Non-Hodgkin’s lymphoma is a type of cancer that originates in the cells of the lymphatic system – a set made up of organs (lymph nodes or ganglia) and tissues that produce the cells responsible for immunity and defense. The distinction between non-Hodgkin’s lymphoma and Hodgkin’s lymphoma is made through biopsy.
These cells multiply uncontrollably and spread in a disorderly manner. Because lymph tissue is found throughout the body, non-Hodgkin lymphoma can start anywhere — but the most common sites of incidence are the lymph nodes, bone marrow, gastrointestinal tract, skin, bones, and central nervous system.
This disease can occur in all age groups and becomes more common as people age. In the last 25 years, the number of cases has doubled, mainly among people over 60 years old.
People with immunity deficiency (either due to hereditary genetic disease, use of immunosuppressive drugs or HIV infection), carriers of the Epstein-Barr and HTLV1 viruses and the bacterium Helicobacter pylori (which can cause gastric lymphomas) are more prone to non-Hodgkin lymphoma. and individuals exposed to chemicals such as pesticides, aromatic amines, and radiation.
In 2020, INCA (National Cancer Institute) estimated 12,030 new cases of non-Hodgkin’s lymphomas, 6,580 in men and 5,450 in women. Worldwide, the number of new cases of this type of lymphoma presented by the WHO (World Health Organization) for 2020 was 544,352.
Subtypes of non-Hodgkin’s lymphoma
There are dozens of types of non-Hodgkin lymphomas. They are divided into two large groups: aggressive and indolent. These, in turn, have the following main subtypes:
Aggressive non-Hodgkin lymphomas:
- Diffuse large B-cell lymphoma – this is the most common type and accounts for about 30% of cases. Occurs in older people, with rapidly growing lymph nodes in the neck, armpits, or groin, or in organs such as the liver, spleen, bone marrow, and brain;
- Central nervous system lymphoma – is rare and can be primary or secondary. The primary starts in the brain, eyes or meninges, while the secondary starts in other parts of the body and spreads until it reaches the brain or meninges;
- Lymphoma linked to the HTLV virus – is caused by infection with the HTLV virus, from the same family as HIV. It can cause skin lesions and bone problems;
- Burkitt’s Lymphoma – affects younger people and grows extremely fast;
- Mantle cell lymphoma – affects the lymph nodes, bone marrow and spleen. It is more common in men, especially around age 60;
- T-cell lymphoma – is much rarer than diffuse large B-cell lymphomas. It usually affects people over 60 years of age. Among its most common types are: anaplastic large cell lymphoma, angioimmunoblastic lymphoma, extranodal natural killer cell/nasal T cell lymphoma.
Indolent non-Hodgkin lymphomas:
- Follicular lymphoma – originating in the germinal center of the lymphatic follicle, it is the second most frequent subtype of non-Hodgkin’s lymphoma after 60 years of age;
- Cutaneous T-cell lymphoma (mycosis fungoides) – is a type of lymphoma that arises in the skin and has itching as the main symptom;
- Lymphoplasmocytic lymphoma (Waldenstrom’s macroglobulinemia) – very rare, it is composed of small cells, affects lymph nodes and bone marrow and produces type M immunoglobulin (IgM);
- Large cell mediastinal lymphoma – causes large chest masses. It is rare, affects more women in their 30s and, as it starts in the chest region, it can cause breathing difficulties;
- Marginal zone lymphoma – can affect several organs in addition to the lymph nodes, such as the spleen, stomach and eye appendages.
Symptoms and signs of non-Hodgkin lymphoma
Regardless of the type or subtype of non-Hodgkin lymphoma, the main symptoms of the disease are:
- Enlarged nodes in the neck, armpits, groin;
- Excessive night sweats;
- Itchy skin;
- Loss of more than 10% of body weight for no apparent reason.
Diagnosis and staging of non-Hodgkin lymphoma
Once the symptoms of non-Hodgkin lymphoma have been observed, the next step is to confirm its diagnosis and subtype. A biopsy of the affected region is performed, with the removal of a small portion of tissue (usually from the lymph nodes or any affected area) for analysis in a pathological anatomy laboratory.
The complementary immunohistochemistry exam is essential for the proper classification of the lymphoma subtype. Accurate diagnosis and classification are essential for defining the best treatment and obtaining the best results.
Then proceed with the staging of the disease to determine which organs are affected. This is done through imaging tests such as computed tomography, PET-CT and, in some cases, analysis of bone marrow and cerebrospinal fluid through punctures.
The staging of non-Hodgkin lymphoma uses Roman numerals (I, II, III and IV) followed by A or B – with A being the absence of systemic symptoms (fever, night sweats, weight loss for no apparent reason) and B the presence of symptoms. systemic.
In terms of numbering, the classification is:
- I – there is only one lymph node chain or organ affected;
- II – two regions of the body on the same side of the diaphragm are affected by lymphoma;
- III – both the region above and below the diaphragm are compromised;
- IV – the lymphoma infiltrates the bone marrow or organs, such as the lung and liver.
The treatment strategy will depend on the type of non-Hodgkin lymphoma. Most are treated with chemotherapy in combination with monoclonal antibody immunotherapy and sometimes with radiation therapy.
Chemotherapy usually uses a combination of several drugs, given orally or intravenously.
In immunotherapy, drugs are used against specific targets in lymphoma cells (CD20, CD30).
Radiation therapy, in turn, uses radiation to eradicate or reduce the tumor burden at specific sites, to relieve symptoms or to reinforce chemotherapy treatment, reducing the risk of the disease returning.
In special cases, high-dose chemotherapy and bone marrow or blood cell transplantation are necessary to cure the patient.
For indolent lymphomas, treatment options range from simple clinical observation to very intensive treatments.
The best way to prevent non-Hodgkin’s lymphoma is to avoid or eliminate the physical factors that increase the risk of its development (exposure to chemical substances such as pesticides, aromatic amines, benzidine, polychlorinated biphenyl and carbon tetrachloride or to high doses of radiation) and keeping under control and treatment the diseases and conditions that make people more likely to develop it (immune deficiency, either from hereditary genetic disease, use of immunosuppressive drugs or from HIV infection, Epstein-Barr virus and HTLV1 and Helicobacter pylori bacteria ).
There is evidence that diets rich in vegetables and fruits may have a protective effect against non-Hodgkin’s lymphoma.