Table 2. Univariable and Multivariable Cox Regression Analyses of Factors Associated with Disease-Free Survival in the Matched Data Sets of Patients With AC vs Patients With NEC.
| Clinicopathological features | Univariable analysis | Multivariable analysis Ia | Multivariable analysis IIb | |||
|---|---|---|---|---|---|---|
| HR (95% CI) | P value | HR (95% CI)c | P value | HR (95% CI)c | P value | |
| Age, per 1-y increase | 1.02 (1.01-1.03) | <.001 | 1.02 (1.01-1.03) | <.001 | 1.02 (1.01-1.03) | <.001 |
| Sex | ||||||
| Men | 1 [Reference] | .03 | NA | .36 | NA | .36 |
| Women | 0.83 (0.71-0.99) | NA | NA | |||
| Center volume | ||||||
| Low | 1 [Reference] | .26 | NA | NA | NA | NA |
| High | 0.77 (0.49-1.21) | NA | NA | NA | NA | |
| Tumor location | ||||||
| Lower | 1 [Reference] | NA | NA | NA | NA | NA |
| Middle | 1.10 (0.91-1.33) | .32 | NA | .14 | NA | .14 |
| Upper | 1.21 (1.04-1.42) | .02 | NA | .50 | NA | .50 |
| Mix | 1.59 (1.29-1.96) | <.001 | NA | .45 | NA | .45 |
| Tumor size, per 1-cm increase | 1.16 (1.14-1.19) | <.001 | 1.06 (1.03-1.09) | <.001 | 1.06 (1.03-1.09) | <.001 |
| Lymph nodes examined, per 1-unit increase | 1.00 (0.99-1.00) | .25 | NA | NA | NA | NA |
| No. of metastatic lymph nodes, per 1-unit increase | 1.06 (1.06-1.07) | <.001 | 1.05 (1.04-1.06) | <.001 | 1.05 (1.04-1.06) | <.001 |
| Invasion | ||||||
| Vascular | 1.72 (1.50-1.96) | <.001 | NA | .93 | NA | .93 |
| Neural | 1.72 (1.51-1.97) | <.001 | 1.24 (1.08-1.43) | .002 | 1.24 (1.08-1.43) | .002 |
| T stage | ||||||
| T1-T2 | 1 [Reference] | <.001 | 1 [Reference] | <.001 | 1 [Reference] | <.001 |
| T3-T4 | 3.84 (3.02-4.90) | 2.00 (1.54-2.59) | 2.00 (1.54-2.59) | |||
| N stage | ||||||
| N0 | 1 [Reference] | <.001 | 1 [Reference] | <.001 | 1 [Reference] | <.001 |
| N1-N3 | 2.91 (2.40-3.54) | 1.51 (1.22-1.86) | 1.51 (1.22-1.86) | |||
| Type of gastrectomy | ||||||
| Total | 1 [Reference] | <.001 | NA | .61 | NA | .61 |
| <Total | 0.70 (0.61-0.80) | NA | NA | |||
| Received neoadjuvant chemotherapy | ||||||
| No | 1 [Reference] | <.001 | 1 [Reference] | .001 | 1 [Reference] | .001 |
| Yes | 1.92 (1.36-2.72) | 1.78 (1.26-2.53) | 1.78 (1.26-2.53) | |||
| Received adjuvant chemotherapy | ||||||
| No | 1 [Reference] | NA | NA | NA | NA | NA |
| Yes | 1.12 (0.97-1.29) | .13 | NA | NA | NA | NA |
| Unknown | 0.96 (0.63-1.47) | .86 | NA | NA | NA | NA |
| Pathological type I | ||||||
| AC | 1 [Reference] | <.001 | 1 [Reference] | <.001 | NA | NA |
| NEC | 1.36 (1.17-1.57) | 1.64 (1.40-1.93) | NA | NA | ||
| Pathological type II | ||||||
| Poorly differentiated AC | 1 [Reference] | NA | NA | NA | 1 [Reference] | NA |
| Well or moderately differentiated AC | 0.72 (0.62-0.84) | <.001 | NA | NA | 1.00 (0.85-1.17) | .99 |
| NEC | 1.18 (1.01-1.38) | .04 | NA | NA | 1.64 (1.38-1.96) | <.001 |
Abbreviations: AC, adenocarcinoma; HR, hazard ratio: NA, not applicable; NEC, neuroendocrine carcinoma.
a
Multivariable analysis I included pathological type I and excluded pathological type II.
b
Multivariable analysis II included pathological type II, excluding pathological type I.
c
Because multivariate analyses used a forward likelihood ratio method, there are no corresponding HR data for factors with P > .05.