Lymphoma is staged from I to IV based on how many groups of lymph nodes are affected and whether the cancer has spread beyond the lymphatic system. The staging system uses the diaphragm, the muscle separating your chest from your abdomen, as a key dividing line. Where the disease falls on this scale shapes what treatment looks like and what outcomes to expect.
How Lymphoma Staging Works
Both Hodgkin and non-Hodgkin lymphoma use the same four-stage framework, known as the Lugano classification. Staging is determined primarily through PET-CT scans, which combine two types of imaging to show both the size and metabolic activity of tumors throughout the body. For certain types of non-Hodgkin lymphoma, a bone marrow biopsy may also be needed because PET-CT can miss low-grade disease hiding there. In one study of diffuse large B-cell lymphoma, bone marrow biopsy upstaged 6% of patients who appeared to have early-stage disease on imaging alone.
Stage I: One Lymph Node Region
Stage I means lymphoma is found in a single lymph node or a group of adjacent lymph nodes. It can also apply when there’s a single tumor in one organ outside the lymphatic system with no lymph node involvement. This is the most contained form of the disease. When lymphoma sits in just one area, treatment is often shorter and less intensive, typically involving a few cycles of chemotherapy, sometimes combined with targeted radiation to that specific region.
Stage II: Same Side of the Diaphragm
Stage II means two or more lymph node groups are involved, but they’re all on the same side of the diaphragm. So the disease might be in nodes in your neck and armpit (both above the diaphragm), or in your groin and abdomen (both below), but not on both sides. If the lymphoma has also spread into a nearby organ directly from an affected lymph node, the letter “E” (for extranodal) is added to the stage, making it IIE.
Stage II can also be classified as “Stage II bulky” when a tumor mass reaches a certain size. Bulky disease is generally defined as any lymph node mass measuring 10 cm or more in its largest dimension. In the chest specifically, bulky disease is defined as a mass wider than one-third of the chest cavity’s internal width. Bulky disease matters because larger masses are harder to eliminate and often call for more aggressive treatment.
Stages I and II are collectively called “early-stage” or “limited-stage” lymphoma. Roughly half of Hodgkin lymphoma cases are caught at these early stages.
Stage III: Both Sides of the Diaphragm
Stage III is where lymphoma crosses the diaphragm boundary. Lymph nodes above and below the diaphragm are both involved. Involvement of the spleen also counts toward Stage III (since the spleen is considered part of the lymphatic system), and this is sometimes noted with the letter “S,” as in IIIS.
This stage marks the beginning of what doctors call “advanced-stage” disease. The shift from Stage II to Stage III changes the treatment approach significantly. Rather than combining short-course chemotherapy with localized radiation, Stage III is treated primarily with chemotherapy alone over more cycles, typically six. Radiation may be added afterward only if large masses remain.
Stage IV: Spread Beyond the Lymph System
Stage IV means lymphoma has spread into organs outside the lymphatic system that aren’t directly next to an affected lymph node. The most common sites include the bone marrow, liver, lungs, and the fluid surrounding the brain and spinal cord. If any of these four are involved, the disease is automatically classified as Stage IV regardless of how many lymph node regions are affected.
Stage IV can also be assigned when lymphoma is found in an organ that isn’t adjacent to the involved lymph nodes, even if that organ isn’t one of the four listed above. The key distinction from the “E” designation in earlier stages is that Stage IV spread is not a direct extension from nearby nodes. It represents disease that has traveled through the bloodstream or lymphatic channels to distant sites.
Letters That Modify the Stage
You’ll often see a letter added after the Roman numeral. The most important is the distinction between “A” and “B.” The letter B indicates the presence of specific systemic symptoms:
- Unexplained weight loss of more than 10% of body weight over six months
- Unexplained fever of at least 100.4°F (38°C) lasting days to weeks
- Drenching night sweats
If none of these symptoms are present, the stage gets an “A.” So a person with Stage IIIB has lymphoma on both sides of the diaphragm plus one or more of these B symptoms. B symptoms often signal more active disease and can influence treatment intensity. The letter “E” indicates direct spread into a nearby organ, and “S” indicates splenic involvement.
How Stage Affects Treatment
Early-stage Hodgkin lymphoma (Stages I and II without bulky disease) is typically treated with two to four cycles of chemotherapy. If interim imaging shows the disease is responding well, radiation may be skipped entirely. When the disease has unfavorable features, such as bulky masses or B symptoms, treatment extends to four or six cycles, often with radiation to the affected area.
Advanced-stage Hodgkin lymphoma (Stages III and IV) requires six cycles of chemotherapy, now commonly paired with immunotherapy. Multiple clinical trials have shown that adding radiation after chemotherapy for advanced-stage disease does not improve overall survival, so it’s generally reserved for residual masses that still show activity on follow-up scans. Non-Hodgkin lymphoma follows similar principles, though the specific regimens differ depending on the subtype and how quickly it’s growing.
Survival Rates by Stage
Survival statistics for lymphoma are reported using three categories: localized (roughly equivalent to Stage I), regional (Stage II), and distant (Stages III and IV). Based on SEER data from the National Cancer Institute, five-year relative survival rates for Hodgkin lymphoma are around 91 to 93% for localized disease and 92 to 95% for regional disease. Even for distant-stage Hodgkin lymphoma, five-year survival is approximately 77 to 83%, reflecting how treatable this cancer is across all stages.
Non-Hodgkin lymphoma has a wider range of outcomes because it encompasses dozens of different subtypes, from slow-growing forms that may not need treatment for years to aggressive types requiring immediate intervention. Five-year survival for localized non-Hodgkin lymphoma runs between 76 and 84%, regional disease between 70 and 76%, and distant disease between 55 and 67%. These numbers represent averages across all subtypes, so individual prognosis can vary substantially depending on the specific type of non-Hodgkin lymphoma involved.
It’s worth noting that staging alone doesn’t determine outcomes. Factors like age, overall health, specific lymphoma subtype, and how the disease responds to initial treatment all play significant roles. A person with Stage IV indolent non-Hodgkin lymphoma may live for decades, while a more aggressive subtype at the same stage requires urgent, intensive treatment but can still often be cured.