Non-Hodgkin lymphoma

According to the National Cancer Registry’s (NCR) latest published statistics (2019), non-Hodgkin lymphoma (NHL) ranks as the fifth most common cancer in South African women.

Impact of HIV

In the South African context, no discussion on lymphoma is complete without discussing the impact of HIV. Persons infected with HIV are at an increased risk of developing non-Hodgkin lymphoma. The NCR statistics clearly shows a steady increase in NHL cases in females from 2001 to 2019. Of note is that the age-specific incidence rates reflect a shift of non-Hodgkin lymphoma cases to younger patient groups (less than 60 years). This likely reflects the demographics of persons living with HIV who develop HIV-associated lymphomas. 

Lymphocytes

Lymphoma is a cancer that arises in lymphocytes (specialised cells of the immune system). Lymphocytes are divided into B-lymphocytes and T-lymphocytes. 

There are various sub-populations of B- and T-lymphocytes depending on the maturity of the lymphocyte, it’s location in the body and function. 

Primary lymphoid tissues (where lymphocytes are produced and develop), are the bone marrow and thymus. Secondary lymphoid organs (where lymphocytes mature and perform the bulk of their immune functions) include lymph nodes, spleen, tonsils, adenoids and clumps of lymphoid tissue surrounding the intestines. In addition, lymphocytes can be found in and amongst the cells of most of the body’s tissues. 

Diagnosis

The symptoms of non-Hodgkin lymphoma reflect the type and location of lymphocyte population that has become cancerous. General symptoms include fatigue, unintentional weight loss in a short period of time (loss of 10% or more of body weight is significant), fevers and drenching night sweats. 

Given the usual location of lymphocytes, signs could include enlarging (sometimes painful) lymph glands (neck, armpits and groin area). If the bone marrow is involved, blood counts can drop: decreased red cells (anaemia) resulting in fatigue; decreased platelets (thrombocytopenia) resulting in bleeding; and decreased white cells (leukopenia) resulting in recurrent infections. You can also experience abdominal pain from enlarging lymph nodes and/or spleen. Lymphocytes are present in almost all body tissues, and tumour masses can occur anywhere. 

To make the diagnosis, cancerous lymphocytes must be demonstrated on tissue. Depending on the site of involvement, investigations done may include:

• Blood sample
• Lymph node aspirate (needle inserted into gland) or excisional biopsy (surgical procedure to remove entire lymph gland)
• Bone marrow biopsy 
• Biopsy of suspected organ/tissue  involved e.g. liver, brain, skin, tonsil, etc.
• Gastroscopy and/or colonoscopy to obtain stomach or intestinal biopsies
• Lumbar puncture to obtain spinal fluid 

The involved lymphocytes can undergo specific genetic mutations and demonstrate tumour markers (proteins) on the surface or inside the cell and the specimen will be sent for an array of tests. The results guide classification of the lymphoma, prognosis and treatment choice.

Staging investigations are then done to determine the extent of lymphoma involvement and your baseline fitness to withstand therapy:

• Blood tests to determine blood counts, kidney and liver function, HIV and Hepatitis B and C status, etc. 
• Full body CT scan or PET-CT scan.

Treatment

The subtype and stage of non-Hodgkin lymphoma, as well as your general level of health will determine treatment choice. Treatment will include one or a combination of the following:

• No treatment – Watch and wait. Some lymphomas are diagnosed at an early stage, are slow-growing and don’t require treatment upfront. You will be followed-up at regular intervals to look for lymphoma progression. 

• Chemotherapy – Nukes cancer cells. 

• Immunotherapy – Harnesses your immune system to destroy cancer cells. 

• Radiotherapy – High doses of radiation are used to kill cancer cells. 

• Intrathecal chemotherapy – Injected via a lumbar puncture into spinal fluid. 

• Haematopoietic stem cell transplant – Using either your own blood or bone marrow stem cells or donor stem cells.

• Targeted therapy – Designer drugs targeting specific pathways of tumour cell growth and survival. 

• CAR-T cells – Currently not available in SA but collaborations are underway in the private sector to drive investigator led trials which will hopefully enable patients in both the private and public sector to access this therapy in the next few years. 

Survivorship

Generally 70% or more of B-cell lymphomas can be cured or controlled with treatment. However, T-cell lymphomas don’t have the same outcome, and some aggressive subtypes can have unrelenting courses with a survival of weeks to a handful of months even in the best centres. 

Even after attaining remission, you will require close follow-up for at least five years to check for relapse, and longer-term follow-up to monitor for second malignancies, osteoporosis, delayed adverse effects from chemotherapy (heart failure and bone marrow dysfunction). 

The psychosocial, fertility and financial aftermath shouldn’t be overlooked, and you should ideally be managed as part of a multi-disciplinary team to provide ongoing support after diagnosis and treatment. 

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