Table 1.
Baseline Characteristics of the Patients in the Per-Protocol Analysis.*
| Characteristic | Dissection (N = 824) | Observation (N = 931) |
|---|---|---|
| Sex — no. (%) | ||
| Female | 346 (42.0) | 382 (41.0) |
| Male | 478 (58.0) | 549 (59.0) |
| Age — yr | ||
| Mean | 52.5±12.9 | 53.2±13.6 |
| Median (range) | 53.7 (18–76) | 54.9 (19–76) |
| Smoking status — no./total no. (%)† | ||
| Never | 463/803 (57.7) | 522/907 (57.6) |
| Former | 193/803 (24.0) | 227/907 (25.0) |
| Current | 147/803 (18.3) | 158/907 (17.4) |
| Breslow thickness | ||
| Mean — mm | 2.76±2.34 | 2.70±2.11 |
| Median (range) — mm | 2.10 (0.34–28.0) | 2.10 (0.35–30.0) |
| <1.50 mm — no. (%) | 237 (28.8) | 257 (27.6) |
| 1.50–3.50 mm — no. (%) | 404 (49.0) | 462 (49.6) |
| >3.50 mm — no. (%) | 183 (22.2) | 212 (22.8) |
| Primary site — no. (%) | ||
| Arm or leg | 327 (39.7) | 382 (41.0) |
| Head or neck | 113 (13.7) | 128 (13.7) |
| Trunk | 384 (46.6) | 421 (45.2) |
| Ulceration — no. (%) | ||
| Absent | 508 (61.7) | 578 (62.1) |
| Present | 316 (38.3) | 353 (37.9) |
| No. of positive sentinel lymph nodes — no. of patients (%) | ||
| 0, RT-PCR–positive | 80 (9.7) | 111 (11.9) |
| 1 | 596 (72.3) | 643 (69.1) |
| 2 | 121 (14.7) | 162 (17.4) |
| 3 | 18 (2.2) | 10 (1.1) |
| >3 | 9 (1.1) | 5 (0.5) |
| Diameter of sentinel-lymph-node metastasis — mm‡ | ||
| Mean | 1.07 | 1.11 |
| Median | 0.61 | 0.67 |
| Interquartile range | 0.27–1.32 | 0.23–1.38 |
| Size of sentinel-lymph-node metastasis — no. of patients/total no. (%) | ||
| <0.1 mm | 45/566 (8.0) | 65/623 (10.4) |
| 0.1–1.0 mm | 333/566 (58.8) | 343/623 (55.1) |
| >1.0 mm | 188/566 (33.2) | 215/623 (34.5) |
| Received adjuvant therapy — no./total no. (%)§ | 66/814 (8.1) | 60/922 (6.5) |
*
Plus–minus values are means ±SD. There were no significant between-group differences in the characteristics listed here. Percentages may not total 100 because of rounding. RT-PCR denotes reverse-transcriptase polymerase chain reaction.
†
Data were missing for 21 patients in the dissection group and 24 patients in the observation group.
‡
The sentinel-node metastasis burden, the longest diameter of the largest tumor deposit, was not available for 178 patients in the dissection group and 197 patients in the observation group.
§
Data were not available for 10 patients in the dissection group and 9 patients in the observation group.