Table 2.
Comparison of the characteristics of second primary rectal cancer (SPRC) patients receiving radiotherapy (RT) or not.
| NRT-SPRC n = 979 |
RT-SPRC n = 512 |
p-value | |||
|---|---|---|---|---|---|
| n a | n (%) or mean ± SD | n a | n (%) or mean ± SD | ||
| Age at diagnosis | 979 | 74.74 ± 10.29 | 512 | 76.20 ± 9.20 | 0.007 |
| ≤60 | 96 (9.81) | 30 (5.86) | |||
| >60 | 883 (90.19) | 482 (94.14) | |||
| Gender | 979 | 512 | 0.836 | ||
| Male | 632 (64.56) | 327 (63.87) | |||
| Female | 347 (35.44) | 185 (36.13) | |||
| Race | 979 | 512 | 0.178 | ||
| White | 837 (85.50) | 419 (81.84) | |||
| Black | 74 (7.56) | 50 (9.77) | |||
| Other | 68 (6.95) | 43 (8.40) | |||
| Site | 979 | 512 | <0.001 | ||
| Rectum | 714 (72.93) | 416 (81.25) | |||
| Rectosigmoid junction | 265 (27.07) | 96 (18.75) | |||
| Pathological type | 979 | 512 | 0.001 | ||
| Adenocarcinoma | 831 (84.88) | 436 (85.16) | |||
| Mucinous adenocarcinoma | 47 (4.80) | 44 (8.59) | |||
| Other | 101 (10.32) | 32 (6.25) | |||
| Grade | 775 | 413 | 0.43 | ||
| I~II | 632 (81.55) | 326 (78.93) | |||
| III~IV | 143 (18.45) | 87 (21.07) | |||
| Stage | 865 | 428 | 0.045 | ||
| Localized | 439 (50.75) | 206 (48.13) | |||
| Regional | 289 (33.41) | 157 (36.68) | |||
| Distant | 137 (15.84) | 65 (15.19) | |||
| Tumor size | 394 | 239 | 0.017 | ||
| ≤2 cm | 89 (22.59) | 39 (16.32) | |||
| >2 cm, ≤5 | 200 (50.76) | 138 (57.74) | |||
| >5 cm | 105 (26.65) | 62 (25.94) | |||
| Chemotherapy | 979 | 512 | 0.009 | ||
| Yes | 322 (32.89) | 134 (26.17) | |||
| No | 657 (67.11) | 378 (73.83) | |||
| Radiation | 979 | 512 | <0.001 | ||
| Yes | 297 (30.34) | 49 (9.57) | |||
| No | 682 (69.66) | 463 (90.43) | |||
| Surgery | 967 | 504 | 0.151 | ||
| Yes | 735 (76.01) | 366 (72.62) | |||
| No | 232 (23.99) | 138 (27.38) | |||
a
patients with data available.
NRT-SPRC, SPRC without RT; RT-SPRC, SPRC with RT.