1119 - Observational Study of the Peritoneal Washing Cytology Positive Gastric Cancer without Gross Peritoneal Metastasis Underwent Radical D2 Gastrectomy.

Background

Clinical features and therapeutic strategies for peritoneal washing cytology- positive (CY+) gastric cancer without gross peritoneal metastasis have not yet been defined. The aim of the study was to evaluate the clinical prognostic impacts of postoperative chemotherapy for treating gastric cancer patients with CY+ without peritoneal metastasis.

Methods

Intraoperative peritoneal washing cytology was performed in 285 patients who underwent curative D2 gastrectomy between April 2004 and May 2016. Of them, 88 patients with CY+ without peritoneal metastasis were included in the study. 64 patients received postoperative chemotherapy, whereas 24 patients underwent surgery only. We combined CY + 64 patients who received postoperative chemotherapy with another cohort of stage II/III gastric cancer patients (n = 819) who received adjuvant chemotherapy, for survival comparison.

Results

The Disease-free survival (DFS) and overall survival (OS) curves were well separated according to stage and CY+ in combined cohort (both, P < 0.001). CY+ gastric cancer patients demonstrated the worst DFS and OS in combined cohort. CY+ gastric cancer patients showed poorer DFS and OS than CY- gastric cancer patients (CY+ vs. CY-, median DFS 10.270 months vs. not reached, P < 0.001; median OS 19.730 vs. 59.400 months, P < 0.001). Postoperative chemotherapy improved DFS and OS compared to surgery only in CY+ patients group (median DFS 11.630 vs. 6.980 months, P < 0.001; median OS 25.500 vs. 12.110 months, P < 0.001). In multivariate analyses in the CY+ patients group, no chemotherapy was the strongest clinical factor for poorer DFS (HR 3.761, P < 0.001) and OS (HR 4.366, P < 0.001).

Conclusions

The prognosis of gastric cancer with CY+ without gross peritoneal metastasis is somewhat different from gastric cancer with overt peritoneal metastasis, and postoperative chemotherapy improves survival outcome in this patient group.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.