Table 6. Comparison of published EGFR FISH results using the criteria proposed by Cappuzzo et al (2005) with present data.
| Study | Number of evaluated NSCLC | Number of scored cells | FISH positive (%) | Balanced (‘high’) polysomy (%) | Amplification (%) |
|---|---|---|---|---|---|
| Cappuzzo et al (2005) a | 102 | —b | 33 | 20 | 13 |
| Tsao et al (2005) a | 125 | 33–100 | 45 | 34 | 11 |
| Hirsch et al (2005) a | 81 | ⩾100 | 32 | —b | —b |
| Hirsch et al (2006) a | 370 | —b | 31 | 17 | 14 |
| Jeon et al (2006) a | 262 | —b | 30.2 | 19.1 | 11.1 |
| Ichihara et al (2007) a | 75 | ⩾100 | 41.3 | 25.3 | 16 |
| Present study | |||||
| Histology | 33 | 43–100 (mean: 88.6±17.6) | 24.2 | 15.1 | 9.1 |
| Cytology | 67 | 12–100 (mean: 66.1±31.6) | 67.1 | 52.2 | 14.9 |
EGFR=epidermal growth factor receptor gene; FISH=fluorescence in situ hybridisation; NSCLC=non-small-cell lung carcinoma.
Criteria for a positive FISH result: presence of high polysomy (⩾4 EGFR gene copies per nucleus in ⩾40% of the analysed cancer cells) or of amplification (presence of tight EGFR gene clusters and a ratio of EGFR gene to chromosome of ⩾2, or ⩾15 EGFR gene copies per nucleus in ⩾10% of the analysed cancer cells).
a
All cited FISH analyses were performed on histological specimens.
b
No information.