Lymphoma is a type of cancer that affects the body’s lymphatic system. It is a cancer of a type of white blood cells called Lymphocytes which are part of this system. The lymphatic system is part of the body’s immune system made up of a network of cells and tissues including the white cells called Lymphocytes, lymphatic vessels and organs that work together to fight germs and rid the body of toxins, waste and unwanted materials. The lymphatic system transports lymph, a fluid containing infection-fighting white blood cells, throughout the body.

Patients with lymphoma often notice a swelling of their lymph nodes caused by the formation of painless lumps or tumours. Clusters of lymph nodes are located in the neck, armpits and groin and in Lymphoma patients might have lumps in these regions. Lymphoma can also occur in other organs as small amounts of lymph and lymph tissue pass through virtually all organs in the body.

Lymphoma can be broadly divided into two categories based on pattern of cells noticed in the biopsy (small chunk of tissue obtained via a needle or a minor surgical procedure) of the affected lymph node or tissue as follows:

• Hodgkin’s lymphoma (also known as Hodgkin’s disease): Patients diagnosed with Hodgkin’s lymphoma often have large abnormal cells called Reed-Sternberg cells in their lymph nodes. This disease is highly curable and accounts for about 10 per cent of all lymphoma cases. Hodgkin’s lymphoma is most prevalent in:
  • People between 15 and 40 years of age
  • People aged 55 years and above

• Non-Hodgkin’s lymphoma: Non-Hodgkin’s lymphoma is more common and can be divided into two types:
  1. Aggressive (high grade) non-Hodgkin’s lymphoma which tends to grow and spread quickly and cause severe symptoms. If left untreated, it can be fatal within a few months or sooner.
  2. Slow-growing (low-grade) non-Hodgkin’s lymphoma which tends to grow and spread slowly and cause few symptoms. It is harder to treat and carries a higher risk of relapse.
  
  Based on type of the Lymphocytes in which the lymphoma originates, lymphomas can also be classified as B cell or T cell Lymphoma respectively arising from B or T Lymphocytes. B-Cell Lymphomas are generally much more common than T-Cell lymphomas. Globally T-Cell Lymphomas are more common in Asia than in the west. NK (Natural-Killer cells) lymphomas are classified under T-cell Lymphomas.
  
  The risk of developing non-Hodgkin’s lymphoma increases with age, with most patients diagnosed in their 60s and beyond.
  

Lymphoma - Prevalence

Lymphoma is the fourth most common cancer in males and fifth most common cancer in females in Singapore. Over a five-year period from 2017 to 2021, more than 5,000 cases were reported in Singapore.

Some of the symptoms of lymphoma include:

• Painless swelling of the lymph nodes in the neck, underarm or groin. This is the most common symptom.
• Persistent fever
• Drenching night sweats
• Unexplained weight loss
• Patchy red skin and itching
• Shortness of breath
• Persistent fatigue, lack of energy or tiredness

When to see a doctor

The symptoms above can be caused by a number of reasons and may not indicate the presence of cancer. However, make an appointment with your doctor if you have any signs or symptoms that worry you.

At present there is no routine screening for lymphoma. Individuals should seek medical attention if they have any of the symptoms above.

Currently there are also no proven preventive strategies for lymphoma. However, adopting a healthy lifestyle may help to prevent disease. This includes:

• Eating a diet rich in fruits and vegetables.
• Quitting or not starting smoking.
• Limiting alcohol consumption.
• Regular exercise.

There is no specific cause for lymphoma, but some factors that can increase the risk of lymphoma include:

• Age – Some types of lymphoma are more common in young adults while others are more commonly diagnosed in people over the age of 55.
• Gender – Males are slightly more likely to develop lymphoma compared to females.
• An impaired immune system – Lymphoma is more common in people with diseases that affect the immune system (like autoimmune diseases) or in people who take drugs that suppress their immune system.
• Infection – Some infections are associated with an increased risk of lymphoma such as Epstein-Barr virus and Helicobacter pylori infection.

A common symptom of lymphoma is painless swelling of the lymph nodes in the neck, underarm or groin. Benign conditions can also cause swelling, so tests and procedures are needed to diagnose lymphoma and develop an effective treatment plan.

These may include:

• Physical exam: Your doctor will check for swollen lymph nodes in your neck, underarm and groin as well as an enlarged spleen or liver.
• Blood tests: To test blood cell, kidney and liver performance. Blood tests can also detect lactase dehydrogenase (LDH), a chemical associated with the aggressive form of non-Hodgkin’s lymphoma.
• Bone marrow biopsy: Bone marrow samples are usually taken by inserting a needle into the hip bone to extract samples. These are then examined in the lab for the presence of cancer cells.
• Imaging tests: Imaging tests including CT scan, MRI scans and PET scans may be used to look for signs of lymphoma in the body.

Treatment for lymphoma depends on several factors including the stage of the lymphoma and whether it is slow growing or aggressive.

An individual with lymphoma should be assessed by a specialist to determine which modality of treatment is best suited for them. It is important to discuss all the possible treatment choices, including what to expect and possible side effects, to help you make an informed decision.

Types of approaches and treatments

Active surveillance

As some forms of low-grade lymphoma are slow growing with patients being entirely unaffected by them, patients may not need immediate treatment. Doctors may advise to monitor and observe to see if the cancer progresses, before starting any treatment at an appropriate time point. Periodic tests will be conducted to monitor the condition.

Chemotherapy

Chemotherapy is the use of anti-cancer drugs to eradicate cancer cells or prevent their growth. Treatment is given orally or injected through a vein to kill cancer cells. The drugs circulate throughout the body to reach cancer cells even when they are widespread. Chemotherapy is given at regulated intervals to allow the body to recover between each treatment course.

Radiation therapy

Radiation therapy or radiotherapy, is the use of high-energy radiation (rays or particles) to kill or damage cancer cells. The area covered may just be the lymph nodes or organs affected by lymphoma or, in some cases, to a wider area encompassing the lymph nodes in the neck, chest and under both armpits. Radiation therapy may be given alone or combined with chemotherapy.

Stem cell or bone marrow transplant

A stem cell or bone marrow transplant involves the use of high doses of chemotherapy and/or radiation to suppress unhealthy bone marrow. Healthy stem cells from the bone marrow or from a donor, which are capable of producing new blood cells, are extracted and infused into the patient’s blood and reintroduced into the body to help rebuild the immune system.

Other treatments

Other treatments such as immunotherapy are used to treat lymphoma when conventional treatments are deemed ineffective.

One such example is chimeric antigen receptor (CAR) T-cell therapy, an innovative approach which involves extracting a patient’s T-cells, training them to recognise the lymphoma and then administering them back into the body to kill the cancer cells.

Another example is the use of monoclonal antibodies. These antibodies attach themselves to B cells, making cancerous B cells more visible so that the body’s immune system can destroy them. Although non-cancerous B cells will be targeted as well, the body is capable of replacing them.