The stopping rule was applied because of low response rates.

Aggressive non-Hodgkin's lymphoma is difficult to handle once it relapses or becomes refractory to chemotherapy. Various second or third line chemotherapies, which are called salvage chemotherapy, were developed without promising results. Improvement in efficacy by adding relatively new agent, rituximab, to chemotherapy is now widely accepted in non-Hodgkin's lymphoma. This study will test the safety and efficacy of adding rituximab to existing salvage chemotherapy, ESHAP (R-ESHAP). Our aim is also to proceed to high-dose chemotherapy with autologous hematopoietic stem cell transplantation after successful R-ESHAP therapy.

Inclusion Criteria:

• Clinical diagnosis of aggressive non-Hodgkin's lymphoma
• Refractory to the first line chemotherapy or relapsed
• Expression of CD20 on lymphoma cells
• Measurable lesions on imaging studies

Exclusion Criteria:

• Blood cell counts not reaching to 3,000/microliter for white blood cells, 7 g/dl for hemoglobin, and 50,000/microliter for platelets without transfusion at the time of registration
• Circulating lymphoma cells equal to or more than 25,000/microliter
• Hepatic dysfunction
• Renal insufficiency
• Cardiac dysfunction or arrhythmia
• Sever infection (bacterial, viral)
• CNS involvement
• Other malignancies
• Pregnancy or breast feeding