TABLE 2.
Univariable and multivariable analysis of overall survival
| No. of events/patients | Median OS, months (95% CI) | Log‐rank P‐value | Univariable | Multivariable | |||
|---|---|---|---|---|---|---|---|
| Hazard ratio (95% CI) | Cox model P‐value | Hazard ratio (95% CI) | Cox model P‐value | ||||
| All patients | 111/165 | 19.7 (16.9, 23.7) | 98/146 | ||||
| Age at surgery (years) | |||||||
| <65 | 66/97 | 19.7 (16.9, 24.4) | 1 | ||||
| ≥65 | 45/68 | 20.1 (14.1, 24.9) | .389 | 1.18 (0.81, 1.74) | .392 | ||
| Gender | |||||||
| Male | 59/91 | 19.7 (15.5, 24.4) | 1 | ||||
| Female | 52/74 | 20.0 (16.8, 31.0) | .463 | 0.87 (0.60, 1.26) | .463 | ||
| Race | |||||||
| Chinese | 93/128 | 20.1 (17.4, 24.1) | 1 | ||||
| Non‐Chinese | 18/36 | 13.5 (10.6, 31.5) | .198 | 1.40 (0.84, 2.33) | .216 | ||
| Smoking status | |||||||
| Never | 58/86 | 21.4 (17.9, 31.0) | 1 | ||||
| Former | 21/30 | 15.7 (12.8, 19.6) | 1.73 (1.04, 2.88) | ||||
| Current | 6/10 | 31.6 (24.9, UD) | .027 | 0.58 (0.25, 1.36) | .032 | ||
| Alcohol consumption | |||||||
| Never | 64/96 | 20.0 (17.2, 28.2) | 1 | ||||
| Former | 7/9 | 12.3 (6.9, 28.8) | 1.70 (0.77, 3.73) | ||||
| Current | 14/19 | 26.4 (16.9, 36.1) | .406 | 1.02 (0.57, 1.84) | .465 | ||
| Charlson comorbidities index | |||||||
| 1–2 | 46/63 | 19.7 (15.4, 28.8) | 1 | ||||
| >2 | 65/102 | 19.7 (15.7, 23.7) | .463 | 1.16 (0.78, 1.71) | .462 | ||
| Tumor site | |||||||
| Head involved | 74/121 | 21.1 (17.9, 24.9) | 1 | 1 | |||
| Head not involved | 37/44 | 15.4 (11.4, 24.4) | .031 | 1.54 (1.04, 2.29) | .037 | 1.59 (1.02, 2.48) | .046 |
| AJCC TNM stage | |||||||
| I | 15/21 | 23.7 (11.4, 50.2) | 1 | ||||
| II | 90/135 | 19.6 (15.7, 23.7) | 1.16 (0.67, 2.02) | ||||
| III | 6/9 | 26.9 (8.9, UD) | .730 | 0.89 (0.34, 2.31) | .719 | ||
| T stage | |||||||
| T1/T2 | 26/34 | 19.7 (11.4, 30.2) | 1 | ||||
| T3/T4 | 85/131 | 19.7 (16.6, 24.4) | .505 | 0.86 (0.55, 1.34) | .511 | ||
| N stage | |||||||
| N0 | 42/69 | 28.8 (20.4, 45.4) | 1 | ||||
| N1 | 68/95 | 15.5 (13.2, 19.7) | .002 | 1.84 (1.24, 2.72) | .002 | ||
| Histological grade | |||||||
| Well/moderately differentiated | 95/142 | 21.1 (17.4, 24.9) | 1 | 1 | |||
| Poorly differentiated/Undifferentiated | 15/21 | 11.2 (7.6, 20.0) | .005 | 2.15 (1.24, 3.74) | .013 | 1.86 (1.02, 3.38) | .058 |
| Type of surgery | |||||||
| Whipples operation or PPPD | 77/121 | 20.1 (17.4, 24.1) | 1 | ||||
| Pancreatectomy, distal or subtotal | 29/37 | 17.6 (11.4, 31.6) | 1.29 (0.84, 1.98) | ||||
| Pancreatectomy, total | 3/4 | 4.3 (3.1, UD) | 7.24 (2.22, 23.60) | ||||
| Pancreatectomy, NOS | 2/3 | 14.2 (14.2, UD) | .002 | 1.31 (0.32, 5.37) | .057 | ||
| Resection margins | |||||||
| R0 | 52/80 | 19.7 (16.9, 26.9) | 1 | ||||
| R1 | 59/85 | 19.7 (14.2, 24.1) | .612 | 1.10 (0.76, 1.60) | .611 | ||
| Perineural invasion | |||||||
| No | 7/14 | 50.2 (17.2, UD) | 1 | 1 | |||
| Yes | 94/135 | 19.1 (15.5, 22.6) | .013 | 2.62 (1.20, 5.73) | .006 | 2.36 (1.07, 5.23) | .018 |
| Lymphovascular invasion | |||||||
| No | 54/80 | 23.7 (17.7, 35.4) | 1 | ||||
| Yes | 42/62 | 16.6 (11.7, 20.1) | .042 | 1.52 (1.01, 2.29) | .045 | ||
| Lymph node ratio | |||||||
| 0 | 38/64 | 31.0 (20.1, 45.4) | 1 | 1 | |||
| >0–0.3 | 49/70 | 17.9 (14.1, 22.0) | 1.68 (1.09, 2.58) | 1.58 (1.00, 2.49) | |||
| >0.3 | 20/26 | 12.3 (7.5, 19.6) | <.001 | 3.06 (1.75, 5.37) | .001 | 3.36 (1.83, 6.16) | .001 |
| Tumor size (largest diameter) (cm) | |||||||
| ≤3 | 50/78 | 23.7 (17.9, 28.8) | 1 | ||||
| >3 | 51/69 | 14.1 (11.5, 21.1) | .017 | 1.61 (1.09, 2.38) | .018 | ||
| Posterior margins involved | |||||||
| No | 68/102 | 19.7 (15.7, 26.4) | 1 | ||||
| Yes | 24/36 | 18.5 (10.8, 31.6) | .797 | 1.06 (0.67, 1.70) | .798 | ||
| Adjuvant treatment | |||||||
| None | 48/76 | 15.7 (11.7, 26.9) | 1 | ||||
| Chemotherapy only | 19/33 | 23.8 (19.1, 31.5) | 0.74 (0.43, 1.26) | ||||
| Chemoradiotherapy | 43/55 | 20.1 (15.7, 28.2) | .528 | 0.89 (0.59, 1.35) | .520 | ||
| Pre‐op CEA (ng/ml) | |||||||
| ≤5 | 27/44 | 22.0 (17.6, 44.6) | 1 | ||||
| >5 | 28/34 | 14.1 (10.0, 24.4) | .110 | 1.54 (0.90, 2.61) | .114 | ||
| Post‐op CEA (ng/ml) | |||||||
| ≤5 | 27/34 | 21.8 (14.7, 30.2) | 1 | ||||
| >5 | 6/7 | 21.4 (3.1, UD) | .330 | 1.55 (0.64, 3.80) | .356 | ||
| Pre‐op CA19‐9 (U/ml) | |||||||
| ≤75 | 13/28 | 55.5 (14.0, 74.4) | 1 | ||||
| >75 | 51/64 | 19.1 (15.3, 22.0) | .008 | 2.39 (1.23, 4.63) | .005 | ||
| Post‐op CA19‐9 (U/ml) | |||||||
| ≤75 | 48/72 | 22.6 (18.5, 30.2) | 1 | ||||
| >75 | 22/27 | 13.2 (8.4, 19.4) | <.001 | 2.61 (1.56, 4.38) | .001 | ||
| Pre‐op albumin (g/L) | |||||||
| >35 | 38/54 | 22.0 (14.2, 31.6) | 1 | ||||
| ≤35 | 50/77 | 17.9 (14.1, 23.7) | .870 | 1.04 (0.68, 1.58) | .869 | ||
| Post‐op albumin (g/L) | |||||||
| >35 | 11/17 | 24.4 (17.6, 36.0) | 1 | ||||
| ≤35 | 83/122 | 18.5 (14.7, 22.6) | .300 | 1.39 (0.74, 2.62) | .283 | ||
| Pre‐op NLR | |||||||
| ≤5 | 77/109 | 19.1 (15.4, 26.4) | 1 | ||||
| >5 | 16/27 | 19.4 (12.8, 24.1) | .363 | 1.29 (0.74, 2.24) | .377 | ||
| Post‐op NLR | |||||||
| ≤5 | 14/18 | 22.6 (13.2, 50.0) | 1 | ||||
| >5 | 83/124 | 19.4 (15.4, 24.1) | .861 | 1.05 (0.60, 1.86) | .861 | ||
Abbreviations: NLR, neutrophil‐lymphocyte ratio; PPPD, pylori preserving pancreaticoduodenectomy; UD, undefined.
Note: For the multivariable analysis, only variables with less than 10% missing data were considered in the forward selection procedure. The criterion for variable addition was P < .10.