Table 1.
(a) Univariable and (b) multivariable comparisons of sociodemographic and clinicopathologic characteristics of patients receiving preoperative chemotherapy and gastrectomy for gastric adenocarcinoma who did and did not receive postoperative chemotherapy
| (a) Characteristic | Overall (n = 3449) n (%) |
No postoperative chemotherapy (n = 2358) n (%) |
Postoperative chemotherapy (n = 1091) n (%) |
p Value | (b) OR | 95% CI | p Value |
|---|---|---|---|---|---|---|---|
| Median age: years (IQR) | 63 (46–79) | 64 (48–80) | 61 (44–78) | <0.001 | 0.985 | (0.975–0.995) | 0.002 |
| Sex | 0.101 | ||||||
| Male | 2308 (66.9) | 1599 (67.8) | 709 (65.0) | Ref | – | – | |
| Female | 1141 (33.1) | 759 (32.2) | 382 (35.0) | 1.021 | (0.867–1.203) | 0.803 | |
| Race | 0.026 | ||||||
| White | 2600 (75.4) | 1787 (75.8) | 813 (74.5) | Ref | – | – | |
| Black | 514 (14.9) | 365 (15.5) | 149 (13.7) | 0.793 | (0.634–0.993) | 0.043 | |
| Asian | 257 (7.5) | 157 (6.7) | 100 (9.2) | 1.192 | (0.898–1.583) | 0.224 | |
| Other | 78 (2.3) | 49 (2.1) | 29 (2.7) | 0.999 | (0.613–1.626) | 0.995 | |
| Year of diagnosis | <0.001 | ||||||
| 2006–2009 | 909 (26.4) | 704 (29.9) | 205 (18.8) | Ref | – | – | |
| 2010–2014 | 2540 (73.6) | 1654 (70.1) | 886 (81.2) | 1.951 | (1.511–2.518) | <0.001 | |
| Insurance status | <0.001 | ||||||
| No insurance | 128 (3.7) | 88 (3.7) | 40 (3.7) | 0.730 | (0.483–1.102) | 0.134 | |
| Private insurance | 1594 (46.2) | 1024 (43.4) | 570 (52.2) | Ref | – | – | |
| Medicare | 1401 (40.6) | 1029 (43.6) | 372 (34.1) | 0.820 | (0.667–1.009) | 0.055 | |
| Medicaid/other government aid | 326 (9.5) | 217 (9.2) | 109 (10.0) | 0.874 | (0.672–1.136) | 0.266 | |
| Charlson-Deyo Comorbidity score | 0.001 | ||||||
| 0 | 2510 (72.8) | 1678 (71.2) | 832 (76.3) | Ref | – | – | |
| 1 | 749 (21.7) | 531 (22.5) | 218 (20.0) | 0.866 | (0.718–1.044) | 0.130 | |
| > 1 | 190 (5.5) | 149 (6.3) | 41 (3.8) | 0.601 | (0.418–0.865) | 0.006 | |
| Surgical procedure | 0.906 | ||||||
| Partial gastrectomy (excluding wedge) | 1221 (35.4) | 829 (35.2) | 392 (35.9) | ||||
| Total gastrectomy | 1736 (50.3) | 1191 (50.5) | 545 (50.0) | ||||
| Extended gastrectomy | 492 (14.3) | 338 (14.3) | 154 (14.1) | ||||
| Primary tumor site | 0.024 | ||||||
| Proximal | 1293 (37.5) | 914 (38.8) | 379 (34.7) | Ref | – | – | |
| Middle | 820 (23.8) | 556 (23.6) | 264 (24.2) | 1.112 | (0.905–1.367) | 0.313 | |
| Distal | 741 (21.5) | 476 (20.2) | 265 (24.3) | 1.355 | (1.096–1.676) | 0.005 | |
| Unspecified | 595 (17.3) | 412 (17.5) | 183 (16.8) | 1.059 | (0.842–1.332) | 0.624 | |
| Facility type | 0.002 | ||||||
| Academic | 1990 (57.7) | 1348 (57.2) | 642 (58.8) | Ref | – | – | |
| Other | 1321 (38.3) | 932 (39.5) | 389 (35.7) | 0.955 | (0.815–1.120) | 0.574 | |
| Unknown | 138 (4.0) | 78 (3.3) | 60 (5.5) | 0.926 | (0.603–1.422) | 0.724 | |
| AJCC tumor classification | 0.006 | ||||||
| T1 | 371 (10.8) | 278 (11.8) | 93 (8.5) | Ref | – | – | |
| T2 | 454 (13.2) | 317 (13.4) | 137 (12.6) | 1.209 | (0.853–1.713) | 0.285 | |
| T3 | 1719 (49.8) | 1136 (48.2) | 583 (53.4) | 1.389 | (0.848–2.276) | 0.192 | |
| T4 | 905 (26.2) | 627 (26.6) | 278 (25.5) | 1.234 | (0.712–2.139) | 0.454 | |
| AJCC nodal classification | 0.061 | ||||||
| NX | 103 (3.0) | 76 (3.2) | 27 (2.5) | ||||
| N0 | 1546 (44.8) | 1091 (46.3) | 455 (41.7) | Ref | – | – | |
| N1 | 678 (19.7) | 456 (19.3) | 222 (20.3) | 1.203 | (0.954–1.518) | 0.118 | |
| N2 | 578 (16.8) | 381 (16.2) | 197 (18.1) | 1.173 | (0.800–1.720) | 0.413 | |
| N3a | 386 (11.2) | 256 (10.9) | 130 (11.9) | 1.035 | (0.680–1.575) | 0.873 | |
| N3b | 158 (4.6) | 98 (4.2) | 60 (5.5) | 1.246 | (0.766–2.028) | 0.375 | |
| AJCC stage (ypTNM)a | 0.008 | ||||||
| I | 590 (17.7) | 431 (19.0) | 159 (15.1) | Ref | – | – | |
| II | 1490 (44.7) | 1020 (44.9) | 470 (44.5) | 0.940 | (0.600–1.472) | 0.786 | |
| III | 1250 (37.5) | 823 (36.2) | 427 (40.4) | 1.003 | (0.513–1.964) | 0.992 | |
| Lymph nodes examined | <0.001 | ||||||
| < 15 | 1172 (34.0) | 852 (36.1) | 320 (29.3) | Ref | – | – | |
| ≥ 15 | 2277 (66.0) | 1506 (63.9) | 771 (70.7) | 1.215 | (1.025–1.440) | 0.025 | |
| Grade | 0.003 | ||||||
| Well-/moderately differentiated | 901 (26.1) | 655 (27.8) | 246 (22.5) | Ref | – | – | |
| Poorly differentiated/undifferentiated | 2272 (65.9) | 1511 (64.1) | 761 (69.8) | 1.165 | (0.969–1.399) | 0.104 | |
| Undetermined/unknown | 276 (8.0) | 192 (8.1) | 84 (7.7) | 1.078 | (0.786–1.478) | 0.641 | |
| Lymphovascular invasion | <0.001 | ||||||
| Not present | 1174 (34.0) | 779 (33.0) | 395 (36.2) | Ref | – | – | |
| Present | 824 (23.9) | 529 (22.4) | 295 (27.0) | 0.956 | (0.774–1.182) | 0.679 | |
| Unknown | 1451 (42.1) | 1050 (44.5) | 401 (36.8) | 1.051 | (0.838–1.318) | 0.666 | |
| Unplanned readmission | 170 (4.9) | 122 (5.2) | 48 (4.4) | 0.329 | |||
| Margin status | 0.608 | ||||||
| R0 | 3194 (92.6) | 2180 (92.5) | 1014 (92.9) | ||||
| R1 | 255 (7.4) | 178 (7.5) | 77 (7.1) | Favors no chemo | ←1→ | Favors chemo |
OR odds ratio, CI confidence interval, IQR interquartile range, AJCC American Joint Committee on Cancer
aPatients labeled as T4 with no subclassification or NX were excluded