Flow-cytometric DNA content analysis of oesophageal carcinoma. Comparison between tumour and sequential non-tumour mucosae

The DNA content in oesophageal carcinoma and in sequential non-tumour mucosa was evaluated in 35 patients with oesophageal carcinoma, to explore the hypotheses that DNA distribution pattern and S-phase fraction can reflect malignant potential and that DNA aneuploidy can provide an early-warning signal of developing cancer. DNA flow cytometry was performed on 129 specimens from the tumours and on 119 specimens from non-tumour mucosa. Control specimens from gastric fundus had normal diploid DNA content and low S-phase fraction. Aneuploidy was found in 94.3% of the carcinoma specimens and intratumoral heterogeneity in 54.3%. Of the non-tumour specimens, 43.7% showed aneuploidy and none multiple aneuploidy. Pattern III distribution was present in 8.6% of the tumour specimens but not in non-tumour mucosa, where the incidence of aneuploidy rose with closeness to the tumour (p < 0.001). S-phase fraction was smaller in non-tumour than in tumour specimens (p < 0.0001). The study indicated that histologically tumour-free oesophageal mucosa may have a high malignant potential in patients with oesophageal carcinoma. The relative instability of such mucosa, with aneuploid cells and low S-phase fraction, may facilitate transition to abnormally proliferating cells in response to environmental signals. Cigarette smoking and alcohol may increase the risk of multicentric cancer development.