Table 1.

HNSCC patient and tumor characteristics

Specimen ID	Tumor anatomic location	Histologic subtype	Patient age at diagnosis (years)	Tumor stagea			Tumor HPV statusb	Tumor cell PD-L1 statusc	CPS for PD-L1d
				T	N	M
1	Base of tongue	NK	38	3	0	0	+	–	10
2	Base of tongue	NK	45	3	0	0	+	–	20
3	Tonsil	NK	70	3	0	0	+	–	10
4	Tonsil	NK	61	1	2B	0	+	–	20
5	Tonsil	C	73	4A	2B	0	–	–	20
6	Tonsil	C	64	2	0	0	–	–	0
7	Base of tongue	NK	60	4A	2C	0	–	–	10
8	Base of tongue	C	63	2	0	0	–	–	20
9	Base of tongue	C	28	4	0	0	+	+	10
10	Base of tongue	NK	53	2	1	0	+	+	20
11	Tonsil	NK	61	3	3	0	+	+	100
12	Base of tongue	NK	51	2	2A	0	+	+	100
13	Tonsil	NK	71	1	2A	0	+	+	20
14	Tonsil	NK	61	1	1	0	+	+	60
15	Tonsil	C	49	4A	2B	0	+	+	20
16	Tonsil	NK	56	1	1	0	+	+	50
17	Tonsil	NK	51	2	2B	0	+	+	90
18	Oropharynx	C	34	4A	0	0	–	+	40
19	Base of tongue	C	39	4B	1	0	–	+	20
20	Base of tongue	C	34	4A	2	0	–	+	100
21	Base of tongue	C	51	4	0	0	–	+	50
22	Tonsil	C	64	3	3	0	–	+	5
23	Soft palate	C	50	4	2C	0	–	+	10
24	Tonsil	C	56	4	3	0	–	+	5
25	Tonsil	NK	57	3	2C	0	–	+	10
26	Tonsil	C	55	4B	2B	0	–	+	40
27	Tonsil	C	74	3	2B	0	–	+	70

NK non-keratinizing, C conventional

^aAmerican Joint Committee on Cancer (AJCC) staging

^bHPV status determined by p16 IHC and confirmed by HPV genotyping, as described in Methods. All had the HPV16 genotype except for tumor #14, which was HPV58

^cTumors are defined as PD-L1+ if ≥ 5% of tumor cells express membranous (cell surface) PD-L1 by IHC

^dCPS is defined as the percentage of PD-L1 TCs and ICs relative to the total number of tumor cells