Table 1. Characteristics of study populations and tumors.
| American cohort | Chinese cohort | P-value | |
|---|---|---|---|
| n = 159 | n = 113 | ||
| Area of recruitment | Baltimore, MD | Hong Kong, China | |
| Age at enrollment (y) | |||
| Mean (SD) | 66.2 (11.3) | 55.8 (14.9) | P<0.0001 |
| Range | 32–87 | 32–84 | |
| Gender, no. (%) | P = 0.0003 | ||
| Male | 113 (71.1) | 56 (49.6) | |
| Female | 46 (28.9) | 57 (50.4) | |
| Tumor location a , no. (%) | P = 0.0014 | ||
| Distal | 48 (58.5) | 90 (79.6) | |
| Proximal | 34 (41.5) | 23 (20.4) | |
| Adenocarcinoma histology, no. (%) | NS | ||
| Adenocarcinoma | 142 (89.3) | 105 (92.9) | |
| Mucinous adenocarcinoma | 16 (10.1) | 7 (6.2) | |
| Adenosquamous | 1 (0.6) | 0 (0) | |
| Signet ring cell and mucinous | 0 (0) | 1 (0.8) | |
| TP53 status b , no. (%) | NS | ||
| Wild-type TP53 | 39 (49.4) | 52 (48.2) | |
| Mutant TP53 | 40 (50.6) | 56 (51.8) | |
| TNM staging c , no. (%) | NS | ||
| I | 21 (13.3) | 9 (8.0) | |
| II | 54 (34.2) | 37 (32.7) | |
| III | 65 (41.1) | 48 (42.5) | |
| IV | 18 (11.4) | 19 (16.8) |
a Distal includes tumors located in or distal to the descending colon. Proximal tumors include tumors in or proximal to the splenic flexure. Tumor location was available for all cases in the Chinese cohort and 82 cases in the American cohort.
b TP53 status was evaluated by immunohistochemistry of Formalin-Fixed Paraffin-Embedded (FFPE) tissues. Patients with available data were included.
c For one patient in the American cohort, it was unclear if that patient had stage III or stage IV colon cancer, therefore this patient was removed from analyses stratifying by TNM stage.