Acute and delayed toxicity of gemcitabine administered during isolated lung perfusion: a preclinical dose-escalation study in pigs.

OBJECTIVES: Colorectal cancer is the third most commonly diagnosed cancer worldwide, with up to 25% of patients presenting with metastases at the time of diagnosis. Despite pulmonary metastasectomy many patients go on to develop pulmonary recurrence, which might be linked to the presence of lung micrometastases. In this setting, the adjuvant administration of high-dose chemotherapy by isolated lung perfusion (ILP) has shown encouraging results. However, the tolerance to and efficacy of modern gemcitabine (GEM)-based chemotherapy regimens during adjuvant ILP remain unknown. We conducted a dose-escalating preclinical study to evaluate the immediate and delayed toxicity of GEM in a pig model to define dose-limiting toxicity (DLT) and maximum tolerated concentration. METHODS: Twenty-three pigs were given increasing concentrations of GEM during ILP, and were awakened at the end of the procedure. The concentrations of GEM were 40, 80, 160, 320, 640 and 1280 µg/ml. Serum and lung samples were taken to measure GEM concentrations. Pulmonary damage was evaluated by histological examination and cleaved caspase-3 detection. Immediate and delayed (1 month) toxicity were recorded. RESULTS: All of the animals underwent successful ILP with GEM. No systemic leak was observed. The three pigs that received a concentration of GEM of 1280 µg/ml died of hypoxia after lung recirculation at the end of the procedure. Eleven pigs survived for 1 month. Major lung toxicity was observed for the concentration of GEM of 640 µg/ml, both at the end of the procedure and after 1 month. DLT was defined at the concentration of 640 µg/ml and the maximum tolerated dose (MTD) was defined at the concentration of 320 µg/ml. CONCLUSIONS: ILP with GEM is a safe and reproducible technique in this large-animal model, which includes 1 month of survival. The MTD in this pig model was a concentration of GEM of 320 µg/ml.

High pressure does not counterbalance the advantages of open techniques over closed techniques during heated intraperitoneal chemotherapy with oxaliplatin.

BACKGROUND: Heated intraperitoneal chemotherapy (HIPEC) treats residual microscopic disease after cytoreductive surgery. In experimental models, the open HIPEC technique has shown a higher and more homogenous concentration of platinum in the peritoneum than achieved using the closed technique. A 25-cm H2O pressure enhances the penetration of oxaliplatin. Because pressure is easier to set up with the closed technique, high pressure may counterbalance the drawbacks of this technique versus open HIPEC, and a higher pressure may induce a higher penetration. Because higher concentration does not mean deeper penetration, a study of tissues beneath the peritoneum is required. Finally, achieving a deeper penetration (and a higher concentration) raises the question of the passage of drugs through the surgical glove and the surgeon's safety. METHODS: Four groups of pigs underwent HIPEC with oxaliplatin (150 mg/L) for 30 minutes in open isobaric pressure and pressure at 25 cm H2O, and closed pressure at 25 and 40 cm H2O. Systemic absorption and peritoneal mapping of the concentration of platinum were analyzed, as well as in the retroperitoneal tissue and the surgical gloves. RESULTS: Blood concentrations were higher in open groups. In the parietal surfaces, the concentrations were not different between the isobaric and the closed groups (47.08, 56.39, and 48.57 mg/kg, respectively), but were higher in the open high-pressure group (85.93 mg/kg). In the visceral surfaces, they were lower in the closed groups (3.2 and 3.05 mg/kg) than in the open groups (7.03 and 9.56 mg/kg). Platinum concentrations were similar in the deep retroperitoneal tissue when compared between isobaric and high-pressure procedures. No platin was detected in the internal aspect of the gloves. CONCLUSION: The use of high pressure during HIPEC does not counterbalance the drawbacks of closed techniques. The tissue concentration of oxaliplatin achieved with the open techniques is higher, even if high pressure is applied during a closed technique. Open 25 cm H2O HIPEC achieved the highest tissue penetration of oxaliplatin, but did not enhance the depth of oxaliplatin penetration. High pressure did not enhance the risk of HIPEC.

Isolated lung perfusion as an adjuvant treatment of colorectal cancer lung metastases: a preclinical study in a pig model.

BACKGROUND: The lung is a frequent site of colorectal cancer (CRC) metastases. After surgical resection, lung metastases recurrences have been related to the presence of micrometastases, potentially accessible to a high dose chemotherapy administered via adjuvant isolated lung perfusion (ILP). We sought to determine in vitro the most efficient drug when administered to CRC cell lines during a short exposure and in vivo its immediate and delayed tolerance when administered via ILP. METHODS: First, efficacy of various cytotoxic molecules against a panel of human CRC cell lines was tested in vitro using cytotoxic assay after a 30-minute exposure. Then, early (operative) and delayed (1 month) tolerance of two concentrations of the molecule administered via ILP was tested on 19 adult pigs using hemodynamic, biological and histological criteria. RESULTS: In vitro, gemcitabine (GEM) was the most efficient drug against selected CRC cell lines. In vivo, GEM was administered via ILP at regular (20 µg/ml) or high (100 µg/ml) concentrations. GEM administration was associated with transient and dose-dependant pulmonary vasoconstriction, leading to a voluntary decrease in pump inflow in order to maintain a stable pulmonary artery pressure. After this modulation, ILP using GEM was not associated with any systemic leak, systemic damage, and acute or delayed histological pulmonary toxicity. Pharmacokinetics studies revealed dose-dependant uptake associated with heterogenous distribution of the molecule into the lung parenchyma, and persistent cytotoxicity of venous effluent. CONCLUSIONS: GEM is effective against CRC cells even after a short exposure. ILP with GEM is a safe and reproducible technique.

High pressure enhances the effect of hyperthermia in intraperitoneal chemotherapy with oxaliplatin: an experimental study.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) achieve good results in selected patients with peritoneal carcinomatosis. High intra-abdominal pressure could enhance the penetration of chemotherapy drugs. The aim of this study was to compare the effects of high pressure and hyperthermia when used separately and when combined in terms of blood and tissue absorption of oxaliplatin in a swine model of intraperitoneal chemotherapy. METHODS: Four groups of 5 pigs each underwent laparotomy and open intraperitoneal chemotherapy with oxaliplatin at a constant concentration (150 mg/L) for 30 minutes in normothermia and atmospheric pressure (group 1), or hyperthermia (42°C) and atmospheric pressure (group 2), or normothermia and high pressure (25 cm H2O) (group 3), or hyperthermia and high pressure (group 4). High pressure was achieved thorough a water column over the abdomen. Systemic absorption and abdominal tissue mapping of the penetration of oxaliplatin in each group were studied. RESULTS: Blood concentrations of oxaliplatin were similar in the different groups. Hyperthermia achieved higher concentrations in visceral surfaces (P = 0.0014), but not in parietal surfaces. High pressure enhanced diffusion of the drug in both the visceral and parietal peritoneum (P = 0.0058 and P = 0.0044, respectively). The combination of hyperthermia and high pressure significantly increased the penetration of oxaliplatin and achieved the highest tissue concentrations (10.39 mg/kg vs 5.48 mg/kg; P = 0.00001 in the visceral peritoneum, and 66.16 mg/kg vs 35.62 mg/kg; P = 0.0003 in the parietal peritoneum). CONCLUSIONS: Open high-pressure HIPEC with oxaliplatin is feasible in the pig. Hyperthermia enhances diffusion in the visceral peritoneum, whereas high pressure is effective in the visceral and parietal peritoneum. The combination of the two achieves the highest tissue concentrations of oxaliplatin.

High-pressure intrapleural chemotherapy: feasibility in the pig model.

BACKGROUND: The usual treatments for pleural malignancies are mostly palliative. In contrast, peritoneal malignancies are often treated with a curative intent by cytoreductive surgery and intraperitoneal chemotherapy. As pressure has been shown to increase antitumor efficacy, we applied the concept of high-pressure intracavitary chemotherapy to the pleural space in a swine model. METHODS: Cisplatin and gemcitabine were selected because of their antineoplasic efficacy in vitro in a wide spectrum of cancer cell lines. The pleural cavity of 21 pigs was filled with saline solution; haemodynamic and respiratory parameters were monitored. The pressure was increased to 15-25 cm H2O. This treatment was associated with pneumonectomy in 6 pigs. Five pigs were treated with chemotherapy under pressure. RESULTS: The combination of gemcitabine (100 mg/l) and cisplatin (30 mg/l) was highly cytotoxic in vitro. The maximum tolerated pressure was 20 cm H20, due to haemodynamic failure. Pneumonectomy was not tolerated, either before or after pleural infusion. Five pigs survived intrapleural chemotherapy associating gemcitabine and cisplatin with 20 cm H2O pressure for 60 min. CONCLUSIONS: High-pressure intrapleural chemotherapy is feasible in pigs. Further experiments will establish the pharmacokinetics and determine whether the benefit already shown in the peritoneum is also obtained in the pleura.

Which method to deliver hyperthermic intraperitoneal chemotherapy with oxaliplatin? An experimental comparison of open and closed techniques.

BACKGROUND: Hyperthermic intraperitoneal chemotherapy (HIPEC) achieves good results in selected patients with peritoneal carcinomatosis. There are two main procedures to deliver this therapy: the open abdomen and the closed abdomen techniques. A true comparison of the two techniques has never been performed. The aim of this study was to compare blood and abdominal tissue concentrations of oxaliplatin after open and closed techniques to deliver HIPEC. METHODS: Nine pigs underwent HIPEC at 42-43 degrees C for 30 min with oxaliplatin (400 mg/m(2)) according to two techniques: closed (three animals) or open (six animals). The open technique used either an external heater with a pump (three animals) or an intra-abdominal heating cable (three animals) to achieve hyperthermia. Temperature homogeneity, systemic absorption, and abdominal tissue mapping of the penetration of oxaliplatin with each technique were studied. Two additional pigs underwent hyperthermia with dyes instead of oxaliplatin to depict the distribution of the liquid within the abdomen with both techniques. RESULTS: Hyperthermia was satisfactory with both techniques. The closed technique achieved higher temperatures within the diaphragmatic area, while the open technique obtained higher temperatures in the mid and lower abdomen (P < 0.001 for both comparisons). The systemic absorption of oxaliplatin was higher with the open technique (P < 0.04 for all comparisons), as was the accumulation within the abdominal cavity. The operating time for the two techniques was not greatly different. CONCLUSIONS: Intraperitoneal hyperthermia can be achieved with both techniques. The open technique had far higher systemic absorption and abdominal tissue penetration of oxaliplatin than the closed technique.

Hypoxic single-pass isolated hepatic perfusion of hypotonic Cisplatin: safety study in the pig.

BACKGROUND: Isolated hepatic perfusion (IHP) of chemotherapy has been proposed to deliver high doses of drug while avoiding systemic toxicity. Hypotonic cisplatin has a high in vitro activity on human colon cancer cells. We studied the safety of a 30-min hypoxic single-pass IHP with hypotonic cisplatin. METHODS: A preliminary in vitro assay was performed to compare the cytotoxicity of cisplatin and oxaliplatin, in either a normotonic or hypotonic medium. Cisplatin in hypotonic medium was then chosen for the in vivo IHP. Eleven pigs underwent 30 min of IHP with 0, 50, 75, or 100 mg/L of cisplatin in a hypotonic solution under total vascular exclusion of the liver. Clinical and biological parameters were recorded for 30 days, and liver histology was performed at necropsy. The cytotoxic activity of the effluent against resistant human colon cancer cells was tested in vitro. RESULTS: No hepatic failure was recorded after IHP with cisplatin, but limited foci of necrosis were found at necropsy in animals receiving 75 or 100 mg/L of cisplatin. No clinical, biological, macroscopic, or microscopic toxicity was observed after IHP with 50 mg/L of hypotonic cisplatin. The liver effluent showed high in vitro cytotoxic activity against colon cancer cells. CONCLUSIONS: A hypoxic single-pass isolated liver perfusion with hypotonic cisplatin is feasible and safe. Effluent from the liver is highly cytotoxic on cancer cells. A clinical study with 50 mg/L of hypotonic cisplatin is warranted in patients with unresectable liver metastases from colon cancer.

Intraoperative chemotherapy with cisplatin and epinephrine after cytoreductive surgery in patients with recurrent ovarian cancer: a phase I study.

BACKGROUND: Intraperitoneal (i.p.) epinephrine was shown to increase the accumulation of i.p. cisplatin in tumours, and thus its antitumour effect in a model of peritoneal carcinomatosis in rats. METHODS: To determine the tolerance to i.p. epinephrine with cisplatin, 18 patients with recurrent ovarian carcinoma were intraoperatively treated in this phase 1 study. After maximal cytoreductive surgery, the peritoneal cavity was filled twice for 1 h with 30 mg/l of cisplatin and increasing concentrations of epinephrine (0, 1, 2, 3 mg/l) in 3 l of saline solution at 37 degrees C. RESULTS: No deaths occurred. Three patients were treated at each of the 0, 1 and 2 mg/l epinephrine levels without adverse events. Two of the three patients who received 3 mg/l epinephrine experienced cardiac intolerance. Six additional patients received 2 mg/l of epinephrine without toxicity. A relationship between the serum concentration of epinephrine and occurrence of cardiac toxicity was established. A 60% decrease in serum area under the curve of platinum was calculated in patients receiving i.p. epinephrine compared with i.p. cisplatin alone. Renal toxicity from cisplatin was not increased by epinephrine. No haematological or neurological toxicity was recorded. The other grade 3-4 adverse events [thromboembolism (5), peritonitis (1), abdominal bleeding (1), bowel fistula (1)] occurred as often as usually reported for this heavy surgical procedure. CONCLUSION: The combination of i.p. epinephrine with cisplatin as intraoperative chemotherapy after optimal cytoreductive surgery is feasible. The recommended concentration for further studies is 2 mg/l for i.p. epinephrine.

High intra-abdominal pressure enhances the penetration and antitumor effect of intraperitoneal cisplatin on experimental peritoneal carcinomatosis.

OBJECTIVE: To investigate the role of increased intra-abdominal pressure (IAP) on the intratumoral accumulation and the antitumor effect of intraperitoneal cisplatin in rats with advanced peritoneal carcinomatosis. To evaluate the tolerance of IAP in pigs, as it is a large animal with a body size equivalent to humans. SUMMARY BACKGROUND DATA: To investigate if an active convection, driven by a positive IAP, increases cisplatin penetration and antitumor effectiveness in a model of advanced peritoneal carcinomatosis in rats. EXPERIMENTAL DESIGN: BDIX rats with macroscopic peritoneal tumors received cisplatin administered as intravenous injection (IV), conventional intraperitoneal injection (IP), or sustained intraperitoneal injection of cisplatin given in a large volume of solvent for maintaining IAP for 1 hour. Platinum tissue concentration was measured by atomic absorption spectroscopy (AAS), and platinum distribution into the tumor nodules was assessed by the particular-induced x-ray emission (PIXE) method. The antitumor effect was assessed in a survival experiment. The hemodynamic, local, and systemic tolerance of IAP, with or without cisplatin, was evaluated in Large White pigs. RESULTS: The maximum tolerated IAP was 22 mm Hg for 1 hour in nonventilated rats. IAP, in comparison with IV or conventional IP injections, resulted in the increased concentration and depth of diffusion of platinum into diaphragm and peritoneal tumor nodules. Consequently, IAP treatment induced an extended survival of rats treated at an advanced stage of carcinomatosis. In 7 50- to 70-kg ventilated pigs, a 40-mm Hg IAP was well tolerated when maintained stable for 2 hours. Renal failure occurred in pigs receiving a total dose of 200 and 400 mg of cisplatin with IAP, but a dose of 100 mg was well tolerated. CONCLUSIONS: Intraperitoneal chemotherapy with increased IAP, in comparison with conventional IP or IV chemotherapy, improved the tumor accumulation and the antitumor effect of cisplatin in rats bearing advanced peritoneal carcinomatosis. In preclinical conditions, the tolerance of sustained IAP was manageable in ventilated pigs.