Efficacy and Safety Study of P-Gemox vs.EPOCH as First-line Chemotherapy to Treat NK/T-cell Lymphoma With Early Stage

ENKTL is an aggressive type of NHL characterized by poor survival, for which the optimal treatment strategies have not been fully defined. Radiation therapy (RT) is widely administered for patients with localized nasal disease, and produces a complete response (CR) rate of up to 70%.However, local and systemic failures are observed frequently in patients who receive RT alone.Therefore, chemotherapy is needed in combination with RT to reduce the risk of recurrence. Unfortunately, ENKTL shows a poor response to the CHOP chemotherapy regimen (cyclophosphamide, doxorubicin, vincristine and prednisone) . EPOCH (etoposide, vincristine, doxorubicin, cyclophosphamide and prednisone) chemotherapy followed by involved field radiotherapy (IFRT) results in a CR rate of 75.0%. Recently, a chemotherapy regimen including gemcitabine,oxaliplatin and l-asparaginase (GELOX) has emerged, with promising results.Since 2003, a proportion of patients newly diagnosed with ENKTL were treated with the EPOCH chemotherapy regimen at some hospitals in China. From 2008, many hospitals in the southern part of China began to use the GELOX( Pegaspargase is used instead of l-asparaginase,P-Gemox).Our multicenter retrospective study showed the GELOX regimen produces a better long outcome with less toxicity than the EPOCH regimen for patients with early stage ENKTL.However,further prospective randomized clinical trials are needed to confirm the conclusion.

1. Patients

• All patients should sign a written informed consent form before enrollment, and the study should be approved by the Sun Yat-sen University Cancer Center Ethics Board.
• Baseline of patients: Computed tomography (CT) scans of the chest, abdomen, and pelvis, magnetic resonance imaging studies of the head and neck, and bilateral bone marrow aspiration or biopsy. Positron emission tomography-CT scans (optional). Epstein-Barr virus (E B V) DNA blood levels, titer of EBV antibody (EA-IgA, VCA-IgA), β2-micro globulin (β2-MG) , IL-9 and IL-15 in the serum.
• Recheck before and after every course: Epstein-Barr virus (EBV) DNA blood levels, titer of EBV antibody (EA-IgA, VCA-IgA), β2-micro globulin (β2-MG), IL-9 and IL-15 in the serum.
• Recheck every two course: Computed tomography (CT) scans of the chest, abdomen, and pelvis, magnetic resonance imaging studies of the head and neck, and bilateral bone marrow aspiration or biopsy. Positron emission tomography-CT scans (optional)

1. Treatment Protocol:

• The GELOX regimen consist of the following drugs: gemcitabine ：1250 mg/ m2 on days 1,ivdrip oxaliplatin ：85 mg/m2 on day 1, ivdrip pegaspargase : 2500 IU/m 2 daily on day 1,intramuscular. The treatment cycle is repeated every 14 days.
• The EPOCH regimen included a 24 h continuous infusion of etoposide (50 mg/m 2 /day), vincristine (0.4 mg/m 2 /day) and doxorubicin(10 mg/m 2 /day administered on days 1-4, followed by cyclophosphamide (750 mg/m2 /day) over 15 min intravenously on day 5 and prednisone (60 mg/m 2 /day) 60 mg/m 2 /day on days 1-5.The treatment cycle is repeated every 21 days.

After at least two cycles of chemotherapy, patients who have achieved stable disease (SD) following two cycles, partial response (PR) after four cycles or complete response (CR) after six cycles of chemotherapy are referred to primary IFRT.

◦IFRT was delivered using 6-MeV linear accelerator using 3-dimensional conformable treatment planning. The IFRT dose was 56 grays (Gy) in 28 fractions, we define the clinical target volume of limited stage IE disease as the bilateral nasal cavity, bilateral ethmoid sinuses, and ipsilateral maxillary sinus; and the clinical target volume would extend to involved tissues for patients who had extensive stage IE disease. For patients who had stage IIE disease, the clinical target volume also, included the bilateral cervical lymph node area.