Subclinical cancer cell dissemination in peritoneal lavage fluid detected by reverse-transcription polymerase chain reaction identifies patients at high risk for peritoneal recurrence and consequent impaired survival in the setting of preoperative chemoradiation therapy for pancreatic cancer.

BACKGROUND

Preoperative chemoradiation therapy is a promising strategy for pancreatic cancer. Peritoneal recurrence is a major recurrence pattern after surgery for pancreatic cancer following preoperative chemoradiation therapy, even in patients with negative peritoneal lavage fluid cytology. Previous reports have indicated that the detection of carcinoembryonic antigen mRNA by reverse transcription polymerase chain reaction is useful for evaluating subclinical tumor cell dissemination in peritoneal lavage fluid.

METHODS

Patients with resectable and borderline resectable pancreatic cancer treated with preoperative gemcitabine-based chemoradiation therapy and subsequent surgery were enrolled in this study. In all patients, a conventional cytologic examination of peritoneal lavage fluid from laparotomy confirmed the negative peritoneal cytology status. Carcinoembryonic antigen mRNA was detected in the peritoneal lavage fluid at laparotomy using reverse transcription polymerase chain reaction. Recurrence patterns and survival were evaluated in association with the carcinoembryonic antigen mRNA status in the peritoneal lavage fluid.

RESULTS

The peritoneal lavage fluid from 57 of the 237 patients (24%) was carcinoembryonic antigen mRNA(+). The carcinoembryonic antigen mRNA(+) patients had a significantly higher incidence of peritoneal recurrence than the carcinoembryonic antigen mRNA(-) patients (36% vs. 15%, P < .001). The 5-year survival rates of the carcinoembryonic antigen mRNA(+) and carcinoembryonic antigen mRNA(-) patients were 31% and 51%, respectively (P = .037). A multivariable analysis for survival revealed that borderline resectability, positive nodal status, and positive carcinoembryonic antigen mRNA status were independent variables for impaired survival.

CONCLUSION

Carcinoembryonic antigen mRNA(+) status was associated with a significantly increased incidence of peritoneal recurrence in patients with pancreatic cancer treated with preoperative chemoradiation therapy, resulting in impaired survival.