Mantle cell lymphoma: 2017 update on diagnosis, risk‐stratification, and clinical management

Disease Overview Mantle cell lymphoma (MCL) is a non‐Hodgkin lymphoma characterized by involvement of the lymph nodes, spleen, blood and bone marrow with a short remission duration to standard therapies and a median overall survival (OS) of 4‐5 years. Diagnosis Diagnosis is based on lymph node, bone marrow, or tissue morphology of centrocytic lymphocytes, small cell type, or blastoid variant cells. A chromosomal translocation t (11:14) is the molecular hallmark of MCL, resulting in the overexpression of cyclin D1. Cyclin D1 is detected by immunohistochemistry in 98% of cases. The absence of SOX‐11 or a low Ki‐67 may correlate with a more indolent form of MCL. The differential diagnosis of MCL includes small lymphocytic lymphoma, marginal zone lymphoma, and follicular lymphoma. Risk Stratification The MCL International Prognostic Index (MIPI) is the prognostic model most often used and incorporates ECOG performance status, age, leukocyte count, and lactic dehydrogenase. A modification of the MIPI also adds the Ki‐67 proliferative index if available. The median OS for the low‐risk group was not reached (5‐year OS of 60%). The median OS for the intermediate risk group was 51 months and 29 months for the high risk group. Risk‐Adapted Therapy For selected indolent, low MIPI MCL patients, initial observation may be appropriate therapy. For younger patients with intermediate or high risk MIPI MCL, aggressive therapy with a cytotoxic Regimen followed by autologous stem cell transplantation should be considered. Rituximab maintenance after autologous stem cell transplantation has also improved the progression‐free and overall survival. For older symptomatic MCL patients with intermediate or high risk MIPI, combination chemotherapy with R‐CHOP, R‐Bendamustine, or a clinical trial should be considered. In addition, rituximab maintenance therapy may prolong the progression‐free survival. At the time of relapse, agents directed at activated pathways in MCL cells such as bortezomib (NFkB inhibitor), lenalidamide (anti‐angiogenesis) and Ibruitinib (Bruton's Tyrosine Kinase [BTK] inhibitor) have demonstrated excellent clinical activity in MCL patients. Autologous or allogeneic stem cell transplantation can also be considered in young patients. Clinical trials with novel agents are always a consideration for MCL patients.