Large B-Cell Non-Hodgkin Lymphoma (DLBCL) is a cancer affecting B lymphocytes, a type of white blood cell. It originates in the lymphatic system, which helps rid the body of toxins and waste. DLBCL is the most common aggressive non-Hodgkin lymphoma, accounting for 30-40% of cases. Its rapid growth requires prompt diagnosis and treatment.
Understanding Large B-Cell Non-Hodgkin Lymphoma
DLBCL arises from mature B cells, a type of lymphocyte. These abnormal B lymphocytes accumulate in lymph nodes or other organs, impairing immune function. The name “diffuse large B-cell lymphoma” describes its appearance: cancerous B cells are larger than normal and spread diffusely.
This lymphoma can affect various parts of the body, including lymph nodes, the gastrointestinal tract, spleen, and bone marrow. DLBCL is often curable, with approximately 60-70% of patients achieving long-term remission.
DLBCL encompasses several molecular subtypes, primarily germinal center B-cell like (GCB) and activated B-cell like (ABC). These subtypes are identified through genetic testing, such as gene expression profiling or immunohistochemistry. The specific subtype influences treatment decisions and patient outcomes, with ABC-DLBCL generally associated with less favorable outcomes to standard immunochemotherapy compared to GCB-DLBCL.
Recognizing Symptoms and Diagnosis
The symptoms of DLBCL can vary depending on where the lymphoma develops. A common sign is the rapid appearance of a new mass or lump, often painless, in areas such as the neck, armpit, or groin, which are locations of lymph nodes. This occurs as abnormal lymphocytes build up in these nodes.
Many individuals with DLBCL also experience what are known as “B symptoms.” These include unexplained fevers, drenching night sweats, and unintentional weight loss. Other symptoms can include persistent fatigue and itching.
The diagnostic process typically begins with a physical examination to check for swollen lymph nodes and an enlarged spleen or liver. Blood tests are often performed to assess overall health and organ function. Imaging scans, such as CT and PET scans, help determine the extent of the disease and identify affected areas throughout the body.
The definitive diagnosis of DLBCL relies on a biopsy, usually of an affected lymph node or other involved tissue. This tissue sample is then examined by a pathologist under a microscope to confirm the presence of large, abnormal B cells. Further molecular testing, including immunohistochemistry and fluorescence in situ hybridization (FISH), is then performed on the biopsy sample to classify the specific subtype of DLBCL and identify genetic markers that can guide treatment decisions.
Treatment Approaches
The primary treatment for DLBCL is typically a combination chemotherapy regimen known as R-CHOP. This standard first-line treatment involves a combination of several medications: Rituximab, Cyclophosphamide, Hydroxydaunorubicin (Doxorubicin), Oncovin (Vincristine), and Prednisone.
Rituximab is a monoclonal antibody that targets the CD20 protein found on the surface of B cells, helping the immune system destroy them. Cyclophosphamide and Doxorubicin are chemotherapy drugs that damage the DNA of cancer cells, preventing them from growing and dividing. Vincristine disrupts cell division, while Prednisone, a corticosteroid, reduces inflammation and kills lymphoma cells.
R-CHOP is usually administered in cycles, often every 21 days for six cycles, and has a high complete response rate, ranging from 75-80%. Radiation therapy may be used in combination with chemotherapy, especially for localized disease. This treatment uses high-energy rays to kill cancer cells in a specific area of the body. It can be particularly effective for bulky tumors or in areas where the lymphoma is confined.
For patients whose DLBCL relapses or does not respond to initial treatment, other options become available. High-dose chemotherapy followed by autologous stem cell transplantation, where a patient’s own healthy stem cells are collected and reinfused after intensive chemotherapy, has been a standard approach for relapsed or refractory cases, leading to durable remissions in approximately 40% of patients.
Newer therapies have also emerged for relapsed or refractory DLBCL. Chimeric antigen receptor (CAR) T-cell therapy involves genetically modifying a patient’s own T cells to recognize and attack cancer cells, demonstrating complete response rates of 40-58%. Bispecific antibodies, another innovative treatment, are designed to bring immune cells closer to cancer cells, facilitating their destruction. These therapies are generally considered for patients who have exhausted other treatment options or have specific disease characteristics.
Prognosis and Follow-Up Care
The prognosis for individuals with DLBCL has significantly improved with advancements in treatment. While aggressive, its responsiveness to chemotherapy contributes to favorable outcomes. Approximately 60% of patients are cured with frontline chemotherapy, though around 30-40% may experience relapse or be refractory to initial treatment.
Several factors can influence an individual’s prognosis. These include age at diagnosis, the stage of the lymphoma, the patient’s general health, and specific genetic markers identified in the lymphoma cells. For instance, certain genetic rearrangements, such as “double-hit” lymphomas involving MYC and BCL2 and/or BCL6 genes, are associated with a less favorable prognosis.
After completing treatment, regular follow-up care is important to monitor for any signs of recurrence and manage potential long-term side effects. This often involves routine check-ups, blood tests, and imaging scans, such as PET or CT scans, to assess the patient’s health and detect any changes. Most disease relapses typically occur within the first two years after treatment.
Survivorship issues are also a focus of follow-up care. These include addressing late effects of treatment, such as fatigue, neuropathy, or heart problems, and supporting the patient in maintaining their quality of life. The goal is not only to achieve remission but also to ensure a good long-term quality of life for survivors.