Cytarabine, Ki-67, and SOX11 in patients with mantle cell lymphoma receiving rituximab-containing autologous stem cell transplantation during first remission

Background: In the current study, the authors report the results of 39 patients with mantle cell lymphoma (MCL) who were treated with chemotherapy and high-dose rituximab-containing autologous stem cell transplantation (ASCT) during their first disease remission. Methods: The median age of the patients was 54 years. At the time of diagnosis, 87% of patients had Ann Arbor stage IV disease, and 77% had bone marrow involvement. A Ki-67 level of > 30% was found in 11 of 27 patients (40%), and SOX11 (SRY [sex determining region Y)-box 11] expression was found to be positive in 17 of 18 patients (94%). Twenty-seven patients (69%) underwent induction therapy with high-dose cytarabine-containing chemotherapy. Rituximab was administered during stem cell collection at a dose of 1000 mg/m² on days +1 and +8 after ASCT. Results: The estimated 4-year overall survival and progression-free survival rates were 82% and 59%, respectively. Twelve patients experienced disease recurrence. Fifteen of 16 patients who were alive and in complete remission at 36 months remained so at a median follow-up of 69 months (range, 38 months-145 months). The only determinant of recurrence risk found was a Ki-67 level of > 30%. Seven of 11 patients with a Ki-67 level > 30% experienced disease recurrence within the first 3 years versus only 3 of 16 patients with a Ki-67 level ≤ 30% (P =.02). Patients who received high-dose cytarabine did not have a significantly different risk of developing disease recurrence compared with other patients (P =.7). Conclusions: Administering ASCT with rituximab during stem cell collection and immediately after transplantation may induce a continuous long-term disease remission in patients with MCL with a Ki-67 level of ≤ 30%.