In most cases of anaplastic lymphoma kinase-positive anaplastic large cell lymphoma (ALK + ALCL), long-term survival is achieved using CHOP therapy. However, some cases have a poor prognosis. Here, we investigated the clinical impact of TP53 deletion on adult ALK + ALCL patients via a multicenter, retrospective analysis. TP53 deletion was evaluated by fluorescence in situ hybridization (FISH) using paraffin sections of lymphoma samples. To re-evaluate the FISH results, whole genome copy number changes were analyzed in DNA extracted from paraffin sections using OncoScan analysis. Fourteen patients treated with first-line chemotherapy enrolled at six centers were analyzed. All patients received CHOP-based therapy as initial therapy. The 5-year progression-free survival (PFS) and overall survival (OS) of the 14 patients were 28.6% (median 7 months) and 57.1% (median 99 months), respectively. FISH analysis revealed 6 (43%) patients were positive for TP53 deletion (deletion group) and 8 (57%) were negative (non-deletion group). All six patients in the deletion group were diagnosed at an advanced stage
five were refractory to initial treatment, one relapsed after treatment, and all patients died of ALK + ALCL. The median PFS was 3.5 months in the deletion group and 76 months in the non-deletion group. The median OS was 7 months in the deletion group and has yet to be confirmed in the non-deletion group. OncoScan analysis showed TP53 copy number reduction in the deletion group and no TP53 copy number abnormalities in the non-deletion group. This study suggests that TP53 deletion is a poor prognostic factor in ALK + ALCL treated with CHOP-based therapy.