Prognostic significance of peritoneal lavage cytology at three cavities in patients with gastric cancer.

Background: We sought to determine the prognostic significance of intraoperative peritoneal lavage cytology (CY) at 3 different abdominal cavities and establish the optimal treatment for gastric cancer patients with positive peritoneal cytology (CY1).

Methods: A total of 1,039 patients with primary gastric adenocarcinoma who underwent CY at 3 cavities (Douglas' pouch, left subphrenic cavity, and right subhepatic cavity) were enrolled; 116 (11%) patients had at least one positive cavity. We retrospectively analyzed the clinicopathologic characteristics and survival of these 116 patients with CY1.

Results: Seventeen (15%) of the patients had negative cytology at Douglas' pouch but positive cytology at one or both of the other cavities. The 116 patients' overall 2-year survival rate was 22.9%, with the median survival time of 11 months. The overall 2-year survival rates for the patients with positive cytology at 1, 2, and 3 cavities were 41.9%, 35.8%, and 15%, with median survival times of 17, 18, and 9 months, respectively (P < .01). A multivariate analysis revealed that macroscopic type 4 tumor, R2 resection, lymph node metastasis, and postoperative chemotherapy were independent prognostic factors. Among the CY1 patients with type 4 tumors, there was no substantial difference in survival between the patients who underwent R1 or R2 resection, although the statistical power of this subgroup analysis was low.

Conclusion: CY at 3 cavities might be a useful method to decrease the false-negative rate. Palliative gastrectomy for CY1 patients with type 4 tumors is still controversial.