Table II.
Comparison of pretreatment clinicopathological characteristics according to EGFR TKI responses.
| Patient characteristics | PR, n (%) | SD, n (%) | PD, n (%) | P-value |
|---|---|---|---|---|
| Total (n=116) | 32 (27.6) | 43 (37.1) | 41 (35.3) | |
| Age (years) | ||||
| <65 | 20 (25.6) | 31 (39.8) | 27 (34.6) | 0.663 |
| ≥65 | 12 (31.6) | 12 (31.6) | 14 (36.8) | |
| Gender | ||||
| Male | 16 (24.2) | 28 (42.4) | 22 (33.4) | 0.371 |
| Female | 16 (32.0) | 15 (30.0) | 19 (38.0) | |
| Histologic type | ||||
| Adenocarcinoma | 25 (35.2) | 19 (26.8) | 27 (38.0) | 0.009 |
| Non-adenocarcinoma | 7 (15.6) | 24 (53.3) | 14 (31.1) | |
| Performance status | ||||
| 0–1 | 26 (32.9) | 30 (38.0) | 23 (29.1) | 0.07 |
| 2 | 6 (16.2) | 13 (35.2) | 18 (48.6) | |
| Smoking history | ||||
| None | 17 (30.9) | 18 (32.7) | 20 (36.4) | 0.673 |
| Current + former | 15 (25.0) | 24 (40.0) | 21 (35.0) | |
| No. of prior regimens | ||||
| ≤1 | 13 (35.1) | 13 (35.1) | 11 (29.8) | 0.436 |
| ≥2 | 19 (24.1) | 30 (38.0) | 30 (38.0) | |
| Serum CEA level (ng/ml) | ||||
| <5 | 11 (21.1) | 16 (30.8) | 25 (48.1) | 0.034 |
| ≥5 | 21 (32.8) | 27 (42.2) | 16 (25.0) | |
| Serum CYFRA 21-1 level (ng/ml) | ||||
| <3.3 | 18 (32.7) | 23 (41.8) | 14 (25.5) | 0.104 |
| ≥3.3 | 14 (23.0) | 20 (32.8) | 27 (44.2) | |
| Combination of CEA and CYFRA 21-1 | ||||
| Group C | 11 (42.3) | 12 (46.2) | 3 (11.5) | 0.005 |
| Group B | 17 (25.8) | 26 (39.4) | 23 (34.8) | |
| Group A | 4 (16.7) | 5 (20.8) | 15 (62.5) | |
| EGFR mutation (n=84) | ||||
| Negative | 7 (15.6) | 12 (26.7) | 26 (57.8) | <0.001 |
| Positive | 18 (52.9) | 10 (29.4) | 6 (17.6) |
Group A, CEA <5 and CYFRA 21-1 ≥3.3 ng/ml. Group B, CEA <5 and CYFRA 21-1 <3.3 or CEA ≥5 and CYFRA 21-1 ≥3.3 ng/ml. Group C, CEA ≥5 and CYFRA 21-1 <3.3 ng/ml. PR, partial remission; SD, stable disease; PD, progression of disease; CEA, carcinoembryonic antigen; CYFRA 21-1, cytokeratin-19 fragments; TKI, tyrosine kinase inhibitor; EGFR, epidermal growth factor receptor.