Feasibility of obtaining tissue for fluorescence in situ hybridization(FISH) analysis of Her1 or Her2 in advanced non-small cell lung cancer (NSCLC) patients

Abstract

7156 Background: Randomized trials which tested newer biologic targeted therapies in unselected NSCLC patients(pts) have produced negative results. Although it is possible that performing tumor molecular profiles may identify pts who are most likely to benefit from specific targeted therapy, it has been argued that it is too difficult to obtain adequate tissue from advanced NSCLC pts. The objective of this study was to determine the feasibility of obtaining tissue to evaluate tumor molecular profiles in NSCLC pts. Methods: Tissue specimens were obtained at initial diagnosis and or at the time of recurrence from 113 cases of advanced NSCLC pts. Specimens from 44 pts who were screened for a prospective phase II trial of trastuzumab and from 69 pts who were treated on a gefitinib Expanded Access trial were submitted for Her1 or Her2 FISH analysis. Results: Among 69 cases treated with gefitinib, the relationship of mode of tissue acquisition with FISH analysis of Her2 was examined. The methods and the number of cases were: FNA (11), FNA/core needle biopsy (10), pleural fluid (11), bronchial washing (1), resected tumor (28), bronchoscopy biopsy (5), mediastinoscopy (3). Overall, FISH analysis was accomplished in 53/69 (77%) specimens. FISH analysis was feasible in 18/33 cytologic specimens and 35/36 surgical specimens (χ2=15.29; p<0.0001). We examined the relationship of tissue acquisition and the performance of FISH for Her2 in 44 patients: FNA (9), FNA/core needle biopsy (2), pleural fluid (2), resected tumor (24), bronchoscopy biopsy (4), mediastinoscopy (3). FISH analysis for Her2 was successfully performed in 34/44 (77%) specimens. FISH analysis was feasible in 5/13 cytologic specimens and 29/31 surgical specimens (χ2=12.84; p=0.0003). Conclusions: Our results suggest that obtaining tissue for FISH analysis can be accomplished in approximately 75% of advanced NSCLC pts. There is a significantly higher percentage of successful FISH analysis in surgical specimens (64/67=95%), suggesting that increased efforts to obtain surgical specimens for performing molecular profiles should be encouraged. No significant financial relationships to disclose.