IMPLICATIONS OF PERITONEAL CYTOLOGY FOR PANCREATIC-CANCER MANAGEMENT

Objective: To assess the implications of positive cytology for maligna nt cells (positive results) from peritoneal washings in the management of patients with pancreatic cancer. Design: Retrospective cohort stud y. Setting: Referral practice in a university hospital. Patients: A to tal of 32 consecutive pancreatic cancer patients with positive results from peritoneal washings during a 4-year period, 17 with visible biop sy-proven intraabdominal metastases at the time of laparoscopy or lapa rotomy and 15 without visible metastases. A treatment-matched control group of 30 patients was randomly selected from a group of 105 patient s with negative cytology for malignant cells (negative results) from p eritoneal-fluid cytology. Interventions: Eight of 17 patients with vis ible metastases underwent treatment with chemotherapy, radiation, or b oth; 13 of the 15 patients with no visible metastases underwent furthe r treatment, including pancreatic resection in 2 patients and external beam radiation in 13 patients (3 with intraoperative radiation therap y). Main Outcome Measures: Time to metastases and mortality. Results: Median survival among patients with and without visible metastasis was 7.8 months and 8.6 months, respectively (P=.95), despite the fact tha t patients without visible metastases received more treatment. Patient s without visible metastases at presentation were found to have metast atic disease as documented by computed tomographic scan or subsequent laparotomy at a median time of 2.9 months. The survival of treatment-m atched patients with negative cytology was significantly longer (media n, 13.5 months; P=.04). Conclusions: Pancreatic cancer patients with p eritoneal micrometastases have a dismal outcome even without macroscop ic metastases. Since these patients do not benefit from local therapy, the finding of a positive result from peritoneal-fluid cytologic test ing contraindicates further irradiation or surgery, except for specifi c complications.