All of these fusion proteins are considered to act like NPMI-ALK in possessing high ALK activity that promotes the development and progression ALK-positive ALCL by activating the cell signaling pathways cited in the Introduction. 15% Of individuals with ALK-positive ALCL also have point mutations in the NOTCH1 gene. While most of these abnormalities are thought to be detrimental not all are. For example, DUSP22 gene rearrangements are associated with favorable outcomes in ALK-positive (as well as ALK-negative) ALCL. Treatment and prognosis
A recommended induction therapy for ALK-positive ALCL in individuals with lesions containing more than 10 percent CD30-positive cells consists of brentuximab vedotin (a drug consisting of an anti-CD30 antibody attached to a cell-killing agent, monomethyl auristatin E); two chemotherapy drugs, cyclophosphamide and the anthracycline, doxorubicin; and the  corticosteroid, prednisone. This regimen gave a progression-free survival rate of 48.2 months in one study and overall survival rates of 70–90% at five years in other studies. For >60 year old and medically unfit individuals of any age, the standard CHOP regimen (cyclophosphamide, doxorubicin, prednisone, and the chemotherapeutic agent, vincristine) is used. For younger, medically fit individuals, the chemotherapeutic agent etoposide is added to the CHOP regimen (CHOP plus etoposide is termed the "CHOEP" regimen). For patients with lesions that contain <10% CD30-positive neoplastic cells, brentuximab vedotin, which targets these cells, is not used. Rather, patients are treated with an anthracycline-based chemotherapy regimen.
Patients >60 years or less medically fit are given cyclophosphamide, doxorubicin, vincristine, and prednisone while patients ≤60 years old are given CHOP plus etoposide or one of various other intensive chemotherapy regiments. The intensive chemotherapy regimens give 5 year overall survival rates of 70–93%. The role of radiation therapy for ALK-positive ALCL is unclear but has been used for patients who cannot tolerate or do not achieve complete responses to the drug regimens and to patients with organ-threatening or life-threatening tumorous infiltrates. The role of autologous or less preferably allogenic hematopoietic stem cell transplantation (transplantation using the individuals own bone marrow, i.e. autologous, or a donors, i.e. allogenic) after achieving a complete remission following induction therapy is also unclear. Individuals with relapsed or refractory disease are treated with brentuximab vedotin if they did not receive the drug previously or had not received it in the previous 6 months. A small study reported overall response rates, complete response rates, and disease-free survival rates at 24 months of 63%, 45%, and 54%, respectively, using this regimen. Those who attain a complete response on this drug and can tolerate it are than treated with bone marrow transplantation. Finally, patients who fail or relapse on these treatments are given salvage therapy regimens that have been used for relapsed or refractory aggressive B cell malignancies such as GDP (i.e.