Peripheral T-cell Lymphoma (PTCL)
Table of Contents:
About Lymphoma and PTCL
Lymphoma is a group of blood cell tumors that develop from lymphocytes (type of WBCs).
Lymphoma is the most common blood cancer. The two main forms of lymphoma are Hodgkin lymphoma and non-Hodgkin lymphoma (NHL).
The body has two main types of lymphocytes (type of WBCs) that can develop into lymphomas: B-lymphocytes (B-cells) and T-lymphocytes (T-cells). T cells are involved in cell-mediated immunity and have the presence of T-cell receptor (TCR) on surface, while B cells are primary responsible for humoral immunity (related to antibodies) and have the presence of a protein called B-cell receptor.
Peripheral T-cell lymphomas (PTCLs) are uncommon and aggressive types of NHL that develop in mature white blood cells called "T cells" and "natural killer (NK) cells." The most common subtypes of PTCL are peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), anaplastic large-cell lymphoma (ALCL), adult T-cell leukemia/lymphoma (ATLL) and angioimmunoblastic T-cell lymphoma (AITL).1
How common is PTCL?
Based on the United States Surveillance, Epidemiology, and End Results (SEER) Registry, the incidence of PTCL is < 1 case per 100,000 people in the United States. 2,3 In Europe and North America, T-cell and NK-cell lymphoma account for 5-10% of all cases of NHL whilst in Asia, this percentage is as high as 24%. 4, 5
The relative percentage of malignant lymphoid proliferations varies widely according to geographical locations, probably reflecting exposure to different etiological factors, including viruses. For patients with NHL, the proportion of PTCL is only around 10% in Western countries while the incidence of PTCL is as high as 70% in South-western Japan, where HTLV-1 infection is endemic. 6
Signs and symptoms
The first signs of PTCL vary depending on the disease subtype. Because lymph nodes in several different areas of the body are frequently involved, the most common sign of PTCL is an enlarged, painless lymph node in the neck, armpit or groin. Enlarged lymph nodes can also appear near the ears or elbows. These lymphomas also affect various organs in the body, including the bone marrow, liver, spleen, stomach and skin. Other symptoms may include
Most PTCLs are diagnosed by taking a small sample (a “biopsy”) of an enlarged lymph node and then examining the cells under a microscope. The diagnosis may involve additional diagnostic tests, including blood tests, CT (computerized axial tomography), PET (positron emission tomography) scans, MRI (magnetic resonance imaging), and bone marrow biopsy.
A risk factor is something that affects the chance of getting a disease such as cancer. Some risk factors, like smoking, can be controlled. Others, like a person’s age can’t be changed.
But risk factors don’t tell us everything. Having a risk factor, or even several risk factors, does not mean that the patient will definitely get the disease. And many people who get the disease may have few or no known risk factors. Even if a person has one or more risk factors and develops cancer, it is often very hard to know how much they might have contributed to the cancer.
Risk Factors You Cannot Change:
Race/Ethnicity: PTCL is relatively uncommon in Caucasian populations PTCL incidence rates are higher among Black males and females and the incidence of angioimmunoblastic T-cell lymphoma (AITL) is highest in Black males.6,7
Age: The risk for developing NHL increases with age.7,8
Gender: Men are affected slightly more than women.7,8
Risk Factors Linked to Things You Do: 7, 8
Exposure to certain chemicals: Working in the rubber manufacturing industry and occupational and environmental exposure to certain chemicals (e.g., solvents such as dihloromethane) may increase risk of NHL.
Immune Suppressants: Risk of NHL is elevated in people who receive immune suppressants to prevent organ transplant rejection.
Family history: People with family history of lymphoma and confirmed common genetic variations (including variations in the human leukocyte antigen) are at an increased risk of developing NHL.
Treatment options for PTCL include:
Chemotherapy: Chemotherapy is the use of drugs to fight cancer. The drugs may be put into a vein or given by mouth. Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. A combination of chemotherapy drugs is usually used. Different combinations can be used to treat PTCL, and the best combination is not known.
First-line Consolidation: This includes high-dose therapy with stem cell rescue. 9
High-dose treatment with stem cell support (autologous transplantation) can be sometimes used for first-line consolidation following the initial course of chemotherapy. This involves having intensive chemotherapy, which destroys the lymphoma cells but also destroys the blood cells in the bone marrow. The patient's own stem cells (early blood cells) are taken prior to the chemotherapy and stored. These are given back to the patient (like a blood transfusion) after the chemotherapy. The stem cells make their way back to the bone marrow and start to produce new blood cells.
Some studies suggest that intensification with autologous stem cell transplantation (ASCT) could improve treatment outcomes, especially when patients are in first complete response (CR). However, many patients are not candidates for stem cell transplantation (SCT) because they do not reach stable remission after induction therapy-approximately 30% of the patients will progress before ASCT. 1
The below mentioned risk factors indicate a poorer prognosis (chance of recovery):
Treatment of Relapse
Current therapies, based on historical regimens for aggressive B-cell lymphomas, have resulted in insufficient patient outcomes. The majority of patients relapse rapidly.1