Lymphoma

There are two broad types of lymphoma: Hodgkin lymphoma and non-Hodgkin lymphoma. The latter group encompasses a large number of disease subtypes that are categorized as “indolent” (slow-growing) or “aggressive” (fast-growing).

Standard post-treatment assessment and monitoring

For both Hodgkin and non-Hodgkin lymphoma, response to initial treatment is assessed using the imaging technique known as PET/CT. Your doctor will assess how much cells in areas of your body that might be tumors “light up” due to absorption of a radioactive sugar called FDG compared to two reference organs – the mediastinum and the liver. Lesions will receive a score from 1 to 5 (see below), which will then determine your response category. Your response category will help guide what comes next in your treatment journey.14

In the months and years after your treatment ends, your doctor will use a variety of techniques to keep on eye on your health and detect any signs of relapse. These techniques may include taking a clinical history, physical exams, laboratory tests of your blood, and in some cases, CT imaging.14

Five-point scale:14
  • 1: No uptake above background
  • 2: Uptake less than or equal to mediastinum
  • 3: Uptake greater than mediastinum but less than or equal to liver
  • 4: Uptake moderately greater than liver
  • 5: Uptake markedly higher than liver and/or new lesions
Categories of treatment response:
  • A score of 1, 2 or 3 in the lymph nodes and non-lymph system tissue/organs; it does not matter if there are any remaining masses
  • No new lesions outside of the lymph nodes that light up on PET/CT
  • No evidence of disease in the bone marrow
  • A score of 4 or 5, but with reduced absorption compared to diagnosis, in the lymph nodes and non-lymph system tissue/organs; it does not matter if there are remaining masses
  • No new lesions outside of the lymph nodes that light up on PET/CT
  • Bone marrow shows FDG absorption higher than found in normal, healthy marrow, but less than seen at diagnosis
  • A score of 4 or 5 in the lymph nodes and non-lymph system tissue/organs, with no significant change in FDG absorption from diagnosis to end of therapy
  • No new lesions outside of the lymph nodes that light up on PET/CT
  • No change in the absorption of FDG in the bone marrow from what was seen at diagnosis
  • A score of 4 or 5 in the lymph nodes and non-lymph system tissue/organs, with an increase in FDG absorption compared to the diagnostic scan

And/or

  • New lesions outside of the lymph nodes consistent with lymphoma rather than another cause (e.g., infection/inflammation), including in the bone marrow, that absorb a lot of FDG

Role of mrd testing

Minimal residual disease (MRD) refers to small numbers of cancer cells that may remain in your body after treatment and eventually cause your disease to come back. These residual cells are present at such low levels that they cannot be detected with the imaging and laboratory techniques used for standard post-treatment response assessment and monitoring. Instead, more sensitive tests must be used.

Whether and to what extent MRD testing is being used clinically varies across different types of lymphoma. Below is information on some of the more common types of non-Hodgkin lymphoma, as well as Hodgkin lymphoma.

  • Diffuse Large B-Cell Lymphoma (DLBCL)

    Until recently, MRD testing had not really been attempted in DLBCL patients because it was known that in this type of lymphoma not enough cancer cells enter the bloodstream to be detected. However, new advances with next-generation sequencing based MRD tests have made it possible to measure lymphoma-specific pieces of DNA in the blood. This so-called circulating tumor DNA (ctDNA) can detect residual DLBCL, usually several months before the disease can be detected via CT scan.15, 16

  • Mantle Cell Lymphoma (MCL)

    In patients eligible for autologous (self) stem cell transplant, patients who achieve MRD-negativity after induction or after transplant live longer without their disease progressing (progression-free survival, PFS) and live longer overall (overall survival, OS).17-22 In patients not eligible for transplant, patients who achieve MRD-negativity after induction therapy or during maintenance treatment also live longer without their disease progressing.20, 21

  • Follicular Lymphoma (FL)

    Patients who are MRD-negative after treatment live longer without their disease progressing (progression-free survival, PFS). This has been shown in studies of both newly diagnosed and relapsed patients, and in patients receiving or not receiving autologous (self) stem cell transplant.23-25

  • Hodgkin Lymphoma

    Because the Hodgkin Reed-Sternberg (HRS) cells typical of Hodgkin lymphoma are not present in high numbers in either tumors or the blood, even when disease level is high, there have not yet been any MRD tests developed for this disease. However, new advances with next-generation sequencing based MRD tests have made it possible to measure lymphoma-specific pieces of DNA in the blood. This may eventually be developed into a new method that can measure disease burden and provide prognostic information from a blood test in patients with Hodgkin lymphoma.26

next steps

Find resources that can help you prepare to talk with your doctor about disease level testing and how it might play a part in your treatment plan.