Table 3.

Characteristics in relation to aggressive natural killer leukemia cells in peripheral blood and bone marrow

	<20% (N = 11)a	≥20% (N = 23)b	P‐value
Age (median, years)	48	36	0.28
Male/female	7/4	18/5	0.72
Splenomegaly	7	21	0.07
Performance status ≥ 2	6	8	1
EBV‐positive/negative	8/11	20/22	0.3
Hemophagocytic syndrome	9/9	10/20	0.01c
WBC count (median; ×109/L)	2.42	3.59	0.27
CD16‐positive	7/8	21/22	0.47
Survival (median; days)	35	76	0.09

^aTumor cells <20% in both peripheral blood (PB) and bone marrow (BM).

^bTumor cells more than 20% in either PB or BM.

^cStatistically significant.

EBV, Epstein–Barr virus; WBC, white blood cell count.