BACKGROUND/AIMS: Peritoneal washings from patients with pancreatic cancer demonstrate malignant cells in 0-58% of patients. But the significance of their potential for implantation and growth after radical surgery has not been clarified.

METHODOLOGY

Peritoneal washings were collected from 74 consecutive pancreatic cancer patients during a 5-year period and studied by conventional staining 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 were positive in conventional staining, but all 8 patients were positive in immunocytochemical staining. Five of the 66 (8%) patients without macroscopic peritoneal metastasis were positive in conventional staining, but the positive rate increased to 14 of 66 (22%) in immunocytochemical staining. There was no statistically significant difference in post-operative cumulative survival rate between the 13 positive cytology patients and 37 negative cytology patients without macroscopic peritoneal metastasis.

CONCLUSIONS

The positive rate of peritoneal washings cytology was increased in this study by the use of immunocytochemical staining in addition to conventional staining. No statistically significant difference in post-operative cumulative survival rate between positive cytology patients and negative cytology patients without macroscopic peritoneal metastasis was observed.