Analysis of Clinical and Pathological Features of 117 Chinese Cases of Natural Killer/T Cell Lymphoma

To improve the understanding of natural killer (NK)/T cell lymphoma (NK/TCL) with poor prognosis and provide experiential references via a restrospective analysis of the clinical and pathological features.

117 NK/TCL cases in single center of Northwestern China from April 2009 to April 2012 were retrospectively analyzed on their pathologic diagnosis and clinical manifestations, especially primary sites. Pathologic examinations mainly depended on morphology, immunohistochemisty, In situ hybridizationc and polymerase chain reaction (PCR). Immunohistochemical staining for immunophenotype (LCA, CD3, CD20, CD29a, CD45RO, CD56, TIA-1 and Granzyme B), In situ hybridization for Epstein - Barr virus (EBV) small encoded RNA(EBER) and PCR for the amount of EBV DNA in whole-blood and T-cell receptor (TCR) gene rearrangement were performed respectively. For nasal NK/TCL, combined chemotherapy and radiotherapy were indicated for stage I/II disease. Chemotherapy was the main treatment for stage III/IV NK/TCL. Regimens contained drugs not affected by P-glycoprotein, particularly in combination with L-asparaginase, or pegaspargase. Overall survival (OS) according to clinical characteristics was analyzed.

NK/TCL could be diagnosed via its typical clinical symptom, pathological morphology, phenotype and EBER. 117 cases were nasal or extranodal NK/TCL. The median age was 39 years old. The median survival was 11 months. The primary nasal NK/TCL was 95, accounting for 81. 2% (95/117) and their average Ki67 was 78. 34%+21. 6%. Other primary extranodal NK/TCL was 22, accunting for 18. 8%(22/117), as follows: 4 primary posterior pharyngeal wall cases with average Ki67 60%+11. 3%, 4 primary lymph nodes cases with average Ki67 50%+10. 6%, 4 primary skin cases with average Ki67 45%+8. 6%, 3 primary tonsil cases with average Ki67 67. 3%+2. 8%, 1 primary laryngeal case with Ki67 80%, 1 primary liver case with Ki67 was 90%, 1 primary intestinal case with Ki67 80%, 1 primary tongue case with Ki67 66%, 2 primary central nervous system cases with average Ki67 less than 30%, 1 primary testis case with Ki67 56%. It was found that 31 patients with primary liver and intestinal or Ki67 greater than 80% were dead in first year. Patients with primary liver and intestinal had higher Ki67 than patients with primary nasal (P <0. 01). Rate of 2 year(2y) OS of 45 patients with Ki67 from 60% to 80% was 60% as compared to 86. 3% of rate of OS of 33 patients with Ki67 from 30% to 50% (P <0. 05)and 100% of rate of OS of patients with Ki67 less than 30%(P <0. 01). Rate of 2y OS of 8 CD56⁻ patients whose TCR was positive and primary sites were nasal was 100% higher than 67% of 109 CD56⁺ patients(P <0. 01). It was implied that nasal NK/TCL was of T-cell origin. Rate of 2y OS of 7 EBER⁻ patients was 100% higher than 58% of 110 EBER⁺ patients(P <0. 01). The EBV–DNA was detected in 42 samples with less than 10⁴ copies/ml in whole blood and rate of 2y OS of these patients was 55%+16%. There were 4 samples with more than 10⁵ copie/ml EBV–DNA in whole blood and CD56⁺. The rate of 2y OS of these patients was 22%+9%.

It was implied that Ki67, CD56, EBER, EBV-DNA and primary site was related with the prognosis of NK/TCL. It was also showed that NK/TCL of T-cell origin had a trend for better survival. However, it needs further and more clinical observation and verification to judge if they could be additional markers for prognostication and clinical stratification to be incorporated in clinical individual management algorithms.

No relevant conflicts of interest to declare.