Lymphoma – an overview, types, and genetic risks

August 31 09:58 2023 by admin Print This Article

What is Lymphoma?

Lymphoma is an umbrella term for cancers of the blood and lymphatic system. The lymphatic system is an important component of the body’s immune system. It consists of the spleen, thymus gland, lymph vessels (similar to blood-vessels) and lymph nodes that are distributed throughout the body. A thin, watery fluid called lymph circulates in this system (‘lympha’ is the Latin word for water).

A type of white-blood-cells called lymphocytes also circulate in the lymphatic system. They are responsible for fighting infection or disease and hence, for the overall immunity of the person.

Lymphoma is a type of cancer in which these lymphocytes grow out of control. In the process, they crowd out healthy lymphocytes and bring down the immunity of the person. That is why, lymphoma is treated as a cancer of the immune system. The reduced immunity leads to several consequences over time.

Symptoms

• Lymphadenopathy, which is a painless swelling of lymph nodes in the neck, armpits or groin
• Chronic fatigue
• Fever
• Night sweats
• Shortness of breath (dyspnoea), and respiratory distress
• Itchy skin
• Unexplained weight loss
• Anaemia, bleeding, and recurring infections
• Cough

Types

• Chronic lymphocytic leukaemia: Here, the cancer originates in the bone-marrow or blood and affects the lymphocytes. It progresses slowly (chronic) and generally affects older adults.
• Cutaneous B-cell lymphoma: Lymphocytes are of 2 types – B cells and T cells. Cutaneous B-cell lymphoma as the name implies affects the B-cells only. The symptoms are seen on the skin, such as a round, firm bump of pinkish colour. For this reason, it’s also called non-melanoma skin cancer.
• Cutaneous T-cell lymphoma: Similar to the previous condition, but this affects the T-cells. Again, symptoms are seen on the skin (‘cutaneous’) and include redness, skin rashes, round, scaly patches and sometimes skin tumours.
• Hodgkin’s lymphoma (Hodgkin’s disease): In this, the lymphocytes grow out of control, resulting in swollen lymph-nodes and growths throughout the body.
• Non-Hodgkin’s lymphoma: Similar to the previous condition, but here, it leads to tumours (growths) throughout the body.
• Waldenstrom macroglobulinemia: Also called lymphoplasmacytic lymphoma, a rare type of lymphoma. The bone-marrow starts producing abnormal lymphocytes. These crowd out healthy blood-cells and also produce a protein that accumulates in the blood. This in turn results in improper circulation and various complications. Some scientists treat this condition as a sub-type of non-Hodgkin’s lymphoma.

Causes and Risk Factors

What exactly causes or triggers abnormal production of lymphocytes is still not clear. However, the risk factors are clear.

• Being 60 years or older for non-Hodgkin lymphoma and between 15 and 40 or older than 55 for Hodgkin lymphoma
• Gender: Men are more at risk than women
• Having a weak or impaired immune system: This could be because the person takes drugs that suppress their immune system (immunosuppressants), the person has had an organ transplant, suffers from AIDS/HIV currently, or was born with an immune disease. Immune system diseases include celiac disease, lupus, Sjögren’s syndrome or rheumatoid arthritis.
• Infections: Some infections increase the risk of lymphoma and this includes viruses like Epstein-Barr virus, human T-cell leukemia/lymphoma (HTLV-1), hepatitis C, herpes virus 8, and bacteria like Helicobacter pylori, Chlamydophila psittaci and Campylobacter jejuni.
• Genes: A close relative who currently has or had lymphoma in the past
• Toxins: Exposure to industrial chemicals such as benzene, pesticides, weedicides, some hair-dyes, some solvents, wood preservatives, some organic chemicals, chemotherapy drugs, dust and saw-dust.
• Ethnicity and race: White-Caucasians are more at risk than Asian-Americans or African-Americans for non-Hodgkin lymphoma.
• Geography: Non-Hodgkin’s lymphoma is more common in the US and Europe
• Obesity or being overweight
• Breast implants: In rare cases, women who had a breast-implant may develop non-Hodgkin lymphoma in the scar tissue that surrounds the implant.

Genetic risk

Doctors are frequently asked if incidents of lymphoma are sporadic or genetic?

In general, all types of blood-cancer: leukaemia, lymphoma and myeloma are non-genetic. That is, the risk of passing on a blood-cancer gene from a parent or grandparent to a child/grand-child is extremely rare. All risk factors are purely environmental or pathological.

However, in recent years, scientists are of the opinion that there is a small probability of genetic risk for lymphoma. Some gene mutations that cause Hodgkin’s lymphoma can be passed on to a child. Also, a family history of Hodgkin, non-Hodgkin and CLL types of lymphoma increases the risk of developing some types of lymphoma by 3 or 4 times compared to a person who does not have any close relative with a history of lymphoma.

Diagnosis

• Physical exam: The doctor will check for swollen lymph nodes in the neck, underarms and groin. He/she will also look for an enlarged liver or spleen. This is a natural outcome of the large number of abnormal lymphocytes accumulating in the liver and spleen.
• Lymph node biopsy: A part of, or an entire lymph node is removed using a fine needle and the cells examined under a microscope. If lymphoma is suspected, advanced tests are conducted to confirm their presence and determine the sub-type.
• Blood tests: A blood count test will help count the number of blood-cells in a given sample and hence confirm or rule out lymphoma.
• Bone-marrow biopsy: A thin needle is inserted into the centre of the hip-bone (procedure called as aspiration biopsy) and a sample of bone-marrow extracted. The sample is then examined under a microscope to confirm or rule out lymphoma.
• Imaging tests: CT, MRI and PET scans are done in specific areas of the body where there are some signs or symptoms of lymphoma, which a physical examination may not be able to catch.

Treatment

• Active surveillance: Not all lymphomas grow quickly or aggressively. Some types are indolent. That is, they progress slowly or symptoms are muted. So doctors will adopt a ‘wait and watch’ approach and monitor if the symptoms are affecting the person’s daily life or not. If there is no significant disruption in the person’s life, then treatment will be delayed till symptoms start progressing.
• Chemotherapy: Once the symptoms start progressing, chemotherapy drugs are administered through a vein or through an oral pill. These drugs help destroy fast-growing cancer-cells.
• Radiation therapy: An alternative to chemotherapy, Radiation therapy uses high-powered beams of either X-rays and protons, to kill cancer cells.
• Bone-marrow transplant: To begin with, high-doses of chemotherapy and/or radiation are given to suppress the bone-marrow in the person with lymphoma. Then, healthy stem-cells taken from the bone-marrow of a healthy person are infused into the blood of the patient. From the blood, these stem cells travel to the bone and bone-marrow from where they start a new cycle of generating healthy blood cells. That is why, this procedure is also called stem-cell transplant.
• Other treatments: Targeted drugs are used to treat lymphoma. These focus on specific abnormalities in the cancer cells. Immunotherapy drugs help boost the immune system so that it can fight and destroy the cancer cells. A specialized treatment called chimeric antigen receptor (CAR)-T cell therapy takes a radical approach. In this, the patient’s T cells which help fight infection and disease is extracted from the body and manipulated in a lab so as to be capable of fighting cancer cells and then infused back into the body.

Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai, Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and pediatric trauma care.

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