Table 2.
Correlation of PIK3CA mutation status with the clinicopathological characteristics of breast cancer
| Clinicopathological parameters | Mutated (%) | Wild type (%) | P |
|---|---|---|---|
| All Tumor Cases | 64 (34.4) | 122 (65.6) | NS |
| Histological Type | NS | ||
| Ductal/Other Carcinoma | 53 (32.5) | 110 (67.5) | |
| Lobular Carcinoma | 11 (47.8) | 12 (52.2) | |
| Tumor Stage | NS | ||
| T1 | 13 (30.2) | 28 (65.1) | |
| T2 | 37 (34.9) | 69 (65.1) | |
| T3 | 9 (42.9) | 12 (57.1) | |
| T4 | 5 (41.7) | 7 (58.3) | |
| Node Status | 0.042 | ||
| N0 | 25 (27.8) | 65 (72.2) | |
| N+ | 37 (42.5) | 50 (57.5) | |
| Tumor Grade | <0.001 | ||
| G1 | 16 (80.0) | 4 (20.0) | |
| G2 | 35 (36.5) | 61 (63.5) | |
| G3 | 13 (18.8) | 56 (81.2) | |
| Hormone Receptor Status | 0.002 | ||
| HR+ | 58 (40.3) | 86 (59.7) | |
| HR- | 6 (14.3) | 36 (85.7) | |
| HER2 Status | 0.032 | ||
| HER2+ | 3 (13.6) | 19 (86.4) | |
| HER2- | 61 (37.2) | 103 (62.8) | |
| Age | NS | ||
| <50 years | 6 (26.1) | 17 (73.9) | |
| >50 years | 58 (35.6) | 105 (64.4) | |
| Molecular Type | 0.003 | ||
| HR+/HER2- | 57 (42.5) | 77 (57.5) | |
| HR+/HER2+ | 1 (10.0) | 9 (90.0) | |
| HR-/HER2+ | 2 (16.7) | 10 (83.3) | |
| HR-/HER2- | 4 (13.3) | 26 (86.7) |
The mutation frequency, as determined by NGS, decreased with increasing tumor grade: 85 % for G1, 37 % for G2, and 20 % for G3. PIK3CA mutations were more frequently detected (42 %) in HR+ breast cancer than in HR- breast cancer (14 %). PIK3CA mutations were more frequently detected in HER2- breast cancer (38 %) than in HER2+ breast cancer (14 %)