Peritoneal washings cytology combined with immunocytochemical staining in pancreatic cancer

BACKGROUND/AIMS: Peritoneal washings from patients with pancreatic cancer d emonstrate malignant cells in 0-58% of patients. But the significance of th eir potential for implantation and growth after radical surgery has not bee n clarified. METHODOLOGY: Peritoneal washings were collected from 74 consecutive pancrea tic cancer patients during a 5-year period and studied by conventional stai ning and immunocytochemical staining using anti-CEA and anti-CA 19-9. Fifty of the 74 patients were resectable and the others were nonresectable. RESULTS: Seven out of 8 patients with macroscopic peritoneal metastasis wer e positive in conventional staining, but all 8 patients were positive in im munocytochemical staining. Five of the 66 (8%) patients without macroscopic peritoneal metastasis were positive in conventional staining, but the posi tive rate increased to 14 of 66 (22%) in immunocytochemical staining. There was no statistically significant difference in post-operative cumulative s urvival rate between the 13 positive cytology patients and 37 negative cyto logy patients without macroscopic peritoneal metastasis. CONCLUSIONS: The positive rate of peritoneal washings cytology was increase d in this study by the use of immunocytochemical staining in addition to co nventional staining. No statistically significant difference in post-operat ive cumulative survival rate between positive cytology patients and negativ e cytology patients without macroscopic peritoneal metastasis was observed.