Bidirectional chemotherapy combining intraperitoneal docetaxel with intravenous 5-fluorouracil and oxaliplatin for patients with unresectable peritoneal metastasis from gastric cancer: the first study in Western countries.

Background: A new treatment using bidirectional intraperitoneal (IP) and intravenous (IV) chemotherapy developed by Asiatic surgeons improves outcomes in patients with synchronous peritoneal metastasis (PM) from gastric cancer (GC).

Methods: We enrolled six consecutive patients with unresectable PM from GC who underwent bidirectional chemotherapy using IP docetaxel and IV FOLFOX or LV5FU2. In one course, IP docetaxel 30 mg/m² was administrated on days 1, 8 and 15, and IV FOLFOX or LV5FU2 was administered on days 1 and 15, followed by 7 days of rest. Before and after a complete bidirectional cycle of three courses, the peritoneal cancer index (PCI) was evaluated by laparoscopy. The primary endpoint was to evaluate the feasibility and safety of bidirectional chemotherapy. Secondary endpoints were overall survival (OS), and the success of the therapeutic strategy was reflected by a decrease of 25% of the initial PCI.

Results: All patients completed one bidirectional cycle. The regimen was well tolerated. The median OS was 13 months [range 5-18], and the 1-year OS rate was 67%. After the first bidirectional cycle, the PCI decrease ≥25% of the initial value in four patients. A major histological response was observed in four patients.

Conclusions: This is the first Western study and confirms the feasibility and safety of bidirectional treatment using IP and IV chemotherapy for patients with unresectable PM from GC, resulting in a 13-month median OS with limited morbidity. The decrease in PCI after one bidirectional cycle is promising.