Table 1. Association between patterns of PIK3CA mutation, PD-L1 expression and clinicopathological characteristics.
| Characteristics | Subcategories | No. | PIK3CA, n (%) | PD-L1, n (%) | |||
|---|---|---|---|---|---|---|---|
| Mutation | P | Positive | P | ||||
| Age, years | <70 | 103 | 19 (18.4) | 0.316 | 10 (9.7) | 0.799 | |
| ≥70 | 121 | 29 (24.0) | 13 (10.7) | ||||
| Sex | Male | 127 | 25 (19.7) | 0.467 | 14 (11.0) | 0.670 | |
| Female | 97 | 23 (23.7) | 9 (9.3) | ||||
| Tumor site† | Right | 73 | 23 (31.5) | 0.011 | 12 (16.4) | 0.034 | |
| Left | 151 | 25 (16.6) | 11 (7.3) | ||||
| Histologic grade | Well | 14 | 4 (28.6) | 0.769 | 2 (14.3) | <0.001 | |
| Moderated | 193 | 40 (20.7) | 14 (7.3) | ||||
| Poorly | 17 | 4 (23.5) | 7 (41.2) | ||||
| TILs | Low | 80 | 14 (17.5) | 0.285 | 7 (8.8) | 0.577 | |
| High | 144 | 34 (23.6) | 16 (11.1) | ||||
| Serum CEA‡ | Elevation | 56 | 13 (23.2) | 0.707 | 17 (30.4) | 0.899 | |
| Normal | 168 | 35 (20.8) | 6 (3.6) | ||||
| Serum CA19-9‡ | Elevation | 31 | 5 (16.1) | 0.439 | 22 (71.0) | 0.164 | |
| Normal | 193 | 43 (22.3) | 1 (0.5) | ||||
| pT category | pT1–T3 | 188 | 42 (22.3) | 0.447 | 19 (10.1) | 0.856 | |
| pT4 | 36 | 6 (16.7) | 4 (11.1) | ||||
| pN stage | pN0 | 127 | 34 (26.8) | 0.026 | 15 (11.8) | 0.384 | |
| pN1+2 | 97 | 14 (14.4) | 8 (8.2) | ||||
| Metastasis | Absent | 172 | 42 (24.4) | 0.047 | 22 (12.8) | 0.024 | |
| Present | 52 | 6 (11.5) | 1 (1.9) | ||||
| TNM stage | I + II | 129 | 34 (26.4) | 0.036 | 15 (11.6) | 0.435 | |
| III + IV | 95 | 14 (14.7) | 8 (8.4) | ||||
| PD-L1 IHC | Negative | 201 | 33 (16.4) | <0.001 | – | – | |
| Positive | 23 | 15 (65.2) | – | ||||
| Relapse | Absent | 186 | 45 (24.2) | 0.026 | 21 (11.3) | 0.265 | |
| Present | 38 | 3 (7.9) | 2 (5.3) | ||||
†, right colon: defined as the segment from the cecum to the proximal two-thirds of the transverse colon; left colon: defined as the segment from the distal one third of the transverse colon to the rectum. ‡, serum CEA elevation; defined as >5.0 ng/mL. Serum CA19-9 elevation defined as >37 kU/L. CA19-9, cancer antigen 19-9; CEA, carcinoembryonic antigen; IHC, immunohistochemistry; PD-L1, programmed death ligand-1; TILs, tumor infiltrating lymphocytes.