Cancer Types: Hodgkin Lymphoma
Hodgkin lymphoma originates in the lymphatic system (lymph nodes or glands) and immune cell tissues. There is no effective way to prevent Hodgkin lymphoma.
Hodgkin lymphoma, also known as Hodgkin’s disease, is a type of cancer that originates in the lymphatic system – a system composed of organs (lymph nodes or glands) and tissues that produce the cells responsible for immunity and vessels that carry these cells throughout the body.
Lymphoma occurs when lymphocytes, present in the lymph nodes and responsible for protecting the body against bacteria, viruses, and other dangers, transform into a malignant cell called Reed-Sternberg cell. It is this cell that triggers the inflammatory reaction that generates a cluster of malignant and normal cells that form the tumor mass.
In Hodgkin’s lymphoma, cells multiply uncontrollably and spread in an orderly fashion from one group of lymph nodes to another, through the lymphatic vessels. Over time, they can spread to nearby tissues and, if left untreated, to other parts of the body.
The disease usually arises more frequently in the lymph nodes of the neck, chest, and armpits. Men are more likely to develop Hodgkin’s lymphoma than women, and the age groups in which cases are most common are 15 to 39 years and 75 years and older.
For 2020, the National Cancer Institute (INCA) estimated 12,030 new cases of non-Hodgkin lymphoma in Brazil. Globally, the number of new cases of this type of lymphoma presented by the World Health Organization (WHO) for 2020 was 83,087.
Types of Hodgkin lymphoma
There are two types of Hodgkin lymphoma:
- Hodgkin lymphoma with nodular lymphocyte-predominant – features affects 5% of patients and is more common in young adults. It may not always show symptoms, but when they occur, they are the common ones of Hodgkin lymphoma. It is rarely found outside the lymph nodes, being more common in the neck and chest regions. It has high cure rates and a 3% risk of transforming into non-Hodgkin lymphoma.
- Classical Hodgkin lymphoma – affects 95% of patients and is divided into four subtypes:
- Nodular sclerosis Hodgkin lymphoma – constitutes about 60% of all cases and is the most common type in teenagers and young adults. It typically manifests in the neck, supraclavicular, and chest regions and is highly curable.
- Lymphocyte-rich Hodgkin lymphoma – is similar to nodular lymphocyte-predominant Hodgkin lymphoma but has more characteristics in common with the classical subtype.
- Mixed cellularity Hodgkin lymphoma – is the second most common subtype, accounting for 25% of all cases. It is more common in children up to 14 years old and adults between 55 and 74 years old, and it is also prevalent in people with immune system disorders, such as HIV/AIDS. It is often associated with a more advanced stage of the disease but is highly curable.
- Lymphocyte-depleted Hodgkin lymphoma – mainly occurs in elderly individuals and those with HIV/AIDS, and patients may present with extensive disease without lymph node enlargement. Its diagnosis is not uncommonly confused with non-Hodgkin lymphoma.
Symptoms and signs of Hodgkin lymphoma
The symptoms of Hodgkin lymphoma depend on its location. If it develops in superficial lymph nodes in the neck, armpits, and groin, painless local swelling (swollen glands) occurs. If it occurs in the chest region, symptoms may include cough, shortness of breath, and chest pain. In the pelvis or abdomen, symptoms are usually discomfort and abdominal distension.
Other warning signs that may accompany localized symptoms are systemic symptoms: fever, fatigue, night sweats, unexplained weight loss, and itching all over the body.
Diagnosis of Hodgkin lymphoma
After observing the symptoms of Hodgkin lymphoma, the next step is to confirm its diagnosis and type/subtype. A biopsy of the affected area is performed, either removing a small part or the entire lymph node, followed by pathological examination.
Ideally, an excisional biopsy is performed, which involves the complete removal of the lymph node or affected tissue. This preserves the architecture of the lymph node, making it easier to classify. In certain situations, however, an incisional biopsy (removal of a small part of the affected tissue) may be the best alternative.
Imaging tests are also necessary to determine the extent of the disease, known as staging. Currently, PET-CT is the recommended test for this purpose. However, since it is not available in most health centers in Brazil, contrast-enhanced computed tomography can be used for the same purpose. Chest X-ray can detect mediastinal involvement.
A bone marrow biopsy should only be performed in cases where PET-CT examination was not possible and staging of IB-IIB, III, or IV was detected by computed tomography. Bone marrow biopsy is not necessary in stages IA and IIA.
Staging of Hodgkin lymphoma is classified from one to four in Roman numerals (I, II, III, and IV), accompanied by A or B – A indicating the absence of systemic symptoms (fever, fatigue, night sweats, unexplained weight loss, and itching), and B indicating the presence of systemic symptoms.
Regarding numbering, the classification is:
- I – there is only one chain of lymph nodes affected, which means that only one region of the body is affected (it could be the cervical or axillary);
- II – two regions of the body are affected by lymph nodes, both on the same side of the diaphragm (either above or below – for example, axillae and neck);
- III – both the region above and the region below the diaphragm are affected (the disease is spread – for example, neck and groin);
- IV – the lymphoma has already infiltrated the lymphatic tissue and some other organ, such as the stomach, liver, kidney, or central nervous system.
Treatment for Hodgkin’s lymphoma
The classic treatment for Hodgkin’s lymphoma is polychemotherapy (chemotherapy with multiple drugs), with or without associated radiotherapy. The number of cycles will depend on the initial stage assessment of the tumor and the interim PET-CT result, and the routine regimen or protocol is called ABVD. The acronym identifies the initials of the medications used: Adriamycin, Bleomycin, Vinblastine, and Dacarbazine, sometimes associated with Brentuximab Vedotin. Bleomycin is not used in patients with advanced stages and high risk.
If there is a return of the disease or no response to treatment, alternatives are polychemotherapy and bone marrow transplantation.
Approximately 70 to 80% of patients are currently cured.
Prevention of Hodgkin’s lymphoma
There is no effective way to prevent Hodgkin’s lymphoma.
