Table. Univariate and Multivariable Cox Analysis of Recurrence-Free Survival by Clinicopathologic Variables and ctDNA Status and CEA Status at POM1.
| Variable | Univariate analysis | Multivariable analysis | ||
|---|---|---|---|---|
| HR (95% CI) | P value | HR (95% CI) | P value | |
| Age (older than or equal to mean vs younger than mean) | 1.0 (0.6-1.7) | .96 | NA | NA |
| Sex (male vs female) | 1.0 (0.6-1.8) | .98 | NA | NA |
| Primary tumor site (left vs right) | 1.2 (0.6-2.3) | .64 | NA | NA |
| Histologic type (mucinous adenocarcinoma or SRCC vs adenocarcinoma) | 2.1 (1.1-4.1) | .02 | 1.6 (0.7-3.6) | .29 |
| Tumor differentiation (well moderated vs poor) | 0.5 (0.3-0.9) | .03 | 0.9 (0.4-1.7) | .71 |
| T stage (T4 vs T1, T2, or T3) | 3.1 (1.7-5.6) | <.001 | 1.3 (0.7-2.7) | .43 |
| Nodal involvement (N1-N2 vs N0) | 3.6 (1.9-7.0) | <.001 | 1.4 (0.6-3.1) | .43 |
| Invasion (yes vs no) | ||||
| Vascular | 2.7 (1.5-4.9) | .001 | 1.2 (0.6-2.6) | .60 |
| Perineural | 2.6 (1.5-4.6) | <.001 | 1.2 (0.6-2.3) | .62 |
| MMR status (proficient vs efficient) | 1.3 (0.3-5.4) | .71 | NA | NA |
| At POM1 (positive vs negative) | ||||
| CEA | 7.5 (3.9-14.0) | <.001 | 5.5 (2.3-13.0) | <.001 |
| ctDNA | 17.0 (8.7-34.0) | <.001 | 17.0 (8.2-34.0) | <.001 |
Abbreviations: CEA, carcinoembryonic antigen; ctDNA, circulating tumor DNA; HR, hazard ratio; MMR, mismatch repair; NA, not applicable; POM1, postoperative month 1; SRCC, signet-ring cell carcinoma.