What Is T-Cell Lymphoma?

Introduction

The lymphatic system is an important part of your body’s defence system. It filters some of your blood from your tissues, puts it through a screening process and hunts for any potential threats to your health. Once the blood is verified as healthy, it is returned back into your heart and circulates throughout the body.
There are organs within your body called lymph nodes and the spleen which act as the headquarters for your immune system. This is where all of your T cells can replicate and form a defence army before being let out into the circulation to defend your body. However, sometimes mistakes occur, which can lead to the formation of cancer within these parts of the body. 

Lymphoma is a type of cancer which begins in the lymphatic system and affects all cells within the lymph system. Furthermore, T cell lymphoma is a type of cancer where T cells, an important cell of the immune system, continue to grow and multiply uncontrollably. This disease unfortunately is serious and does not normally have a good outcome. This highlights the importance of research and improving our knowledge of this disease to improve the prognosis and treatment strategies. 

There are two types of lymphoma; Hodgkin and Non-Hodgkin lymphoma, and T cell lymphoma falls in the latter group. Your doctor must be able to distinguish between these two groups as they are different from each other and require different treatments.

Characteristics of T-cell lymphoma

T cells are an important part of your body’s immune system. Their development starts in the thymus, an organ located in the upper chest. The cells will then move to other organs called the lymph nodes or the spleen, where they will wait until a danger has been detected.
When a danger is detected, your T cells will start to multiply and, essentially, form an army to help protect you from illness.

Like everything, sometimes errors take place, and with T cell lymphoma, these T cells will grow and multiply uncontrollably, resulting in the formation of a tumour. The exact reasons for this remain an area for research, but a few possible causes have been discussed in more detail in this article. Some of the reasons include gene mutations and chronic infection, which can cause your immune system to go into overdrive and, therefore, trigger uncontrolled cell growth. This can also happen if you get infected with a bacterial or viral infection; your immune system will go into overdrive and create a highly inflammatory environment. This may trigger the uncontrollable cell growth seen in cancer.

Additionally, repeated injury or damage to a part of your body can also trigger the growth of cancer cells. This is because your cells have to regrow after each injury or damage, which can increase the chance of gene mutations occurring.¹

Epidemiology and risk factors

This type of cancer affects some people more than others. If you are a person who was assigned male at birth (AMAB)  and between the ages of 55 and 74 years, you are more likely to be diagnosed with T-cell lymphoma. There are also some geographical and ethnic variations which have to be acknowledged. Both Japan and the Caribbean islands are going through endemic levels of T-cell lymphoma, which furthers the need for more research.¹ People who live in low-income housing in the US were also seen to have an increased risk of T-cell lymphoma.

It is well known that alcohol use, smoking and being out in the sun too long can harm your health and increase your risk of cancer. However, some therapeutic drugs can also increase your risk of T-cell lymphoma. If you are prescribed medication to treat high blood pressure and to suppress the immune system, you are more likely to develop T-cell lymphoma. Immunosuppressive drugs will dampen your body’s defence system, which makes it much harder for your body to find and destroy cancer cells, increasing the risk of tumours growing.² Additionally, a type of high blood pressure medication called thiazide diuretics will cause your skin to become more sensitive to the sun's UV rays which can increase the risk of T-cell lymphoma occurence.³ 
Genetic history can also have a role in T-cell lymphoma development. If you have a family history of eczema and multiple myeloma, a bone marrow cancer, it will increase your risk of T cell lymphoma.⁴ 

Other common risk factors are air pollutants and insecticides. So, if you live in a city with lots of road traffic or work in vegetable or crop farms, this increases your risk of T-cell lymphoma.⁴ 

Sub-types of T-cell lymphoma

There are a few types of T-cell lymphoma which affect different types of the body. These include the following:

Peripheral T-cell lymphomas:

• Angioimmunoblastic T-cell lymphoma: this is an aggressive and fast-growing type of T-cell lymphoma.
• Anaplastic large cell lymphoma: this type is characterised by its normal-looking cells – hence ‘anaplastic’ – with a distinctive horseshoe shape.⁵

Cutaneous T-cell lymphomas:

• Mycosis fungoides: this type of lymphoma starts with small lesions on the skin surface but can progress into an aggressive cancer form with tumours on the skin and eventually, this can enter into organs, causing organ damage.
• Sézary syndrome: this type of cancer is aggressive and shows up with severe irritation and burns of the skin. This type can also develop from mycosis fungoides or can originate independently.¹

Diagnosis, treatment and clinical presentation

If you catch this cancer early, your outcome and life expectancy can be relatively positive. However, these types of cancers can grow fast and develop to be quite aggressive and generally have low remission rates. This makes it crucial for this type of cancer to be detected early to allow for the best possible outcome. As mentioned above, there are multiple forms of this lymphoma, and determining which subtype you are dealing with is crucial to treating it as quickly and effectively as possible. An MRI, CT or PET scan be used to identify any tumours within the soft tissue of the patient. Following this, you can work with your doctor to identify exactly which type you are dealing with.

After you have determined which subtype you have, the next step is to treat the disease. Treatment of the disease is unfortunately not curable but helps to slow the progression of the disease and helps the patient live with the disease as pain-free as possible. Treatment options include chemotherapy, topical therapy such as skin radiation and topical chemotherapy, as well as treatment with retinoids. 

Chemotherapy is probably the best-known type of treatment for cancer. It works by preventing fast-growing cells within your body from dividing into two new cells and, therefore, prevents the growth of cancer. It does, however, have its downside. Chemotherapy makes it hard to distinguish between cancer cells and healthy cells in your own body. This can lead to other fast-growing cells in your body, such as cells in your hair follicle, also being targeted and destroyed, which explains the common side effect of hair loss that chemotherapy causes.

Retinoids can also be used as treatment. They are derived from vitamin A and work within your cells to prevent cell growth, which can be very beneficial in cancer by slowing the progression of the disease and tumour growth.⁶

T-cell lymphoma normally comes with some negative symptoms, which range from skin redness, swollen lymph nodes and unexpected weight loss.⁷ As this type of cancer affects your skin, it will show up as skin abnormalities such as redness or dryness, but as it progresses, it can move into your organs, which will start to affect organ function. This means that if it is not caught quickly, this type of cancer can lead to organ damage or failure which can have devastating consequences.

Summary

• T-cell lymphoma is a rare type of cancer which affects a type of immune cell called T cells. It is an aggressive form of cancer, and not many people are cured of it.
• T cells originate in an organ called the thymus. The cells then move to lymph nodes or the spleen which is where they can multiply and produce an army of cells before fighting the infection.
•  People assigned male at birth (AMAB) and those who are 55 to 74 years of age are at a higher risk of being diagnosed with T cell lymphoma.
•  Japan and the Caribbean islands are undergoing an endemic in T cell lymphoma, which exaggerates the necessity of research around T cell lymphoma to improve the treatment and lives of millions of people.
• Living in a city or working with insecticides can increase your risk of T-cell lymphoma.
• There are multiple forms of the disease, which can cause severe skin rashes and unexpected weight loss and can eventually lead to organ damage.
• Treatment comes in many forms through chemotherapy, radiotherapy, and retinoids, which can all work to slow the progression of cancer. Unfortunately, these are not curable but can minimise the pain associated with cancer.
• Some risk factors, including family history and genetic predisposition, are unavoidable, but living a healthy and balanced lifestyle can help reduce your risk of developing cancer.