The efficacy of treatment options for patients with gastric cancer and peritoneal metastasis.

BACKGROUND

Patients with peritoneal metastases of gastric cancer have a poor prognosis and median survival of 7 months. This study compared treatment options and outcomes based on the Peritoneal Cancer Index (PCI).

METHODS

This retrospective analysis included patients with gastric cancer treated between August 2008 and December 2017 with synchronous peritoneal metastases only diagnosed by laparoscopy. The three treatments were as follows: (1) cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in combination with pre- and postoperative systemic chemotherapy (n = 58), (2) laparotomy/laparoscopy without CRS, but HIPEC in combination with pre- and postoperative systemic chemotherapy (n = 11), and (3) systemic chemotherapy only (n = 19).

RESULTS

A total of 88 patients aged 54.6 ± 10.9 years with mean PCI of 14.3 ± 11.3 were included. The PCI was significantly lower in group 1 (8.3 ± 5.7) than in group 2 (23.9 ± 11.1, p < 0.001) and group 3 (27.3 ± 9.3, p < 0.001). Mean time from diagnosis to laparoscopy was 5.2 ± 2.9 months. The median overall survival was 9.8 ± 0.7 for group 1, 6.3 ± 3.0 for group 2 and 4.9 ± 1.9 months for group 3 (p < 0.001). Predictors for deteriorated overall patient survival included > 4 cycles of preoperative chemotherapy (HR 4.49, p < 0.001), lymph-node metastasis (HR 3.53, p = 0.005), PCI ≥ 12 (HR 2.11, p = 0.036), and incompleteness of cytoreduction (HR 4.30, p = 0.001) in patients treated with CRS and HIPEC.

CONCLUSION

CRS and HIPEC showed convincing results in selected patients with PCI < 12 and complete cytoreduction. Prolonged duration (> 4 cycles) of preoperative intravenous chemotherapy reduced patient survival in patients suitable for CRS and HIPEC.