Table 2.
Activation of PI3K Pathway by Low PTEN expression levels and/or PIK3CA Mutations as Pretreatment Predictive Markers of Response to the Trastuzumab + Lapatinib regimen
| Marker | pCR | No pCR | OR | 95% CI | p* | ||
|---|---|---|---|---|---|---|---|
|
| |||||||
| n | % | n | % | ||||
| PTEN (n=59) | 0.04 | ||||||
| High (≥100) | 12 | 32 | 25 | 68 | 4.80 | 0.96–23.97 | |
| Low (< 100) | 2 | 9 | 20 | 91 | 1 | – | |
|
| |||||||
| PIK3CA (n=46) | 0.14 | ||||||
| WT | 9 | 28 | 23 | 72 | 5.09 | 0.58–44.78 | |
| Mutant | 1 | 7 | 13 | 93 | 1 | – | |
|
| |||||||
| PTEN low or PIK3CA mutation (n=43) | |||||||
| No | 7 | 39 | 11 | 61 | 15.27 | 1.67–139.68 | 0.006 |
| Yes | 1 | 4 | 24 | 96 | 1 | – | |
Abbreviations: PI3K, phosphoinositol-3 kinase; pCR, pathologic complete response; OR, odds ratio; PTEN, phosphatase and tensin homolog; WT, wild type.
*
Chi-square or Fisher’s exact test, whichever is appropriate.