Table 2.
Univariate and Multivariate Cox Regression for Patients with Locally Advanced HNSCC Undergoing Primary Surgery and Adjuvant Radiation. CI = confidence interval. Y = year. pT = pathologic T stage. pN = pathologic N stage. CD = Charlson-Deyo comorbidity index. HPV = human papillomavirus. OC = oral cavity. OP = oropharynx. pENE = pathologic extranodal extension. LVSF = Low-volume surgical facility. HV = High-volume. PORT = post-operative radiotherapy. CRT = chemoradiation.
| Univariate Analysis | Multivariate Analysis | |||
|---|---|---|---|---|
| Variable | HR (95% CI) | P | HR (95% CI) | P |
| Overall Survival | ||||
| Age (continuous) | 1.02 (1.02–1.03) | < 0.001 | 1.01 (1.01–1.02) | < 0.001 |
| Sex | 0.43 | |||
| Male | 1 [Ref.] | |||
| Female | 1.03 (0.95–1.12) | |||
| Race | < 0.001 | Dropped | ||
| White | 1 [Ref.] | |||
| Non-white | 1.25 (1.13–1.37) | |||
| pT Stage | ||||
| pT1 | 1 [Ref.] | 1 [Ref.] | ||
| pT2 | 1.96 (1.67–2.29) | < 0.001 | 1.75 (1.40–2.20) | < 0.001 |
| pT3 | 2.89 (2.47–3.37) | < 0.001 | 2.63 (2.09–3.22) | < 0.001 |
| pT4 | 3.41 (2.96–3.92) | < 0.001 | 2.63 (2.09–3.22) | < 0.001 |
| pN Stage | ||||
| pN0 | 1 [Ref.] | 1 [Ref.] | ||
| pN1 | 1.05 (0.93–1.18) | 0.47 | 1.33 (1.12–1.58) | < 0.001 |
| pN2 | 1.42 (1.29–1.57) | < 0.001 | 1.98 (1.72–2.29) | < 0.001 |
| pN3 | 1.69 (1.28–2.23) | < 0.001 | 3.78 (2.52–5.67) | < 0.001 |
| Charlson Comorbidity Index | < 0.001 | Dropped | ||
| 0 | 1 [Ref.] | |||
| ≥1 | 1.29 (1.19–1.41) | |||
| Anatomic Site | ||||
| HPV+ OPC | 1 [Ref.] | 1 [Ref.] | ||
| HPV− OPC | 3.37 (2.45–4.63) | < 0.001 | 3.36 (2.41–4.68) | < 0.001 |
| Oral Cavity | 10.9 (8.5–14.1) | < 0.001 | 7.87 (5.95–10.42) | < 0.001 |
| Hypopharynx | 12.3 (9.2–16.4) | < 0.001 | 6.27 (4.33–9.06) | < 0.001 |
| Larynx | 9.5 (7.4–12.3) | < 0.001 | 6.06 (4.50–8.16) | < 0.001 |
| OC/OP | 10.3 (7.4–14.4) | < 0.001 | 5.22 (3.34–8.16) | < 0.001 |
| Insurance Status | < 0.001 | < 0.001 | ||
| Non-Private | 1 [Ref.] | 1 [Ref.] | ||
| Private | 0.56 (0.52–0.60) | 0.79 (0.71–0.89) | ||
| Income | < 0.001 | Dropped | ||
| <$35,000 | 1 [Ref.] | |||
| ≥$35,000 | 0.75 (0.70–0.81) | |||
| Facility Type | 0.08 | Dropped | ||
| Non-academic | 1 [Ref.] | |||
| Uraban | 0.93 (0.86–1.01) | |||
| City Population | 0.02 | Dropped | ||
| Non-Urban | 1 [Ref.] | |||
| Urban | 0.91 (0.84–0.99) | |||
| Time to PORT (continuous) | 1.01 (1.01–1.01) | < 0.001 | Dropped | |
| RT duration (continuous) | 1.00 (1.00–1.00) | 0.001 | 1.00 (1.00–1.00) | 0.001 |
| Margins Status | < 0.001 | < 0.001 | ||
| Negative | 1 [Ref.] | 1 [Ref.] | ||
| Positive | 1.30 (1.18–1.42) | 1.33 (1.18–1.51) | ||
| pENE Status | < 0.001 | < 0.001 | ||
| Negative | 1 [Ref.] | 1 [Ref.] | ||
| Positive | 1.35 (1.21–1.49) | 1.40 (1.23–1.59) | ||
| Concomitant CRT | 0.03 | 0.04 | ||
| No | 1 [Ref.] | 1 [Ref.] | ||
| Yes | 0.92 (0.85–0.99) | 0.89 (0.79–0.99) | ||
| Surgical Facility Volume | ||||
| LVSF w/ Same RT Facility | 1 [Ref.] | 1 [Ref.] | ||
| LVSF w/Different RT Facility | 0.94 (0.86–1.03) | 0.20 | 0.95 (0.84–1.08) | 0.42 |
| HVSF w/ Same RT Facility | 0.70 (0.63–0.79) | < 0.001 | 0.81 (0.69–0.94) | 0.006 |
| HVSF w/ Different RT Facility | 1.06 (0.94–1.20) | 0.34 | 1.02 (0.87–1.20) | 0.79 |