Table 1:
Patient characteristics and outcomes before and after propensity score matching – MIS vs. Thoracotomy
| Before matching (n = 1 303) |
After matching (n = 676) |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| MIS | Thoracotomy | MIS | Thoracotomy | |||||||
| n = 607 (%) | n = 696 (%) | n = 338 (%) | n = 338 (%) | |||||||
| Clinicopathologic variables | ASMD | ASMD | ||||||||
| Period of surgery | 0.702 | 0.091 | ||||||||
| 2002–2005 | 120 | (20) | 323 | (46) | 100 | (30) | 104 | (31) | ||
| 2006–2009 | 210 | (35) | 243 | (35) | 126 | (37) | 136 | (40) | ||
| 2010–2013 | 277 | (46) | 130 | (19) | 112 | (33) | 98 | (29) | ||
| Age at surgery (year) | 73 | (69–78) | 72 | (68–77) | 0.079 | 72 | (68–77) | 72 | (68–78) | 0.012 |
| Sex | 0.134 | 0.048 | ||||||||
| Female | 363 | (60) | 370 | (53) | 185 | (55) | 193 | (57) | ||
| Male | 244 | (40) | 326 | (47) | 153 | (45) | 145 | (43) | ||
| Smoking | 0.116 | 0.040 | ||||||||
| Never | 112 | (18) | 101 | (15) | 53 | (16) | 58 | (17) | ||
| Former | 435 | (72) | 513 | (74) | 247 | (73) | 243 | (72) | ||
| Current | 60 | (10) | 82 | (12) | 38 | (11) | 37 | (11) | ||
| COPD history | 109 | (18) | 170 | (24) | 0.156 | 66 | (20) | 73 | (22) | 0.051 |
| CVD history | 116 | (19) | 152 | (22) | 0.068 | 75 | (22) | 71 | (21) | 0.029 |
| DM history | 80 | (13) | 88 | (13) | 0.016 | 49 | (14) | 42 | (12) | 0.061 |
| BMI | 27 | (23–30) | 27 | (24–30) | 0.066 | 27 | (24–30) | 27 | (24–30) | 0.029 |
| Serum creatinine (mg/dL) | 1.0 | (0.9–1.2) | 1.1 | (0.9–1.2) | 0.107 | 1.1 | (0.9–1.3) | 1.1 | (0.9–1.2) | 0.017 |
| ppoFEV1 (%) (N =1 281) | 73 | (63–85) | 68 | (55–80) | 0.360 | 70 | (61–82) | 72 | (59–81) | 0.039 |
| ppoDLCO (%) (N=1 240) | 65 | (55–76) | 61 | (50–73) | 0.268 | 63 | (53–74) | 62 | (52–77) | 0.034 |
| Resected lobe | 0.199 | 0.093 | ||||||||
| RUL | 251 | (41) | 244 | (35) | 124 | (37) | 128 | (38) | ||
| RML | 35 | (6) | 44 | (6) | 18 | (5) | 17 | (5) | ||
| RLL | 92 | (15) | 139 | (20) | 56 | (17) | 64 | (19) | ||
| LUL | 154 | (25) | 155 | (22) | 95 | (28) | 83 | (25) | ||
| LLL | 75 | (12) | 114 | (16) | 45 | (13) | 46 | (14) | ||
| Histologic subtypes | 0.426 | 0.063 | ||||||||
| Adenocarcinoma | 513 | (85) | 466 | (67) | 270 | (80) | 275 | (81) | ||
| Squamous | 72 | (12) | 182 | (26) | 53 | (16) | 46 | (14) | ||
| Adenosquamous | 12 | (2) | 18 | (3) | 8 | (2) | 9 | (3) | ||
| Large | 8 | (1) | 23 | (3) | 7 | (2) | 8 | (2) | ||
| Pleomorphic | 2 | (<1) | 7 | (1) | 0 | (0) | 0 | (0) | ||
| Pathologic size (cm) | 2.0 | (1.5–2.8) | 3.0 | (2.0–4.2) | 0.639 | 2.2 | (1.7–3.0) | 2.3 | (1.6–3.3) | 0.090 |
| p-Stage | 0.400 | 0.034 | ||||||||
| I | 491 | (81) | 441 | (63) | 257 | (76) | 252 | (75) | ||
| II | 77 | (13) | 162 | (23) | 53 | (16) | 56 | (17) | ||
| III | 39 | (6) | 93 | (13) | 28 | (8) | 30 | (9) | ||
| Adjuvant therapy (N = 1 275) | 0.173 | 0.047 | ||||||||
| No | 521 | (87) | 549 | (81) | 283 | (84) | 277 | (82) | ||
| Yes | 76 | (13) | 129 | (19) | 55 | (16) | 61 | (18) | ||
| Outcomes | P | |||||||||
| Length of stay (day) | 4 | (3–6) | 5 | (4–8) | 4 | (3–5) | 5 | (4–7) | <0.001 | |
| Postoperative morbidity | ||||||||||
| None/CTCAE grade 1 | 481 | (79) | 468 | (67) | 271 | (80) | 242 | (72) | ||
| CTCAE grade 2 | 91 | (15) | 158 | (23) | 50 | (15) | 69 | (20) | ||
| CTCAE grade ≥3 | 35 | (6) | 70 | (10) | 17 | (5) | 27 | (8) | 0.12# | |
| 30-day mortality | 1 | (0.2) | 10 | (1) | 0 | (0) | 2 | (0.6) | ¶ | |
| 90-day mortality | 3 | (0.5) | 18 | (3) | 1 | (0.3) | 7 | (2) | ¶ | |
| 1-year LC mortality | 11 | (2) | 28 | (4) | 8 | (2) | 6 | (2) | 0.8 | |
| 1-year NC mortality | 3 | (0) | 31 | (4) | 1 | (0.3) | 10 | (3) | 0.027 | |
| 5-year LC-CID (%)* | 11 | (8–14) | 19 | (17–23) | 15 | (12–20) | 14 | (10–19) | 0.9 | |
| 5-year NC-CID (%)* | 3 | (1–5) | 8 | (6–10) | 2 | (1–5) | 7 | (5–11) | 0.014 | |
Data are number (%) or median (25th–75th percentile).
Data are shown as estimated CID or survival probability (95% CI).
Comparison of CTCAE grade ≥3 between MIS vs. thoracotomy.
No statistical comparison due to small number of events.
Abbreviations: ASMD, absolute standardized mean difference; BMI, body mass index; CI, confidence interval; CID, cumulative incidence of death; COPD, chronic obstructive pulmonary disease; CTCAE, Common Terminology Criteria for Adverse Events; CVD, cardiovascular disease; DLCO, diffusion capacity of the lungs for carbon monoxide; DM, diabetes mellitus; FEV1, forced expiratory volume in 1 second; LC, lung cancer; LLL, left lower lobe; LUL, left upper lobe; NC noncancer; MIS, minimally invasive surgery; RLL, right lower lobe; RML, right middle lobe; RUL, right upper lobe; ppo, predictive postoperative; p-Stage, pathologic stage.