Table 1. Patient and tumour characteristics for the test cohort.

Variable	Number of cases
Number of patients	55
T-stage
1	6
2	25
3	15
4	9
N-stage
0	7
1	6
2A	2
2B	28
2C	12
Treatment
IC+CCRT	12
CCRT	43
Pack-years (includes ex smokers)
Non-smoker	15
⩽10	11
>10	29
Tumour sub-site
Oropharynx	47
Larynx	4
Hypopharynx	4

Abbreviations: IC=induction chemotherapy; CCRT=cisplatin-based chemoradiotherapy.