Technology development of hyperthermic pressurized intraperitoneal aerosol chemotherapy (hPIPAC).

BACKGROUND: Optimized drug delivery systems are needed for intraperitoneal chemotherapy. The aim of this study was to develop a technology for applying pressurized intraperitoneal aerosol chemotherapy (PIPAC) under hyperthermic conditions (hPIPAC). METHODS: This is an ex-vivo study in an inverted bovine urinary bladder (IBUB). Hyperthermia was established using a modified industry-standard device (Humigard). Two entry and one exit ports were placed. Warm-humid CO2 was insufflated in the IBUB placed in a normothermic bath to simulate body thermal inertia. The temperature of the aerosol, tissue, and water bath was measured in real-time. RESULTS: Therapeutic hyperthermia (target tissue temperature 41-43 °C) could be established and maintained over 30 min. In the first phase (insufflation phase), tissue hyperthermia was created by insufflating continuously warm-humid CO2. In the second phase (aerosolization phase), chemotherapeutic drugs were heated up and aerosolized into the IBUB. In a third phase (application phase), hyperthermia was maintained within the therapeutic range using an endoscopic infrared heating device. In a fourth phase, the toxic aerosol was discarded using a closed aerosol waste system (CAWS). DISCUSSION: We introduce a simple and effective technology for hPIPAC. hPIPAC is feasible in an ex-vivo model by using a combination of industry-standard medical devices after modification. Potential pharmacological and biological advantages of hPIPAC over PIPAC should now be evaluated.

COVID-19: impact on colorectal surgery.

AIM: The rapid spread of the COVID-19 pandemic has created unprecedented challenges for the medical and surgical healthcare systems. With the ongoing need for urgent and emergency colorectal surgery, including surgery for colorectal cancer, several questions pertaining to operating room (OR) utilization and techniques needed to be rapidly addressed. METHOD: This manuscript discusses knowledge related to the critical considerations of patient and caregiver safety relating to personal protective equipment (PPE) and the operating room environment. RESULTS: During the COVID-19 pandemic, additional personal protective equipment (PPE) may be required contingent upon local availability of COVID-19 testing and the incidence of known COVID-19 infection in the respective community. In addition to standard COVID-19 PPE precautions, a negative-pressure environment, including an OR, has been recommended, especially for the performance of aerosol-generating procedures (AGPs). Hospital spaces ranging from patient wards to ORs to endoscopy rooms have been successfully converted from standard positive-pressure to negative-pressure spaces. Another important consideration is the method of surgical access; specifically, minimally invasive surgery with pneumoperitoneum is an AGP and thus must be carefully considered. Current debate centres around whether it should be avoided in patients known to be infected with SARS-CoV-2 or whether it can be performed under precautions with safety measures in place to minimize exposure to aerosolized virus particles. Several important lessons learned from pressurized intraperitoneal aerosolized chemotherapy procedures are demonstrated to help improve our understanding and management. CONCLUSION: This paper evaluates the issues surrounding these challenges including the OR environment and AGPs which are germane to surgical practices around the world. Although there is no single universally agreed upon set of answers, we have presented what we think is a balanced cogent description of logical safe approaches to colorectal surgery during the COVID-19 pandemic.

Pressurized intraperitoneal aerosol chemotherapy with oxaliplatin in colorectal peritoneal metastasis.

AIM: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is an experimental drug delivery method that applies chemotherapy into the abdominal cavity as an aerosol under pressure. We present the first results obtained with PIPAC in colorectal peritoneal metastasis (CPM). METHOD: This is a retrospective analysis. PIPAC was applied in 17 consecutive patients with pretreated CPM. All patients had previously undergone surgery, and 16 had undergone previous lines of systemic chemotherapy (median, two lines). The mean peritoneal metastasis index (peritoneal cancer index) was 16 ± 10. Forty-eight applications of PIPAC with oxaliplatin (92 mg/m2 ) were given every 6 weeks at 37 °C and 12 mmHg for 30 min. The outcome criteria were microscopic pathological response, survival and adverse events according to Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. RESULTS: Forty-eight PIPAC administrations were performed with no intra-operative complications. The mean number of PIPAC administrations per patient was 2.8 (minimum one, maximum six). Postoperative adverse events (CTCAE level 3) were observed in four patients (23%), no CTCAE level-4 adverse events were reported. The hospital mortality was zero. Objective tumour responses were observed in 12/17 patients (71%), and the overall responses were as follows: complete pathological response (seven patients), major response (four patients), partial response (one patient), no response (two patients) and not eligible (three patients). The mean survival after first PIPAC was 15.7 months. CONCLUSION: Repeated PIPAC with oxaliplatin can induce the regression of pretreated CPM. The toxicity appears to be low. These preliminary results are encouraging and justify prospective clinical studies.

Key genes in lung cancer translational research: a meta-analysis.

In lung cancer, integrating translational data from various histologies obtained in different patients under different conditions can increase their robustness. This is a meta-analysis of cDNA array data obtained in 688 tumor patients (541 non-small cell lung cancer, 33 small cell lung cancer and 114 others) and 205 controls. 1,206 genes were found to be dysregulated in one of the 12 transcriptomics studies available. 748 results (62%) were obtained only once and might be questioned. 38% of observations could be reproduced twice or more. 346 genes were reported twice, 80 three times, 27 four and 5 five times. A common set of genes dysregulated in lung cancer was obtained, including BPA1, DUSP6, ASCL1, RNAS1 and S100P. p63 and CK 5/6 p63 are useful for differentiating adenocarcinoma and small cell lung cancer from squamous cell carcinoma. TFF-3 and MUC1 are over-expressed in adenocarcinoma. INSM1, SGNE1 and H2AFZ are typical for small cell lung cancer. Using a meta-analysis approach, it was possible to detect a robust set of genes differentially expressed in lung cancer and to determine a limited number of key genes linked to subtypes in lung cancer molecular pathology.

[Value of surgery in the palliative therapy for rectal cancer]. / Stellenwert der Chirurgie in der palliativen Behandlung des Rektumkarzinoms.

The treatment of advanced rectal cancer is a complicated task that can only poorly be reduced to the simple question "to operate or not to operate?" Instead the following factors must be taken into consideration: symptomatic versus non-symptomatic patients, emergency surgery versus elective surgery, proximal versus distal rectal cancer, local advanced versus metastatic disease, primary tumour versus recurrence, unresectable versus potentially resectable metastases, resection versus diversionary surgical procedures, etc. Also within the conservative group one must decide between interventional therapy (combined chemotherapy, stent placement, radiotherapy, etc.) and purely palliative therapy. Results from studies are not sufficient for the formulation of general recommendations. However, there are only few arguments against a surgical procedure in a symptomatic situation when the primary tumour dominates. In cases of metastasizing colorectal cancer modern chemotherapeutic procedures and new antibody therapies can markedly prolong survival. These results cannot be achieved by surgery alone. In this situation, it should be considered whether the longer life expectancy will be accompanied by the later occurrence of symptoms, which again justifies a surgical indication within the framework of multimodality therapy. The widely differing starting situations lead to different therapeutic approaches so that an individual indication can be made in the course of a tumour board discussion.

Caveolin-1 levels are down-regulated in human colon tumors, and ectopic expression of caveolin-1 in colon carcinoma cell lines reduces cell tumorigenicity.

Caveolin-1 expression and function were investigated in human colon cancer. Low levels of caveolin-1 mRNA and protein were detected in several colon carcinoma cell lines. Moreover, caveolin-1 protein levels were significantly reduced in human tumor epithelial mucosa (3.6 +/- 1.4-fold) when compared with normal colon mucosa for a majority (10 of 15) of the patients characterized. To directly assess the role of caveolin-1 in tumor development, caveolin-1 was reexpressed in the HT29 and DLD1 colon carcinoma cells, and the resulting HT29-cav-1 or DLD1-cav-1 cells were tested for tumorigenicity in nude mice. In most experiments, tumor formation was either blocked or retarded for HT29-cav-1 cells (10 of 13 mice) and DLD1-cav-1 cells (5 of 7 mice), as compared with both mock-transfected and parental HT29 or DLD1 cells. Interestingly, basal caveolin-1 levels were significantly reduced in HT29-cav-1 and DLD1-cav-1 cells isolated from tumors. Likewise, endogenous caveolin-1 mRNA and protein levels were found to be reduced in NIH-3T3 cells recovered from tumors after injection into nude mice. Thus, reexpression of caveolin-1 in colon carcinoma lines reduced the probability of tumor formation in vivo, and when tumors did develop from either HT29-cav-1, DLD1-cav-1, or NIH-3T3 cells, lower basal levels of caveolin-1 were detected. Finally, evidence was obtained indicating that initial caveolin-1 down-regulation in colon cancer cells need not be an entirely irreversible process because cell survival on selection for either drug resistance or increased metastatic potential correlated with increased caveolin-1 expression levels.

Influence of surgery on metachronous distant metastases and survival in rectal cancer.

PURPOSE: Total mesorectal excision (TME) and other technical surgical factors reduce local recurrence rate in rectal cancer. Scientific evidence of the positive effect of optimal surgery on survival is locking. Whether a reduction in the incidence of distant metastases can be achieved with optimal surgery is uncertain. We examine the effects of the quality of surgery, as reflected by local recurrence rate, on survival and the incidence of initial distant metastases. PATIENTS AND METHODS: Between 1974 and 1991, 1,581 consecutive patients who underwent curative resection (RO) for rectal carcinoma were monitored for recurrence and survival. TME was introduced in 1985. No patient received adjuvant radiotherapy or chemotherapy. The median follow-up time was greater than 13 years. RESULTS: The local recurrence rate decreased from 39.4% to 9.8% during the study period (P < .0001). The observed 5-year survival rate improved from 50% to 71% (P < .0001). Three hundred six patients with local recurrence had a significantly lower observed 5-year survival rate (P < .0001). A total of 1,285 patients had no local recurrence, but 275 of them developed distant metastases (International Union Against Cancer [UICC] stage I, 8%; stage II, 16%; stage III, 40%). Better-quality surgery had no effect on the incidence of initial distant metastases, which remained constant (P = .44). CONCLUSION: Quality of surgery is an independent prognostic factor for survival in rectal cancer, but has no influence on initial occurrence of distant metastases. Local recurrence cannot be considered an outcome criterion of adjuvant treatment without consideration of the surgeon as a risk factor.

Discordance between K-ras mutations in bone marrow micrometastases and the primary tumor in colorectal cancer.

PURPOSE: To study bone marrow micrometastases from colorectal cancer patients for the presence of K-ras mutations and to compare their genotype with that of the corresponding primary tumor. PATIENTS AND METHODS: Bilateral iliac crest aspiration was performed in 51 patients undergoing surgery for colorectal cancer, and bone marrow micrometastases were detected by immunohistochemistry. The presence of K-ras mutations was determined by single-strand conformation polymorphism analysis on both primary tumors and paired bone marrow samples and was confirmed by sequencing. RESULTS: In six patients with primary tumor mutations, it was possible to amplify a mutated K-ras gene also from the bone marrow sample. In three of those patients the pattern of K-ras mutations differed between both samples, in two patients the mutation was identical between the bone marrow and its primary tumor, and in one patient the same mutation plus a different one were found. Fifteen of 17 K-ras mutations found in primary tumors were located in codon 12, whereas in bone marrow, five of seven mutations were found in codon 13 (P =.003). CONCLUSION: Our results demonstrate that, at least for K-ras mutations, disseminated epithelial cells are not always clonal with the primary tumor and they question the malignant genotype of bone marrow micrometastases. They also indicate that different tumoral clones may be circulating simultaneously or sequentially in the same patient. Analysis of the type of mutations suggests that cell dissemination might be an early event in colorectal carcinogenesis.

Quality of life of patients with end-stage peritoneal metastasis treated with Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC).

BACKGROUND: Quality of Life (QoL) plays an important role in patients with peritoneal metastasis and is deteriorating continuously until death. Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is an innovative palliative treatment of peritoneal metastasis. We present the first QoL results under PIPAC therapy. METHODS: Retrospective analysis of QLQ30 questionnaire results during repeated courses of PIPAC applications in palliative patients with pretreated peritoneal metastasis. RESULTS: 91 patients (M:F = 40:51, median age 64 (34-77) years) with 158 PIPAC applications were analyzed. 86% patients had previously received systemic chemotherapy. Peritoneal metastasis was advanced (Peritoneal Carcinomatosis Index I = 16 ± 10). At admission, only moderate impairment of functioning (62-83%) and symptom scores (17-47%) was observed. 48 patients received at least 2 PIPAC every 6 weeks. After PIPAC # 1, the global physical score deteriorated slightly (from 82% to 75%), but improved after PIPAC # 2 (up to 89%). Gastrointestinal symptoms (nausea/vomiting, constipation, diarrhoea, anorexia) remained stable under PIPAC therapy. CONCLUSIONS: Quality of life was relatively high in this group of patients with advanced, pretreated peritoneal metastasis, explaining their wish for further therapy. Functioning scores and disease-related symptoms were not altered for at least 3 months in the patients able to receive repeated PIPAC. Except for a transient moderate increase of pain scores, PIPAC did not cause therapy-related QoL deterioration, especially no gastrointestinal symptoms.

Proteomic prediction of disease outcome in cancer : clinical framework and current status.

Better than gene sequencing or quantitative amplification, proteomics tools allow the study of tumor phenotype. Indeed, most current prognostic tests in cancer (carcinoembryonary antigen [CEA], prostate-specific antigen [PSA], CA 19-1, CA 125, alpha-fetoprotein [AFP], etc.) are based on the detection and quantification of single proteins in body fluids. However, a common characteristic of these tests is their relatively low predictive value, so that they are usually complemented with other procedures such as biopsy and/or endoscopy. Recently, improved analytical and bioinformatics tools have driven the attention on pattern recognition approaches rather then single-marker tests for prognostic forecasting. It is expected that predicting metastasization on the basis of tumoral protein patterns will soon be a reality. However, currently available technologies either limit the number of proteins that can be analyzed simultaneously or they are expensive, difficult, and time-consuming. Moreover, the tools adapted for expression proteomics might not be the same as those for prognostic studies that require investigation of protein function over time. We believe that clinical proteomics research designed within a precise clinical and pathology framework should be strongly supported, since many prognostic factors are determined not by the tumor itself, but by the patient, the treatment and the environment.

Real-time assessment of intraperitoneal tumor growth in a rat model using CEA immunoscintigraphy.

BACKGROUND: In most preclinical models, assessment of intraperitoneal tumor location and size require killing the animal. The dynamics of postoperative intraperitoneal tumor implantation and growth remain unclear. A noninvasive method allowing reliable in vivo, real-time assessment of tumor growth is desirable. METHODS: An intraperitoneal tumor homograft using cultured CC531 colorectal cells was created by laparotomy in 24 Wistar Albino Glaxo rats. Eight additional rats were used as controls. Then, 10 MBq technetium 99m-labeled anticarcinoembryonic antigen (anti-CEA) monoclonal antibodies were administrated intravenously and radioactivity uptake was measured by using extracorporeal gamma counting at various time points. Subsequently, the animals were killed for tumor weighting. In 2 more groups of 8 animals, real-time, repeated measures were performed. RESULTS: Correlation between gamma counting and tumor weight was highly significant (P <.001). The regression equation obtained by using the least squares method was: tumor weight (g) = 2.422 + 0.267 x counts. It was possible to obtain real-time tumor growth curves when repeated measurements of radioactivity were performed. At day 25, the predicted tumor weight was 8.49 +/- 0.76 g, the measured weight was 8.16 +/- 0.99 g. CONCLUSIONS: Immunoscintigraphic measurements with technetium 99m anti-CEA antibodies are highly correlated with tumor weight in this model. As opposed to other tumor graft models based on autopsy findings, real-time monitoring is possible. This will allow dynamic studies of intraperitoneal tumor implantation and growth and will reduce the number of animals used in further studies.

The role of proteomics in the diagnosis and outcome prediction in colorectal cancer.

Colorectal cancer is the second most frequent cancer in Western countries. Exogenous factors play a major role in the aetiology of sporadic colorectal cancer representing about 90% of all cases, hereditary cancers accounting for about 10% of patients. Thus, in the large majority of cases, cell dysfunction in CRC results from multiple rather than single, gene interactions. Numerous cellular events and environmental influences modify gene expression or post-translational protein modifications. Changes like glycosylation of proteins and lipids which are a common feature in colorectal cancer and influence cancer cell behaviour, cannot be directly detected by genetic studies. Better than genomics studies, functional proteomics studies allow the investigation of environmental factors over time, allowing the monitoring of metabolic responses to various stimuli. However, proteomics studies also have several drawbacks: a) current tools only allow narrow-range analyses, b) identification of proteins of interest remains cumbersome, c) protein studies address multiple compounds of high complexity, d) large amount of proteins are necessary to allow analysis, e) protein research require specific tools, e.g. tagged antibodies, that first have to be developed. Some protein tests are already in application for CRC: a classical prognostic test in colorectal cancer is based on the detection and quantification of a single protein (CEA) in body fluids. Recently, a screening assay based on APC protein truncation test has also been proposed. However, studies linking large protein expression patterns with clinical outcome in colorectal cancer are still in their infancy. To be able to predict occurrence of disease, and treatment outcome, more studies on genotype-phenotype correlations are needed both in sporadic and in hereditary colorectal cancer.

The pathogenesis of port-site recurrences.

The major factors underlying the seeding of tumor cells during laparoscopy are mechanical, with CO2 playing only a secondary role. The peritoneal wound is of great importance, especially in advanced tumor stages, when cells are present within the abdominal cavity. Most reported port-site metastases were found within the extraction port when no protective measures were taken. Gasless laparoscopy is no solution to the problem, since numerous port-site metastases have been described after thoracoscopy, during which no C02 is used. The surgeon's role in the seeding of tumor cells is based on tumor perforation, excessive manipulation, and replacement of trocars. This presumably explains the large differences (0% and 21 %) in the reported incidence of port-site metastases. Prospective studies now show that it is possible to keep the incidence of abdominal wall metastases to about 1%-which is comparable to that seen in open surgery-by the use of a meticulous operating technique and preventive measures.

Description of an intraperitoneal tumour xenograft survival model in the pig.

AIMS: Experimental animal studies are necessary if the results of minimally invasive oncological surgery are to be improved. In particular the influence of surgical technique on tumour implantation needs further assessment. Small animals such as rodents are inappropriate for such laparoscopic surgical studies. There is a requirement for another animal tumour model with animals greater in size. METHODS: Accordingly we developed an intraperitoneal tumour xenograft survival model using the domesticated pig. After creating a 12 mmHg pneumoperitoneum, 10(7)human HeLa cells were injected into the peritoneal cavity of nine non-syngeneic animals to induce tumour xenograft. Resection of the sigmoid colon using four trocars and a transanal double-stapling technique was performed. The mean operating time was 69 min. No signs of post-operative pain symptoms were observed, and all the animals survived the procedure and gained weight. After 4 weeks, the animals were sacrified and all incision sites and anastomoses were excised. RESULTS: Immunohistochemical staining with antihuman pancytokeratin antibodies confirmed tumour implants in 25 out of 36 port-sites (63.8%). No peritoneal carcinosis nor tumour implants at anastomosis sites were observed. CONCLUSION: This intraperitoneal xenograft tumour model in the pig can be applied in survival studies to check the quality of surgical techniques and its influence on tumour implantation following laparoscopy for cancer.

Hemodynamic effects of intermittent pneumatic compression of the lower limbs during laparoscopic cholecystectomy.

BACKGROUND: The effects of surgical pneumoperitoneum on lower-limb venous hemodynamics have already been studied; however, the effects of intermittent compression boots are not known in such venous-stasis conditions. METHODS: In 12 volunteers and 12 patients, the venous hemodynamic effects of intermittent leg compression were studied under external abdominal pressure or during laparoscopic cholecystectomy, respectively. Femoral venous diameter and velocity were measured. Venous pressure was monitored during the surgical procedures. RESULTS: External abdominal pressure of 50 mm Hg and pneumoperitoneum were found to increase the diameter (17% in the volunteers and 14% in the patients) and decrease peak velocity (49% and 32%, respectively) in the femoral vein. Femoral pressure was increased (106%) during pneumoperitoneum. In both venous-stasis circumstances, intermittent compression of the legs restored venous flow velocity, but had no effect on vessel diameter and pressure. CONCLUSIONS: The lower-limb venous hemodynamic changes were similar during external abdominal pressure or pneumoperitoneum, and the flow velocity decrease was intermittently reversed by pneumatic compression boots.

Feasibility of therapeutic pneumoperitoneum in a large animal model using a microvaporisator.

BACKGROUND: Multimodal therapy is used increasingly in advanced gastrointestinal tumors. Potential benefits of using an intraoperative adjuvant therapy during laparoscopy for cancer have been documented in animal studies. The aim of this study was to develop a device that could deliver such an intraoperative drug therapy. METHODS: We developed a micropump suitable for minimally invasive surgery procedures that allowed microdroplets of therapeutic substance to be distributed into the pneumoperitoneum (CO2), creating a "therapeutic pneumoperitoneum." A closed-loop control system regulates drug delivery according to the gas flow. In vitro, the micropump is able to aerosolize various aqueous and ethanol solutions, including cytostatic and bacteriostatic drugs and adhesion-modulating agents. The size of the microdroplets has been optimized to prevent visual artifacts. RESULTS: The micropump was tested in an animal model (pig). The system was inserted into a 5-mm trocar. After insufflation of a 12-mm CO2 pneumoperitoneum, laparoscopic sigmoid colon resections could be performed with no special difficulties. No fog developed, and no system-related complication was observed. At autopsy, the active principle was distributed to all exposed peritoneal surfaces. CONCLUSIONS: As opposed to conventional peritoneal washing, therapeutic pneumoperitoneum reaches the entire peritoneal surface, allowing an optimal drug distribution. Drug diffusion into the tissues is enhanced by the intraperitoneal pressure. Precise determination of the instantaneous and total drug quantity is possible. Therefore, this drug delivery system has several advantages over conventional irrigation. Its potential domains of application are locoregional cancer therapy, prevention of port-site recurrences, immunomodulation, analgesia, peritonitis, and prevention of postoperative adhesions.

Oncologic implications of laparoscopic and open surgery.

Although instrumental manipulation and mechanical tumor cell spillage seem to play the major role in port-site metastases from laparoscopic cancer surgery, minimally invasive procedures are used more and more in the resection of malignancies. However, port-site metastases also have been reported after resection of colon cancer in International Union Against Cancer (UICC) stage I [2, 14]. Therefore, changes in the peritoneal environment during laparoscopy also might influence intra- and extraperitoneal tumor growth during laparoscopy and pneumoperitoneum. Different results of experimental studies presented at the Third International Conference for Laparoscopic Surgery are analyzed and discussed.