Update on mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma that is most commonly treated with combination chemo-immunotherapy at diagnosis because of the poor prognosis. More indolent presentations have been described including patients who can defer initial therapy without adverse impact on survival. The 2016 World Health Organization updated classification describes 2 major subtypes, classical and leukemic nonnodal MCL, each with unique molecular features and clinical presentations. Although there is no standard of care for MCL, aggressive chemo-immunotherapy regimens containing rituximab and cytarabine, followed by consolidation with autologous stem cell transplantation and maintenance rituximab, are the most used approach in young fit patients, and chemo-immunotherapy, followed by rituximab maintenance, is most commonly used in older patients. Despite the improvement in response durations with currently available therapies, patients will inevitably relapse. A number of targeted therapies are approved in the relapsed setting and are now under evaluation in combination with standard frontline therapy. Although the approval of ibrutinib changed the landscape of therapy for relapsed MCL, prognosis remains poor after progression on ibrutinib supporting the development of ibrutinib combinations to prolong response duration as well as the development of other novel agents for ibrutinib refractory disease. With ibrutinib being incorporated into initial therapy regimens, new options will be needed at relapse. Prognostic markers, such as minimal residual disease, have been shown to correlate independently with outcomes along with predicting relapse, with the potential to guide therapeutic decisions. The future treatment of MCL therapy will need to incorporate therapy based on risk-stratification and nonchemotherapeutic approaches.