Table 1. Patient characteristics.
| Characteristics | N (%) | χ2 values | p values | ||
|---|---|---|---|---|---|
| Overall (N = 112) | Early PORT (N = 41) | Late PORT (N =71) | |||
| Gender | |||||
| Male | 77 (68.8) | 32 (78.1) | 45 (63.4) | 2.60 | 0.11 |
| Female | 35 (31.2) | 9 (21.9) | 26 (36.6) | ||
| Age (median years) | |||||
| ≤ 58 | 59 (52.7) | 19 (46.3) | 40 (56.3) | 1.04 | 0.31 |
| > 58 | 53 (47.3) | 22 (53.7) | 31 (43.7) | ||
| Smoking history | |||||
| Yes | 69 (61.6) | 29 (70.7) | 40 (56.3) | 2.28 | 0.13 |
| No | 43 (38.4) | 12 (29.3) | 31 (43.7) | ||
| COPD history† | |||||
| Yes | 4 (3.6) | 2 (4.9) | 2 (2.8) | 0.32 | 0.57 |
| No | 108 (96.4) | 39 (95.1) | 69 (97.2) | ||
| ECOG-PS score† | |||||
| 0-1 | 111 (99.1) | 40 (97.6) | 71 (100) | 2.03 | 0.16 |
| 2 | 1 (0.9) | 1 (2.4) | 0 | ||
| Tumor location | |||||
| RUL | 30 (26.8) | 12 (29.3) | 18 (25.4) | 2.23 | 0.69 |
| RML | 5 (4.5) | 2 (4.9) | 3 (4.2) | ||
| RLL | 24 (21.4) | 7 (17.1) | 17 (23.9) | ||
| LUL | 32 (28.5) | 10 (24.4) | 22 (31.0) | ||
| LLL | 21 (18.8) | 10 (24.3) | 11 (15.5) | ||
| Tumor histology | |||||
| Squamous cell | 42 (37.5) | 18 (43.9) | 24 (33.8) | 4.58 | 0.10 |
| Adenocarcinoma | 55 (49.1) | 15 (36.6) | 40 (56.3) | ||
| Others | 15 (13.4) | 8 (19.5) | 7 (9.9) | ||
| Type of surgery† | |||||
| Lobectomy | 111 (99.1) | 41 (100) | 70 (98.6) | 0.92 | 0.34 |
| Ipsilateral pneumonectomy | 1 (0.9) | 0 | 1 (1.4) | ||
| T classification | |||||
| T1 | 32 (28.6) | 14 (34.2) | 18 (25.4) | 2.08 | 0.56 |
| T2 | 55 (49.1) | 17 (41.5) | 38 (53.5) | ||
| T3 | 17 (15.2) | 6 (14.6) | 11 (15.5) | ||
| T4 | 8 (7.1) | 4 (9.7) | 4 (5.6) | ||
| Number of dissected N2 nodes | |||||
| < 9 | 41 (36.6) | 15 (36.6) | 26 (36.6) | 0.00001 | 1.00 |
| ≥ 9 | 71 (63.4) | 26 (63.4) | 45 (63.4) | ||
| Number of positive N2 MLNs | |||||
| Single | 45 (40.2) | 15 (36.6) | 30 (42.3) | 0.35 | 0.56 |
| Multiple | 67 (59.8) | 26 (63.4) | 41 (57.7) | ||
| Positive N2 MLN ratio | |||||
| < 25% | 54 (48.2) | 23 (56.1) | 31 (43.7) | 1.61 | 0.21 |
| ≥ 25% | 58 (51.8) | 18 (43.9) | 40 (56.3) | ||
| Number of N2 MLN positive stations | |||||
| Single | 59 (52.7) | 21 (51.2) | 38 (53.5) | 0.06 | 0.81 |
| Multiple | 53 (47.3) | 20 (48.8) | 33 (46.45) | ||
| Interval between surgery and POCT (months) | 1.3 ± 0.6 | 1.4 ± 0.8 | 1.2 ± 0.5 | 1.14 | 0.26 |
| Interval between surgery and PORT (months) | 4.9 ± 2.6 | 3.2 ± 1.1 | 5.9 ± 2.8 | 4.99 | 0.0001 |
| Total dose of PORT | |||||
| < 50 Gy | 5 (4.4) | 0 | 5 (7.0) | 3.02 | 0.08 |
| ≥ 50 Gy | 107 (95.6) | 41 (100) | 66 (93.0) | ||
| POCT regimen‡ | |||||
| TP/DP | 53 (47.3) | 26 (63.4) | 27 (38.0) | 14.16 | 0.003 |
| CP | 40 (25.7) | 14 (34.2) | 26 (36.6) | ||
| GP/GC | 18 (16.1) | 1 (2.4) | 17 (23.9) | ||
| NP | 1 (0.9) | 0 | 1 (1.5) | ||
| # of POCT cycles | |||||
| < 4 | 15 (13.4) | 15 (36.6) | 0 | 29.99 | 0.0001 |
| ≥ 4 | 97 (86.6) | 26 (63.4) | 71 (100) | ||
| Gene expression status | |||||
| EGFR mutation | 9 (8.0) | 2 (4.9) | 7 (9.9) | 1.49 | 0.47 |
| ALK positive | 1 (0.9) | 0 | 1 (1.4) | ||
| N/A | 102 (91.1) | 39 (95.1) | 63 (88.7) | ||
| Molecular targeted therapy | |||||
| Erlotinib | 2 (1.8) | 1 (2.4) | 1 (1.4) | 2.35 | 0.50 |
| Gefitinib | 7 (6.3) | 1 (2.4) | 6 (8.5) | ||
| Crizotinib | 1 (0.9) | 0 | 1 (1.4) | ||
| None | 102 (91.0) | 39 (95.2) | 63 (88.7) | ||
| Treatment strategies after progression | |||||
| RT | 12 (10.7) | 3 (7.3) | 9 (12.7) | 2.91 | 0.41 |
| S | 20 (17.9) | 1 (2.4) | 0 | ||
| CT | 9 (8.0) | 9 (22.0) | 19 (26.8) | ||
| BSC | 71 (63.4) | 28 (68.3) | 43 (60.5) | ||
Note: Bold-face denotes p-value < 0.05.
†Subgroups have less than five patients.
‡ Platinum-based CT regimens included cisplatin, carboplatin, or oxaliplatin.
COPD: chronic obstructive pulmonary disease; ECOG-PS: the Eastern Cooperative Oncology Group scale-performance status; RUL: right upper lobe; RML: right middle lobe; RLL: right lower lobe; LUL: left upper lobe; LLL: left lower lobe; TP/DP: paclitaxel or docetaxel + platinum included cisplatin, carboplatin, or oxaliplatin; CP: pemetrexed + platinum included cisplatin, carboplatin, or oxaliplatin; GP/GC: gemcitabine + platinum included cisplatin, carboplatin, or oxaliplatin; NP: vinorelbine + platinum included cisplatin, carboplatin, or oxaliplatin; PORT: postoperative radiotherapy; POCT: postoperative chemotherapy; EGFR: epidermal growth factor receptor; ALK: anaplastic lymphoma kinase; N/A: not report; RT: radiotherapy; CT: chemotherapy; S: surgery; BSC: best supportive care.