Table 2.
Propensity-matched clinical characteristics of PTC patients with no extrathyroidal extension versus with extrathyroidal extensions.
| Characteristics | All data | SMD | After IPTW | SMD | After SMRW | SMD | After PSM | SMD | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No ETE | ETE | No ETE | ETE | No ETE | ETE | No ETE | ETE | |||||
| n = 83,124 | n = 25,302 | n = 83,142 | n = 24,953 | n = 83,199 | n = 25,302 | n = 22,904 | n = 22,904 | |||||
| Age at diagnosis | 0.195 | 0.04 | 0.024 | 0.011 | ||||||||
| ≤19 (%) | 1,323 (1.6) | 605 (2.4) | 1,476 (1.8) | 447 (1.8) | 1,979 (2.4) | 605 (2.4) | 535 (2.3) | 507 (2.2) | ||||
| 20–54 (%) | 51,539 (62.0) | 14,756 (58.3) | 51,065 (61.4) | 15,804 (63.3) | 49,508 (59.5) | 14,756 (58.3) | 13,972 (61.0) | 14,069 (61.4) | ||||
| ≥55 (%) | 30,262 (36.4) | 9,941 (39.3) | 30,601 (36.8) | 8,702 (34.9) | 31,712 (38.1) | 9,941 (39.3) | 8,397 (36.7) | 8,328 (36.4) | ||||
| Sex | 0.135 | 0.007 | 0.008 | 0.001 | ||||||||
| Female (%) | 65,541 (78.8) | 18,380 (72.6) | 64,423 (77.5) | 19,406 (77.8) | 60,749 (73.0) | 18,380 (72.6) | 17,077 (74.6) | 17,083 (74.6) | ||||
| Male (%) | 17,583 (21.2) | 6,922 (27.4) | 18,719 (22.5) | 5,547 (22.2) | 22,450 (27.0) | 6,922 (27.4) | 5,827 (25.4) | 5,821 (25.4) | ||||
| Multifocality | 0.186 | 0.038 | 0.018 | 0.002 | ||||||||
| Solitary (%) | 50,998 (61.4) | 11,918 (47.1) | 48,072 (57.8) | 13,956 (55.9) | 38,458 (46.2) | 11,918 (47.1) | 11,030 (48.2) | 11,011 (48.1) | ||||
| Multifocal (%) | 32,126 (38.6) | 13,384 (52.9) | 35,070 (42.2) | 10,997 (44.1) | 44,741 (53.8) | 13,384 (52.9) | 11,874 (51.8) | 11,893 (51.9) | ||||
| Tumor size | 0.535 | 0.026 | 0.011 | 0.007 | ||||||||
| ≤1 cm (%) | 41,326 (49.7) | 4,375 (17.3) | 35011 (42.1) | 10,195 (40.9) | 14,266 (17.1) | 4,375 (17.3) | 4,340 (18.9) | 4,366 (19.1) | ||||
| ≤2 cm (%) | 22,785 (27.4) | 8,809 (34.8) | 24323 (29.3) | 7,481 (30.0) | 29,376 (35.3) | 8,809 (34.8) | 8,602 (37.6) | 8,598 (37.5) | ||||
| ≤4 cm (%) | 14,673 (17.7) | 8,284 (32.7) | 17577 (21.1) | 5,346 (21.4) | 27,115 (32.6) | 8,284 (32.7) | 7,247 (31.6) | 7,187 (31.4) | ||||
| >4 cm (%) | 4,340 (5.2) | 3,834 (15.2) | 6231 (7.5) | 1,931 (7.7) | 12,442 (15.0) | 3,834 (15.2) | 2,715 (11.9) | 2,753 (12.0) | ||||
| N category | 0.577 | 0.014 | 0.001 | 0.006 | ||||||||
| N0 (%) | 69,877 (84.1) | 13,524 (53.5) | 63,953 (76.9) | 19,041 (76.3) | 44,491 (53.5) | 13,524 (53.5) | 13,532 (59.1) | 13,462 (58.8) | ||||
| N1 (%) | 13,247 (15.9) | 11,778 (46.5) | 19,189 (23.1) | 5,912 (23.7) | 38,708 (46.5) | 11,778 (46.5) | 9,372 (40.9) | 9,442 (41.2) | ||||
| Metastasis | 0.218 | 0.004 | 0.006 | 0.011 | ||||||||
| None (%) | 82,795 (99.6) | 24,623 (97.3) | 82,374 (99.1) | 24,714 (99.0) | 80,989 (97.3) | 24,623 (97.3) | 22,636 (98.8) | 22,655 (98.9) | ||||
| Distant LN (%) | 41 (0.0) | 59 (0.2) | 81 (0.1) | 24 (0.1) | 213 (0.3) | 59 (0.2) | 34 (0.1) | 26 (0.1) | ||||
| Distant metastasis (%) | 288 (0.3) | 620 (2.5) | 687 (0.8) | 215 (0.9) | 1,997 (2.4) | 620 (2.5) | 234 (1.0) | 223 (1.0) | ||||
| Surgery | 0.3 | 0.057 | 0.015 | 0.012 | ||||||||
| Near TT/TT (%) | 69,267 (83.3) | 23,866 (94.3) | 71,469 (86.0) | 21,871 (87.6) | 78,705 (94.6) | 23,866 (94.3) | 21,553 (94.1) | 21,515 (93.9) | ||||
| Lobectomy (%) | 12,052 (14.5) | 1,206 (4.8) | 10,134 (12.2) | 2,751 (11.0) | 3,831 (4.6) | 1,206 (4.8) | 1,167 (5.1) | 1,182 (5.2) | ||||
| Partial (%) | 686 (0.8) | 105 (0.4) | 595 (0.7) | 139 (0.6) | 294 (0.4) | 105 (0.4) | 89 (0.4) | 95 (0.4) | ||||
| No surgery (%) | 1,119 (1.3) | 125 (0.5) | 944 (1.1) | 192 (0.8) | 369 (0.4) | 125 (0.5) | 95 (0.4) | 112 (0.5) | ||||
| LN surgery | 0.33 | 0.028 | 0.001 | 0.005 | ||||||||
| None (%) | 44,177 (53.1) | 7,869 (31.1) | 39,896 (48.0) | 11,624 (46.6) | 25,829 (31.0) | 7,869 (31.1) | 7,845 (34.3) | 7,796 (34.0) | ||||
| Partial (%) | 38,947 (46.9) | 17,433 (68.9) | 43,246 (52.0) | 13,329 (53.4) | 57,370 (69.0) | 17,433 (68.9) | 15,059 (65.7) | 15,108 (66.0) | ||||
SMD assessed the balance between no extrathyroidal extension and all extrathyroidal extensions.
PTC, papillary thyroid cancer; ETE, extrathyroidal extension; LN, lymph node; TT, total thyroidectomy; SMD, standardized mean difference.