Know your nodes - the lymphatic system

The lymphatic system is a network of tissue, ducts and organs, and is an important part of the immune system, playing a major role in the body's defence against infection. Lymph nodes, which are part of this defence, are located throughout the body (eg, armpits, neck, groin) and become enlarged when fighting infection. Cancer of the lymphatic system is called lymphoma, and symptoms of lymphoma can be similar to the flu or other illnesses. 

What does the lymphatic system do?

The lymphatic system transports lymph fluid from the body's tissues back to the circulatory system, removing excess fluid from these tissues and filtering the fluid in the lymph nodes. The lymph nodes also produce types of cells important to the body's immune system. When bacteria or cancer cells are recognised in lymph, the lymph nodes become active, produce more infection-fighting white blood cells and swell. They can sometimes be felt in the armpits, groin and neck.

Lymphoma

Lymphoma (a cancer of the lymphatic system) develops when problems occur in the production of lymphocytes - a type of white blood cell produced in the bone marrow which travels to other parts of the body, normally the lymph nodes. This results in abnormal cells that become cancerous. There are more than 35 types of lymphoma which can be categorised as Hodgkin and non-Hodgkin lymphoma.

Unravelling the mystery

Lymphoma has been dubbed "the cancer that no one knows" and it occurs in a part of the body that remains a mystery to most New Zealanders (see diagram).

According to a global survey by the Lymphoma Coalition, a non-profit network of international lymphoma patient groups, 55% of people living with lymphoma had never heard of it before they were diagnosed. Similarly, 43% did not understand, or only partially understood, what they were told by their doctors upon diagnosis.

This is reflected in research conducted by the Leukaemia & Blood Foundation, which revealed only 9% of 500 New Zealanders surveyed could name lymphoma as a type of cancer, while less than 1% considered it a possible cause of the most common symptoms (listed further below).

Test your knowledge

To mark World Lymphoma Awareness Day (which is held on 15 September), the Leukaemia & Blood Foundation (LBF) is promoting its easy and fun way to unravel the mysteries of your lymphatic system. Simply visit www.knowyournodes.org.nz to take part in a quiz and find out what you know - or more importantly, don't know - about one of the body's most vital systems.

Also, see our Human Atlas movie on Hodgkin lymphoma, which shows the distribution of the lymphatic system throughout the body.

Common symptoms of lymphoma

The common symptoms of lymphoma are often misdiagnosed as flu or fatigue and include:

• painless swelling in the upper body lymph nodes, which can be felt in places like your neck, collarbone region, armpits or groin
• fevers, especially at night
• chills or temperature swings
• unexplained weight loss
• loss of appetite
• unusual tiredness or lack of energy
• persistent coughing and/or breathlessness
• persistent itch all over the body without an apparent cause or rash
• enlarged tonsils
• headache.

Most people who have complaints like these will not have lymphoma. However, according to the LBF's Medical Director, Dr Peter Browett, anyone experiencing these symptoms over a period of more than two weeks, should visit a medical professional and have them checked out.

Early detection is the goal

Pru Etcheverry, Executive Director of the Leukaemia & Blood Foundation, says, "New Zealanders really need to know their nodes - both the lymphatic system and the signs and symptoms of lymphoma. If detected early, there is a better chance for quicker diagnosis, treatment and overall survival." An early diagnosis is important because, if untreated, some types of lymphoma can be fatal within as little as six months.

Dr Browett adds that, "Early diagnosis makes a huge difference in the ability to combat the disease. Most patients are distressed when they find out they have lymphoma and are understandably frightened as they often don't know what it is. In many cases, patients don't realise how effective treatment is and how good the outlook can be."

All ages can be affected

Lymphoma can occur in all ages, but it is most common in people 50 years and over, despite only 29% of people in this age range identifying it as a type of cancer.

The rise in diagnoses of lymphoma can therefore be partly blamed on a growing and ageing population, but that alone does not fully account for the doubling of incidence. Around 750 people will be diagnosed with lymphoma in New Zealand each year - around 80 with Hodgkin and around 670 with non-Hodgkin lymphoma.

Original material provided by the Leukaemia & Blood Foundation, and edited by everybody, September 2007.