Despite being considered as rare diseases, blood cancers account for 8% of all cancers and mainly affect children, young adults and the elderly. Each of the three main families of hematological cancers (leukemias, lymphomas and myelomas) have a diverse range of prognoses and treatment options. In this post we will explore the current and future blood cancer treatments associated with four of the most common malignancies: chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML), diffuse large B-Cell lymphoma (DLBCL), and multiple myeloma (MM).
Disease Classification
- Leukemias are characterized by the invasion of abnormal cells into the bone marrow which then move into the blood. Depending on the original invading cell, leukemias can be myeloid or lymphoid and are also distinguished as being either chronic or acute. Chronic lymphocytic leukemia (CLL), is characterized by the bone marrow having produced too many lymphocytes. Acute myeloid leukemia (AML) is a cancer of the myeloid white blood cells and is a much rarer disease.
- Lymphomas refer to more than fifty different cancers that are identified by an excessive proliferation of lymphocytes (mostly B or T). Lymphomas are largely split into two categories: Hodgkin’s Lymphoma and Non-Hodgkin’s Lymphoma (NHL). Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma accounting for 30% - 60% of all cases.
- Myeloma is a cancer arising from plasma cells which occurs during the final stage of cell development into B lymphocytes. The aggressive disease can develop rapidly, and so treatment usually begins soon after a diagnosis is confirmed.
The classification of lymphomas and acute leukemias has advanced significantly in recent years such that the World Health Organisation published new classifications for the diseases in 2016.
Over the last fifty years, certain extraordinary medical breakthroughs have meant that a diagnosis with blood cancer is no longer synonymous with a short life span.
Not only is the knowledge of the causes of the diseases progressing, developments in genetic analysis have allowed health care professionals and scientists to detect molecular abnormalities in cancerous blood cells thus aiding them to predict blood cancer treatment responses for individual patients. Furthermore, in the field of immunology, there have been developments in treatments which preferentially target cancer cells which are being used more and more widely.
Blood Cancer Treatments for the Four Most Common Diseases
Chronic Lymphocytic Leukemia
As the prognosis for CLL is relatively good, patients often do not require immediate treatment. Doctors decide on a blood cancer treatment program for each patient based on factors including the stage of the cancer, the presence of genetic abnormalities, performance status, treatment response or the presence of symptoms including fever and weight loss.
First line blood cancer treatments for CLL currently include chemotherapies, immunotherapies, targeted therapies and stem cell transplants. The relapsed or refractory treatment for the disease is usually identical to the first line if the patient responded well and it was effective.
Looking towards the future of treatments for chronic lymphocytic leukemia, dozens of new drugs are being developed in the sphere of conventional chemotherapy as well as targeted therapies. Beyond this, there have also been developments in immunotherapy and radio-immunotherapy as well as in chimeric antigen receptors (CARs).
Acute Myeloid Leukemia
The average age of people affected by AML is 67, and age is a key choice criterion for disease management for first line therapies (both induction and consolidation). Other factors considered are the patient’s complete blood cell count, any cytogenetic and molecular abnormalities, performance status and comorbidities.
The current treatment options are divided into three phases: induction treatments, consolidation treatments and then treatments for relapsed or refractory patients. Within the first line therapies chemotherapy, targeted therapies, and CNS treatment (if needed) are used. In the consolidation phase, stem cell transplants and radiation therapies are also sometimes used. Second and third line therapies can include a combination of those used in the first line.
Regarding the future treatments of AML, there has been great progress in understanding changes that happen in the DNA in bone marrow cells and the affect this has on the intensity of treatment a patient should receive. This knowledge is being used to develop targeted therapies which specifically attack gene changes found in AML. Significant progress is also being made in the capabilities to detect minimal residual disease, and doctors continue to research how this could affect a patient’s need for further treatment.
Diffuse Large B-Cell Lymphoma
There have been important developments in treating patients suffering from this disease in recent years. Namely, patients can now be classified according to their prognosis using the IPI (International Prognostic Index).
Three lines of blood cancer treatment currently exist for patients affected by DLBCL, who are split into two subgroups depending on their gene expression profile. There are many DLBCL treatments in the clinical trial stage, most of which concentrate on relapsed or refractory patients. These include assessing new ways to combine drugs, new stem cell transplant methods with a focus on autologous transplants, targeted therapies, and immunotherapies.
Multiple Myeloma
As there is currently no cure for multiple myeloma, treatments aim to reduce the patient’s symptoms and slow the progression, ideally achieving remission. The decision of which blood cancer treatment to use for patients with this disease considers several factors including eligibility for stem cell transplantation, comorbidities, the cytogenetic risk and the ISS (International Staging System) stage.
Stem cell transplantation is the primary first line treatment used for eligible patients, followed by systemic treatments. There are continual developments in the research of multiple myeloma, particularly relating to the minimal residual disease. Recent studies have shown for example that the therapeutic use of CAR-T cells with the BCMA antigen is showing promising results.
For a more detailed overview of hemato-oncology, download our latest eBook.
