Proteomics pattern of peritoneal sApo-2L but not CD200 (OX-2) as a possible screening biomarker for metastatic ovarian, endometrial and breast carcinoma.

PURPOSE: The purpose of this study was to evaluate the soluble Apo-2L (sApo-2L) levels in the ascitic fluid and to study its potential in detecting malignant ascites and soluble CD200 (sCD200,sOX-2) levels so as to predict its clinical usage for detecting stage 4 metastatic endometrial, ovarian and breast cancer in serum samples.

METHODS: Ascitic fluid from 53 and blood from 25 subjects without known malignancy on admission were collected. There were 14 breast cancer (BC), 17 ovarian cancer (OC) and 19 endometrial cancer (EC) patients diagnosed later on. Blood samples for sApo-2L, sCD200, liver function tests and CEA, CA-19.9 and CA-125 were always taken and assayed in the morning.

RESULTS: Significantly low levels of sApo-2L were observed in peritoneal fluid from OC and EC patients compared to benign peritoneal fluid from control individuals. Positive correlation was observed between sApo-2L and aspartate aminotransferase (AST) in benign peritoneal fluid and sCD200, and creatinine and sCD200 and platelets in OC patients; also, sCD200 and CEA in EC patients and sCD200 and blood urea nitrogen (BUN) in healthy subjects.

CONCLUSIONS: Our data indicate that low proteomics pattern of sApo-2L but not sCD200 is a good biochemical marker. Further decline in the level of sApo-2L was seen in EC compared to OC. Since higher levels of sApo-2L were seen with higher levels of AST, the liver might be involved in its metabolism. The positive correlation detected between sCD200 and creatinine, platelets, CEA and BUN needs to be elucidated.