Cytology of peritoneal lavage performed during staging laparoscopy for gastrointestinal malignancies: Is it useful?

Objective: To evaluate the potential benefit of cytology of the peritoneal lavage obtained during diagnostic laparoscopy for staging gastrointestinal (GI) malignancies. Summary Background Data: Peritoneal lavage is a simple procedure that can be performed during laparotomy for GI tumors. Tumor cells in the lavage fluid are thought to indicate intraperitoneal tumor seeding and to have a negative effect on survival. For this reason, peritoneal lavage is frequently added to diagnostic laparoscopy for staging GI malignancies. Methods: Patients who underwent peritoneal lavage during laparoscopic staging for GI malignancies between June 1992 and September 1997 were included. Lavage fluids were stained using Giemsa and Papanicolaou methods. Cytology results were correlated with the presence of metastases and tumor ingrowth found during laparoscopy and with survival. Results: Cytology of peritoneal lavage was performed in 449 patients. Tumor cells were found in 28 patients (6%): 8/87 with an esophageal tumor, 2/32 with liver metastases, 11/72 with a proximal bile duct tumor, 7/236 with a periampullary tumor, and none in 7 and 15 patients with a primary liver tumor or pancreatic body or tail tumor, respectively. In 19 of the 28 patients (68%) in whom tumor cells were found, metastatic disease was detected during laparoscopy, and 3 of the 28 patients had a false-positive (n = 1) or a misleading positive (n = 2) lavage result. Therefore, lavage was beneficial in only 6/449 patients (1.3%); in these patients, the lavage result changed the assessment of tumor stage and adequately predicted irresectable disease. Univariate analysis showed a significant survival difference between patients in whom lavage detected tumor cells and those in whom it did not, but multivariate analysis revealed that these survival differences were caused by metastatic or ingrowing disease. Conclusion: Cytology of peritoneal lavage with conventional staining should no longer be performed during laparoscopic staging of GI malignancies because it provides an additional benefit in only 1.3% of patients and has limited prognostic value for survival in this group of patients.