New and experimental skin-directed therapies for cutaneous lymphomas

Primary cutaneous lymphomas (CLs) originate in the skin and should be differentiated from secondary skin infiltrates, which are manifestations of lymphomas of nodal or extranodal origin. These rare diseases include various lymphoproliferative disorders: cutaneous T-cell lymphomas, cutaneous B-cell lymphomas and some rare subtypes. As definitive cure is often not possible, it is important to control the disease and alleviate symptoms. Patients with early-stage disease limited to the skin usually require skin-directed therapies using topical agents including corticosteroids, chemotherapeutic drugs, bexarotene gel, electron beam therapy and phototherapy. Each of these are effective; however, all have some disadvantages and are associated with significant adverse events. In the field of skin-directed therapies there are interesting developments using antineoplastic compounds, the retinoid tazarotene, imiquimod, gene therapy products (adenovirus vector expressing gamma-interferon), the monoclonal anti-CD20 antibody rituximab, photodynamic therapy and 308-nm excimer laser to mention a few. This review highlights some of the promising new and experimental local therapies for primary CLs and focuses on their efficacy and side effects.