Long Term Survival after Cytoreductive Surgery Combined with Perioperative Chemotherapy in Gastric Cancer Patients with Peritoneal Metastasis

Abstract

The present study demonstrated prognostic factors for long-term survival in patients after a comprehensive treatment (CHT) for peritoneal metastasis (PM) from gastric cancer (GC). Materials and Methods: Among 419 patients treated with neoadjuvant intraperitoneal/systemic chemotherapy (NIPS), 266 (63.5%) patients received complete resection (CC-0) of the macroscopic tumors. In total, 184 (43.9%) patients were treated with postoperative systemic chemotherapy. Results: All patients treated who received incomplete cytoreduction (CC-1) died of GC within 6 years. In contrast, 10- year survival rates (-YSR) of CC-0 resection were 8.3% with median survival time (MST) of 20.5 months. Post-NIPS peritoneal cancer index (PCI) ≤11, and pre-NIPS PCI ≤13 were the significant favorable prognostic factors. Patients with numbers of involved peritoneal sectors ≤5 survived significant longer than those with ≥6. Both negative pre- and post-NIPS cytology was associated with significant favorable prognosis. Multivariate analyses identified pre-PCI (≤13 vs. ≥14), and cytology after NIPS (negative cytology vs. positive cytology) as independent prognostic factors. Ten year-survivors were found in patients with involvement of the greater omentum (9%), pelvic peritoneum (3%), para-colic gutter (13.9%), upper jejunum (5.6%), lower jejunum (5.5%), spermatic cord (21.9%), rectum (9.5%), ureter (6.3%), ovary (6.7%), and diaphragm (7.0%) at the time of cytoreduction. Twenty-one patients survived longer than 5 years, and 17 patients are still alive without recurrence. Conclusions: GC-PM should be removed aggressively, in patients with PCI after NIPS ≤11, PCI before NIPS ≤13, mall bowel PCI ≤2, and complete cytoreduction should be performed for metastasis in ≤5 peritoneal sectors.