First Line Treatment of Aggressive Cutaneous NK/T Cell Lymphomas Based on High Dose Cytarabine and Stem Cell Transplantation Does Not Lead to Durable Remissions.
Authors: Halkes C.J.M. , Vermeer M.H. , Noordijk E.M. , Willemze R. , Willemze Roelof 
Published: April 2020

Abstract
Aggressive cutaneous NK/T-cell lymphomas are extremely rare with an estimated yearly incidence of less than 1 per 2,000,000 and a disease-specific 5 year survival of 0–16%. This dismal prognosis seems independent of the presence of extracutaneous localizations at diagnosis. Only a minority of patients respond to CHOP-like multiagent chemotherapy. Sustained complete remissions (CR) have been observed after stem cell transplantation of some heavily pre-treated patients. We hypothesized that stem cell transplantation may be the only treatment modality that may induce long term remissions in this very resistant disease. In order to get as many possible patients eligible for a stem cell transplantation we designed an intensive protocol in which patients with newly diagnosed aggressive cutaneous NK/T-cell lymphoma were treated with AML-like induction and consolidation courses followed by an allogeneic or an autologous stem cell transplantation.
All patients with newly diagnosed aggressive cutaneous NK/T-cell lymphoma who were referred to our centre between 06-2003 and 06-2006 were screened for this study. Patients who were able to undergo this intensive therapy, were enrolled after informed consent. Induction treatment consisted of etoposide 120 mg/m2 and amsacrine 115 mg/m2 on days 1 and 7, methylprednisolone 60 mg/m2 on days 1–7, intrathecal methotrexate on day 1 and cytarabine on days 1–6: either 1000 mg/m2 twice daily (age &lt;61) or 100 mg/m2 daily (age &gt; 60). In case of partial remission (PR), induction treatment was repeated. In case of CR, consolidation treatment was given consisting of amsacrine and etoposide in similar doses as during induction, and cytarabin 3000 mg/m2 twice daily on days 1–4 or 300 mg/m2 twice daily on days 1–4 in older patients. In case of persisting CR after consolidation therapy, patients were eligible for allogeneic stem cell transplantation with total body irradiation (TBI) and high dose cyclophosphamide as conditioning regimen. In the absence of a HLA matched donor, autologous transplantation was planned.
Six patients (3 males, 3 females) were treated for cutaneous peripheral T cell lymphoma not otherwise specified (n=3), cutaneous blastic NK cell lymphoma (n=2) or cutaneous NK-T cell lymphoma, nasal type (n=1). Mean age was 52 years (range 33–65). In two patients no extracutaneous localizations were found. After induction treatment two patients had progressive disease, and one patient showing PR died suddenly during leukopenic period after the second induction cycle. Three patients achieved the CR. One of them died due to an intracerebral hemorrhage just before transplantation. Two patients underwent stem cell transplantation (one autologous and one allogeneic) but both relapsed, 204 and 218 days after transplantation, respectively and died within weeks. Median overall survival was 214 days (range 30–382).First line treatment of aggressive cutaneous NK/T cell lymphoma using an intensive AML-like chemotherapy approach resulted in CR in 3 out of 6 patients. Only two of them reached a stem cell transplantation, but both patients died of relapsing disease. Based on these outcomes, first line treatment of aggressive cutaneous NK/T-cell lymphoma consisting of AML-like induction and consolidation therapy did not result in durable remissions, necessary to perform stem cell transplantation.