include ibrutinib for chronic GVHD and ruxolitinib for acute GVHD.
Conclusion
The significance of stem cell therapy cannot be overlooked, as up to 50% of recipients may develop GVHD. Unfortunately, chronic GVHD can be as challenging to endure as cancer itself, underscoring the need for ongoing care strategies for patients receiving stem cell therapy as a last line of defense against cancer.
Reference
Cohen J. A stem cell transplant helped beat back a young doctor’s cancer. Now, it’s assaulting his body. Science Health. 2017. Available at: DOI: 10.1126/science.aan7079.