Diffuse Large B-cell Lymphoma (DLBCL) is an aggressive cancer of the immune system. DLBCL is the most frequently diagnosed subtype of Non-Hodgkin Lymphoma (NHL), representing approximately 25% to 30% of all NHL cases worldwide. This fast-growing cancer requires prompt diagnosis and treatment. DLBCL often responds well to modern therapeutic approaches, offering a favorable prognosis for many patients.
What Diffuse Large B-cell Lymphoma Is
The term “lymphoma” indicates a cancer that originates in the lymphocytes. These cancerous cells accumulate in the lymph nodes or other lymphoid tissues. The cancer cells involved are abnormal B-cells, which are normally responsible for producing antibodies to fight infection.
These malignant B-cells are noticeably “Large” when viewed under a microscope. The adjective “Diffuse” refers to the growth pattern of the cancer cells, which are spread out throughout the tissue rather than being clustered in defined nodules. DLBCL is classified as a high-grade or aggressive Non-Hodgkin Lymphoma. The disease can arise in the lymph nodes or outside of them, affecting virtually any organ in the body, which is referred to as extranodal involvement.
Recognizing Warning Signs and Risk Factors
The most common initial sign of DLBCL is a fast-growing, often painless lump, typically in the neck, armpit, or groin, caused by swollen lymph nodes. The specific symptoms a person experiences depend on where the lymphoma develops, such as abdominal pain if the gastrointestinal tract is involved.
About 30% of patients also experience systemic indicators known as “B symptoms.” These include unexplained fevers, drenching night sweats that soak clothing, and significant unintentional weight loss (more than 10% of body weight over six months). Several factors increase a person’s risk, including advanced age (median diagnosis around 70 years) and a weakened immune system, such as in individuals with HIV or those taking immunosuppressive drugs after an organ transplant.
Diagnostic Testing and Staging
Confirming a diagnosis of DLBCL requires a series of specific medical procedures. The primary diagnostic step is an excisional biopsy, where a surgeon removes an entire suspicious lymph node or a tissue mass for laboratory analysis. Pathologists examine the tissue under a microscope to confirm the presence of large, diffuse B-cells and determine the specific subtype of lymphoma.
Once the diagnosis is established, imaging scans are performed to map the disease’s spread throughout the body. Positron Emission Tomography-Computed Tomography (PET/CT) scans are standard, as they can highlight areas of increased metabolic activity, revealing all sites where the aggressive cancer cells are present. Blood tests, including a complete blood count and a measurement of lactate dehydrogenase (LDH) levels, are also collected, as elevated LDH can be an indicator of high tumor turnover.
The extent of the cancer is formally measured using the Ann Arbor staging system, which categorizes the disease from Stage I (single lymph node region or extranodal site) to Stage IV (widespread involvement of one or more extranodal organs). Clinicians also calculate the International Prognostic Index (IPI) score, which helps predict a patient’s outcome and guide treatment intensity. The IPI score assigns points based on five factors:
- Age over 60
- Advanced Ann Arbor stage (III or IV)
- Elevated LDH
- Poor performance status
- Involvement of more than one extranodal site
Standard Treatment Approaches
The standard first-line treatment for newly diagnosed DLBCL is a regimen known as R-CHOP, which is a combination of five therapeutic agents. The “R” stands for rituximab, a monoclonal antibody that targets the CD20 protein found on the surface of B-cells, including the cancerous ones. The “CHOP” components are a combination of four chemotherapy drugs: cyclophosphamide, doxorubicin (hydroxydaunorubicin), vincristine (Oncovin), and the steroid prednisone. This chemo-immunotherapy combination is highly effective, leading to a complete remission in many patients.
Treatment is typically administered in cycles, often every 21 days, for a total of six cycles, though the exact number depends on the disease stage and a patient’s risk profile. For patients with localized disease or a large tumor mass, R-CHOP may be followed by localized radiation therapy to the affected area. If the disease returns or does not respond to R-CHOP (relapsed or refractory DLBCL), more intensive chemotherapy, sometimes followed by an autologous stem cell transplant, may be considered to offer a chance at long-term control.