Table 1. Patient demographic characteristics and difference between lobar and sublobar resection before and after propensity-score matching.
| Before matching (n=1497) | After matching (n=698) | ||||||
|---|---|---|---|---|---|---|---|
| Lobectomy N=970 |
Sublobar N=527 |
Lobectomy N=349 |
Sublobar N=349 |
||||
| Clinicopathologic variables | ASMD* | ASMD* | |||||
| Period of surgery | 1995–1999 | 68 (7) | 22 (4) | 0.435 | 15 (4) | 15 (4) | 0.030 |
| 2000–2004 | 244 (25) | 63 (12) | 45 (13) | 46 (13) | |||
| 2005–2009 | 341 (35) | 179 (34) | 117 (34) | 121 (35) | |||
| 2010–2014 | 317 (33) | 263 (50) | 172 (49) | 167 (48) | |||
| Age at surgery (year) | 69 (61–75) | 70 (64–76) | 0.203 | 69 (64–75) | 70 (63–76) | 0.045 | |
| Sex | Female | 601 (62) | 337 (64) | 0.041 | 222 (64) | 222 (64) | <0.001 |
| Male | 369 (38) | 190 (36) | 127 (36) | 127 (36) | |||
| Smoking | Never | 181 (19) | 87 (17) | 0.066 | 64 (18) | 59 (17) | 0.085 |
| Former | 669 (69) | 379 (72) | 236 (68) | 249 (71) | |||
| Current | 120 (12) | 61 (12) | 49 (14) | 41 (12) | |||
| COPD positive | 157 (16) | 135 (26) | 0.234 | 73 (21) | 78 (22) | 0.035 | |
| CVD positive | 175 (18) | 141 (27) | 0.210 | 84 (24) | 84 (24) | <0.001 | |
| DM positive | 90 (9) | 75 (14) | 0.154 | 43 (12) | 54 (15) | 0.091 | |
| Prior LC positive | 24 (2) | 105 (20) | 0.576 | 18 (5) | 27 (8) | 0.105 | |
| Prior malignancy positive | 240 (25) | 199 (38) | 0.280 | 120 (34) | 129 (37) | 0.054 | |
| BMI (n=1495) | 26 (23–30) | 27 (24–30) | 0.098 | 27 (23–30) | 27 (24–30) | 0.054 | |
| FEV1 (%) (n=1435) | 92 (80–105) | 86 (69–101) | 0.323 | 89 (78–101) | 90 (71–104) | 0.071 | |
| DLCO (%) (n=1377) | 84 (70–97) | 79 (64–92) | 0.328 | 82 (67–95) | 82 (66–94) | 0.097 | |
| Serum creatinine (mg/dL) (n=1450) | 1.0 (0.8–1.2) | 1.0 (0.8–1.2) | 0.044 | 1.0 (0.8–1.2) | 1.0 (0.8–1.2) | 0.038 | |
| SUVmax (n=1226) | 2.5 (1.4–4.7) | 2.1 (1.0–3.6) | 0.259 | 2.1 (1.1–4.0) | 2.2 (1.2–3.9) | 0.062 | |
| Pathologic tumor size (cm) | 1.8 (1.3–2.3) | 1.4 (1.0–1.8) | 0.670 | 1.5 (1.1–1.9) | 1.5 (1.1–1.9) | 0.037 | |
| Invasive tumor size (cm) | 1.4 (1.0–2.0) | 1.0 (0.6–1.5) | 0.678 | 1.1 (0.7–1.5) | 1.1 (0.7–1.5) | 0.017 | |
| p-Stage | IA1 | 144 (15) | 172 (33) | 0.573 | 96 (28) | 96 (28) | 0.019 |
| IA2 | 453 (47) | 223 (42) | 158 (45) | 160 (46) | |||
| IA3 | 252 (26) | 49 (9) | 43 (12) | 41 (12) | |||
| IB | 121 (12) | 83 (16) | 52 (15) | 52 (15) | |||
| LVI positive | 384 (40) | 165 (31) | 0.174 | 108 (31) | 111 (32) | 0.019 | |
| VPI positive | 120 (12) | 83 (16) | 0.097 | 52 (15) | 52 (15) | <0.001 | |
| Necrosis (n=1478) positive | 121 (13) | 35 (7) | 0.201 | 34 (10) | 28 (8) | 0.060 | |
| Histologic grade | Low | 132 (14) | 129 (24) | 0.281 | 73 (21) | 78 (22) | 0.066 |
| Intermediate | 604 (62) | 292 (55) | 197 (56) | 201 (58) | |||
| High | 234 (24) | 106 (20) | 79 (23) | 70 (20) | |||
| Presence (≥5%) of LEP pattern | 616 (64) | 366 (69) | 0.126 | 242 (69) | 241 (69) | 0.006 | |
| Presence (≥5%) of MIP pattern | 473 (49) | 231 (44) | 0.099 | 160 (46) | 143 (41) | 0.098 | |
| Presence (≥5%) of SOL pattern | 386 (40) | 194 (37) | 0.061 | 122 (35) | 128 (37) | 0.036 | |
| STAS positive | 389 (40) | 218 (41) | 0.026 | 141 (40) | 135 (39) | 0.035 | |
| Mutation status (n=1306) | Wild type | 440 (51) | 230 (52) | 0.117 | 161 (50) | 151 (52) | 0.057 |
| EGFR | 181 (21) | 75 (17) | 61 (19) | 49 (17) | |||
| KRAS | 240 (28) | 140 (31) | 99 (31) | 91 (31) | |||
| Outcomes | P | ||||||
| Number of any recurrence | 99 | 102 | 30 | 63 | |||
| Only locoregional recurrence | 24 | 57 | 6 | 34 | |||
| Distant recurrence | 75 | 45 | 24 | 29 | |||
| Number of any death | 212 | 155 | 68 | 96 | |||
| Lung cancer-specific death | 57 | 58 | 16 | 34 | |||
| Other cause / unknown death | 155 | 97 | 52 | 62 | |||
| 5-year CIR (%) | 12 (10–14) | 21 (18–26) | 10 (7–14) | 20 (16–25) | <0.001 | ||
| 5-year LC-CID (%) | 6 (4–7) | 11 (8–15) | 6 (4–10) | 9 (6–13) | 0.013 | ||
| 5-year Overall survival (%) | 84 (82–87) | 74 (69–78) | 82 (77–87) | 78 (74–83) | 0.015 | ||
Data are number (%), median (25, and 75 percentiles), or 5-year cumulative incidence or survival rate (95% confidence interval [lower-upper]).
*
ASMD (absolute standardized mean difference) ≤0.1 indicates balance in the covariate between the two groups.
Abbreviation: BMI, body mass index; CI, confidence interval; COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; DLCO, diffusion capacity of the lung for carbon monoxide; DM, diabetes mellitus; FEV1, forced expiratory volume in one second; LC, lung cancer; LEP, lepidic; MIP, micropapillary; p-Stage, pathologic stage; SOL, solid; STAS, spread through air spaces; SUVmax, maximum standardized uptake value; VPI, visceral pleural invasion.