Abstract:

Background and purpose: Advanced extranodal NK/T-cell lymphoma is a highly aggressive disease with a grim prognosis in elderly patients. No therapeutic strategy is currently identified in these setting of patients. Pegaspargase formed by covalently attaching polyethylene glycol to asparaginase has been shown to induce apoptosis of tumoral NK cells in vitro and well tolerated. This clinical study was to investigate the clinical efficacy and toxicity of pegaspargase combined with dexamethasone (PegAD) regimen in the treatment of elderly patients with extranodal NK/T-cell lymphoma, nasal type (ENKTL). Methods: A total of 15 elderly patients with pathologically diagnosed ENKTL and presented with Ann Arbor stage Ⅲ-Ⅳ were treated with PegAD regimen, which consisted of pegaspargase 2 500 U/(m²·d) given as intramuscular injection on day 1 and dexamethasone 20 mg/d administered intravenously on day1 through 4. The PegAD regimen was repeated every 21 days. Clinical efficacy and safty profiles of PegAD regimen was systemically reviewed and analysed. Results: ① All the 15 patients received a total of 45 cycles of PegAD regimen. The median cycles was 3. Two patients achieved complete response, while seven cases obtained partial response. The overall response rate was 60%. The median survival time was 10 months. ②In newly diagnosed patients, overall response rate (OR) reached 75%, which was significantly higher than that in refractory cases, whose OR were 43% (P<0.05). In addition, the median survival duration of newly diagnosed patients was longer than that of refractory cases, whose median survival time was 14 and 6months, respectively. ③The major adverse events was liver dysfunction and disturbances of blood coagulation with grade 3-4 hepatitis in 20% cases and low levels of fibrinogen as well as prolonged PT and APTT in 60% patients. However, hematologic toxicities were moderate. Conclusion: PegAD regimen was an effective and well tolerated therapeutic schedule for elderly patients with ENKTL.

Key words: Extranodal NK/T-cell lymphoma, Elderly patients, Pegaspargase