Table 6.

Patient tumor and combined frequency of PD-1 expression

	No. Patients	0	1	2	3	4	P-value
		aCombined PD-1 Level, n (%)
Stage of cancer
I-II	9	0 (0.0)	0 (0.0)	6 (66.7)	1 (11.1)	2 (22.2)	0.028
III-IV	46	7 (15.2)	8 (17.4)	23 (50.0)	7 (15.2)	1 (2.2)
Tumor grade
1–2	13	1 (7.7)	4 (30.8)	7 (53.8)	0 (0.0)	1 (7.7)	0.54
3	41	6 (14.6)	4 (9.8)	21 (51.2)	8 (19.5)	2 (4.9)

^aCombined PD-1 was derived by adding the observed pathology scores for tumor PD-1 (T-PD-1) and S-PD-1 in each patient tumor section. Significant P-value in table is indicated in italics