Table 1. Clinicopathological characteristics and treatment modalities between recurrent and non-recurrent group.
| Characteristics | All (N=220) | No recurrence (N=156) | Recurrence (N=64) | P value |
|---|---|---|---|---|
| Age at diagnosis (years), n (%) | ||||
| <65 | 102 (46.4) | 72 (46.2) | 30 (46.9) | 0.92 |
| ≥65 | 118 (53.6) | 84 (53.8) | 34 (53.1) | |
| Sex, n (%) | 0.16 | |||
| Male | 84 (38.2) | 55 (35.3) | 29 (45.3) | |
| Female | 136 (61.8) | 101 (64.7) | 35 (54.7) | |
| Smoking status, n (%) | 0.031 | |||
| Never | 149 (67.7) | 111 (71.2) | 38 (59.4) | |
| Light | 33 (15.0) | 24 (15.4) | 9 (14.1) | |
| Heavy | 23 (10.5) | 11 (7.0) | 11 (17.2) | |
| Missing | 15 (6.8) | 10 (6.4) | 6 (9.3) | |
| ECOG PS, n (%) | 0.203 | |||
| 0/1 | 217 (98.6) | 155 (99.4) | 62 (96.9) | |
| 2 | 3 (1.4) | 1 (0.6) | 2 (3.1) | |
| AJCC 7th staging, n (%) | <0.001 | |||
| 0 | 12 (5.5) | 12 (7.7) | 0 | |
| IA | 110 (50.0) | 90 (57.7) | 20 (31.3) | |
| IB | 78 (35.5) | 45 (28.8) | 33 (51.6) | |
| IIA | 12 (5.5) | 4 (2.6) | 8 (12.5) | |
| IIB | 8 (3.5) | 5 (3.2) | 3 (4.7) | |
| AJCC 8th staging, n (%) | <0.001 | |||
| 0 | 12 (5.4) | 12 (7.7) | 0 | |
| IA | 142 (64.5) | 111 (71.2) | 31 (48.4) | |
| IB | 34 (15.5) | 20 (12.8) | 14 (21.9) | |
| IIA | 16 (7.3) | 6 (3.8) | 10 (15.6) | |
| IIB | 11 (5) | 5 (3.2) | 6 (9.4) | |
| IIIA | 5 (2.3) | 2 (1.3) | 3 (4.7) | |
| Tumor size (cm), n (%) | <0.001 | |||
| <4 | 179 (81.4) | 138 (88.5) | 41 (64.1) | |
| ≥4 | 41 (18.6) | 18 (11.5) | 23 (35.9) | |
| Adenocarcinoma subtype, n (%) | 0.002 | |||
| AIS | 13 (5.9) | 13 (8.3) | 0 | |
| MIA | 29 (13.2) | 28 (17.9) | 1 (1.6) | |
| Lepidic | 66 (30.0) | 49 (31.4) | 17 (26.5) | |
| Acinar | 74 (33.6) | 45 (28.9) | 29 (45.3) | |
| Papillary | 7 (3.2) | 4 (2.6) | 3 (4.7) | |
| Micropapillary | 8 (3.6) | 4 (2.6) | 4 (6.3) | |
| Colloid | 1 (0.5) | 1 (0.6) | 0 | |
| Solid | 20 (9.1) | 12 (7.7) | 8 (12.5) | |
| Missing | 2 (0.9) | 0 | 2 (3.1) | |
| Histologic grade, n (%) | <0.001 | |||
| Grade 1 | 111 (50.5) | 93 (59.6) | 18 (28.1) | |
| Grade 2 | 78 (35.5) | 46 (29.5) | 32 (50.0) | |
| Grade 3 | 30 (13.5) | 17 (10.9) | 13 (20.3) | |
| Missing | 1 (0.5) | 0 | 1 (1.6) | |
| Tumor cell type, n (%) | 0.44 | |||
| Non mucinous | 197 (89.6) | 141 (90.4) | 56 (87.5) | |
| Mucinous | 16 (7.2) | 13 (8.3) | 3 (4.7) | |
| Mixed | 4 (1.8) | 2 (1.3) | 2 (3.1) | |
| Missing | 3 (1.4) | 0 | 3 (4.7) | |
| Lymphovascular invasion, n (%) | <0.001 | |||
| No | 155 (70.5) | 122 (78.2) | 33 (51.6) | |
| Yes | 63 (28.6) | 34 (21.8) | 29 (45.3) | |
| Missing | 2 (0.9) | 0 | 2 (3.1) | |
| Visceral pleural invasion, n (%) | <0.001 | |||
| No | 161 (73.5) | 129 (82.7) | 32 (50.0) | |
| Into (PL1) | 37 (16.9) | 19 (12.2) | 18 (28.1) | |
| Through (PL2) | 21 (9.6) | 8 (5.1) | 13 (20.3) | |
| Missing | 1 (0.5) | 0 | 1 (1.6) | |
| Level of tumor necrosis, n (%) | <0.001 | |||
| No | 163 (74.0) | 134 (85.9) | 29 (45.3) | |
| 1+ | 29 (13.2) | 13 (8.3) | 16 (25.0) | |
| 2+ | 12 (5.5) | 5 (3.2) | 7 (10.9) | |
| 3+ | 12 (5.5) | 4 (2.6) | 8 (12.5) | |
| Missing | 4 (1.8) | 0 | 4 (6.3) | |
| EGFR testing, n (%) | ||||
| Wild type | 99 (47.1) | 67 (45.6) | 32 (50.0) | 0.49 |
| EGFR mutation | 111 (52.9) | 80 (54.4) | 31 (48.4) | |
| Exon 19 deletion | 57 (51.4) | 41 (51.2) | 16 (51.6) | 0.44 |
| L858R | 48 (43.2) | 35 (43.7) | 13 (41.9) | |
| G719X | 3 (2.7) | 1 (1.3) | 2 (6.5) | |
| L861Q | 3 (2.7) | 3 (3.8) | 0 | |
| Missing | 10 (4.5) | 9 (5.8) | 1 (1.6) | |
| Type of surgery, n (%) | 0.28 | |||
| Lobectomy | 215 (97.7) | 154 (98.8) | 61 (95.3) | |
| Bilobectomy | 3 (1.4) | 1 (0.6) | 2 (3.1) | |
| Wedge resection | 2 (0.9) | 1 (0.6) | 1 (1.6) | |
| Number of mediastinal LN removal, n (%) | ||||
| <3 LN | 55 (25.0) | 37 (23.7) | 18 (28.1) | 0.31 |
| ≥3 LN | 160 (72.7) | 119 (76.3) | 41 (64.1) | |
| Missing | 5 (2.3) | 0 | 5 (7.8) | |
| Bronchial resection margin (cm) | 0.001 | |||
| <2 | 60 (27.3) | 33 (21.2) | 27 (42.2) | |
| ≥2 | 154 (70.0) | 121 (77.6) | 33 (51.6) | |
| Missing | 6 (2.7) | 2 (1.2) | 4 (6.2) | |
| Adjuvant systemic treatment | 0.002 | |||
| No adjuvant | 191 (86.8) | 143 (91.7) | 48 (75.0) | |
| Adjuvant chemotherapy | 26 (11.8) | 11 (7.1) | 15 (23.4) | |
| Adjuvant CCRT with consolidation CMT† | 1 (0.5) | 0 | 1 (1.6) | |
| Adjuvant EGFR TKI | 2 (0.9) | 2 (1.2) | 0 | |
| Adjuvant radiation | 0.025 | |||
| No radiation | 217 (98.6) | 156 (100.0) | 61 (95.3) | |
| Adjuvant radiation | 2 (0.9) | 0 | 2 (3.1) | |
| Adjuvant CCRT with consolidation CMT† | 1 (0.5) | 0 | 1 (1.6) |
†, the patient was treated with adjuvant concurrent chemoradiation with consolidation chemotherapy because of closed margin. ECOG, Eastern Cooperative Oncology Group; AJCC, American Joint Committee on Cancer; PS, performance status; AIS, adenocarcinoma in situ; MIA, Microinvasive adenocarcinoma; PL, level of pleural invasion; EGFR, epidermal growth factor receptor; LN, lymph node; CMT, chemotherapy; CCRT, concurrent chemoradiation; TKIs, tyrosine kinase inhibitors.