Expression of decay accelerating factor in endometrial adenocarcinoma is inversely related to the stage of tumor

PROBLEM: Decay accelerating factor (DAF) is implicated in protection of cel l membrane from toxicity of complement. In this study, we investigated a hy pothesis that DAF is up-regulated in the endometrial adenocarcinoma, which could increase potential of malignant cells to escape destruction by comple ment. METHODS: DAF density was evaluated in endometrial biopsies of patients with adenocarcinoma at various stages and compared with ten endometrial biopsie s from non-malignant patients at the proliferative phase. RESULTS: DAF expression in normal proliferative endometrium varied between I and 30%. While DAF density in patients with stage I cancer was in the ran ge 56-98%,, (mean 78%), stage III values varied from 28 to 16% (mean 21%), P < 0.05. DAF density in the well-differentiated Ishikawa cell line was two -fold higher than in metastatic cell line AN3CA. CONCLUSIONS: Our findings are consistent with a hypothesis that endometrial adenocarcinoma of early stage that is exposed to complement attack may up- regulate DAF to protect malignant cells from complement lysis.