Table 1.
Clinicopathological characteristics and immunohistochemistry results according to used formalin solution n (%)
| All cases (n = 32) | 10% formalin (n = 22) | 1% NBF (n = 10) | P | |
| Age (mean ± SD) | 74.5 ± 7.8 | 73.3 ± 8.0 | 77.1 ± 7.0 | 0.2020 |
| Gender | 0.7731 | |||
| Male | 18 (56.3) | 12 (54.6) | 6 (60.0) | |
| Female | 14 (43.7) | 10 (45.4) | 4 (40.0) | |
| T-Stage | 0.6793 | |||
| T1b2 | 6 (18.8) | 3 (13.6) | 3 (30.0) | |
| T2 | 9 (28.1) | 6 (27.3) | 3 (30.0) | |
| T3 | 5 (15.6) | 4 (18.2) | 1 (10.0) | |
| T4a | 12 (37.5) | 9 (40.9) | 3 (30.0) | |
| Lauren's classification | ||||
| Intestinal | 18 (56.2) | 12 (54.6) | 6 (60.0) | 0.7731 |
| Diffuse / mixed | 14 (43.8) | 10 (45.4) | 4 (40.0) | |
| HER-2 IHC | ||||
| Complete negative1 | 24 (75) | 18 (81.8) | 6 (60.0) | 0.1966 |
| Final positive by DISH | 5 (15.6) | 2 (9.1) | 3 (30.0) | 0.1311 |
| PD-L1 positivity | ||||
| Cut off 1% | 20 (62.5) | 14 (63.4) | 6 (60.0) | 0.8439 |
| Cut off 10% | 13 (40.6) | 8 (36.4) | 5 (50.0) | 0.4666 |
| Cut off 50% | 7 (21.9) | 4 (18.2) | 3 (30.0) | 0.4535 |
1
The cases that all four specimens of different fixation time were assessed as score 0.
IHC: Immunohistochemistry; NBF: Neutral buffered formalin; DISH: Dual color in situ hybridization; HER-2: Human epidermal growth factor receptor 2; PD-L1: Programmed death-ligand 1.