A Prospective Clinical Study of the Combination Therapy of Obutinib or Decitabine with Rituximab, Cyclophosphamide, and Prednisone for the Primary Treatment of Elderly Patients with Newly Diagnosed Diffuse Large B-cell Lymphoma

"For non GCB type: Rituximab, 375mg/m2, QD, D1,8,15(the first cycle), d1(Starting from the second cycle), ivgtt; Compound Cyclophosphamide Tablets, 50mg:50mg BID, P.O.; Obutinib, 150mg, QD, P.O.; Prednisone, 60mg, QD D1-7, P.O. Every 21 days is a cycle, and the efficacy is evaluated every 2 cycles. Obutinib maintain treatment for 6 months. Obutinib, 150mg, QD, P.O. After 6 cycles of initial treatment, the efficacy was evaluated.~For GCB type: Rituximab, 375mg/m2, QD, D1,8,15(the first cycle), d1(Starting from the second cycle), ivgtt; Compound Cyclophosphamide Tablets, 50mg:50mg BID, P.O.; Decitabine, 10mg, QD，D1-5, ivgtt; Prednisone, 60mg, QD D1-7, P.O. Every 21 days is a cycle, and the efficacy is evaluated every 2 cycles. Decitabine maintenance treatment for 4 cycles, 21 days per cycle. Decitabine, 10mg, QD，D1-5, ivgtt. Evaluate the efficacy after 6 cycles of treatment."