What you need to know about lymphoma

It is a cancer, i.e. an abnormal cell growth forming a tumour, which develops within the lymphatic system.

The lymphatic system contains a network of vessels, or thin tubes, connecting certain organs called lymph nodes. We can find them particularly in the armpit, groins, neck, thorax and abdomen and they can sometimes be felt when they are inflamed by an infection.

The lymphatic system carries whitish liquid called lymph, which contains lymphocytes. These are white blood cells, which have an important role in infection control since the immune system, of which it is part, is responsible for the defence of the body against external aggressions.

The lymphoma is a tumour caused by the abnormal growth of lymphocytes and it can appear in a lymph node or in another location.

Types

There are several types of lymphomas and classification is based on differences among them: by origin, by location or by connection with other important organs . This is an essential aspect because depending on the specific type, the aggressiveness of the lymphoma and prognosis are different.

However, a simple classification could be:

Hodgkin's lymphoma: It is characterized by the appearance of lymph nodes in different parts, mainly the thorax. With an adequate treatment, the prognosis is usually good.

Non-Hodgkin's lymphoma A group of over 30 different diseases that can be grouped as follows:

It is important to note that when we mention the aggressiveness of a lymphoma, we refer to the intrinsic malignant character thereof, not necessarily to the extent of the disease. Thus, indolent lymphoma has usually spread but it still has a quite favourable prognosis. Aggressive lymphomas usually respond to the treatment and can be cured.

Aggressive lymphomas
These represent approximately half of all the non-Hodgkin's lymphomas. Their rate of growth is very rapid. They are characterized by lymph node inflammation, but they can also infiltrate other organs as metastasis. In spite of their clinical aggressiveness, they are more sensitive to treatment than indolent lymphomas, so that most of them can be cured with the proper treatment.
Indolent lymphomas
They represent approximately 40% of non-Hodgkin's lymphomas. Their rate of growth and aggressiveness is low, but they have usually spread considerably by the time of the diagnosis. They need to be continually monitored by a doctor because in some cases, they become aggressive. Although patients with indolent lymphoma can live many years, this lymphoma can, paradoxically, be difficult to cure.
Highly aggressive lymphomas
These represent approximately 10% of all non-Hodgkin's lymphomas. The rate of tumour cell growth is very rapid, so that the number of cells (and, thus, the mass of the tumour) may double within 24 hours. They are equivalent to acute leukemia, therefore require radical and immediate treatment. In addition to the lymph node inflammations, other organs such as the bone marrow and the nervous system may also become affected.

Causes

Who does it affect?

Symptoms

Diagnosis

Treatment

Once the type of lymphoma and the degree of extension (stage) is determined, the treatment can be started. The specialist will assess each particular case to determine the most appropriate treatment. There are no golden rules because each patient and his/her lymphoma is different

Therapeutic abstention
In many indolent lymphomas, it is not necessary to act immediately. In the event that the disease is asymptomatic and the growth is very slow, the best option may be to not have any treatment until more symptoms appear . This is called therapeutic abstention. Obviously, the patient must have regular medical monitoring (every 3 months, for instance) in order to determine when an active treatment is needed. Although the lymphoma may not be cured, the patient can live many years thanks to the proper monitoring. In these cases, the indolent lymphoma must be understood as a chronic disease.
Chemotherapy
This is the most common treatment because of its high effectiveness. It uses combinations of drugs that are very toxic to tumour cells and kill them, so that the lymphoma can be completely erradicated.. Although chemotherapy is used for treating most lymphomas, occassionally other treatments need to be used in conjunction with this.
Radiotherapy
This may be used to treat lymphomas in combination with chemotherapy and is given after it. There are few cases where radiotherapy is the main treatment.

It consists of giving high-dose radiation that destroys cancer cells.

The administration is local, on certain nodular regions. As in chemotherapy, there is no need for admission at the hospital. Sessions are short, lasting up to half an hour.
Biological therapies
New techniques, arising from research on how the human body works, are called biological therapies because they use substances made by the body's own cells or similar to them but made in a laboratory. The most frequently used therapies of the category used in the treatment of lymphomas are monoclonal antibodies.
Antibodies are substances produced by the immune system as an effective defense against external agents (or antigens) . They are called monoclonal because they refer to a sole B lymphocyte clone, which are the cells that produce these antibodies.. A clone means that they are cells derived from the culture of a single cell. This discovery represents a great advance because antibodies interact only with a specific antigen "target" located in the tumour cell. Thus, the lymphoma cells can be destroyed in a selective way and with low toxicity to normal cells. Rituximab (anti-CD20) is the most common monoclonal antibody. It is administered intravenously in a medical centre and there is no need for admission to the hospital.
Haematopoietic stem-cell transplant
In many highly-aggressive lymphomas and in some aggressive or indolent lymphomas, the treatment selected may be a powerful chemotherapy treatment and followed by haematopoietic stem-cell transplant, which means stem cells from the bone marrow. These cells can also be found in blood, from where they can be easily withdrawn. A transplant is performed when the chemotherapy treatment in the patient has shown good results.
The transplant is used after giving a high-chemotherapy dose to achieve the complete remission of the tumour. Such dose would damage the healthy cells in the bone marrow in a nearly irreversible way. In order to counteract this and achieve a speedy recovery, healthy cells are obtained from the body before having aggressive chemotherapy. Then, when the therapy is over, they are reinserted into the patient. Stem cells or haematopoietic cell are obtained by means of blood withdrawal and blood centrifugation. That material is frozen for later intravenous insertion (as a serum), after chemotherapy has been given . This procedure is called Self-transplant of haematopoietic stem-cells. The patient has to be admitted to hospital for approximately a month for this procedure to be performed.
In special circumstances, a haematopoietic stem-cell transplant can be done from a compatible brother or sister. This procedure is called Allogenic haematopoietic stem-cell transplant.