Table 1.
Clinicopathologic features of the study population undergoing surgery alone and receiving adjuvant S-1 plus oxaliplatin chemotherapy before and after propensity score-matching n (%)
| Variable |
Before PSM (n = 807) |
After PSM (n = 351) |
||||
| Surgery alone (n = 683) | Adjuvant SOX (n = 124) | P value | Surgery alone (n = 234) | Adjuvant SOX (n = 117) | P value | |
| Age at diagnosis (yr) | 0.099 | 0.443 | ||||
| < 35 | 9 (1.32) | 3 (2.42) | 3 (1.28) | 0 (0.00) | ||
| 35-60 | 303 (44.36) | 66 (53.23) | 118 (50.43) | 62 (52.99) | ||
| > 60 | 371 (54.32) | 55 (44.35) | 113 (48.29) | 55 (47.01) | ||
| Gender | 0.83 | 1 | ||||
| Female | 177 (25.92) | 31 (25.00) | 60 (25.64) | 30 (25.64) | ||
| Male | 506 (74.08) | 93 (75.00) | 174 (74.36) | 87 (74.36) | ||
| Tumor location | 0.063 | 0.424 | ||||
| None-Cardia cancer | 425 (62.23) | 88 (70.97) | 152 (64.96) | 81 (69.23) | ||
| Cardia cancer | 258 (37.77) | 36 (29.03) | 82 (35.04) | 36 (30.77) | ||
| Tumor grade | 0.006 | 0.725 | ||||
| Moderate to well | 50 (7.32) | 4 (3.23) | 14 (5.98) | 4 (3.42) | ||
| Moderate | 171 (25.04) | 21 (16.94) | 36 (15.38) | 21 (17.95) | ||
| Poor to moderate | 427 (62.52) | 97 (78.23) | 180 (76.92) | 90 (76.92) | ||
| Early cancer or not reported | 35 (5.12) | 2 (1.61) | 4 (1.71) | 2 (1.71) | ||
| Pathological stage | < 0.001 | 0.604 | ||||
| IB1 | 302 (44.22) | 8 (6.45) | 20 (8.55) | 8 (6.84) | ||
| II | 127 (18.59) | 29 (23.39) | 48 (20.51) | 29 (24.79) | ||
| III | 254 (37.19) | 87 (70.16) | 166 (70.94) | 80 (68.38) | ||
| Lymphatic and venous invasion | < 0.001 | 0.574 | ||||
| No | 573 (83.89) | 86 (69.35) | 155 (66.24) | 81 (69.23) | ||
| Yes | 110 (16.11) | 38 (30.65) | 79 (33.76) | 36 (30.77) | ||
| Perineural invasion | 0.437 | 0.754 | ||||
| No | 606 (88.73) | 107 (86.29) | 197 (84.19) | 100 (85.47) | ||
| Yes | 77 (11.27) | 17 (13.71) | 37 (15.81) | 17 (14.53) | ||
1
Patients of stage IB (pT2N0M0) without high-risk features including poorly differentiated or higher grade cancer, lymphovascular invasion, neural invasion, or < 50 years of age were not included. SOX: S-1 plus oxaliplatin; PSM: Propensity score-matching.