Table 1.

Frequency of mutations in the PIK3CA, AKT1, and PTEN genes in 547 human breast cancers and 41 breast cancer cell lines

Tumor subtypeMutation
PIK3CA catalytic domain *PIK3CA other PIK3CA totalPTENAKT1 E17K
All human breast tumors73/547 (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 TN12/240 (5.0%)8/240 (3.3%)20/240 (8.3%)0/20 (0%)0/111 (0%)
All breast cancer cell lines7/41 (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.