Non-Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) is a term for all the types of lymphoma that are not Hodgkin lymphoma, as such it includes a wide array of different cancers which can be high-grade or low-grade and have a wide variety of presentations and severities. Generally, NHL is more common in men compared to women although the reason for this is unknown.

Diagnosis

What all types of NHL have in common is that they come from cancerous lymphocytes (immune cells that are supposed to protect the body from both infection and cancer). They circulate in the lymphatic system which is a series of glands throughout the body, as well as through the liver, spleen and bone marrow. 

Symptoms in NHL arise from three main disease processes:

1. Lymph node and organ enlargement with NHL cells. You may notice this as lumps in your neck, under your armpit, or in your groin. You may also notice discomfort or bloating in your abdomen, or a feeling of fullness after eating a small amount of food, despite being hungry. A rapid increase in the number of NHL cells can result in loss of weight, and sometimes night sweats; this would indicate a higher-grade NHL.
2. Immune dysregulation/autoimmune symptoms. Because NHL cells are immune system cells, when they increase in number they can suppress healthy immune cell function (reduced healthy antibody production) leading to infections. They can also cause overactivation of other aspects of the immune system, causing mistaken immune attack of healthy tissues (immune destruction of healthy blood cells).
3. Displacement of the healthy bone marrow by NHL cells. Lymphoma cells can spread to the bone marrow. This leads to dropping blood counts as production of healthy blood cells reduces in an overcrowded bone marrow. A low red cell count (anaemia) leads to fatigue, shortness of breath on exertion, and dizziness. 

A low white cell count (neutropenia) can predispose you to infections. A low platelet count (thrombocytopenia) can lead to increased bruising or bleeding from areas such as the gums or nose.

The diagnosis is made from a biopsy of either a lymph node or bone marrow. Staging involves imaging most of the body with a CT or PET scan to see which areas are involved. This is to gage the extent of spread (which can have an impact on survival).

Treatment

Not all NHL needs treatment. There are types that are very slow-growing and may never cause any of the problems listed above; in these patients there is no benefit to treatment as their disease doesn’t cause any significant medical problems. These patients do need monitoring to make sure progression requiring treatment isn’t missed though.

Low-grade NHL causing symptoms and all high-grade NHL require treatment. The standard treatment is either immunotherapy alone (treatment that engages your own immune system to target your cancer), chemotherapy, radiotherapy, or a combination. Some patients with very aggressive disease may need a stem cell/bone marrow transplant to reduce their risk of relapse. 

There are a number of targeted therapies which have become available in the last decade or so for patients who relapse, which show a lot of promise and are now being used upfront for those who can’t tolerate more aggressive therapy. 

There are also a number of new immunotherapies, from more potent versions of previous therapies to brand-new modalities of treatment (CAR-T cell therapy).

Survivorship

Non-Hodgkin lymphomas are generally very responsive to treatment. Low-grade NHL is difficult to cure but usually well-controlled with treatment required intermittently as symptoms and relapses emerge. As such, maintenance treatment with targeted and immune therapies in some low-grade NHL is prolonging time periods between treatments. This provides a clear improvement in quality of life for these patients. 

High-grade NHL can be more life-threatening at diagnosis but with a high rate of cure in the long term. This is because higher grade cancers are more susceptible to treatments like chemotherapy. 

More and more NHL patients are surviving long term as the treatments and therapies improve and become more tolerable to patients. For example, patients who are older and previously couldn’t be treated, can be now with significant improvement in both quality and quantity of life. 

Significant numbers of patients can expect to be cured as understanding the specific biolgy in the different kinds of NHL has led to more nuanced and effective therapy.