Chimeric antigen receptor T-cell therapy for refractory/relapsed primary breast lymphoma: A retrospective cohort study.

Patients with relapsed or refractory primary breast lymphoma (r/r PBL) face a poor prognosis, and data regarding chimeric antigen receptor (CAR) T-cell therapy for this specific population remain scarce. This retrospective study aimed to evaluate the clinical efficacy and toxicity of CAR T-cell therapy (CD19 or sequential CD19/CD22), administered either alone or combined with autologous stem cell transplantation (ASCT), in 11 adult patients with r/r PBL. The cohort included nine patients with diffuse large B-cell lymphoma and two with Burkitt lymphoma. The treatment demonstrated high efficacy: at three months post-treatment, the overall response rate was 81.8%, and the complete remission rate was 72.7% (eight patients). Over a median follow-up of 38 months, seven patients remained alive, yielding estimated 1-year overall and progression-free survival rates of 63.6% and 61.4%, respectively. Notably, the safety profile was highly favorable; no patients experienced grade 3-4 cytokine release syndrome or any grade of immune effector cell-associated neurotoxicity syndrome. In conclusion, CAR T-cell therapy, with or without ASCT, represents a highly effective and safe therapeutic strategy for adult patients with r/r PBL, offering durable remissions with manageable toxicities.