Prognostic factors for mature natural killer (NK) cell neoplasms: aggressive NK cell leukemia and extranodal NK cell lymphoma, nasal type.
BACKGROUND
Patients with natural killer (NK) cell neoplasms, aggressive NK cell leukemia (ANKL) and extranodal NK cell lymphoma, nasal type (ENKL), have poor outcome. Both diseases show a spectrum and the boundary of them remains unclear. The purpose of this study is to draw a prognostic model of total NK cell neoplasms.


METHODS
We retrospectively analyzed 172 patients (22 with ANKL and 150 with ENKL). The ENKLs consisted of 123 nasal and 27 extranasal (16 cutaneous, 9 hepatosplenic, 1 intestinal and 1 nodal) lymphomas.


RESULTS
Complete remission rate for ENKL was 73% in stage I, but 15% in stage IV, which was consistent with that for ANKL (18%). The prognosis of ENKL was better than that of ANKL (median survival 10 versus 1.9 months, P < 0.0001) but was comparable when restricted to stage IV cases (4.0 months, P = 0.16). Multivariate analysis showed that four factors (non-nasal type, stage, performance status and numbers of extranodal involvement) were significant prognostic factors. Using these four variables, an NK prognostic index was successfully constructed. Four-year overall survival of patients with zero, one, two and three or four adverse factors were 55%, 33%, 15% and 6%, respectively.


CONCLUSIONS
The current prognostic model successfully stratified patients with NK cell neoplasms with different outcomes.
Suzuki
R
R
Department of HSCT Data Management, Nagoya University School of Medicine, Nagoya, Japan. r-suzuki@med.nagoya-u.ac.jp
Suzumiya
J
J
Yamaguchi
M
M
Nakamura
S
S
Kameoka
J
J
Kojima
H
H
Abe
M
M
Kinoshita
T
T
Yoshino
T
T
Iwatsuki
K
K
Kagami
Y
Y
Tsuzuki
T
T
Kurokawa
M
M
Ito
K
K
Kawa
K
K
Oshimi
K
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000473:pathology*; D007938:Leukemia / Q000175:diagnosis* / Q000628:therapy; D054391:Lymphoma, Extranodal NK-T-Cell / Q000175:diagnosis* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009669:Nose Neoplasms / Q000175:diagnosis* / Q000628:therapy; D011379:Prognosis; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult