TABLE 1.
Basic characteristics of extrahepatic digestive system cancers and cancer‐free controls before and after matching
| Variables | Unmatched dataset | Matched dataset | ||||
|---|---|---|---|---|---|---|
|
Cancers (n = 4748) No. (%) |
Controls (n = 57499) No. (%) |
p |
Cancers (n = 4605) No. (%) |
Controls (n = 4605) No. (%) |
p | |
| Sex | <0.001 | 0.949 | ||||
| Female | 1824 (38.4) | 27141 (47.2) | 1805 (39.2) | 1801 (39.1) | ||
| Male | 2924 (61.6) | 30358 (52.8) | 2800 (60.8) | 2804 (60.9) | ||
| Age (mean ± SD), years | 59.99±12.32 | 45.01±12.16 | <0.001 | 59.40±12.00 | 58.83±12.96 | 0.026 |
| BMI (kg/m2) | <0.001 | 0.772 | ||||
| <23.0 | 2689 (56.6) | 25408 (44.2) | 2548 (55.3) | 2516 (54.6) | ||
| 23.0–29.9 | 1972 (41.5) | 30232 (52.6) | 1971 (42.8) | 2005 (43.5) | ||
| ≥30.0 | 87 (1.8) | 1859 (3.2) | 86 (1.9) | 84 (1.8) | ||
| Smoker | <0.001 | 0.135 | ||||
| Never | 2916 (61.4) | 43951 (76.4) | 2888 (62.7) | 2958 (64.2) | ||
| Previous/Current | 1832 (38.6) | 13548 (23.6) | 1717 (37.3) | 1647 (35.8) | ||
| Alcohol drinker | <0.001 | 0.535 | ||||
| Never | 3969 (83.6) | 51028 (88.7) | 3842 (83.4) | 3865 (83.9) | ||
| Previous/Current | 779 (16.4) | 6471 (11.3) | 763 (16.6) | 740 (16.1) | ||
| Diabetes mellitus (yes) | 167 (3.5) | 1490 (2.6) | <0.001 | 166 (3.6) | 158 (3.4) | 0.692 |
| Family history of cancers (yes) | 667 (14.0) | 7419 (12.9) | 0.026 | 651 (14.1) | 615 (13.4) | 0.290 |
| HBV markers | ||||||
| HBsAg positive | 397 (8.4) | 4752 (8.3) | 0.837 | 389 (8.4) | 336 (7.3) | 0.044 |
| Anti‐HBs positive | 2754 (58.0) | 37727 (65.6) | <0.001 | 2667 (57.9) | 3022 (65.6) | <0.001 |
| HBeAg positive | 23 (0.5) | 333 (0.6) | 0.464 | 23 (0.5) | 11 (0.2) | 0.059 |
| Anti‐HBe positive | 1488 (31.3) | 16968 (29.5) | 0.008 | 1439 (31.2) | 1461 (31.7) | 0.638 |
| Anti‐HBc positive | 3437 (72.4) | 33763 (58.7) | <0.001 | 3318 (72.1) | 3255 (70.7) | 0.153 |
| Classifications a | <0.001 | 0.057 | ||||
| Group A | 1300 (27.4) | 23669 (41.2) | 1276 (27.7) | 1345 (29.2) | ||
| Group B | 3051 (64.3) | 29078 (50.6) | 2940 (63.8) | 2924 (63.5) | ||
| Group C | 397 (8.4) | 4752 (8.3) | 389 (8.4) | 336 (7.3) | ||
a
(1) Group A characterized by HBsAg–, HBeAg–, anti‐HBe– and anti‐HBc–, without or with anti‐HBs+ (non‐infection and vaccination); (2) Group B referred to HBsAg–/HBeAg–, and at least one of anti‐HBe+or anti‐HBc+, regardless of anti‐HBs+or not (resolved HBV infection); (3) Group C featured with HBsAg+/HBeAg±, regardless of the status of anti‐HBs, anti‐HBe and anti‐HBc (inactive HBsAg carriers and active HBV infection).