Table 4.
Correlation between EGFR immunohistochemical (IHC) expression, EGFR gene copy number, determined by FISH techniques and SNP-arrays, and GEP, detected by oligonucleotide arrays, in patients with sporadic colorectal cancer at diagnosis.
| EGFR IHC expression | p | ||
|---|---|---|---|
| <35% | ≥35% | ||
| FISH | |||
| Normal | 27 (75%) | 0 | <0.001 |
| Amplification | 0 | 8 (57%) | |
| Polysomy | 9 (25%) | 6 (43%) | |
| SNPs | |||
| Normal | 21 (68%) | 2 (29%) | 0.07 |
| Gain | 10 (32%) | 5 (71%) | |
| GEP* | |||
| <4 | 17 (55%) | 0 | 0.009 |
| ≥4 | 14 (45%) | 7 (100%) | |
FISH: interphase fluorescence in situ hybridization; SNP: single nucleotide polymorphism;
GEP: gene expression profile; IHC: immunohistochemistry; Results expressed as number
of cases and percentage in parentheses.
*Log2 expression.
SNPs arrays and GEP studies were performed in 38 cases due to sample restrictions