Mantle cell lymphoma

Synonyms

1

Overview

Mantle cell lymphoma (MCL) belongs to a group of diseases known as non-Hodgkin’s lymphomas (NHL). NHL's are cancers that affect the the lymphatic system (part of the immune system). In MCL, there are cancerous B-cells (a type of immune system cell). The cancerous B-cells are within a region of the lymph node known as the mantle zone. Although MCLs are slow-growing cancers, the cancer is usually widespread by the time it is diagnosed. In these situations, treatment must be intensive since MCL can become life threatening within a short period of time.MCL accounts for 6% of all NHL's and is mostly found in males during their early 60s.

Median survival time were about 3 years, but it-s nowadays estimated by approx. 6 years.

Symptoms

Some symptoms may include:

• Hematological neoplasm
• Lymphadenopathy 
• Anorexia
• Splenomegaly
• Weight loss

Causes

Most lymphomas are not inherited, but rather are acquired when the DNA within select body cells has been damaged. Some risk factors for non-Hodgkin lymphomas (NHL) include age (older), gender (male), race (white), and having a condition which weakens the immune system, such as autoimmune conditions, certain genetic disorders, being on immune suppressing medications, HIV/AIDS, HTLV-1, Ebstein-Barr virus and helicobacter pylori infection.

Prevention

Not available.

Diagnosis

Prognosis

The overall 5-year survival rate for MCL is generally 50% (advanced stage MCL) to 70% (for limited-stage MCL).

Prognosis for individuals with MCL is problematic and indexes do not work as well due to patients presenting with advanced stage disease. Staging is used but is not very informative, since the malignant B-cells can travel freely though the lymphatic system and therefore most patients are at stage III or IV at diagnosis. Prognosis is not strongly affected by staging in MCL and the concept of metastasis does not really apply.

The Mantle Cell Lymphoma International Prognostic Index (MIPI) was derived from a data set of 455 advanced stage MCL patients treated in series of clinical trials in Germany/Europe. Of the evaluable population, approximately 18% were treated with high-dose therapy and stem cell transplantation in first remission. The MIPI is able to classify patients into three risk groups: low risk (median survival not reached after median 32 mos follow-up and 5-year OS rate of 60%), intermediate risk (median survival 51 months) and high risk (median survival 29 months). In addition to the 4 independent prognostic factors included in the model, the cell proliferation index (Ki-67) was also shown to have additional prognostic relevance. When the Ki67 is available, a biologic MIPI can be calculated.

MCL is one of the few NHLs that can cross the boundary into the brain, yet it can be treated in that event.

There are a number of prognostic indicators that have been studied. There is not universal agreement on their importance or usefulness in prognosis.

Ki-67 is an indicator of how fast cells mature and is expressed in a range from about 10% to 90%. The lower the percentage, the lower the speed of maturity, and the more indolent the disease. Katzenberger et al. Blood 2006;107:3407 graphs survival versus time for subsets of patients with varying Ki-67 indices. He shows median survival times of about one year for 61-90% Ki-67 and nearly 4 years for 5-20% Ki-67 index.

MCL cell types can aid in prognosis in a subjective way. Blastic is a larger cell type. Diffuse is spread through the node. Nodular are small groups of collected cells spread through the node. Diffuse and nodular are similar in behavior. Blastic is faster growing and it is harder to get long remissions. Some thought is that given a long time, some non-blastic MCL transforms to blastic. Although survival of most blastic patients is shorter, some data shows that 25% of blastic MCL patients survive to 5 years. That is longer than diffuse type and almost as long as nodular (almost 7 yrs).

Testing for high levels of LDH in NHL patients is useful because LDH is released when body tissues break down for any reason. While it cannot be used as a sole means of diagnosing NHL, it is a surrogate for tracking tumor burden in those diagnosed by other means. The normal range is approximately 100-190.

Treatment

There is so far, no proven a standard of care for MCL. Many regimens are available and often respond well to treatment, but patients may relapse after chemotherapy, what makes treatment more challenging. 

Chemotherapy
Chemotherapy is widely used as frontline treatment, and often is not repeated in relapse due to side effects. Alternate chemotherapy is sometimes used at first relapse. For frontline treatment, CHOP with rituximab is the most common chemotherapy, and often given as outpatient by IV. A stronger chemotherapy with greater side effects (mostly hematologic) is HyperCVAD, often given as in-patient, with rituximab and generally to fitter patients (some of which are over 65). HyperCVAD is becoming popular and showing promising results, especially with rituximab. It can be used on some elderly (over 65) patients, but seems only beneficial when the baseline Beta-2-MG blood test was normal. It is showing better complete remissions (CR) and progression free survival (PFS) than CHOP regimens. A less intensive option is bendamustine with rituximab.

Second line treatment may include fludarabine, combined with cyclophosphamide and/or mitoxantrone, usually with rituximab. Cladribine and clofarabine are two other drugs being investigated in MCL. A relatively new regimen that uses old drugs is PEP-C, which includes relatively small, daily doses of prednisone, etoposide, procarbazine, and cyclophosphamide, taken orally, has proven effective for relapsed patients. According to John Leonard, PEP-C may have anti-angiogenetic properties, something that he and his colleagues are testing through an ongoing drug trial.

Another approach involves using very high doses of chemotherapy, sometimes combined with total body irradiation (TBI), in an attempt to destroy all evidence of the disease. The downside to this is the destruction of the patients' entire immune system as well, requiring rescue by transplantation of a new immune system (hematopoietic stem cell transplantation), using either autologous stem cell transplantation, or those from a matched donor (an allogeneic stem cell transplant). A presentation at the December 2007 American Society of Hematology (ASH) conference by Christian Geisler, chairman of the Nordic Lymphoma Group claimed that according to trial results, mantle cell lymphoma is potentially curable with very intensive chemo-immunotherapy followed by a stem cell transplant, when treated upon first presentation of the disease.

These results seem to be confirmed by a large trial of the European Mantel Cell Lymphoma Network indicating that induction regimens containing monoclonal antibodies and high dose ARA-C (Cytarabine) followed by ASCT should become the new standard of care of MCL patients up to approximately 65 years.

A study released in April, 2013 showed that patients with previously untreated indolent lymphoma, bendamustine plus rituximab can be considered as a preferred first-line treatment approach to R-CHOP because of increased progression-free survival and fewer toxic effects.

Immunotherapy
Immune-based therapy is dominated by the use of the rituximab monoclonal antibody, sold under the trade name Rituxan (or as Mabthera in Europe and Australia). Rituximab may have good activity against MCL as a single agent, but it is typically given in combination with chemotherapies, which prolongs response duration. There are newer variations on monoclonal antibodies combined with radioactive molecules known as Radioimmunotherapy (RIT). These include Zevalin and Bexxar. Rituximab has also been used in small numbers of patients in combination with thalidomide with some effect. In contrast to these antibody-based 'passive' immunotherapies, the field of 'active' immunotherapy tries to activate a patient's immune system to specifically eliminate their own tumor cells. Examples of active immunotherapy include cancer vaccines, adoptive cell transfer, and immunotransplant, which combines vaccination and autologous stem cell transplant. Though no active immunotherapies are currently a standard of care, numerous clinical trials are ongoing.

Targeted therapy

• Ibrutinib  (Imbruvica) - FDA approved indication: Treatment of patients with mantle cell lymphoma (MCL) who have received at least one prior therapy/
•  Bortezomib (Velcade) - FDA-approved indication: Treatment of multiple myeloma patients who have received at least one prior therapy. Treatment of patients with mantle cell lymphoma.
• Lenolidomide (Revmilid) - FDA-approved indication: Treatment of mantle cell lymphoma whose disease has relapsed or progressed after two prior therapies, one of which included bortezomib.