Background: Survivin, a member of the inhibitor-of-apoptosis family, is reported to be overexpressed in esophageal cancer but no data are available about its status in the metaplastic/dysplastic sequence. The aim of this study was to measure survivin gene expression in normal squamous/columnar epithelium and in the various stages of development of Barrett's adenocarcinoma.
Methods: Endoscopic biopsy or operative specimen samples from 5 tissue types were analyzed: (1) squamous epithelium from 3 cm above the gastroesophageal junction in patients with a negative pH study and no histologic injury (n = 17, pH- control); (2) antral tissue from patients with no evidence of Barrett's, dysplasia, or cancer (n = 29, antral control); (3) specialized intestinal metaplasia from patients with Barrett's esophagus (n = 16; Barrett's group); (4) low- or high-grade dysplasia (n = 12, dysplasia group), and (5) adenocarcinoma (n = 45 cancer group). After laser-capture microdissection cellular RNA was extracted from each tissue and reverse transcribed to complementary DNA. Expression levels of survivin were measured by reverse-transcription polymerase chain reaction.
Results: Survivin gene expression was greater in columnar (antral) compared with squamous (pH-) control tissues (P = .03). Expression in quiescent Barrett's epithelium was similar to both control tissues. Expression levels in dysplastic epithelium were greater than in squamous control (P = .01) and Barrett's tissues (P = .04), but not higher than columnar control tissues, whereas expression in adenocarcinoma was greater than all tissues except dysplasia (P < .001).
Conclusions: Survivin expression may be a biomarker in the development of Barrett's adenocarcinoma that is able to distinguish between quiescent Barrett's, dysplastic Barrett's, and Barrett's adenocarcinoma.