Factors associated with poorer overall survival in an analysis of patients with known HPV status, combining data from Toronto, Edmonton and Calgary (total n = 1282)
| Factor | HR (95% CI) | |
|---|---|---|
| Unadjusted | Adjusted* | |
| HPV status | ||
| Known positive | 1.00 (ref) | 1.00 (ref) |
| Known negative | 3.03 (2.44–3.76) | 2.16 (1.67–2.79) |
| Age at diagnosis, yr, × 10 | 1.57 (1.41–1.74) | 1.46 (1.29–1.66) |
| Sex | ||
| Female | 1.00 (ref) | 1.00 (ref) |
| Male | 0.87 (0.67–1.12) | 0.83 (0.63–1.10) |
| Cancer subsite | ||
| Tonsil | 1.00 (ref) | 1.00 (ref) |
| Base of tongue | 1.31 (1.03–1.67) | 1.30 (1.01–1.66) |
| Other | 2.16 (1.58–2.94) | 1.56 (1.12–2.17) |
| Smoking status | ||
| Never | 1.00 (ref) | 1.00 (ref) |
| Former | 1.71 (1.20–2.44) | 1.16 (0.79–1.71) |
| Current | 2.99 (2.15–4.17) | 2.00 (1.33–3.01) |
| Pack-years, × 10† | 1.12 (1.08–1.15) | 1.02 (0.97–1.06) |
| Alcohol consumption† | ||
| None/light | 1.00 (ref) | 1.00 (ref) |
| Moderate/heavy | 1.57 (1.26–1.96) | 0.99 (0.75–1.29) |
| Tumour (T) stage | ||
| 1 | 1.00 (ref) | 1.00 (ref) |
| 2 | 1.43 (0.96–2.14) | 1.24 (0.82–1.87) |
| 3 | 2.28 (1.52–3.42) | 1.64 (1.08–2.50) |
| 4 | 3.82 (2.59–5.62) | 2.60 (1.74–3.89) |
| Nodal (N) stage | ||
| 0 | 1.00 (ref) | 1.00 (ref) |
| 1 | 1.01 (0.67–1.51) | 1.18 (0.77–1.80) |
| 2 | 0.97 (0.72–1.31) | 2.03 (1.45–2.86) |
| 3 | 2.01 (1.33–3.02) | 4.51 (2.90–7.00) |
Note: CI = confidence interval, HPV = human papillomavirus, HR = hazard ratio.
↵* Adjusted for all variables in table and stratified by province, complete-case data (n = 1099/1282).
↵† Collinearity was not observed for smoking status or alcohol consumption. Removal of the pack-years variable only marginally changed the estimates for former smoking (HR 1.33, 95% CI 0.92–1.93), current smoking (HR 2.35, 95% CI 1.62–3.42) and alcohol consumption (HR 1.02, 95% CI 0.79–1.33).