Peripheral T-Cell Lymphoma Unspecified
Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is a rare and aggressive blood cancer that develops from mature white blood cells called T-cells, affecting the lymphatic system and potentially spreading throughout the body.
Table of contents
- What Is PTCL-NOS
- Signs and Symptoms
- Causes and Risk Factors
- How Doctors Make the Diagnosis
- Treatment Approaches
- Outlook and Prognosis
What Is PTCL-NOS
Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is a diverse group of aggressive lymphomas that develop from mature-stage white blood cells called T-cells[1]. A lymphoma is a type of cancer that affects the lymphatic system, which is part of the body’s immune system and includes tissues and organs that help protect the body from infection and disease[1].
PTCL-NOS is classified as a subtype of non-Hodgkin lymphoma (NHL), which is a broader category of lymphomas affecting white blood cells[1]. The term “peripheral” does not refer to the arms or legs. Instead, it identifies PTCL-NOS as a cancer that arises in the lymphoid tissues outside of the bone marrow, such as lymph nodes, spleen, gastrointestinal tract, and skin[1].
PTCL-NOS is the most common subtype within the peripheral T-cell lymphoma group and is most frequently diagnosed in individuals living in North America and Europe[1]. This subtype accounts for only about 1 out of every 10 cases of non-Hodgkin lymphoma[2]. The designation “not otherwise specified” means that PTCL-NOS includes cases that don’t fit into the more specific subtypes of peripheral T-cell lymphoma[2].
PTCL-NOS is considered an aggressive or fast-growing lymphoma[1]. The World Health Organization recognizes more than 30 subtypes of peripheral T-cell lymphomas, each with distinct characteristics[2]. Because of the rarity and diversity of these diseases, there is still a lot that medical experts are learning about this condition[2].
Signs and Symptoms
Peripheral T-cell lymphoma, not otherwise specified can cause a range of symptoms throughout the body. At presentation, most patients exhibit what doctors call B symptoms along with generalized swollen lymph nodes, with or without involvement of other organs outside the lymph nodes[6].
Common symptoms of PTCL-NOS include swollen lymph nodes, which are often painless lumps that can appear in the neck, underarms, or groin[2]. Many people experience drenching night sweats that may require changing clothes or bedding[2]. Unexplained fever and unexplained weight loss are also frequent symptoms[2].
Other signs include persistent fatigue that doesn’t improve with rest[2]. Some patients develop a skin rash[2]. Belly pain or swelling can occur as a sign of an enlarged spleen[2]. In some cases, patients may experience persistent eosinophilia, which means an abnormally high number of a specific type of white blood cell called eosinophils[6].
Because the cancer can grow within and affect nearly every part of the body, symptoms may vary depending on which organs are involved[2]. Each PTCL subtype has specific symptoms, so the exact presentation can differ from person to person[2].
Causes and Risk Factors
Peripheral T-cell lymphomas happen when T-cells, a type of white blood cell, change or mutate[2]. These mutations make the cells turn into cancerous cells that multiply uncontrollably[2]. However, experts don’t know what makes T-cells mutate in the first place[2].
Several factors may increase the risk of developing PTCL-NOS. Where you live can play a role, as many subtypes of these lymphomas are more common in Asia, including China, Thailand and Japan, as well as Africa and the Caribbean[2]. Age is another important factor, as the most common subtypes usually affect people over 60[2].
Certain health conditions may increase risk. Some subtypes are linked to celiac disease, EBV (Epstein-Barr virus), and HTLV-1 (human T-cell lymphotrophic virus type 1)[2]. Having a condition that causes a weakened immune system may also increase the risk of developing peripheral T-cell lymphoma[2].
How Doctors Make the Diagnosis
Diagnosis of peripheral T-cell lymphoma, not otherwise specified often begins with a physical exam. During this exam, the healthcare provider checks for swollen lymph nodes in the neck, underarms and groin, and looks for an enlarged spleen or liver[2].
Blood tests are an important part of the diagnostic process. These tests can check the health of blood cells and may test for substances that indicate organ damage or viruses related to some types of PTCL[2]. Blood tests may also be used to test for viruses, including Epstein-Barr virus and human T-cell lymphotrophic virus[4]. Blood tests also measure levels of lactate dehydrogenase (LDH), which is often higher in people with lymphoma[18].
Imaging tests make pictures of the body and can show the location and extent of the lymphoma. Tests might include CT scan (computed tomography), MRI (magnetic resonance imaging), and PET scan (positron emission tomography)[2].
A biopsy is the most definitive diagnostic procedure. This involves taking a sample of tissue for testing in a laboratory[2]. The healthcare provider may suggest a lymph node biopsy or a biopsy of other tissue to look for cancer cells. A lymph node biopsy involves removing all or part of a lymph node[18]. The excisional lymph node biopsy is critical for diagnosing PTCL-NOS[6]. In the laboratory, tests can show whether PTCL-NOS is present[2].
Bone marrow aspiration and biopsy are procedures to collect cells from the bone marrow for testing. Bone marrow is the soft matter inside bones where blood cells are made[18]. In a bone marrow aspiration, a needle is used to collect a sample of the fluid part, while in a bone marrow biopsy, a needle collects a small amount of the solid tissue[18]. Most often, the samples are taken from the hip bone and sent to a laboratory for testing[18].
Treatment Approaches
For most cases of peripheral T-cell lymphoma, not otherwise specified, the initial treatment is typically a combination chemotherapy regimen[7]. Chemotherapy is a treatment that uses drugs to kill cancer cells. Common combinations include CHOP, which consists of cyclophosphamide, doxorubicin, vincristine, and prednisone, or CHOEP, which includes etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisone[7].
Because most patients with PTCL-NOS will experience a return of the disease, some physicians recommend high-dose chemotherapy followed by an autologous stem cell transplant[7]. This is a type of stem cell transplant in which the patient receives his or her own stem cells, collected several weeks before the transplant[7].
In very specific cases, radiation therapy is given after chemotherapy as a part of first-line treatment[7]. Radiation therapy uses high-energy rays to kill cancer cells.
Many new drugs are being studied in clinical trials for the treatment of PTCL-NOS. These include drugs such as azacitidine, bendamustine, bortezomib, cemiplimab, lenalidomide, and venetoclax, among others[7]. Clinical trials are research studies that test new treatments to determine if they are safe and effective.
Healthcare providers can successfully treat most of these lymphomas, but they often come back[2]. Medical specialists are studying treatments that may help people live longer with this condition[2].
Outlook and Prognosis
Peripheral T-cell lymphoma, not otherwise specified is generally associated with a challenging prognosis. In general, PTCL is associated with a poor prognosis, with a 5-year survival rate of approximately 30% to 40%[9]. This means that about 3 to 4 out of 10 people with this condition are alive five years after diagnosis.
Most PTCL subtypes are associated with worse outcomes than those of B-cell lymphomas, which are other types of non-Hodgkin lymphoma[9]. The prognosis in PTCL varies depending on the specific subtype, the stage of disease at diagnosis, and other individual factors[9].
Because of the rarity and diversity of peripheral T-cell lymphomas, large clinical trials have not been conducted and optimal therapy is not well defined[10]. Most subtypes are treated with similar combination chemotherapy regimens as used for aggressive B-cell non-Hodgkin lymphoma, but with poorer outcomes[10].
New treatment combinations and novel agents are currently being explored for PTCL-NOS, offering hope for improved outcomes in the future[10]. Because there is still much that medical experts are learning about this condition, participation in clinical trials may provide access to newer treatment options[2].
