[Prognostic factors for development of peritoneal carcinosis in stomach carcinoma]

Intraperitoneal immunotherapy to prevent peritoneal carcinomatosis in patients with advanced gastrointestinal malignancies

Prognosis of peritoneal carcinomatosis (PC) from GI tract cancers remains poor. As 30% of patients develop PC after curative surgery, prevention of PC during cancer resection would be desirable. Regarding physiopathology of PC and intraperitoneal immunology, intraoperative application of trifunctional antibodies offers advanced opportunities for destruction of intraperitoneal tumor cells and prevention of PC. First results indicated, the intraoperative treatment with trifunctional antibodies was safe and clinically feasible. Long-term results will be available in 2010.

Inhibition of gastric cancer cell adhesion in nude mice by inraperitoneal phospholipids

Adhesion of tumor cells to mesothelial cells or extracellular matrix components is a pivotal step in developing peritoneal dissemination after gastric cancer. As phospholipids were found to reduce adhesion formation, especially at sites of peritoneal lesions, we assessed the inhibition of attachment of NUGC-4 gastric cancer cells by local treatment with phospholipids to the peritoneum in nude mice. Gastric cancer cells (1xl0(6)) suspended in either normal saline (controls) or phospholipid suspension 75 mg/kg body weight (PL75) or 150 mg/kg (PL150) were injected intraperitoneally into 90 female BALB/c nu/nu mice. The treatment groups were subdivided into animals with defined peritoneal lesions and animals without lesions. After 30 days the extent of peritoneal carcinosis and the Peritoneal Cancer Index were evaluated. Statistical analysis was performed with two factorial ANOVAs. The level of significance was adjusted according to Bonferrorni (alpha = 0.00278). During a 90-day observation period the survival rate was determined using the log rank test. After 30 days the intraperitoneal tumor volume was reduced by PL150 up to 0.6 ml (SEM 0.16) and 0.48 ml (SEM 0.09) in mice with peritoneal lesions compared to 0.9 ml (SEM 0.2) and 0.9 ml (SEM 0.1) in the control group (P = 0.04). The mean area of tumor adhesion amounted to 145 mm(2) (SEM 17) (P = 0.08) and 164 mm(2) (SEM 32.8) (P = 0.049) with peritoneal lesions after treatment with PL150 [controls: 216 mm(2) (SEM 28.5) and 245 mm(2) (SEM 29.3)]. The peritoneal cancer index was 16.4 (SEM 1.7) in the control group and 9 (SEM 1.68) with PL150 (P = 0.0002). In the subgroup with peritoneal lesions, the respective values were as follows: controls: 20.8 (SEM 0.85); PL 150:14.3 (SEM 1.07) (P = 0.0001). We found a prolonged survival rate after treatment with PL150. However, this effect was not significantly different to that seen in the control group. Treatment with PL75 had no significant influence. Phospholipids may be an efficacious and economic tool for reducing peritoneal tumor cell adhesion and consequently the development of peritoneal carcinosis after resection of gastric cancer.

Phospholipids reduce the intraperitoneal adhesion of colonic tumor cells in rats and adhesion on extracellular matrix in vitro

OBJECTIVE

To evaluate the influence of intraperitoneal treatment with phospholipids on the formation of peritoneal carcinosis after inoculation of colonic tumor cells in rats. The presence of tumor cells in the peritoneal cavity serves as a prognostic marker for postoperative survival after resection of gastrointestinal cancer. Intraperitoneal tumor cell attachment is a pivotal step in developing peritoneal carcinosis. Intraabdominal application of phospholipids resulted in a significant decrease of adhesion formation, especially at sites of peritoneal lesions.

METHODS

2x10(6) colonic tumor cells (DHD/K12/TRb) were injected intraperitonely in female BD-IX rats. A total of 90 rats were divided into three groups with treatments of phospholipids at 75 mg/kg or 150 mg/kg bodyweight or sodium chloride at 0.9% in the control group. The treatment groups were subdivided into animals with defined peritoneal lesions and animals without lesions. After 30 days, the extent of peritoneal carcinosis was determined by measuring the tumor volume, the area of tumor attachment and the Peritoneal Cancer Index. Over a 90-day observation period, the survival rate was analyzed. In vitro, we examined the reduction of tumor cell adhesion on extracellular matrix components after treatment with phospholipids. Microtiter plates were coated with laminin, fibronectin or collagen IV for adhesion experiments.

RESULTS

In our study, we found a significant reduction of peritoneal dissemination with respect to all evaluation methods after treatment with phospholipids at 150 mg/kg in animals without peritoneal lesions. This could not be achieved using the lower concentration of phospholipids (75 mg/kg). In vitro, the maximum reductions of tumor cell adhesion by phospholipids compared with the control values for laminin and fibronectin were 46% and 37%, respectively, whereas for collagen IV the reduction was only 24% ( p<0.0001).

CONCLUSIONS

A new method of prevention of intraperitoneal tumor cell adhesion, possibly leading to a reduced incidence of peritoneal carcinosis after surgery of gastrointestinal tumors, is introduced.

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Weekly treatment with irinotecan, folinic acid and infusional 5-fluorouracil (ILF) in patients with advanced gastric cancer

Although 5-fluorouracil remains the mainstay of treatment for advanced gastric cancer (AGC), no standard chemotherapy regimen exists. Combinations of irinotecan with folinic acid and infusional 5-fluorouracil (5-FU) (ILF) have shown good efficacy with acceptable toxicity in patients with metastatic colorectal cancer. At present, only sparse data on ILF are available for AGC. Therefore we conducted a prospective study of this combination in 25 consecutive patients with metastatic gastric cancer. Median age was 63 years, 10 had received prior chemotherapy and 13 presented initially with peritoneal carcinosis. Treatment consisted of irinotecan 80 mg/m2, folinic acid 500 mg/m2 and infusional 5-FU 2.0 g/m2 over 24 h, given weekly for 6 weeks followed by a 1-week rest. Grade 3/4 hematologic toxicity occurred in six patients (anemia = 4, neutropenia = 1 and leukopenia = 1). Non-hematologic toxicity consisted mainly of nausea/vomiting (grade 3/4 in six patients) and diarrhea (grade 3/4 in 10 patients). The overall response rate was 20% for first- and second-line treatment, with two complete and three partial responses. Another nine patients (36%) had stable disease, for a tumor control rate of 56%. Median time to progression was 4 months, median overall survival and survival for patients with tumor control was 7 and 13 months, respectively. We conclude that ILF is a feasible outpatient regimen with manageable toxicity that provides tumor control in a high proportion of patients with advanced gastric cancer, even among those with unfavorable prognostic features.