New therapeutic strategies to avoid intra- and extraperitoneal metastases during laparoscopy: results of a tumor model in the rat

Innovative substance 2250 as a highly promising anti-neoplastic agent in malignant pancreatic carcinoma - in vitro and in vivo

BACKGROUND

Former studies already revealed the anti-neoplastic properties of the anti-infective agent Taurolidine (TRD) against many tumor species in vitro and in vivo. Its anti-proliferative and cell death inducing capacity is largely due to its main derivative Taurultam (TRLT). In this study it could be demonstrated, that substance 2250 - a newly defined innovative structural analogue of TRLT - exhibits an anti-neoplastic effect on malignant pancreatic carcinoma in vitro and in vivo.

METHODS

The anti-neoplastic potential of substance 2250 as well as its mode of action was demonstrated in extensive in vitro analysis, followed by successful and effective in vivo testings, using xenograft models derived from established pancreatic cancer cell lines as well as patient derived tissue.

RESULTS

Our functional analysis regarding the role of oxidative stress (ROS) and caspase activated apoptosis showed, that ROS driven programmed cell death (PCD) is the major mechanisms induced by substance 2250 in pancreatic carcinoma. What is strongly relevant towards clinical practice is especially the observed inhibition of patient derived pancreatic cancer tumor growth in mice treated with this new substance in combination with its sharply higher metabolic stability.

CONCLUSION

These encouraging results provide new therapeutical opportunities in pancreatic cancer treatment and build the basis for further functional analysis as well as first clinical studies for this promising agent.

Animal models of colorectal peritoneal metastasis

Colorectal cancer remains an important cause of mortality worldwide. The presence of peritoneal carcinomatosis (PC) causes significant symptoms and is notoriously difficult to treat. Therefore, informative preclinical research into the mechanisms and possible novel treatment options of colorectal PC is essential in order to improve the prognostic outlook in these patients. Several syngeneic and xenograft animal models of colorectal PC were established, studying a wide range of experimental procedures and substances. Regrettably, more sophisticated models such as those giving rise to spontaneous PC or involving genetically engineered mice are lacking. Here, we provide an overview of all reported colorectal PC animal models and briefly discuss their use, strengths, and limitations.

Taurolidine cooperates with antineoplastic drugs in neuroblastoma cells

Neuroblastoma is the most common extracranial tumor in childhood. Outcome of stage 4 disease remains poor and the development of novel therapeutic approaches is thus urgently needed. Taurolidine (TRD), originally invented to avoid catheter infections, has shown to exhibit antineoplastic activity in various cancers. The growth of neuroblastoma cell lines is inhibited by TRD as recently demonstrated. Further analysis disclosed a significant negative growth effect of TRD on the four neuroblastoma cell lines SH-EP TET21N, SK-N-AS, SK-N-BE(2)-M17 and SK-N-SH. Detected IC50 (51-274 μM; 48 h) are promising and correspond to clinically-achievable plasma levels. Apoptosis was induced (76-86%; 48 h) in a time-dependent manner mediated by a simultaneous activation of the intrinsic and extrinsic pathways. This was confirmed by cleavage of caspases -3, -8 and -9 and abrogation of apoptosis by pan-caspase inhibition. Application of TRD resulted in a significant enhancement of cytotoxic drugs vincristine/doxorubicin (2/3 of 4 cell lines) making TRD a promising candidate to be included in neuroblastoma therapy regimens in the future.

Redox-directed cancer therapeutics: Taurolidine and Piperlongumine as broadly effective antineoplastic agents (review)

Targeting the oxygen stress response pathway is considered a promising strategy to exert antineoplastic activity in a broad spectrum of tumor types. Supporting this view, we summarize the mechanism of action of Taurolidine and Piperlongumine, two antineoplastic agents with strikingly broad tumor selectivity. Taurolidine enhances the oxidative stress (ROS) selectively in tumor cells. Its cytotoxicity for various tumor cells in vitro and in vivo, which includes tumor stem cells, is based on the induction of programmed cell death, largely via apoptosis but also necroptosis and autophagy. The redox-directed mechanism of action of Taurolidine is apparent from the finding that reducing agents e.g., N-acetylcysteine or glutathione impair its cytotoxicity, while its effectiveness is enhanced by agents which inhibit the cellular anti‑oxidant capacity. A similar redox-directed antineoplastic action is shown by Piperlongumine, a recently described experimental drug of plant origin. Taurolidine is particularly advantageous in surgical oncology as this taurine-derivative can be applied perioperatively or systemically with good tolerability as shown in initial clinical applications.

Selection of irrigation fluid to eradicate free cancer cells during head and neck cancer surgery

BACKGROUND

Free cancer cells can be spilled out from exposed tumors or ruptured tumors. We examined the cytocidal effect of various irrigation fluids on free cancer cells in an animal wound model mimicking head and neck surgery.

METHODS

Cancer cell-contaminated wounds were made with C3H/HeJ mice and syngeneic squamous cell carcinoma (SCC VII) cells. Distilled water, 5% povidone-iodine, 1.5% H(2)O(2), normal saline, and cisplatin were used to irrigate for 5 minutes. In vitro tumor growth assays were done with different concentrations and exposure times of povidone-iodine and distilled water.

RESULTS

In the animal study, povidone-iodine significantly inhibited tumor growth. Povidone-iodine caused substantial inhibition of in vitro tumor growth, even at the concentration of 0.05%. After 30 seconds of exposure to 1% povidone-iodine, cancer cells were completely inhibited.

CONCLUSIONS

Povidone-iodine could be selected preferentially for the irrigation fluid during head and neck surgery, especially when the wound is suspected of cancer cell contamination.

Oral administration of the anti-proliferative substance taurolidine has no impact on dextran sulfate sodium induced colitis-associated carcinogenesis in mice

Background:

New chemopreventive strategies for ulcerative colitis (UC)-associated dysplasia and cancer have to be evaluated. Taurolidine (TRD) has anti-inflammatory, anti-proliferative and anti-neoplastic properties with almost absent toxicity. The aim of the study was to determine whether TRD decreases dysplasia in the well-characterized Dextran Sulfate Sodium – Azoxymethane (DSS-AOM) animal model for UC-associated carcinogenesis.

Material and Methods:

The DSS-AOM model of carcinogenesis was induced in female inbred C57BL/6 mice. Half of the mice were treated with TRD, the other served as control. After 100 days macroscopic, histological and immunhistochemical (β-Catenin, E-Cadherin, SOX9, Ki-67, Cyclin-D1) examination of the colon was performed.

Results:

Incidence, multiplicity, grading and growth pattern of adenomas did not differ significantly between TRD and control group. In all animals, inflammatory changes were absent. Immunhistochemistry revealed increased expression of Ki-67, β-catenin, SOX9 and Cyclin-D1 in adenomas compared to normal mucosa – without significant difference between TRD and control treatment.

Conclusion:

Oral administration of TRD has no impact on DSS-induced colitis-associated carcinogenesis. However, SOX9 and Cyclin-D1 representing key members of the Wnt pathway have not yet been described in the DSS-AOM model of carcinogenesis – underlining the importance of this oncogenic pathway in this setting.

The evolving role of taurolidine in cancer therapy

BACKGROUND AND DESIGN

Taurolidine consists of two taurinamide rings derived from the naturally occurring amino acid taurine. It has been utilized to prevent adhesions, as an antimicrobial, and as an anti-inflammatory agent. More recently, it has been found to exert antineoplastic activity. We reviewed the literature regarding taurolidine and its role in cancer treatment.

RESULTS AND CONCLUSION

Taurolidine induces cancer cell death through a variety of mechanisms. Even now, all the antineoplastic pathways it employs are not completely elucidated. It has been shown to enhance apoptosis, inhibit angiogenesis, reduce tumor adherence, downregulate proinflammatory cytokine release, and stimulate anticancer immune regulation following surgical trauma. Apoptosis is activated through both a mitochondrial cytochrome-c-dependent mechanism and an extrinsic direct pathway. A lot of in vitro and animal data support taurolidine's tumoricidal action. Taurolidine has been used as an antimicrobial agent in the clinical setting since the 1970s and thus far appears nontoxic. The nontoxic nature of taurolidine makes it a favorable option compared with current chemotherapeutic regimens. Few published clinical studies exist evaluating the role of taurolidine as a chemotherapeutic agent. The literature lacks a gold-standard level 1 randomized clinical trial to evaluate taurolidine's potential antineoplastic benefits. However, these trials are currently underway. Such randomized control studies are vital to clarify the role of taurolidine in modern cancer treatment.

Taurolidine reduces the tumor stimulating cytokine interleukin-1beta in patients with resectable gastrointestinal cancer: a multicentre prospective randomized trial

BACKGROUND

The effect of additional treatment strategies with antineoplastic agents on intraperitoneal tumor stimulating interleukin levels are unclear. Taurolidine and Povidone-iodine have been mainly used for abdominal lavage in Germany and Europe.

METHODS

In the settings of a multicentre (three University Hospitals) prospective randomized controlled trial 120 patients were randomly allocated to receive either 0.5% taurolidine/2,500 IU heparin (TRD) or 0.25% povidone-iodine (control) intraperitoneally for resectable colorectal, gastric or pancreatic cancers. Due to the fact that IL-1beta (produced by macrophages) is preoperatively indifferent in various gastrointestinal cancer types our major outcome criterion was the perioperative (overall) level of IL-1beta in peritoneal fluid.

RESULTS

Cytokine values were significantly lower after TRD lavage for IL-1beta, IL-6, and IL-10. Perioperative complications did not differ. The median follow-up was 50.0 months. The overall mortality rate (28 vs. 25, p = 0.36), the cancer-related death rate (17 vs. 19, p = .2), the local recurrence rate (7 vs. 12, p = .16), the distant metastasis rate (13 vs. 18, p = 0.2) as well as the time to relapse were not statistically significant different.

CONCLUSION

Reduced cytokine levels might explain a short term antitumorigenic intraperitoneal effect of TRD. But, this study analyzed different types of cancer. Therefore, we set up a multicentre randomized trial in patients undergoing curative colorectal cancer resection.

TRIAL REGISTRATION

ISRCTN66478538.

The use of a wound protector to prevent port site recurrence may not be totally logical

The wound protector has been used widely to prevent port site metastases (PSM). Although port site metastases ties in with poor survival, it is not because of PSM itself, but rather because PSM is a sign of more widespread metastatic disease. Whilst being touted as a method of preventing PSM, it fails to address the bigger issue of preventing intra-abdominal recurrence. Proper surgical technique in tumour handling following rigorous oncological principles, and not just putting in a wound protector is the key to good surgery with low recurrences and excellent survival rates.

Application of a solid tumor model to evaluate tumor recurrence after an open or laparoscopic rectal resection in rats

PURPOSE

We used a solid tumor model to evaluate the influence of laparotomy versus laparoscopy on tumor growth after curative resection for rectal cancer in rats.

METHODS

Colon tumor cells (DHD/K12/TRb) were administered intraperitoneally in 15 rats, which were used as solid tumor donors. Twenty-one days later, a 20-mg piece was then implanted in the rectal submucosa of the study rats (n=45). Animals were randomized into 3 groups for rectal resection either open or laparoscopic using either carbon dioxide (CO2) or helium for pneumoperitoneum. Autopsy took place 21 days after resection and tumor recurrence was evaluated.

RESULTS

Port-site metastasis was observed after laparoscopy with CO2 (1 animal) and helium (1), whereas intraperitoneal tumor growth was detected in 2 and 3 animals of these groups. No tumor recurrence was observed after open surgery.

CONCLUSIONS

Our solid tumor model is a novel neoplastic model that might simulate the clinical situation of an upper rectal carcinoma. It might be helpful to develop new protocols in studying solid tumor biology and different surgical procedures for cancer to address problematic issues in oncologic research.

The tumor suppressive reagent taurolidine inhibits growth of malignant melanoma--a mouse model

BACKGROUND

The tumor suppressive agent taurolidine (TRD) inhibits tumor growth of more than 30 cell lines in vitro and reduces tumor load in early and advanced stages of neoplastic disease in animals. TRD has been shown to induce apoptosis of melanoma cells in vitro. Therefore, the effects of TRD on disseminated melanoma were evaluated in a mice model.

METHODS

After general anesthesia, a midline laparotomy was performed and 1.5 million malignant melanoma cells (B78-D14) were applied in the spleen and 1 million cells at the back (C57BL/6). Animals were randomized and either treated intraperitoneally (i.p., n = 40, 7 days, 12 hourly) or intravenously (i.v., n = 40, 2 days, 12 hourly) with 1%, 2%, or 3% TRD or with Ringer's solution (control group). On day 28, all animals were sacrificed and the total tumor weight and the number of metastatic lesions were determined by two investigators blinded for randomization.

RESULTS

The i.p. therapy caused a dose-dependent inhibition of total tumor growth (P = 0.003) and i.p. tumor growth (P = < 0.001), whereas subcutaneous (s.c.) tumor growth was not affected (P = 0.132) compared with the i.p. control group. The i.v. therapy reduced the total tumor growth (P = 0.013) and the s.c. tumor growth (P = 0.016), whereas the i.p. tumor load was not reduced (P = 0.122) compared with the control group. Both i.p. and i.v. therapy with 3% TRD significantly decreased the total number of metastatic lesions. The animal weight was not affected.

CONCLUSIONS

The i.p. and i.v. therapies reduce total tumor weight and number of metastatic lesions of disseminated malignant melanoma in a dose-dependent fashion in mice. Our encouraging findings should be further confirmed in clinical studies examining the influence of TRD in patients with disseminated malignant melanoma for whom prognosis still remains dismal.

Laparoscopic resection of curable colon and rectal cancer: an evidence-based review

The initial enthusiastic application of laparoscopic techniques to colorectal surgical procedures was tempered in the early 1990s by reports of tumor implants in the laparoscopic incisions. Substantial evidence has accumulated, including evidence from randomized controlled trials, to support that laparoscopic resection results in oncologic outcomes similar to open resection, when performed by well-trained, experienced surgeons. This review was developed in conjunction with guidelines published by the Society of American Gastrointestinal and Endoscopic Surgeons. Data from the surgical literature concerning laparoscopic resection of curable colorectal cancer was evaluated regarding diagnostic evaluation, preoperative preparation, operative techniques, prevention of tumor implants, and training and experience. Recommendations are accompanied by an assessment of the level of supporting evidence available at the time of the development of the guidelines.

The pharmacokinetics of taurolidine metabolites in healthy volunteers

Taurolidine is an experimental antibacterial and antiendotoxic compound whose clinical utility as an antitumor agent is being investigated in human clinical trials. Taurolidine in aqueous solution exists in equilibrium with taurultam. Taurultam is subsequently transformed to taurinamide. The pharmacokinetic profiles of these metabolites are not well established. In this study, 18 healthy volunteers were administered 5.0 g of taurolidine in 250 mL of 5% polyvinylpyrrolidone in water over 2, 1, or 0.5 hours by intravenous infusion in a parallel-group design. All subjects noted discomfort at the infusion site, although there were no serious adverse events. t(max) generally occurred at the end of infusion for taurinamide, whereas that of taurultam was reached before completion of infusion. The taurolidine metabolite taurultam demonstrated a shorter half-life and lower systemic exposure than taurinamide. Shortening of infusion duration increased the C(max) and AUC of taurultam. Changes in infusion rate did not substantially change the pharmacokinetic parameters of taurinamide.

Instillation of taurolidine/heparin after laparotomy reduces intraperitoneal tumour growth in a colon cancer rat model

OBJECTIVE

To investigate whether irrigation of the abdominal cavity after laparotomy for caecum resection with taurolidine/heparin or adhesion prophylactic substances reduces intraperitoneal tumour growth or the local recurrence rate in a colon carcinoma rat model.

METHODS

60 BDIX rats underwent caecum resection after intraperitoneal inoculation of 1 x 10(4) colon carcinoma cells (DHD/K12/TRb). Intergel, Interceed, taurolidine/heparin or NaCl 0.9% were intraperitoneally applied after randomisation. Finally, the total number and total weight of intraperitoneal metastases were determined as well as the adhesion score according to Moreno. Metastatic tissue was examined histologically and immunohistochemically (E-cadherin, CD44, beta(1)-integrin).

RESULTS

Taurolidine/heparin significantly reduced not only the total number (3 vs. 11 in the control group) but also the total weight (65 vs. 330 mg) of intraperitoneal metastases in comparison to the control group (p = 0.003 and p = 0.005). E-Cadherin expression in the metastatic tissue of animals treated with taurolidine/heparin was significantly decreased (p = 0.016).

CONCLUSION

Taurolidine/heparin effectively reduces intraperitoneal tumour growth when used as an intraoperative lavage. These results represent a good rationale for intraoperative adjuvant irrigation with taurolidine/heparin during resection of colon cancer.

Influence of intraperitoneal application of taurolidine/heparin on expression of adhesion molecules and colon cancer in rats undergoing laparoscopy

BACKGROUND

Recent experimental studies have shown that intraperitoneal administration of taurolidine/heparin causes a reduction of local tumor growth after laparoscopy in rat models. It might be that the anti-adherent activities of these agents are responsible for this effect. In this study we investigated the adhesion molecules E-cadherin, beta1-integrin, and CD44.

MATERIALS AND METHODS

Following a 10,000 colon adenocarcinoma cells' (DHD/K12/TRb) intraperitoneal application a cecum resection and a partial parietal peritoneum resection (1 x 1 cm) were performed using a three trocar technique in 30 BD IX rats. After randomization in two groups, the cecum suture line and the parietal peritoneal defect were either lavaged with 1 mL of 0.5% taurolidine/10 IU heparin or with equal amounts of 0.9% normal saline solution. Rats were sacrificed four weeks after operation and total tumor growth was determined. E-cadherin, beta1-integrin, and CD44 were assessed immunohistochemically on the tumor tissue.

RESULTS

The expression of E-cadherin was significantly reduced to 46.7% (complete loss of staining) in the taurolidine/heparin group. Although no significant difference was detected concerning the beta1-integrin and CD44 expression, a slightly reduced expression level with 26.7% of negative staining in metastases of the taurolidine/heparin group was observed. The total tumor weight (171.1 +/- 181.2 mg) as well as the total number of tumor lesions was also reduced by the substances compared to the control group (283.2 +/- 91.4 mg).

CONCLUSIONS

Taurolidine/heparin led to a significant reduction of local tumor growth. Additionally a reduction of the expression of E-cadherin was observed. However, the biological behavior of this molecule is multivariant, controversial and still unclear. Further studies should elucidate its role in the epithelial tumor genesis.

Mechanisms of heparin induced anti-cancer activity in experimental cancer models

BACKGROUND

Retrospective analyses of clinical trials and prospective clinical studies have suggested that heparins may have an effect on cancer survival. This putative anti-cancer activity of heparins is supported by data from studies in animal tumour models.

OBJECTIVE

To clarify the various potential mechanisms of heparin anti-cancer activity we evaluated the data from pre-clinical studies in which heparins have been tested as anti-cancer therapy.

METHODS

Pre-clinical studies, published between 1960 and 2005 were assessed. Data were collected on the type and dose of heparin used, duration of exposure to heparin, interval between heparin administration and cancer cell inoculation, and the animal tumour model used. In addition, a distinction was made in the analysis between heparin effects on the primary tumour or on established metastases and effects on the metastatic potential of infused cells.

RESULTS

Heparins seemed to affect the formation of metastasis rather than the growth of primary tumours. Chemically modified heparins with no or limited anticoagulant activity also showed anti-metastatic properties. Possible mechanisms to explain the effects on the process of metastases include inhibition of blood coagulation, inhibition of cancer cell-platelet and -endothelial interactions by selectin inhibition and inhibition of cell invasion and angiogenesis.

CONCLUSION

The anti-cancer activity of heparins depends more on inhibition of metastasis formation than on the effects on primary tumour growth. These effects are probably related to both coagulation and non-coagulation dependent factors. For a definitive proof of the anti-cancer activity of heparins in the clinic, prospective randomized trials especially in patients with early metastatic disease or in the adjuvant setting are urgently needed.

Prevention of disease progression in a patient with a gastric cancer-re-recurrence. Outcome after intravenous treatment with the novel antineoplastic agent taurolidine. Report of a case

Background

Taurolidine (TRD) is a novel agent with multimodal antineoplastic effects. We present the case of a tumor remission after intravenous administration of taurolidine in a patient with gastric cancer re-recurrence.

Case presentation

A 58 years old male patient suffering from a gastric adenocarcinoma was submitted to partial gastrectomy and partial liver resection (pT2, pN1, pM1_L (liver segment 2), N0, V0). 24 months later a local recurrence was diagnosed and the patient was reoperated. Postoperatively the patient underwent a palliative chemotherapy with eloxatin, FU, and leucovorin. A subsequent CT-revealed a liver metastasis and a recurrence adjacent to the hepatic artery. After successful radiofrequency ablation of the liver metastasis the patient was intravenously treated with 2% taurolidine. The patient endured the therapy well and no toxicity was observed. CT-scans revealed a stable disease without a tumor progression or metastatic spread. After 39 cycles the patient was submitted to left nephrectomy due to primary urothelial carcinoma and died 2 days later due to myocardial infarction. Postmortem histology of the esophageal-jejunal anastomosis and liver revealed complete remission of the known metastasized gastric adenocarcinoma.

Conclusion

The intravenous treatment with 2% taurolidine led to a histological remission of the tumor growth without any toxicity for the patient.

High doses of taurolidine inhibit advanced intraperitoneal tumor growth in rats

BACKGROUND

The antitumor agent taurolidine (TRD) affects tumor growth in animals. Thus far, no animal studies have been published concerning the systemic or local toxicity and the effectiveness of long-term intraperitoneal (i.p.) and intravenous (i.v.) administration on advanced tumor growths.

MATERIALS AND METHODS

In a first experiment (A) the systemic toxicity of the liver and kidneys was examined only after i.v. treatment in 40 rats (BD IX). For local toxicity the superior vena cava (SVC) was histologically analyzed. In a second study (B) 20,000 colon adenocarcinoma cells (DHD/K12/TRb) were initially applied i.p. after laparotomy in 80 rats (BD IX). After 28 days a port catheter system was placed in the SVC and left for 1 week. The animals were randomized into eight groups (n = 10) and received a 7-day treatment (eight hourly, 1 ml): 1, 2, 3% TRD or Ringer's solution (control group) either i.p. or i.v. Total i.p. tumor weight was measured 4 weeks after the end of the therapy. Side effects on differential blood counts and animal weight changes were examined.

RESULTS

No organ lesions were detected in liver, kidneys, and SVC in experiment A. The i.v. administration of 2% TRD (P = 0.034) and 3% TRD (P = 0.05) as well the i.p. application of 2% TRD (P = 0.05) decreased the development of advanced i.p. tumor lesions. No changes of differential blood count nor relevant animal weight changes resulted. Three port catheter-related infections were examined.

CONCLUSIONS

TRD does not impair the liver tissue, kidneys, SVC, and leucopoiesis. The intravenous therapy of 2% TRD is safe and anti-tumorigenic in advanced local tumor growth in rats.

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.

Taurolidine–a new drug with anti-tumor and anti-angiogenic effects

Taurolidine [bis(1,1-dioxoperhydro-1,2,4-thiadiazinyl-4)-methane (TRD)], a product derived from the aminosulfoacid taurin, was first described as an anti-bacterial substance. It was mainly used in the treatment of patients with peritonis as well as antiendoxic agent in patients with systematic inflammatory response syndrome. Meanwhile, quite interesting new experimental findings elucidated several new mechanisms concerning not only antibiotic but also anti-tumor effects. TRD significantly reduces the pathogenicity of prokaryotes, leading to a degeneration of the bacterial wall, and binds free lipoplysaccharides (LPSs) and exotoxins. Furthermore syntheses of tumor necrosis factor-a and interleukin-1b are reduced in LPS-stimulated human macrophages in a dose dependent manner. Tumor angiogenesis is promoted by enhanced expression of all these endogenous angiogenic factors, indicating an anti-angiogenetic effect of TRD. Tumor angiogenesis has a key role in tumor growth. TRD additionally inhibits tumor cell growth by a mitochondrial cytochrome c-dependent apoptotic mechanism, has a direct and elective effect on glial and neuronal brain tumor cells via Fas-ligand-mediated cell death, and inhibits protein synthesis at an early phase of translation, which might explain its various apoptotic effects. Subsequent to these experimental observations, TRD has shown encouraging clinical results after intravenous administration in patients with gastrointestinal malignancies and tumors of the central nerve system. A remarkable experimental observation that comes to complete the above-mentioned findings is the low toxicity on leukopoiesis and erythropoiesis as well as on kidney and liver function in animal models. Several other data confirm low toxicity of the agent after its clinical administration in humans. Prospective clinical studies are currently investigating the efficacy of TRD on local and metastatic tumor growth in different malignancies.

Impact of taurolidin and octreotide on liver metastasis and lipid peroxidation after laparoscopy in chemical induced ductal pancreatic cancer

BACKGROUND

There is controversial discussion whether metastasis initiated by laparoscopy with carbon dioxide might be prevented by instillation of taurolidin or radical scavengers like the somatostatin analogue Octreotide. Therefore we evaluated the effects of laparoscopic lavage with taurolidin and Octreotide on liver metastasis after staging laparoscopy in ductal pancreatic cancer.

METHODS

In 60 Syrian hamsters pancreatic adenocarcinoma was induced by weekly subcutanous injection of 10 mg N-nitrosobis-2-oxopropylamin/kg body weight for 10 weeks. In the 16th week laparoscopic staging biopsy by use of carbon dioxide was performed. Finally animals underwent abdominal irrigation with saline (gr.1, n = 20), taurolidin (0.5%) (gr.2, n = 20) or Octreotide (gr.3, n = 20). In week 25 animals were sacrificed, pancreas and liver were analysed.

RESULTS

Size of pancreatic carcinomas was decreased in the taurolidin gr. compared to the other two groups. Furthermore the number of liver metastasis per animal was reduced after lavage with taurolidin (2 +/- 2) and Octreotide (2.5 +/- 2) compared to saline irrigation (4 +/- 4) (p < 0.05). Additionally the incidence of port site metastases was significantly reduced in the taurolidin group. Activity of antioxidative enzyme superoxide dismutase (SOD) was increased while concentration of products of lipidperoxidation was decreased in non-metastatic liver after taurolidin irrigation compared to saline or Octreotide irrigation.

CONCLUSIONS

Taurolidin irrigation during laparoscopy might be a new concept to reduce the number of liver metastasis and port site metastases in pancreatic cancer.

Effects of increasing doses of a bolus injection and an intravenous long-term therapy of taurolidine on subcutaneous (metastatic) tumor growth in rats

BACKGROUND

Experimental studies have shown that taurolidine suppresses intraperitoneal tumor growth following local application in rats. In opposite, a single intravenous therapy affected neither intraperitoneal nor subcutaneous growth of malignancies. Thus, an intravenous long-term therapy with taurolidine was investigated in rats after administration of a subcutaneous tumor load. VEGF and TNFalpha production and their effects on tumor growth have not been elucidated so far.

METHODS

VEGF and TNFalpha levels of rat colon adenocarcinoma cells (DHD/K12/TRb) were analyzed in the supernatant undergoing treatment of increasing taurolidine doses in vitro. Besides the cell experiments rats were treated intravenously. At the beginning of the operation, 10 000 colon adenocarcinoma cells were applied subcutaneously at the back of the rats. Then the animals (n = 80, BD IX rats) were randomized into eight groups and underwent a standardized midline laparotomy for 30 min. At the end of the operation the animals were given either a bolus (1 ml Ringer's solution) or a long-term intravenous therapy (7 days, eight-hourly 1 ml 1%, 2%, or 3% taurolidine) were performed. For long-term therapy, a jugularis vein port catheter system was placed and left for 1 week. The influence on subcutaneous tumor growth, animal growth, general side effects and leukocyte/granulocyte levels were analyzed. Total tumor weights were determined 4 weeks after cell application.

RESULTS

The VEGF and TNFalpha levels decreased rapidly after taurolidine therapy with low doses in vitro. The subcutaneous tumor growth showed a downtrend of tumor weight (P = 0.075) with a statistical significance in solid tumor counts (P = 0.04) at the back of the animals. A slight and temporary depression in animal growth was observed only in long-term therapy groups. Independent of the therapeutic agents and the application forms, the operation itself caused a slight leukopenia shortly after the operation compensated by a moderate leukocytosis in the following course. Fast injections of taurolidine led to a reduction of breathing rate.

CONCLUSIONS

Only the intravenous long-term therapy of 3% taurolidine led to a slight downregulation in subcutaneous tumor growth. The changes of leukocyte counts were not affected by taurolidine. Fast injections have to be avoided. The findings prompted us to start new experiments to determine the influence of increasing doses of taurolidine on progressive tumor growth in rats.

Phospholipids reduce gastric cancer cell adhesion to extracellular matrix in vitro

Background

Nidation of floating tumour cells initiates peritoneal carcinosis and limits prognosis of gastro-intestinal tumours. Adhesion of tumour cells to extracellular matrix components is a pivotal step in developing peritoneal dissemination of intraabdominal malignancies. Since phospholipids efficaciously prevented peritoneal adhesion formation in numerous animal studies we investigated their capacity to reduce adhesions of gastric cancer cells to extracellular matrix components (ECM).

Methods

Human gastric cancer cells (NUGC-4, Japanese Cancer Research Resources Bank, Tokyo, Japan) were used in this study. Microtiter plates were coated with collagen IV (coll), laminin (ln) and fibronectin (fn). Non-specific protein binding of the coated wells was blocked by adding 1% (w/v) BSA (4°C, 12 h) and rinsing the wells with Hepes buffer. 50.000 tumour cells in 100 μl medium were seeded into each well. Beside the controls, phospholipids were added in concentrations of 0.05, 0.1, 0.5, 0.75 and 1.0/100 μl medium. After an incubation interval of 30 min, attached cells were fixed and stained with 0.1% (w/v) crystal violet. The dye was resuspended with 50 μl of 0.2% (v/v) Triton X-100 per well and colour yields were then measured by an ELISA reader at 590 nm. Optical density (OD) showed a linear relationship to the amount of cells and was corrected for dying of BSA/polystyrene without cells.

Results

The attachment of gastric cancer cells to collagen IV, laminin, and fibronectin could be significantly reduced up to 53% by phospholipid concentrations of 0.5 mg/100 μl and higher.

Conclusion

These results, within the scope of additional experimental studies on mice and rats which showed a significant reduction of peritoneal carcinosis, demonstrated the capacity of phospholipids in controlling abdominal nidation of tumour cells to ECM components. Lipid emulsions may be a beneficial adjunct in surgery of gastrointestinal malignancies.

Increased tumor growth after high pressure pneumoperitoneum with helium and air

BACKGROUND

Tumor growth appears proportional to the pressure of carbon dioxide insufflation during laparoscopic surgery. Air and helium are alternative insufflation gases. The objective of this study is to assess tumor growth after air and helium insufflation at different pressures.

METHOD

Ninety-six WAG rats were allocated to either air or helium. In both arms, rats were randomly exposed to a one hour gasless procedure, or to 4 mm Hg, 10 mm Hg, or 16 mm Hg insufflation. At the start of the procedure, 500,000 CC531 tumor cells were injected intraperitoneally. After three weeks, intraperitoneal tumor growth was assessed.

RESULTS

Higher insufflation pressures were associated with greater tumor growth. No difference of tumor growth between air and helium insufflation was found.

CONCLUSION

In this experimental model, insufflation pressure appeared to have a greater impact on tumor growth than the type of gas. Further studies are necessary but it seems prudent to recommend employment of lower insufflation pressures in laparoscopic oncologic surgery.

Impact of taurolidine on the growth of CC531 coloncarcinoma cells in vitro and in a laparoscopic animal model in rats

BACKGROUND

The object of this study was to examine the effect of taurolidine on intraabdominal tumor growth in a laparoscopic animal model. We tested the cytotoxic, antiadhesive, and anti-invasive effects of this substance on CC531 adenocarcinoma cells in vitro and in vivo using WAG rats.

METHODS

For in vitro experiments, Transwell dual chambers with polycarbonate filters coated with 100 microg/cm2 Matrigel were used to investigate the effects of 5, 10, and 20 microl of 2.0% taurolidine on the invasion of 1 x 10(5) CC531 adenocarcinoma cells. For the adhesion assays, tumor cells were applied onto microtiter plates coated with 5, 10, and 20 microl taurolidine and 0.9% NaCl solution for the control group subsequently. For in vivo experiments, 40 WAG rats were randomized into three therapy groups and one control group. All animals underwent laparoscopy and received 1 ml of CC531 adenocarcinoma cells (5 x 10(6) cells/ml) intraabdominally at the beginning of the procedure. According to the randomization, the rats were administered taurolidine with different concentrations or 1 ml of 0.9% NaCl solution for the control group. After 21 days, the animals were killed and the intraabdominal tumor weight was determined.

RESULTS

For the in vitro experiments, we found a moderate cytotoxicity and a significant inhibition of tumor cell adhesion and invasion (p < 0.01) by all taurolidine concentrations used in the assay. For in vivo experiments, the application of all concentrations of taurolidine significantly decreased the intraperitoneal tumor weight (p < 0.001).

CONCLUSION

Taurolidine significantly decreases adhesion and invasion of CC531 adenocarcinoma cells in vitro and significantly diminishes tumor growth in vivo. This may offer additional therapeutic options for laparoscopic surgery for colorectal cancer.

Irrigation of port sites: prevention of port site metastases?

INTRODUCTION

Port site metastases can occur when free viable tumor cells implant at trocar wounds. Irrigation of port sites with cytotoxic agents has been suggested to prevent port site metastases. The objective of this study is to assess whether tumor growth at port sites can be reduced by irrigation of these port sites.

METHODS

WAG rats were insufflated with CO(2) for 20 minutes and 5 x 10(5) CC531 tumor cells were injected intraperitoneally. Port sites were irrigated after completion of the pneumoperitoneum with povidone-iodine, a mixture of taurolidine and heparin, or sodium chloride. Controls did not undergo any irrigation of port sites. In experiment 1, all 16 rats had all 4 irrigation modalities. In experiment 2, four groups of 20 rats had one type of irrigation on two trocar wounds. Tumor growth was evaluated 4 weeks after the procedure.

RESULTS

No difference in tumor growth at trocar wounds was found between any type of irrigation and controls in both experiments.

CONCLUSION

In this experimental model, no beneficial or adverse effects of irrigation of port sites could be shown.

Laparoscopic restaging of early stage invasive adnexal tumors: a 10-year experience

Surgical staging of apparent early stage adnexal carcinoma provides indispensable information. A significant number of patients are referred to tertiary centers with inadequate staging information. We report on our experience with late results of laparoscopic restaging procedure in uncompletely managed early adnexal carcinomas.

MATERIALS AND METHODS

From 1991 to 2001, 53 laparoscopic restaging operations were performed: 42 patients were restaged early after initial surgery for an ovarian carcinoma (OC) in 35 of them, and for fallopian tube carcinomas (FTCs) in 7 others. Eleven patients were assessed as a second-look procedure, after six courses of platinum-based chemotherapy indicated for a high-risk tumor. The procedure systematically followed the guidelines of laparotomy.

RESULTS

All except one (adhesions) procedures were successfully completed. Operative room time averaged 238 min and hospital stay 3.1 days. Only one major complication required laparotomy (1.8%). In the primary restaging group, eight patients were upstaged (19%) and were given chemotherapy. After a 54-month median follow-up, 3 out of the 34 remaining patients diagnosed as stage IA grades 1-2 (6.4%) recurred and died. In the group of 11 second-look operations, 4 were found positive after chemotherapy. One of the positive patient recurred and died.

CONCLUSIONS

Laparoscopy seems to be an acceptable technical option to perform restaging of apparently early adnexal carcinomas. It spares the patients the discomfort of repeat laparotomy. Long-term outcome results suggest that laparoscopic staging, provided it meets the standards, accurately detects the patients who need chemotherapy and safely select the patients who can be proposed surgery only.

Laparoscopic resection of colon Cancer: Consensus of the European Association of Endoscopic Surgery (EAES)

BACKGROUND

The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on the laparoscopic resection of colon cancer during the annual congress in Lisbon, Portugal, in June 2002.

METHODS

A systematic review of the current literature was combined with the opinions, of experts in the field of colon cancer surgery to formulate evidence-based statements and recommendations on the laparoscopic resection of colon cancer.

RESULTS

Advanced age, obesity, and previous abdominal operations are not considered absolute contraindications for laparoscopic colon cancer surgery. The most common cause for conversion is the presence of bulky or invasive tumors. Laparoscopic operation takes longer to perform than the open counterpart, but the outcome is similar in terms of specimen size and pathological examination. Immediate postoperative morbidity and mortality are comparable for laparoscopic and open colonic cancer surgery. The laparoscopically operated patients had less postoperative pain, better-preserved pulmonary function, earlier restoration of gastrointestinal function, and an earlier discharge from the hospital. The postoperative stress response is lower after laparoscopic colectomy. The incidence of port site metastases is <1%. Survival after laparoscopic resection of colon cancer appears to be at least equal to survival after open resection. The costs of laparoscopic surgery for colon cancer are higher than those for open surgery.

CONCLUSION

Laparoscopic resection of colon cancer is a safe and feasible procedure that improves short-term outcome. Results regarding the long-term survival of patients enrolled in large multicenter trials will determine its role in general surgery.

Port site metastases

BACKGROUND

Concerns about port site metastases have limited the application of minimally invasive surgery for intra-abdominal malignancies. The purpose of this review article was to summarize the current literature regarding port site metastases.

METHODS

A Medline search identified >100 articles in English published during the last 15 years regarding the history, incidence, etiology, and prevention of port site metastases. These articles were reviewed and are summarized.

RESULTS

The incidence of port site metastases, initially thought to be as high as 21%, is now thought to be closer to the incidence of wound metastases after open surgery. Multiple etiologic factors have been studied including direct wound contamination, surgical technique, effects of carbon dioxide pneumoperitoneum, and changes in host immune response. Various preventive measures have been proposed.

CONCLUSIONS

Port site metastases are a well-documented and devastating complication after laparoscopic resection of intra-abdominal malignancies. Although the etiology is not yet understood, a number of factors are contributory. All efforts should be made to prevent port site metastases.

Laparoscopic colon resection for colon cancer

INTRODUCTION

Laparoscopic colon resection for cancer is as yet an unproven operation. This review article summarizes current data on the topic.

METHODS

A Medline review identified articles published since 1990 summarizing patients with potentially curable colon cancer who underwent a laparoscopic-assisted colon resection. Only articles that were randomized or had a control group with historical or matched open cases were used.

RESULTS

Very few prospective randomized controls exist. Several clinical trials are under way with one completed. Data thus far support some patient benefits with a laparoscopic approach. No differences in morbidity, oncologic data, or survival appear to exist.

CONCLUSIONS

The results of ongoing clinical trials are still needed to further evaluate the role of laparoscopic assisted colon resection in patients with potentially curable colon cancer.

Intérêt des lavages abdominaux pour la prévention de l’ensemencement néoplasique péritonéal

Spontaneous or iatrogenous peritoneal seeding is responsible for locoregional recurrent cancer or peritoneal carcinomatosis. Few surgeons are used to wash the abdominal cavity to prevent peritoneal seeding. But experimentally, washing is not able to dislodge or destroy tumour cells adherent to the peritoneum or to the surgical wounds. The antitumoral effect of abdominal washing is increased by addition of antiseptics or anti-adherent agents.

Local and systemic chemotherapy with taurolidine and taurolidine/heparin in colon cancer-bearing rats undergoing laparotomy

Experimental studies in the therapy of malignant abdominal tumors have shown that different cytotoxic agents suppress the intraperitoneal tumor growth. Nevertheless, a general accepted approach to prevent tumor recurrences does not exist. Following subcutaneous and intraperitoneal injection of 10(4) colon adenocarcinoma cells (DHD/K12/TRb), the influences of both taurolidine or taurolidine/heparin on intraperitoneal and subcutaneous tumor growth was investigated in 105 rats undergoing midline laparotomy. The animals were randomized into 7 groups and operated on during 30 min. To investigate the intraperitoneal (local) influence of either taurolidine or heparin on tumor growth, the substances were applied intraperitoneally. Systemic and intraperitoneal effects were evaluated after intravenous injection of the substances. Both application forms were also combined to analyze synergistic effects. Tumor weights, as well as the incidence of abdominal wound metastases, were determined four weeks after the intervention. In order to evaluate the effects of the agents, blood was taken to determine the peripheral leukocytes counts. Intraperitoneal tumor growth in rats receiving intraperitoneal application of taurolidine (median 7.0 mg, P = 0.05) and of taurolidine/heparin (median 0 mg, P = 0.02) was significantly reduced when compared to the control group (median 185 mg). The simultaneous instillation of both agents also reduced the intraperitoneal tumor growth (median 4 mg, P = 0.04), while the intravenous injection of the substances caused no local effect. In contrast, the subcutaneous tumor growth did not differ among all groups. In all groups, abdominal wound recurrences were rare and did not differ. Independent of the agents and the application form, the operation itself caused a slight leukopenia shortly after the operation and a leukocytosis in the following course. Intraperitoneal therapy of either taurolidine or in combination with heparin inhibits local tumor growth and abdominal wound recurrences in rats undergoing midline laparotomy. Neither the intraperitoneal nor the intravenous application or the combination of the two agents influenced the subcutaneous tumor growth. The substances did not alter the changes of peripheral leukocytes.

Effects of taurolidine and octreotide on tumor growth and lipid peroxidation after staging-laparoscopy in ductal pancreatic cancer

Irrigation with taurolidine after laparoscopy decreases tumor growth in colon carcinoma. In pancreatic cancer subcutaneous therapy with octreotide decreases oxidative stress and carcinogenesis as well. However, it is still unclear, whether irrigation with taurolidine or octreotide after laparoscopic pancreatic biopsy reduces tumor growth in pancreatic cancer as well. In 60 Syrian hamsters ductal pancreatic adenocarcinoma was induced by weekly injection of 10mg/kg body weight N-nitrosobis-2-oxopropylamine s.c. for 10 weeks. In week 16 laparoscopic pancreatic biopsy by use of carbon dioxide was performed (gr. 1, n = 20) with subsequent laparoscopic irrigation with taurolidine (gr. 2, n = 20) or octreotide (gr. 3, n = 20). In week 25 hamsters were sacrificed. Our results show that macroscopic visible primary tumors were found in only one animal of the taurolidine group (5.9%), compared to 42.1% in the saline and 62.5% in the octreotide group (P<0.05). Carcinomas were smaller after saline (6+/-23 mm(2)) than after octreotide irrigation (70+/-120 mm(2), P<0.05). In conclusion this study showed that laparoscopic irrigation with taurolidine after pancreatic biopsy inhibited tumor growth in ductal pancreatic adenocarcinoma.

Laparoscopic resection of colonic cancer

Laparoscopic resection of colonic cancer can be regarded as a safe and efficacious procedure. Short-term outcome is better after laparoscopic colectomy than after open colectomy. Long-term results of the first published randomized clinical trial indicate improved cancer related survival following laparoscopic resection of colonic cancer. However, patients included in this single center study were operated on by highly experienced laparoscopic surgeons and included relative small numbers of patients. Results of other large randomized controlled trials have to be awaited before laparoscopic resection can be recommended for colonic cancer. Higher in-hospital costs and a long learning curve hinder rapid implementation of laparoscopic colectomy into general surgical practice. Integration of laparoscopic surgery into surgical training programs is mandatory.

Low-molecular-weight heparin (reviparin) diminishes tumor cell adhesion and invasion in vitro, and decreases intraperitoneal growth of colonadeno-carcinoma cells in rats after laparoscopy

BACKGROUND

Metastases, adhesion and invasion of tumor cells involve a cascade of complex phenomena, which potentially can be affected by glycosaminoglycans. We studied the influence of a low-molecular-weight heparin, reviparin, on the intraabdominal tumor growth in rats undergoing laparoscopy. We also studied cytotoxicity, anti-adhesive, and anti-invasive effects of reviparin in vitro using adenocarcinoma cells CC531.

METHODS

In vitro assays: Adhesion of 1 x 10(5) CC531 adenocarcinoma cells onto microtiter plates coated with 10 microg/ml collagen type I or 10 microg/ml Matrigel was studied in the presence of 0.55; 1.10 and 2.76 mg/ml reviparin, and compared to saline. The cytotoxicity of 1 x 10(4) adenocarcinoma cells was studied in a similar assay. Transwell dual chambers with polycarbonate filters coated with 100 microg/cm2 Matrigel were used to investigate the effect of 0.55; 1.10 and 2.76 mg/ml reviparin on the invasion of 1 x 10(5) adenocarcinoma cells/ml. In vivo experiments: CC531 adenocarcinoma cells (5 x 10(6) cells/ml) were intraperitoneally applied to Wistar Albino Glaxo rats (n=150, Harlan, Germany) with a median weight of 278 g. The rats were divided into 15 groups with 10 animals in each group, underwent laparoscopy, and 1 ml saline containing 0, 0.5, 2.0, 4.0, and 10 mg reviparin per kg b.w. was introduced for intraperitoneal lavage or s.c. After 21 days the animals underwent an autopsy, and the tumor weight was determined.

RESULTS

In vitro experiments: We found a highly significant inhibition of tumor cell adhesion and invasion (p<0.001) by all reviparin concentrations used in the assays. There was no effect of reviparin on the viability of cells in the cytoxicity assay. In vivo experiments: We found that application of 4.0 and 10.0 mg/kg b.w., but not 0.5 or 2.0 mg/kg b.w. significantly (p<0.01) decreased the tumor mass compared to controls, receiving only saline. This effect was most pronounced after the combined i.p. and s.c. application, whereas after a sole i.p. application, only the highest dose of 10 mg/kg b.w. caused a significant inhibition of tumor growth.

CONCLUSION

Low-molecular-weight heparin, reviparin, given in combination of i.p. lavage and s.c. injections, significantly diminishes intraabdominal tumor growth of CC531 adenocarcinoma cells in rats undergoing laparoscopy. This may offer additional therapeutic options for patients undergoing laparoscopic cancer surgery.

Tumor cell dissemination during laparoscopy: prevention and therapeutic opportunities

Port-site recurrences (PSRs) are abdominal wall recurrences that occur in the subcutaneous tissue within a trocar site after cancer laparoscopy and are not associated with peritoneal carcinomatosis. In order to develop PSRs, viable tumor cells must be liberated from the primary tumor, be transported to a wound, and find there a favorable environment for growth. The short clinical delay in the occurrence of PSRs and their size suggest massive cell seeding into the abdominal wall. Traumatic handling of the tumor, slipping of trocars, liquid projection, as well as poor extraction techniques can all cause implantation of malignant cells into the subcutaneous tissue. Such contact can also occur postoperatively if the trocar channels remain open. Some histologies (e.g. gallbladder adenocarcinoma), the presence of ascites and advanced tumor stage are risk factors for PSRs. Further conditions--including the use of gas--might also play a limited role. The first preventive measure is the correct indication for a laparoscopic approach. Several techniques have been demonstrated to prevent PSRs in the animal model: (a) fixation of trocars to the abdominal wall; (b) prevention of leakage; (c) careful specimen handling; (d) reducing trauma to the abdominal wall; (e) specimen isolation before extraction from the abdominal cavity; (f) trocar-site irrigation with a cytotoxic solution, and (g) closure of peritoneum. Further innovative therapies are currently under investigation. In the clinical setting, correct indication, surgical expertise and application of prophylactic measures seem to be the best way to prevent the occurrence of PSRs.

[In vitro effect of taurolidine on squamous cell carcinoma in the oral cavity]

Taurolidine (Taurolin) is a derivative of the amino acid taurine, successfully used in the treatment of peritonitis. In vitro and in vivo studies have shown that taurolidine inhibits cell proliferation and induces apoptosis in a variety of tumor cell lines. At present there are no published studies on the use of taurolidine in the treatment of squamous cell carcinoma. Our aim was to examine the inhibition of cell proliferation and induction of apoptosis in cell lines SCC 4 and SCC 15 treated with taurolidine in concentrations of 0.01%, 0.1%, and 0.5%. Analogue to the present investigations on adenocarcinoma cell lines, we used toxic antiseptic povidone iodine in the same concentration as for the reference group. Untreated cells were used as a control group. The cells were incubated with taurolidine or povidone iodine once for 2 h at 37 degrees C in 5% CO(2). Cell proliferation was assessed using WST-1 labeling kit after 3, 24, 48, 72, and 96 h. The additional measurement of cell apoptosis was examined using ELISA(PLUS) cell death detection kit and performed after 0, 24, and 48 h. The findings showed a significant inhibition of cell proliferation and induction of apoptosis in taurolidine-treated cells SCC 4 and SCC 15 in contrast to the reference group treated with povidone iodine or the untreated control group.

Influence of intraperitoneal and systemic application of taurolidine and taurolidine/heparin during laparoscopy on intraperitoneal and subcutaneous tumour growth in rats

BACKGROUND

Recent clinical and experimental studies investigated the problem and possible pathomechanisms of portsite metastases after laparoscopic resection of malignant tumours. A generally accepted approach to prevent these tumour implantations does not exist so far.

METHODS

After subcutaneous and intraperitoneal injection of 10(4) cells of colon adenocarcinoma (DHD/K12/TRb) the influences of either taurolidine or taurolidine/heparin on intraperitoneal and subcutaneous tumour growth were investigated in 105 rats undergoing laparoscopy with carbon dioxide. The animals were then randomised into seven groups. A pneumoperitoneum was established using carbon dioxide for 30 min (8 mmHg). Three incisions were used: median for the insufflation needle, and a right and left approach in the lower abdomen for trocars. To investigate the intraperitoneal (local) influence of either taurolidine and heparin on tumour growth the substances were instilled intraperitoneally. Systemic effects were expected when the substances were applied intravenously (iv). Synergistic influences were tested when both application forms were combined. The number and the weight of tumours as well as the incidence of abdominal wall and port-site metastases were determined four weeks after intervention. Blood was taken to evaluate the influences of taurolidine and heparin on systemic immunologic reactions: seven days before laparoscopy. two hours, two days. seven days, and four weeks after operation, and the peripheral lymphocytes were determined.

RESULTS

Intraperitoneal (ip) tumour weight in rats receiving taurolidine (median 7 mg) and taurolidine/heparin (0 mg) intraperitoneally was significantly reduced when compared to the control group (52 mg) (P = 0.001). There was no difference of subcutaneus tumour growth among the groups (P = 0.4). Trocar recurrences were decreased when taurolidine was applied ip (3115). ipiv (4/15), and ip in combination with heparin (4/15) in comparison to the control group (10/15). Immediately after intervention treated and untreated groups showed a peripheral lymphopenia.

CONCLUSIONS

The intraperitoneal therapy with taurolidine and the combination with heparin inhibits the intraperitoneal tumour growth and trocar recurrences. Neither the intraperitoneal nor the systemic application or the combination of taurolidine and heparin did reduce the subcutaneous tumour growth. The intervention caused a lymphopenia which was compensated on day two.

Taurolidine improves survival by abrogating the accelerated development and proliferation of solid tumors and development of organ metastases from circulating tumor cells released following surgery

BACKGROUND

Surgical trauma is partly responsible for enhancing tumor growth through a variety of mechanisms that are still not fully elucidated. The use of perioperative immunostimulants may modulate these effects. This study examined the effect of administration of taurolidine after laparotomy or laparoscopy on the growth of solid tumor, the establishment of hepatic and lung metastases, and effects on natural killer (NK) and lymphokine-activated killer (LAK) cell function.

METHODS

B16 melanoma right flank tumors were established in mice (n = 180). These animals underwent anesthesia only (control) or laparotomy or laparoscopy (n = 60 per group) and were randomized to receive either saline or taurolidine (n = 30 per group) at specific time points. Survival was determined in each group, and in a further 90 mice tumor growth was followed over 10 days postoperatively. The experiment was repeated in 540 mice, which underwent one of the three procedures and were treated with either saline or taurolidine. NK and LAK cell cytotoxicity (NKCC, LAKCC) was determined at several time points postoperatively. In a further experiment, B16 melanoma tumor cells were delivered via tail vein injection (n = 180) and intrasplenic injection (n = 180). The effect of saline or taurolidine administration on survival after the establishment of metastases was determined, and again in a further 180 mice the establishment of metastatic deposits in the liver or lungs was determined after 8 days.

RESULTS

Survival appeared to be significantly decreased in both the solid-tumor model and the metastatic models undergoing laparotomy compared to laparoscopy and controls (P < 0.0001) and to a lesser extent in the laparoscopy group compared to controls (P < 0.001). Flank tumor growth and metastatic tumor formation were more significant in laparotomy groups compared to laparoscopy groups and controls, but also to a lesser extent in laparoscopy groups compared to controls (P </= 0.05). NKCC and LAKCC were significantly decreased in the same patterns (P < or = 0.03). However, treatment with taurolidine abolished these effects, restoring NKCC and LAKCC (P < or = 0.04) and laparoscopy groups (P < or = 0.001).

CONCLUSION

It appears that changes that occur after the trauma of laparotomy, and to a lesser extent, after laparoscopy, significantly enhance the growth of primary tumors as well as the development of metastases from circulating tumor cells and are associated with a suppression of host antitumor surveillance mechanisms. This not only affected tumor progression in the immediate postoperative period, but also ultimately affected survival. Taurolidine, a known immunostimulant, appears to abrogate the effects of surgical trauma on primary and metastatic tumor growth and also enhances survival. This may have significant value in the management of tumor-bearing patients undergoing resection.

Risk of spread of ovarian cancer after laparoscopic surgery

The incidence of the spread of ovarian cancer after laparoscopic surgery is difficult to establish from the current literature. The prognosis incidence of a trocar site metastasis without peritoneal dissemination is not known. Data from general surgeons in prospective studies from a single institution suggested that in colon cancer the risk is low, whereas it seems to be much higher in multicentric studies of undiagnosed gallbladder cancer. Experimental studies suggested that laparoscopy has advantages and disadvantages. However, the risk of dissemination is high when a large number of malignant cells and a carbon dioxide pneumoperitoneum are present, a situation encountered when managing adnexal tumours with large vegetations. Animal studies will allow the development of a peritoneal environment adapted to the treatment of cancer. The ovary is an intraperitoneal organ and ovarian cancer a peritoneal disease, so the risk of peritoneal spread may be higher in ovarian cancer than in other gynecological cancers. A careful preoperative evaluation appears to be the best way to prevent these risks. It should also be used to choose which patient should be operated by which surgical team. The second step is a careful and cautious laparoscopic diagnosis, so that more than 98% of ovarian cancers encountered can be treated immediately and effectively. The laparoscopic management of ovarian cancer remains controversial; it should be performed only in prospective clinical trials. Until the results of such studies become available, an immediate vertical midline laparotomy remains the gold standard if a cancer is encountered.