Purpose: Systemic anaplastic large-cell lymphoma (ALCL) is a T-cell lymphoma, whose anaplastic lymphoma kinase (ALK) expression varies according to age. Long-term outcomes of chemotherapy-treated adults are not definitively established and should be evaluated.
Patients and methods: Patients treated in three Groupe d'Étude des Lymphomes de l'Adulte prospective clinical trials with confirmed systemic ALCL after immunohistopathologic review and defined ALK expression status were analyzed.
Results: Among the 138 adult patients with ALCL, 64 (46%) were ALK positive, and 74 (54%) were ALK negative. Median follow-up was 8 years. At diagnosis, significantly more patients younger than 40 years old were ALK positive than ALK negative (66% v 23%, respectively; P < .001). Comparing patients with ALK-positive and ALK-negative ALCL, β(2)-microglobulin was ≥ 3 mg/L in 12% and 33% (P = .017); International Prognostic Index was high (score, 3 to 5) in 23% and 48% (P = .03); complete response rates to first-line treatment were 86% and 68% (P = .01); and 8-year overall survival (OS) rates were 82% (95% CI, 69% to 89%) and 49% (95% CI, 37% to 61%), respectively (P < .001). The survival difference mostly affected patients age ≥ 40 years. Multivariate analysis identified β(2)-microglobulin ≥ 3 mg/L (P < .001) and age ≥ 40 years (P = .029), but not ALK status, as prognostic for OS. These two variables distinguished four survival risk groups, with 8-year OS ranging from 84% to 22%. CONCLUSION Results of this long-term study enabled refinement of the prognosis of adult systemic ALCL, with ALK prognostic value dependent on age, and could provide guidance for eventual treatment adjustment.