Combination chemotherapy of i.v. and i.p. PTX with S-1 is well tolerated and active in gastric cancer patients with peritoneal metastasis.

Objectives: A dose-escalation study of weekly intraperitoneal paclitaxel (PTX) combined with S-1 and intravenous PTX was performed to determine the maximum-tolerated dose (MTD) and recommended dose (RD) in gastric cancer patients. Patients and Methods: Nine gastric cancer patients with peritoneal dissemination and/or cancer cells on peritoneal cytology were enrolled. PTX was administered intravenously on days 1 and 8 at a fixed dose of 50 mg/m², and intraperitoneally with an initial dose of 20 mg/m², stepped up to 30 or 40 mg/m². S-1 was administered at a fixed dose of 80 mg/m²/day for 14 consecutive days, followed by 7 days of rest. A pharmacokinetic study of PTX was also performed. Results: The MTD was determined to be 30 mg/m², as 2 of 3 patients developed dose-limiting toxicities, grade 3 febrile neutropenia and diarrhea. Therefore, the RD was determined to be 20 mg/m². The intraperitoneal and serum PTX concentration remained effective for over 72 and 48 h, respectively. Conclusions: Combined chemotherapy of S-1 plus weekly intravenous and intraperitoneal PTX was shown to be a safe regimen that should be further explored in clinical trials.

In situ cross-linkable HA hydrogels represent a promising biomaterial to prolong the retention and sustain the release of intraperitoneally administered CDDP in the peritoneal cavity and to enhance its antitumor effects against peritoneal dissemination.

Intraoperative blood loss in curative gastrectomy for advanced gastric cancer may have a specific association with the development of peritoneal recurrence. Surgeons must remember that clean and dry surgery may lessen not only 30-day mortality and morbidity but long-term peritoneal recurrence in gastric cancer.

Intraperitoneal (i.p.) administration of paclitaxel (PTX) is a hopeful

Intraperitoneal (i.p.) administration of paclitaxel nanoparticles (PTX‐30W) prepared by solubulization with the amphiphilic copolymer of 2‐methacryloxyethyl phosphorylcholine and n‐butyl methacrylate can efficiently suppress the growth of peritoneal metastasis. In this study, we characterized the drug distribution of i.p. injected PTX‐30W in peritoneal tumor and liver in a mouse model using MKN45, human gastric cancer cells. Oregon green‐conjugated PTX‐30W showed perivascular accumulation in MKN45 tumor in the peritoneum at 24 h after intravenous (i.v.) injection; however, the amount of PTX in tumor was markedly less than that in liver. In contrast, a larger amount of PTX accumulated in the peripheral area of disseminated nodules at 1 h after i.p. injection and the area gradually enlarged. The depth of PTX infiltration reached 1 mm from the tumor surface at 48 h after i.p. injection, and the fluorescence intensity was markedly greater than that in liver. Interestingly, i.p. injected PTX preferentially accumulated in relatively hypovascular areas, and many tumor cells in the vicinity of PTX accumulation showed apoptosis. This unique accumulation pattern and lesser washout in hypovascular areas are thought to be attributable to the superior penetrating activity of PTX‐30W, and thus, PTX‐30W is considered to be highly suitable for i.p. chemotherapy for peritoneal dissemination. (Cancer Sci 2011; 102: 200–205)

4542 Background: A phase II study to evaluate the efficacy and tolerability of weekly intravenous and intraperitoneal paclitaxel combined with S-1 was performed in gastric cancer patients with peritoneal metastasis. Methods: Gastric cancer patients with peritoneal dissemination and/or cancer cells on peritoneal cytology were enrolled. Paclitaxel was administered intravenously at 50 mg/m2 and intraperitoneally at 20 mg/m2 on days 1 and 8. S-1 was administered at 80 mg/m2/day for 14 consecutive days, followed by 7 days rest. The primary endpoint was the 1-year overall survival rate. Secondary endpoints were the response rate, efficacy against malignant ascites and safety. Results: Forty patients were enrolled, including 21 with primary tumors with peritoneal dissemination confirmed by staging laparoscopy, 13 with peritoneal recurrence, and 6 with positive peritoneal cytology only. The median number of courses administered was 7 (range 1–23). The 1-year overall survival rate was 78% (95% CI, 65–90%). The overall response rate was 56% (95% CI, 32–79%) in 18 patients with target lesions. Malignant ascites disappeared or decreased in 13 of 21 (62%) patients. The incidences of grade 3/4 hematological and non- hematological toxicities were 40% and 15%, respectively. The frequent grade 3/4 toxicities included neutropenia (38%), leukopenia (18%), anemia (10%), and nausea (8%). Catheter obstruction observed in one patient was the only complication related to the peritoneal access device or intraperitoneal infusion. There were no treatment-related deaths. Conclusions: Combination chemotherapy of intravenous and intraperitoneal paclitaxel with S-1 is well tolerated and active in gastric cancer patients with peritoneal metastasis. No significant financial relationships to disclose.

TLR measured with FACS is an excellent reflection of the tumor spread in the peritoneal cavity and could be a reliable diagnostic biomarker to determine the severity of PM as well as effectiveness of IP chemotherapy.