Table 4. PIK3CA mutation frequencies in breast cancer tissues in pre- and postmenopausal women.
| Premenopausal | Postmenopausal | ||||
|---|---|---|---|---|---|
| No. of patients | 62 | 152 | |||
| Wild-type | 31 (50.0%) | 73 (48.0%) | |||
| Mutant | 29 (46.8%) | 71 (46.7%) | |||
| Invalid | 2 (3.2%) | 8 (5.3%) | |||
| PIK3CA domain | Exon | Nucleotide change | Amino acid mutation | n = 60 | n = 144 |
| Single mutation | 26 (43.3%) | 64 (44.4%) | |||
| p85-regulatory subunit- binding |
1 | 263 G>A | R88Q | 0 | 0 |
| C2 | 4 | 1035 T>A | N345K | 2 (3.3%) | 6 (4.2%) |
| 7 | 1258 T>C | C420R | 1 (1.7%) | 2 (1.4%) | |
| Helical | 9 | 1624 G>A | E542K | 2 (3.3%) | 1 (0.7%) |
| 9 | 1634 A>Ca), 1635 G>Tb), 1634 A>Gc), or 1633 G>Ad) |
E545X (E545Aa), E545Db), E545Gc), or E545Kd)) |
4 (6.7%) | 15 (10.4%) | |
| 9 | 1636 C>Ge), 1636 C>Af), 1637 A>Tg), or 1637 A>Gh) |
Q546X (Q546Ee), Q546Kf), Q546Lg), or Q546Rh)) |
0 | 1 (0.7%) | |
| Kinase | 20 | 3129 G>T | M1043I | 0 | 0 |
| 20 | 3140 A>Ti), 3140 A>Gj), or 3139 C>Tk) | H1047X (H1047Li), H1047Rj), or H1047Yk)) |
17 (28.3%) | 38 (26.4%) | |
| 20 | 3145 G>C | G1049R | 0 | 1 (0.7%) | |
| Double mutations | 3 (5.0%) | 6 (4.2%) | |||
| C2 and kinase | N345K, H1047X | 0 | 1 (0.7%) | ||
| Helical and kinase | E542K, H1047X | 1 (1.7%) | 2 (1.4%) | ||
| E545X, G1047X | 1 (1.7%) | 2 (1.4%) | |||
| E545X, G1049R | 0 | 1 (0.7%) | |||
| Q546X, H1047X | 1 (1.7%) | 0 | |||
| Triple mutations | 0 | 1 (0.7%) | |||
| Helical and kinase | E542K, Q546X, H1047X | 0 | 1 (0.7%) | ||