What is lymphoma?
Lymphoma is the name given to several types of blood cancers that develop in the lymphatic system. It starts when a white blood cell called a lymphocyte becomes a lymphoma cell. Masses of lymphoma cells collect in the lymph nodes and other body parts. The cancerous lymphoma cells crowd out the lymphocytes and weaken the immune system, so it doesn’t guard against infection effectively.
The two main types are Hodgkin lymphoma and non-Hodgkin lymphoma. The exact cause or causes of lymphoma is unknown. Scientists know that it’s a mutation in the lymphocyte’s DNA (white blood cell) that causes a lymphoma cell’s metamorphosis.
Because the immune system is essential to our ability to stay healthy, and the lymphatic system is a significant part of the immune system, lymphoma cancer treatment is incredibly important.
The problem is the lymphatic system is part of the circulatory system reaching everywhere in your body. As lymphoma starts in the lymph system, it can quickly spread to different tissues and organs, most often to the liver, bone marrow, or lungs.
To better understand lymphoma, it is helpful to understand the lymphatic system. Many people are familiar with how blood flows throughout the body, but the lymphatic system is somewhat a mystery to many. Let’s travel around the body with this vital immune system component.
The Lymphatic System
Lymph is the root for – lymphatic, lymphocyte, and lymphoma. Lymph from the Latin lympha means “water.” Lymph is the water, or fluid, that flows throughout your body in the lymphatic system.
As blood makes its way through your body, it enters capillary beds; this is where fresh blood drops off water, oxygen, and nutrients and collects waste materials such as carbon dioxide from the cells. It is here that some of the fluid is forced out of the blood to join the fluid that surrounds your body’s cells (interstitial fluid.) This allows oxygen and various nutrients to be absorbed by nearby tissues.
Most of this fluid is reabsorbed into the capillaries at the venous end, but not all of it. Around fifteen percent remains behind, along with essential blood proteins. This would be a problem, as the bloodstream can’t continuously lose so much fluid.
Maintaining homeostasis is another important function of the lymphatic system. The lymphatic vessels collect the excess interstitial fluid and return it to the bloodstream. However, before the fluid reenters the bloodstream, it passes it through the lymph nodes, which serve as filters, cleansing the fluid as it circulates.
So, on the whole, the lymphatic system is comprised of:
- The lymphatic vessels
- Lymph nodes
- The spleen
- The thymus
- The tonsils
Lymph nodes (lymph glands) are the control centers where the body starts immune responses. Inside lymph nodes, many different types of immune cells meet. Dendritic cells arrive from nearby parts of the body, bringing antigens from external invaders that the body needs to eliminate.
The dendritic cells search for a responsive T-cell to present these antigens to. These T-cells become activated and start to rapidly divide until they form a clone army that will scour the body to find the invasion’s source and get rid of it.
But with all those growing T-cells, the lymph node can quickly fill up, which is a big problem. If there isn’t enough space to build a sufficiently sizeable T-cell army, the immune response is weakened.
Luckily, the dendritic cells have a trick up their sleeve. As they search for T-cells, they crawl across a meshwork of fibroblast cells. These fibroblasts form the structural scaffolding that keeps the lymph node’s shape intact.
On their way to activating the T-cells, dendritic cells warn the fibroblast network that it will get crowded soon. In response to these warning signals, the fibroblasts relax and become stretchier. This gives the lymph nodes enough flexibility to expand when T-cells’ clone army begins to grow quickly.
As the lymph node continues to expand, the fibroblast network grows as well, making sure there are enough fibroblasts to support a large number of T-cells in the expanding lymph node.
But when those activated T-cells have left to fight the infected parts of the body, the fibroblast network regains tension and begins to shrink the lymph node back to normal size. Ready and waiting to build the following immune response to keep us safe from subsequent invaders.
You may have swollen lymph nodes due to infection from bacteria or viruses, causing an increase in T cells. Common areas where you might notice swollen lymph nodes include your neck, under your chin, in your armpits, and your groin. However, swollen lymph glands are rarely caused by lymphoma.
Visit your doctor if you’re concerned or if your swollen lymph nodes:
- Appear for no apparent reason
- Continue to enlarge or have been present for two to four weeks
- Feel hard or rubbery or don’t move when you push on them
- Are accompanied by persistent fever, night sweats, or unexplained weight loss
Treatment options for lymphoma
Traditionally treatment options for lymphoma have been chemotherapy, which directly damages the tumor cells—also, radiation therapy and targeted therapy which gets into specific cell signaling pathways.
Immunotherapy is different because it utilizes either drugs that mimic the immune system or the patient’s own immune system. With these, there are different sets of side effects. Usually, those side effects are more immune-based and less severe than side effects from chemotherapy.
You can have infusion reactions with any type of monoclonal antibody (man-made proteins that function like human antibodies). These reactions look like flu-like symptoms, similar to how you might feel when your immune system acts against the flu.
These can be fevers, muscle aches, fatigue, shortness of breath directly related to when physically giving the patient the antibodies. Once the infusion stops, typically, these get better within hours, if not minutes.
Other specific immune-related side effects called cytokine release syndrome can occur with CAR T cells as neurotoxicity or toxicity affects the neurologic system. And finally, with checkpoint blockade, which is another type of antibody therapy.
Typically, immunotherapy is well tolerated. You won’t see anything aside from some mild fatigue. Occasionally more autoimmune type effects where the immune system is activated can cause rashes or other organs’ inflammation.
The approved immunotherapies for lymphoma depend on which type of lymphoma and at which stage. If you have been diagnosed with Lymphoma, your doctor will advise you on the best treatment.