In the first cohort, FGFR2b immunohistochemistry results correlated very well with those of copy number variation ( r=0.79) and FISH ( r=1.0). In addition, FGFR2b overexpression was studied in 88 matched primary and metastatic gastric cancers.
Selected cases were analyzed for FGFR2 amplification by FISH. Next, we performed immunohistochemistry on tissue microarrays from 1574 gastric cancer patients. We first screened 312 gastric cancer patients with known copy number variations by FGFR2b immunohistochemistry using FPR2-D, an isoform-specific antibody. FGFR2 gene amplification, and resulting FGFR2 protein overexpression, is rare in gastric cancer patients, and development of an accurate and widely available method for mass screening to identify patients who may respond to treatment with fibroblast growth factor receptor (FGFR) inhibitors is important.
