Non-Hodgkin’s Lymphoma

Non-Hodgkin’s lymphoma originates in the lymphatic system. The lymphatic system is part of the immune system which serves the primary purpose of fighting infection within the body. In Non Hodgkin’s lymphoma the cancer originates in the lymphocytes. Lymphocytes are a particular type of white blood cell that fight infections within the body.

About the lymphatic system – The lymphatic system is a network of vessels and nodes where a fluid called “lymph” circulates. Lymph flows in the lymphatic system the same way that blood circulates in the circulatory system, except much more slowly.

The human body has about 600 lymph nodes in the body. These nodes are like small reservoirs of lymph fluid. The lymph nodes serve the purpose of storing lymph fluid to fight infections.

Lymph fluid contains white blood cells. The white blood cells contained in the lymph fluid are primarily lymphocytes and the fluid also contains chyle. Chyle is a fluid produced in the digestive tract and primarily is a mixture of amino acids and lipids.

During times of infection, lymph nodes can swell as they store more lymph fluid as well as fight bacteria, viruses or other invaders during the infection fighting process.

Individual parts of the lymphatic system

  • Lymph nodes – These nodes are small reservoirs of lymph fluid. There are 600 lymph nodes in the human body, most are concentrated in the neck. upper chest and groin area. These lymph nodes are connected by lymphatic vessels.
  • Bone marrow – This is the spongy tissue inside the bone where blood cells are created.
  • Thymus – A small organ located directly behind the sternum and is important in developing T-cells.
  • Spleen – Spleen is very important in creating new lymphocytes as well as filtering out dead and damaged blood cells from the blood. Spleen also filters out bacteria and cell waste from the body.
  • Tonsils and adenoids – This a collection of lymph tissue at the back of the throat. The tonsils and adenoids server the purpose of making antibodies against germs that are inhaled or swallowed.
  • Digestive tract – The digestive tract contains lymph tissue that is responsible for, among other things, making chyle which is a mixture of amino acids and a primary component of lymph.

Lymphatic circulation

Lymph fluid circulates throughout the lymphatic system the same way that blood does in the circulatory system just at far lower pressure and at lower speeds.

Non-Hodgkin’s lymphoma is the more a common type of lymphoma then Hodgkin lymphoma. There are several main types of Non-Hodgkin’s lymphoma; B-cell lymphoma, NK-cell lymphoma, T-cell lymphoma. Non Hodgkin’s lymphoma is also classified by how quickly the cells are dividing. They are given the classification of indolent if they are slow dividing and they are given the classification of aggressive if they are dividing and spreading quickly.

Types of non-Hodgkin’s lymphoma

B-cell lymphoma

B-cell lymphoma makes up approximately 90% of all non-Hodgkin’s lymphoma. There are several sub-types of B-cell lymphoma:

  • Diffuse large B-cell lymphoma – This is one of the more common forms of Non-Hodgkin’s lymphoma, accounting for approximately 30% of all cases. This is considered an aggressive form of the disease.
  • Follicular lymphoma – This is the second most diagnosed form of non-Hodgkin’s lymphoma. This makes up about 20% of all non-Hodgkin’s lymphoma. This is typically an indolent form of non-Hodgkin’s lymphoma.
  • Mantle cell lymphoma – This non-Hodgkin’s lymphoma effects approximately 5-7% of cases of the disease. This cancer typically effects males over the age of 60.

NK-cell lymphoma

NK-cells are called Natural Kill cells. NK-cells are part our innate immune system and are closely related to T-cells, except T-cells have a more powerful “memory” to antigens and are more effective in developing immunity against previous viral and bacterial invaders.

NK-cells typically are not generated in nodal regions of the lymphatic system. Instead they are developed in the bone marrow and liver.

NK-cell lymphoma is classified as extranodal, because the cells are developing outside the lymphatic nodal system.

T-cell lymphoma

T-cell non-Hodgkin’s lymphoma is a form of cancer that develop inside the T-cells of the immune system. This cancer is closely linked to human T-cell lymphotropic virus 1 (HTLV-1). T-cell lymphoma is rare in western countries that we infection with the HTLV-1 virus is less frequent. Instead it is more common in areas where the virus is more common such as, South East Asia, Eastern and Central Asia, Central America and Caribbean and Western Africa.

About HTLV-1 virus – The HTLV-1 virus is a retorvirus. This puts it in the same family as the HIV virus. The HTLV-1 virus is different from the HIV virus in that it is in the oncovirus subfamily of the retroviruses. Ironically enough, when the HIV virus was first discovered, it was named HTLV-3, before it was properly re-classified as HIV after further study was completed on the virus.

The HTLV-1 virus, has a very strong correlation with certain forms of non-Hodgkin’s lymphoma.

Non-Hodgkin’s lymphoma risk factors

In many cases, people that have zero exposure to risk factors develop the disease and many people who had risk factor exposure do no develop. Below are factors that could increase risk.

Non-Hodgkin’s lymphoma symptoms

Having the symptoms below does not definitively mean that one has Non-Hodgkin’s lymphoma. Only a doctor can properly diagnose non-Hodgkin’s lymphoma.

  • Chills
  • Swollen lymph nodes
  • Fatigue
  • Swollen Abdomen
  • Chest pain
  • Pressure in chest with deep breaths
  • Shortness of breath
  • Frequent infections
  • Night sweats
  • Fever
  • Weight loss

Non-Hodgkin’s lymphoma conclusion

Because there are so many types of this cancer, it can be very confusing, even for doctors to properly classify and diagnose this disease to its proper sub-type.

The World Health Organization (WHO) groups non-Hodgkin’s lymphoma based on the following criteria:

  • How the cancer cells look under a microscope
  • The chromosomes of the cancer cells
  • The type of lymphocyte the cancer starts in
  • The presence various proteins on the cancer cells

According to the National Cancer Institute, when averaged out over all stages and subsets, non-Hodgkin’s lymphoma has a 5 year survival rate of 72%. Stage I 5-year survival rate is 82%, Stage II 5-year survival rate is 75%, stage III 5-year survival rate is 69% and the stage IV 5-year survival rate is approximately 62%.

5-year survival rate across all stages and subsets has a 72% survival rate in non-Hodgkin’s lymphoma. Image courtesy of National Cancer Institute

5-year survival rate for non Hodgkin’s lymphoma

5 year survival rates according to stages of the cancer. Image courtesy of National Cancer Institute.

This year in the United States alone, it is estimated that 74,200 patients will be diagnosed with non-Hodgkin’s lymphoma. Over half of all patients are aged 65 or older at the time of diagnosis.

This cancer has a very high success rate when caught early and early detection is key in beating the diagnosis. If you have any symptoms above it is a good idea to talk to your doctor or health care provider immediately.