Table 3.

Characteristics of metachronous head and neck squamous cell carcinoma n (%)

	Group A (n = 254)	Group B (n = 307)	P value
Metachronous HNSCC
No. of patients	10 (3.9)	30 (9.8)	0.008
No. of lesions per patients			0.404
1	9	22
≥ 2	1	8
Total number of cancers	11	53	0.007
Location of cancer
Oropharynx	3	13
Hypopharynx	7	34
Larynx	1	6
Clinical stage			< 0.001
I/II	4 (36)	53 (100)
III/IV	7 (64)	0
Interval between ESCC and HNSCC
Median months (range)	56 (7-80)	31 (7-107)	0.130

HNSCC: Head and neck squamous cell carcinoma.