Table 2.

Elevated Risk of SPM by Site of Index HNSCC

SPM Site	All HN Primaries			Oral Cavity Primaries			Oropharynx Primaries			Larynx Primaries			Hypopharynx Primaries
	SIR		EAR per 10,000 PYR	SIR		EAR per 10,000 PYR	SIR		EAR per 10,000 PYR	SIR		EAR per 10,000 PYR	SIR		EAR per 10,000 PYR
	Rate	95% CI		Rate	95% CI		Rate	95% CI		Rate	95% CI		Rate	95% CI
All solid tumors	2.18	2.15 to 2.21	167.74	2.82	2.74 to 2.90	228.73	2.99	2.88 to 3.10	209.78	1.92	1.88 to 1.97	147.78	3.47	3.27 to 3.68	307.06
Lung and bronchus	3.75	3.66 to 3.85	75.22	3.96	3.74 to 4.20	69.07	4.86	4.54 to 5.20	79.59	4.07	3.92 to 4.22	93.83	6.06	5.46 to 6.71	139.52
HN	12.38	12.03 to 12.74	59.76	26.16	24.92 to 27.44	115.91	22.21	20.80 to 23.70	83.73	5.80	5.42 to 6.19	29.34	18.94	16.74 to 21.35	83.73
Oral cavity/pharynx	15.25	14.78 to 15.73	54.29	31.68	30.08 to 33.33	105.21	26.73	24.9 to 28.65	75.46	7.25	6.74 to 7.77	26.47	23.69	20.76 to 26.91	80.27
Oropharynx	18.22	15.36 to 21.47	1.83	28.04	19.84 to 38.49	2.73	40.16	28.42 to 55.12	3.56	11.24	7.92 to 15.49	1.32	32.15	15.42 to 59.12	2.48
Larynx	5.03	4.64 to 5.43	6.44	10.50	9.14 to 11.99	12.56	9.42	7.86 to 11.20	9.06	2.24	1.86 to 2.68	2.83	7.79	5.51 to 10.69	5.34
Hypopharynx	16.53	15.04 to 18.13	5.54	28.56	23.90 to 33.87	8.73	38.93	32.20 to 46.66	9.19	9.81	8.09 to 11.78	3.73	11.68	6.22 to 19.97	4.67
Esophagus	8.35	7.86 to 8.87	14.24	15.05	13.44 to 16.80	22.95	15.70	13.68 to 17.94	20.95	4.69	4.12 to 5.30	8.65	28.63	24.02 to 33.87	51.78
All non-HNLE sites	1.07	1.05 to 1.09	10.38	1.06	1.03 to 1.10	9.40	1.12	1.03 to 1.22	14.38	1.07	1.03 to 1.10	10.40	1.10	0.98 to 1.24	13.86

Abbreviations: SPM, second primary malignancy; HNSCC, head and neck squamous cell carcinoma; HN, head and neck; SIR, standardized incidence ratio; EAR, excess absolute risk; PYR, person-years at risk; HNLE, head and neck, lung, and esophagus.