Extranodal NK/T-Cell Lymphoma: A Comparative Clinicopathological Study According to Survival Outcome.
Authors: Choi Yong Won , Il Park Jung , Jung Jae Ho , Jeong Sung Heun , Lee Hyun Woo , Han Jae Ho , Jeong Seon Yong , Kang Seok Yun , Park Joon Seong , Choi Jin Hyuk , Kim Hugh C. 
Published: October 2019

Abstract
BACKGROUND Extranodal NK/T-cell lymphoma is notable for its unique behavior; Many patients die before 1 year from the diagnosis. However, the patients who survive the first year from the diagnosis live for longer period. Known prognostic factors were insufficient to explain this unique pattern. The objective of this study was to investigate clinicopathological features according to survival outcome(OS<1 yr vs OS ≥1 yrs).
METHODS We reviewed 28 patients who diagnosed as extranodal NK/T cell lymphoma from March, 1995 to July, 2006. Patients were treated with chemotherapy alone or chemoradiotherapy. Real-time PCR was done from the tissue of the biopsy specimen to quantify the Epstein-Barr virus load.
RESULTS Of the 28 patients, 14 patients(50%) achieved a complete remission(CR). Median survival was 46 months(range, 1–114 months). The B symptoms, IPI score, stage, ECOG status, first treatment response was significant prognostic factor (P<0.05). However ECOG status the only significant prognostic factor by using mutivariate analysis (P=0.001). Seventeen patients (61%) expired; 12 of those patients died during the first year of diagnosis. Thus we divided them into 2 groups; who lived more than 1 year and who lived less than 1 year. The ECOG status, first treatment response rate was different between the two groups significantly(p<0.05). All patients showed positive EBV by PCR. However, there was no significant difference in EBV load between these two groups. (p=0.113)
CONCLUSION The ECOG status, and response to the first treatment related to the survival of first year from the diagnosis. For the patients with poor performance status, and failure to achieve CR after the first treatment, more aggressive treatment should be considered to improve survival. In our study, EBV load measured on the paraffin tissue failed to correlate with survival.
Univariate Analysis of Overall survival Prognostic Factors Median OS(months) P value Age >60yrs 33 <60yrs 10 0.783 Type Nasal 33 Nasal type 5 0.225 B symptom Yes 5 No 42 0.021 IPI Low/Low-intermediate 42 High-intermediate/High 2 0.002 Stage I/II 42 III/IV 2 0.001 ECOG 0,1 45 2,3,4 2 0.001 LDH Normal 33 High 17 0.720 EBV load(copies/ug DNA)(n=22) 46 0.228 Treatment C/T alone 5 C/T and R/T 42 0.196 treatment response CR 45 No-CR 14 0.0127 Multivariate Analysis of Overall survival Prognostic Factors Hazad Ratio 95% CI P B symptom No 1.00 Yes 0.97 0.11–8.58 0.980 IPI score Low/Low-inermediate 1.00 High-intermediate/High 1.35 0.25–7.26 0.730 Stage I,II 1.00 III,IV 0.60 0.06–6.12 0.668 ECOG 0,1 1.00 2,3,4 6.94 2.23–21.55 0.001 Treatment response CR 1.00 No-CR 1.98 0.56–6.96 0.287 Fig. 2 Overall survival according to survival outcome (OS<1 year vs OS ≥ 1 years). The patients who survive more than 1 year showed relativily good prognosis. Fig. 2. Overall survival according to survival outcome (OS<1 year vs OS ≥ 1 years). The patients who survive more than 1 year showed relativily good prognosis.