Flow cytometry in squamous cell esophageal cancer and precancerous lesions

Flow cytometry has also been used to study the nuclear DNA content (ploidy) and cell cycle kinetics of esophageal cancers. Studies of limited numbers of patients with Barrett's esophagus undergoing endoscopic surveillance suggested that aneuploidy may be a useful marker to identify subsets of patients at increased risk for malignancy. Few studies to date have evaluated premalignant tissues associated with the development of squamous-cell cancer of the esophagus. The present retrospective study comprises 80 surgical specimens of squamous-cell carcinoma of the esophagus from a high-incidence region of Thailand. All patients had surgery at the Department of Surgery, Prince of Songkla University, between March 1983 and December 1993. Sets of serial sections were cut every 0.5 cm starting from the proximal margin and down to the distal margin, and histopathology was confirmed to flow cytometric parameters (DNA content, S-phase fraction). Aneuploidy was found in 84% of squamous-cell carcinoma, 22.2% of carcinoma in situ, 28.6% of severe dysplasia, 11.0% of moderate dysplasia and 0% of mild dysplasia and normal esophageal mucosa specimens. The percentage was higher according to the level of severity or dysplasia. S-phase fraction was found to be 21.0 +/- 0.9% in squamous-cell carcinoma, 20.3 +/- 10.3% of carcinoma in situ, 20.9 +/- 5.3% of severe dysplasia, 12.9 +/- 9.7% of moderate dysplasia 7.6 +/- 0.8% of mild dysplasia and 8.9 +/- 3.2% of normal tissue. Similarly, the percentage of S-phase fraction tends to be higher according to the level of severity or dysplasia. These findings demonstrate that the aneuploidy and percentage of S-phase fraction tend to correlate with progression of esophageal premalignant tissues to invasive carcinoma. These measures may be clinically useful to identify patients at increased risk for esophageal malignancy.