Overview of non-Hodgkin lymphoma (NHL)
Non-Hodgkin lymphoma (NHL) is a group of blood cancers that includes all types of lymphoma except Hodgkin Lymphomas. All NHL’s are classified into two groups called B Cell Lymphomas or T Cell Lymphomas. Lymphomas arise when developing B and T lymphocytes undergo a cancerous change, and multiply in an uncontrolled way. These abnormal lymphocytes, called lymphoma cells, form collections of cancer cells called tumours, in lymph nodes and other parts of the body. The majority of lymphomas (around 85%) arise in developing B-lymphocytes (B-cell lymphomas). The remainder arise in developing T-lymphocytes (T-cell lymphomas). There are over 80 specific types of lymphoma.
NHL can begin in any lymph node or lymph tissue found in the body. Tumours may involve just one lymph node or several lymph nodes at the same time. Since lymphocytes move throughout the body through either the bloodstream or more commonly the lymphatic system, any abnormal lymphocyte has a clear path to travel all through the body. This is why. NHL can start in or spread to any part of the body. It is for this reason that many people have widespread disease at the time of diagnosis.
Who is affected by non-Hodgkin lymphoma (NHL)?
In the past 20 years, the number of people diagnosed with NHL has doubled. In Australia, there are over 6000 people diagnosed with NHL each year. Lymphoma is the 6th most common cancer diagnosed in adults in Australia. Non-Hodgkin lymphoma can affect people of all ages, including children and the elderly. The risk of developing non-Hodgkin lymphoma increases with age, especially over the age of 55 years. Some subtypes of NHL are more common in children and young adults.
NHL is slightly more common in men and women and it can develop in people of any ethnic background.
Types of non-Hodgkin lymphoma
There are over 70 different subtypes of non-Hodgkin lymphoma (NHL). There are some subtypes that are common, others that are less common (rare) and some are very rare. All subtypes of NHL are treated and managed differently.
NHL can be divided into different groups, depending on how they have developed or how they behave. It is important for your doctor to determine your lymphoma subtype to work out how to treat or manage lymphoma.
NHL can be divided into the following categories:
- B-cell lymphoma
- T-cell lymphoma
- Indolent (slow growing) lymphoma
- Aggressive (fast growing) lymphoma
B-cell non-Hodgkin lymphomas develop from B-cell lymphocytes. These are the most common type, accounting for around 85% of all lymphomas (including Hodgkin lymphoma).
T-cell non-Hodgkin lymphomas develop from T-cell lymphocytes. These lymphomas account for around 15% of all lymphomas. All T-cell lymphomas are NHL.
Indolent non-Hodgkin lymphoma are slow-growing types of lymphomas and usually develop over months to years. Indolent lymphomas are normally considered incurable but they can be managed for many years Indolent lymphomas can also be called low-grade lymphoma and tend to have fewer signs and symptoms when first diagnosed. Indolent NHL represents approximately 40 percent of all non-Hodgkin lymphomas
The average age of onset is usually about 60 years of age and can affect both men and women.
Most common types of indolent lymphoma include:
- Follicular lymphoma (FL)
- Cutaneous T-cell lymphoma (CTCL)
- Waldenstrom’s Macroglobulinemia (WM)
- Chronic lymphocytic leukaemia (CLL) and small cell lymphocytic lymphoma (SLL)
- Marginal zone lymphoma (MZL)
Indolent lymphoma can respond very well to treatment and long remission periods can be achieved. During remission no active treatment is needed and most people are well during these times. Not all patients will need treatment straight away and are monitored on what is called “watch and wait”.
Aggressive non-Hodgkin lymphomas are fast-growing types of lymphoma and usually develop over weeks to months. Symptoms can develop quickly and treatment will need to start soon after diagnosis. These lymphomas are potentially curable.
Aggressive lymphoma are also called high-grade lymphoma and approximately 60 percent of non-Hodgkin lymphoma are an aggressive subtype.
Most common types of aggressive lymphoma include:
- Anaplastic large-cell lymphoma
- Burkitt lymphoma
- Primary Central nervous system lymphoma
- Diffuse large B-cell lymphoma (DLBCL)
- Mantle cell lymphoma (MCL)
- Peripheral T-cell lymphoma (PTCL)
Most high-grade lymphomas respond very well to treatment and patients remain in remission for a long period of time.