Table 3.
Univariate and multivariate Cox regression analysis using the LND as a continuous variable
| Variable | Univariate analysis
|
Multivariate analysis
|
||||
|---|---|---|---|---|---|---|
| HR | 95% CI | P-value | HR | 95% CI | P-value | |
| Age | 1.045 | 1.03–1.06 | <0.001 | 1.049 | 1.032–1.065 | <0.001 |
| Sex | ||||||
| Male | Reference | |||||
| Female | 0.961 | 0.702–1.317 | 0.806 | |||
| Race | ||||||
| White | Reference | Reference | ||||
| Black | 1.22 | 0.811–1.836 | 0.34 | 1.242 | 0.825–1.869 | 0.299 |
| Other | 1.802 | 1.015–3.202 | 0.044 | 2.949 | 1.081–3.513 | 0.026 |
| LNs examined | 0.984 | 0.954–1.015 | 0.303 | |||
| SEER stage | ||||||
| Localized | Reference | Reference | ||||
| Regional | 1.701 | 1.115–2.593 | 0.014 | 1.531 | 0.988–2.375 | 0.057 |
| Distant | 3.839 | 2.578–5.717 | <0.001 | 2.965 | 1.907–4.612 | <0.001 |
| Tumor laterality | ||||||
| Unilateral | Reference | Reference | ||||
| Bilateral | 1.988 | 1.127–3.51 | 0.018 | 1.998 | 1.101–3.624 | 0.023 |
| Year of diagnosis | ||||||
| 1988 | Reference | |||||
| 1989–1997 | 2.836 | 0.387–20.778 | 0.305 | |||
| 1998–2000 | 3.798 | 0.503–28.656 | 0.196 | |||
| 2000–2014 | 3.156 | 0.434–22.957 | 0.256 | |||
| TLND | 1.143 | 1.095–1.193 | <0.001 | 1.098 | 1.046–1.152 | <0.001 |
Abbreviations: HR, hazard ratio; LNs, lymph nodes; LND, lymph node density; SEER, Surveillance, Epidemiology, and End Result; TLND, ten times the LND.