Table 1.
Frequency of mutations in the PIK3CA, AKT1, and PTEN genes in 547 human breast cancers and 41 breast cancer cell lines
| Tumor subtype | Mutation |
|||||
|---|---|---|---|---|---|---|
| PIK3CA catalytic domain* | PIK3CA other† | PIK3CA total | PTEN‡ | AKT1 E17K | ||
| All human breast tumors | 73/547 (13.3%) | 44/547 (8.0%) | 117/547 | (21.4%) | 2/88 (2.3%) | 6/418 (1.4%) |
| Human breast HR+§ | 48/232 (20.7%) | 32/232 (13.8%) | 80/232 | (34.5%) | 2/58 (3.4%) | 6/232 (2.6%) |
| ER+PR+ | 39/186 (21%) | 22/186 (11.8%) | 61/186 | (32.8%) | 1/48 (2.1%) | 6/186 (3.2%) |
| ER+PR− | 9/41 (22%) | 10/41 (24.4%) | 19/41 | (46.3%) | 1/8 (12.5%) | 0/41 (0%) |
| ER−PR+ | 0/5 (0%) | 0/5 (0%) | 0/5 | (0%) | 0/2 (0%) | 0/5 (0%) |
| Human breast HER2+|| | 13/75 (17.3%) | 4/75 (5.3%) | 17/75 | (22.7%) | 0/10 (0%) | 0/75 (0%) |
| Human breast TN | 12/240 (5.0%) | 8/240 (3.3%) | 20/240 | (8.3%) | 0/20 (0%) | 0/111 (0%) |
| All breast cancer cell lines | 7/41 (17.1%) | 9/41 (22%) | 16/41 | (39%) | 8/41 (20%) | 0/41 (0%) |
| Breast cancer cell lines HR+ | 1/12 (8.3%) | 3/12 (25%) | 4/12 | (33.3%) | 5/12 (41.7%) | 0/12 (0%) |
| Breast cancer cell lines HER2+ | 2/10 (20%) | 4/10 (40%) | 6/10 | (60%) | 0/10 (0%) | 0/10 (0%) |
| Breast cancer cell lines TN¶ | 4/19 (21%) | 2/19 (10.5%) | 6/19 | (31.6%) | 3/19 (15.8%) | 0/19 (0%) |
Abbreviations: HR+, hormone receptor positive; TN, triple negative.
Catalytic domain PIK3CA mutations include H1047R, H1047L, H1047Y, and G1049R in order of frequency.
Other PIK3CA mutations include E545K, E542K, N345K, E418K, and P539R in order of frequency.
Resequencing courtesy of Len Pennacchio and Jan-Fang Cheng of Lawrence Berkeley National Laboratory in breast cancers and by literature/internet (e.g., http://www.sanger.ac.uk) search in cell lines.
Two distinct PIK3CA mutations were found together in four patients with hormone receptor–positive breast cancer (PIK3CA_H1047R with PIK3CA_E545K, PIK3CA_H1047Y with PIK3CA_E545K, PIK3CA_H1047R with PIK3CA_K111N, and PIK3CA_E545K with PIK3CA_E418K).
DNA extraction in these tumors courtesy of Mandy Madiredjo at The Netherlands Cancer Institute.
One triple-negative breast cancer cell line (BT20) had both a catalytic domain H1047R and a noncatalytic domain P539R mutation in PIK3CA.