Table 1.

Studies on prognostic significance of PIK3CA exon 9 and 20 mutations in colorectal cancer

Authors (Ref.)No. of hospitalsTotal no. of eventsaSample sizeTumor locationDisease stageNo. of PIK3CA mutantsBRAF dataKRAS dataCS, OS, DFS, RFS or PFS log-rank PMultivariate HR (95% CI), PNotes and/or a list of variables examined in multivariate analysis
Exon 9Exon 20
Kato and colleagues (2)132158Colon & rectumII/III117NoYesP = 0.022 (RFS)2.48 (1.03–5.97) P = 0.043 (RFS)Lymph node metastasis, CEA level, tumor size and lymphatic invasion.
P = 0.036 (CS)Exon 9 or 20
Abubaker and colleagues (4)1N/A418Colon & rectumI–IV3813NoNoNS (OS)Exon 9 or 20
Barault and colleagues (7)3197586ColonI–IV4629YesYesN/AN/APIK3CA, KRAS and BRAF mutations were not evaluated separately.
Exon 1, 2, 9 or 20
Souglakos and colleagues (8)24392Colon & rectumI–IV188YesYesNS (OS)2.1 (1.2–3.9)Age, tumor grade, metastatectomy, tumor location and number of treatment lines (1 vs. >3). Patients with metastatic colorectal cancer after cetuximab treatment.
P = 0.01 (PFS)
Exon 9 or 20
Sartore-Bianchi and colleagues (11)288110Colon & rectumIII–IV411NoYesP = 0.0035 (PFS)Exon 9 or 20
Ogino and colleagues (12)Many152450ColonI–III82YesYesP = 0.075 (CS)2.23 (1.21–4.11; CS) Exon 9 or 20Age, sex, body mass index, year of diagnosis, tumor location, stage, grade and status of MSI, CIMP, KRAS, BRAF, LINE-1 methylation and TP53.
He and colleagues (13)Many84240RectumI–III127YesYesP = 0.008 (LR)3.4 (1.2–9.2)TNM stage, circumferential margin.
NS (OS)P = 0.017 (LR)
Exon 9 or 20
De Roock and colleagues (14)11N/A743Colon & rectumIV7422YesYesP = 0.013 (PFS)2.27 (1.10–4.66) P = 0.042 (PFS)Age, sex, number of previous chemotherapy lines, center, mutation status of KRAS, BRAF and NRAS.
P = 0.0057 (OS)3.30 (1.46–7.45) P = 0.012 (OS)Exon 9 mutation was not associated with outcome.
Exon 20
Tol and colleagues (15)ManyN/A436Colon & rectumIV3211YesYesNS (PFS, OS)Exon 9 or 20Serum LDH, number of affected organs and previous adjuvant therapy.
Farina Sarasqueta and colleagues (16)??685ColonI–III6617NoNoP = 0.04 (DFS)Exon 20Exon 9 mutation was not associated with outcome.
P = 0.03 (CS)
Liao and colleagues (current study)Many5521,170Colon & rectumI–IV11680YesYesP = 0.031 (CS)3.51 (1.28–9.62; CS)Age, sex, year of diagnosis, tumor location, stage, grade and status of MSI, CIMP, KRAS, BRAF and LINE-1 methylation.
P = 0.0008 (OS)2.68 (1.24—5.77; OS)
Cases with mutations in both exons 9 and 20
1.05 (0.71–1.56; CS)
0.90 (0.67–1.22; OS)
Cases with exon 9 mutation alone
0.96 (0.59–1.55; CS)
0.80 (0.55–1.16; OS)
Cases with exon 20 mutation alone
1.07 (0.79–1.45; CS)
0.91 (0.72–1.15; OS)
Cases with mutations in either or both of exons 9 and 20

Abbreviations: CS, cancer-specific survival; DFS; disease-free survival; LR, local recurrence; N/A, not available; NS, not significant; OS, overall survival; PFS, progression-free survival; RFS, relapse-free survival.

  • a, relapses or deaths.