TABLE 1.
Clinicopathological characteristics of patients with HER2 ex20ins by 1L and 2L targeted therapies.
| Characteristics | 1L total | Afatinib | Pyrotinib | p-Value | 2L total | Afatinib | Pyrotinib | χ2 | p-Value |
|---|---|---|---|---|---|---|---|---|---|
| N (%) | 36 | 26 | 10 | 55 | 24 | 31 | |||
| Age | |||||||||
| ≤55 | 10 (27.8) | 6 (23.1) | 4 (40.0) | 0.41 | 30 (54.5) | 14 (58.3) | 16 (51.6) | 0.25 | 0.62 |
| >55 | 26 (72.2) | 20 (76.9) | 6 (60.0) | 25 (45.5) | 10 (41.7) | 15 (48.4) | |||
| Gender | |||||||||
| Female | 20 (55.6) | 14 (53.8) | 6 (60.0) | 1.0 | 32 (58.2) | 15 (62.5) | 17 (54.8) | 0.33 | 0.57 |
| Male | 16 (44.4) | 12 (46.2) | 4 (40.0) | 23 (41.8) | 9 (37.5) | 14 (45.2) | |||
| Smoking history | |||||||||
| Never | 24 (66.7) | 17 (65.4) | 7 (70.0) | 1.0 | 40 (72.7) | 21 (87.5) | 19 (61.3) | 4.69 | 0.03 |
| Current/Former | 12 (33.3) | 9 (34.6) | 3 (30.0) | 15 (27.3) | 3 (12.5) | 12 (38.7) | |||
| HER2 testing specimen | |||||||||
| Tumor tissue | 34 (94.4) | 24 (92.3) | 10 (100.0) | 1.0 | 52 (94.5) | 22 (91.7) | 30 (96.8) | - | 0.58 |
| Plasma | 2 (5.6) | 2 (7.7) | 0 (0) | 3 (5.5) | 2 (8.3) | 1 (3.2) | |||
| HER2 ex20ins variants | |||||||||
| A775_G776insYVMA | 29 (80.6) | 21 (80.8) | 8 (80.0) | 1.0 | 45 (81.8) | 17 (70.9) | 28 (90.3) | - | 0.08 |
| G776delinsVC | 7 (19.4) | 5 (19.2) | 2 (20.0) | 6 (11.0) | 3 (12.5) | 3 (9.7) | |||
| G776delinsVV | 0 (0) | 0 (0) | 0 (0) | 2 (3.6) | 2 (8.3) | 0 (0) | |||
| G776delinsLC | 0 (0) | 0 (0) | 0 (0) | 2 (3.6) | 2 (8.3) | 0 (0) | |||
| Brain metastasis | |||||||||
| Presence | 7 (19.4) | 5 (19.2) | 2 (20.0) | 1.0 | 5 (9.1) | 2 (8.3) | 3 (9.7) | 0.003 | 0.96 |
| Absence | 29 (80.6) | 21 (80.8) | 8 (80.0) | 50 (90.9) | 22 (91.7) | 28 (90.3) | |||