Intraperitoneal chemotherapy against peritoneal carcinomatosis: current status and future perspective

The effect of electrostatic high pressure nebulization on the stability, activity and ex vivo distribution of ionic self-assembled nanomedicines

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is applied to treat unresectable peritoneal metastasis (PM), an advanced, end-stage disease with a poor prognosis. Electrostatic precipitation of the aerosol (ePIPAC) is aimed at improving the intraperitoneal (IP) drug distribution and tumor penetration. Also, the combination of nanoparticles (NPs) as drug delivery vehicles and IP aerosolization as administration method has been proposed as a promising tool to treat PM. There is currently limited knowledge on how electrostatic precipitation (ePIPAC) and high pressure nebulization (PIPAC) affects the performance of electrostatically formed complexes. Therefore, the stability, in vitro activity and ex vivo distribution and tissue penetration of negatively charged cisPt-pArg-HA NPs and positively charged siRNA-RNAiMAX NPs was evaluated following PIPAC and ePIPAC. Additionally, a multidirectional Medspray® nozzle was developed and compared with the currently used Capnopen® nozzle. For both NP types, PIPAC and ePIPAC did not negatively influence the in vitro activity, although limited aggregation of siRNA-RNAiMAX NPs was observed following nebulization with the Capnopen®. Importantly, ePIPAC was linked to a more uniform distribution and higher tissue penetration of the NPs aerosolized by both nozzles, independent on the NPs charge. Finally, compared to the Capnopen®, an increased NP deposition was observed at the top of the ex vivo model following aerosolization with the Medspray® nozzle, which indicates that this device possesses great potential for IP drug delivery purposes. STATEMENT OF SIGNIFICANCE: Aerosolized drug delivery in the peritoneal cavity holds great promise to treat peritoneal cancer. In addition, electrostatic precipitation of the aerosol to the peritoneal tissue is aimed at improving the drug distribution and tumor penetration. The combination of nanoparticles (NPs), which are nano-sized drug delivery vehicles, and aerosolization has been proposed as a promising tool to treat peritoneal cancer. However, there is currently limited knowledge on how electrostatic precipitation and aerosolization affect the performance of electrostatically formed NPs. Therefore, the stability, activity, distribution and penetration of negatively and positively charged NPs was evaluated after aerosolization and electrostatic precipitation. Additionally, to further optimize the local drug distribution, a multidirectional spray nozzle was developed and compared with the currently used nozzle.

Epithelial SOX9 drives progression and metastases of gastric adenocarcinoma by promoting immunosuppressive tumour microenvironment

OBJECTIVE

Many cancers engage embryonic genes for rapid growth and evading the immune system. SOX9 has been upregulated in many tumours, yet the role of SOX9 in mediating immunosuppressive tumour microenvironment is unclear. Here, we aim to dissect the role of SOX9-mediated cancer stemness attributes and immunosuppressive microenvironment in advanced gastric adenocarcinoma (GAC) for novel therapeutic discoveries.

METHODS

Bulk RNAseq/scRNA-seq, patient-derived cells/models and extensive functional studies were used to identify the expression and functions of SOX9 and its target genes in vitro and in vivo. Immune responses were studied in PBMCs or CD45⁺ immune cells cocultured with tumour cells with SOX9^high or knockout and the KP-Luc2 syngeneic models were used for efficacy of combinations.

RESULTS

SOX9 is one of the most upregulated SOX genes in GAC and highly expressed in primary and metastatic tissues and associated with poor prognosis. Depletion of SOX9 in patient-derived GAC cells significantly decreased cancer stemness attributes, tumour formation and metastases and consistently increased CD8⁺ T cell responses when cocultured with PBMCs/CD45⁺ cells from GAC patients. RNA sequencing identified the leukaemia inhibitory factor (LIF) as the top secreted molecule regulated by SOX9 in tumour cells and was enriched in malignant ascites and mediated SOX9-induced M2 macrophage repolarisation and inhibited T cell function.

CONCLUSION

Epithelial SOX9 is critical in suppressing CD8⁺ T cell responses and modified macrophage function in GAC through the paracrine LIF factor. Cotargeting LIF/LIFR and CSF1R has great potential in targeting SOX9-mediated cancer stemness, T cell immunosuppression and metastases suggesting the novel combination therapy against advanced GAC.

The Hippo signaling pathway in gastric cancer

Gastric cancer (GC) is an aggressive malignant disease which still lacks effective early diagnosis markers and targeted therapies, representing the fourth-leading cause of cancer-associated death worldwide. The Hippo signaling pathway plays crucial roles in organ size control and tissue homeostasis under physiological conditions, yet its aberrations have been closely associated with several hallmarks of cancer. The last decade witnessed a burst of investigations dissecting how Hippo dysregulation contributes to tumorigenesis, highlighting the therapeutic potential of targeting this pathway for tumor intervention. In this review, we systemically document studies on the Hippo pathway in the contexts of gastric tumor initiation, progression, metastasis, acquired drug resistance, and the emerging development of Hippo-targeting strategies. By summarizing major open questions in this field, we aim to inspire further in-depth understanding of Hippo signaling in GC development, as well as the translational implications of targeting Hippo for GC treatment.

The contemporary management of peritoneal metastasis: A journey from the cold past of treatment futility to a warm present and a bright future

Peritoneal metastasis (PM) is often regarded as a less frequent pattern of spread; however, collectively across all spectra of primary tumors, the consequences of PM impact a large population of patients annually. Unlike other modes of metastasis, symptoms at presentation or during the treatment course are common, representing an additional challenge in the management of PM. Early efforts with chemotherapy and incomplete surgical interventions transiently improved symptoms, but durable symptom control and survival extension were rare, which established a perspective of treatment futility for PM through most of the 20th century. Notably, the continued development of better systemic therapy combinations, optimization of cytoreductive surgery (CRS), and rigorous investigation of combining regional therapy-specifically hyperthermic intraperitoneal chemotherapy-with CRS, have resulted in more effective multimodal treatment options for patients with PM. In this article, the authors provide a comprehensive review of the data establishing the contemporary approach for tumors with a high frequency of PM, including appendix, colorectal, mesothelioma, and gastric cancers. The authors also explore the emerging role of adding hyperthermic intraperitoneal chemotherapy to the well established paradigm of CRS and systemic therapy for advanced ovarian cancer, as well as the recent clinical trials identifying the efficacy of poly(adenosine diphosphate ribose) polymerase maintenance therapy. Finally, recent data are included that explore the role of precision medicine technology in PM management that, in the future, may help further improve patient selection, identify the best systemic therapy regimens, detect actionable mutations, and identify new targets for drug development.

[Solubilization of Poorly Water-soluble Drugs with Amphiphilic Phospholipid Polymers]

Most drug candidates developed in recent years are poorly water-soluble, which is a key challenge in pharmaceutical science. Various solubilization methods have been investigated thus far, most of which require solubilizers that provide a local hydrophobic environment wherein a drug can dissolve or induce interactions with drug molecules. We have focused on amphiphilic 2-methacryloyloxyethyl phosphoryl choline (MPC) polymers. In addition to the ease of molecular design of amphiphilic MPC polymers owing to their chemical structures, they have been reported to possess high biocompatibility in various biomaterial applications. Additionally, amphiphilic MPC polymers have been applied in the pharmaceutical field, especially in solubilization. We have qualitatively and quantitatively evaluated the effects of the chemical structure and physical properties of the solubilizer on the MPC polymers. In particular, MPC polymers with different chemical structures were designed and synthesized. The inner polarity and molecular mobility in the polymer aggregates were evaluated, indicating that the intrinsic properties reflect the chemical structure of the polymer. Additionally, amphiphilic MPC polymers were used to improve the solubility of poorly water-soluble drugs and as solid dispersion carriers, and they exhibited superior solubilizing abilities compared to a commonly used polymer. Furthermore, the solubility of biopharmaceuticals, such as peptides, was improved. It is possible to design and synthesize optimal structures based on the polarity of the hydrophobic environment and the intermolecular interaction with a drug. This research provides a unified interpretation of drugs and efficiently summarizes knowledge about drug development, which will facilitate the efficient and rapid development of drug formulations.

Effects of particle size and release property of paclitaxel-loaded nanoparticles on their peritoneal retention and therapeutic efficacy against mouse malignant ascites

Malignant ascites accounts for abdominal pain, dyspnea and anorexia, all of which decrease quality of life in cancer patients. Intraperitoneal chemotherapy is a useful method for managing malignant ascites and nanoparticulate drug delivery system makes it more effective by increasing peritoneal retention of anti-cancer drugs. In this study, we prepared paclitaxel-loaded emulsions and liposomes with different particle sizes and drug release properties, and evaluated their peritoneal retention and therapeutic efficacy in Ehrlich's ascites carcinoma (EAC)-bearing mice. Liposomes with the size of 100 nm were rapidly absorbed from peritoneal cavity into blood after intraperitoneal injection into EAC-bearing mice, whereas 1000-nm liposomes were highly retained in peritoneal cavity. Accordingly, 1000 nm liposomes significantly prolonged survival time of EAC-bearing mice but did not inhibit the ascites accumulation because of too poor paclitaxel release. On the other hand, although peritoneal retention of emulsions themselves was similar irrespective of their sizes, 270-nm emulsions showed the higher PTX retention in ascites than other emulsions, and resulted in significantly prolonged survival time and lower accumulation of ascites in EAC-bearing mice. These results indicate that not only particle size but drug release property is one of key determinants of the biodisposition and therapeutic efficacy of intraperitoneally injected nanoparticulate PTX against malignant ascites.

MiR-29b may suppresses peritoneal metastases through inhibition of the mesothelial-mesenchymal transition (MMT) of human peritoneal mesothelial cells

Peritoneal dissemination is a major metastatic pathway for gastrointestinal and ovarian malignancies. The miR-29b family is downregulated in peritoneal fluids in patients with peritoneal metastases (PM). We examined the effect of miR-29b on mesothelial cells (MC) which play critical a role in the development of PM through mesothelial-mesenchymal transition (MMT). Human peritoneal mesothelial cells (HPMCs) were isolated from surgically resected omental tissue and MMT induced by stimulation with 10 ng/ml TGF-β1. MiR-29b mimics and negative control miR were transfected by lipofection using RNAiMAX and the effects on the MMT evaluated in vitro. HPMC produced substantial amounts of miR-29b which was markedly inhibited by TGF-β1. TGF-β1 stimulation of HPMC induced morphological changes with decreased expression of E-cadherin and calretinin, and increased expression of vimentin and fibronectin. TGF-β1 also enhanced proliferation and migration of HPMC as well as adhesion of tumor cells in a fibronectin dependent manner. However, all events were strongly abrogated by simultaneous transfection of miR-29b. MiR-29b inhibits TGF-β1 induced MMT and replacement of miR-29b in the peritoneal cavity might be effective to prevent development of PM partly through the effects on MC.

Scrotal Necrosis Following Heated Intra-peritoneal Chemotherapy: Case Report and Review of the Literature

Scrotal necrosis is a rare occurrence that is scarcely reported among patients having undergone heated intra-peritoneal chemotherapy (HIPEC) procedures. Due to anatomic factors and the thermally enhanced cytotoxicity of chemotherapeutic agents, this complication can have debilitating post-operative effects. We herein highlight the presentation of scrotal necrosis in a patient who underwent HIPEC procedure for peritoneal metastasis secondary to colorectal carcinoma, and how it contrasts to previously documented cases of a similar nature. Furthermore, we describe a successful management strategy that consisted of conservative measures followed by surgical debridement and primary repair, and enabled the patient to experience significant functional and cosmetic improvement.

Exploring High Pressure Nebulization of Pluronic F127 Hydrogels for Intraperitoneal Drug Delivery

Peritoneal metastasis is an advanced cancer type which can be treated with pressurized intraperitoneal aerosol chemotherapy (PIPAC). Here, chemotherapeutics are nebulized under high pressure in the intraperitoneal (IP) cavity to obtain a better biodistribution and tumor penetration. To prevent the fast leakage of chemotherapeutics from the IP cavity, however, nebulization of controlled release formulations is of interest. In this study, the potential of the thermosensitive hydrogel Pluronic F127 to be applied by high pressure nebulization is evaluated. Therefore, aerosol formation is experimentally examined by laser diffraction and theoretically simulated by computational fluid dynamics (CFD) modelling. Furthermore, Pluronic F127 hydrogels are subjected to rheological characterization after which the release of fluorescent model nanoparticles from the hydrogels is determined. A delicate equilibrium is observed between controlled release properties and suitability for aerosolization, where denser hydrogels (20% and 25% w/v Pluronic F127) are able to sustain nanoparticle release up to 30 hours, but cannot effectively be nebulized and vice versa. This is demonstrated by a growing aerosol droplet size and exponentially decreasing aerosol cone angle when Pluronic F127 concentration and viscosity increase. Novel nozzle designs or alternative controlled release formulations could move intraperitoneal drug delivery by high pressure nebulization forward.

YAP1 mediates gastric adenocarcinoma peritoneal metastases that are attenuated by YAP1 inhibition

OBJECTIVE

Peritoneal carcinomatosis (PC; malignant ascites or implants) occurs in approximately 45% of advanced gastric adenocarcinoma (GAC) patients and associated with a poor survival. The molecular events leading to PC are unknown. The yes-associated protein 1 (YAP1) oncogene has emerged in many tumour types, but its clinical significance in PC is unclear. Here, we investigated the role of YAP1 in PC and its potential as a therapeutic target.

METHODS

Patient-derived PC cells, patient-derived xenograft (PDX) and patient-derived orthotopic (PDO) models were used to study the function of YAP1 in vitro and in vivo. Immunofluorescence and immunohistochemical staining, RNA sequencing (RNA-Seq) and single-cell RNA-Seq (sc-RNA-Seq) were used to elucidate the expression of YAP1 and PC cell heterogeneity. LentiCRISPR/Cas9 knockout of YAP1 and a YAP1 inhibitor were used to dissect its role in PC metastases.

RESULTS

YAP1 was highly upregulated in PC tumour cells, conferred cancer stem cell (CSC) properties and appeared to be a metastatic driver. Dual staining of YAP1/EpCAM and sc-RNA-Seq revealed that PC tumour cells were highly heterogeneous, YAP1^high PC cells had CSC-like properties and easily formed PDX/PDO tumours but also formed PC in mice, while genetic knockout YAP1 significantly slowed tumour growth and eliminated PC in PDO model. Additionally, pharmacologic inhibition of YAP1 specifically reduced CSC-like properties and suppressed tumour growth in YAP1^high PC cells especially in combination with cytotoxics in vivo PDX model.

CONCLUSIONS

YAP1 is essential for PC that is attenuated by YAP1 inhibition. Our data provide a strong rationale to target YAP1 in clinic for GAC patients with PC.

Peritoneal Carcinomatosis Targeting with Tumor Homing Peptides

Over recent decades multiple therapeutic approaches have been explored for improved management of peritoneally disseminated malignancies—a grim condition known as peritoneal carcinomatosis (PC). Intraperitoneal (IP) administration can be used to achieve elevated local concentration and extended half-life of the drugs in the peritoneal cavity to improve their anticancer efficacy. However, IP-administered chemotherapeutics have a short residence time in the IP space, and are not tumor selective. An increasing body of work suggests that functionalization of drugs and nanoparticles with targeting peptides increases their peritoneal retention and provides a robust and specific tumor binding and penetration that translates into improved therapeutic response. Here we review the progress in affinity targeting of intraperitoneal anticancer compounds, imaging agents and nanoparticles with tumor-homing peptides. We review classes of tumor-homing peptides relevant for PC targeting, payloads for peptide-guided precision delivery, applications for targeted compounds, and the effects of nanoformulation of drugs and imaging agents on affinity-based tumor delivery.

Anticancer activity of the intraperitoneal-delivered DFP-10825, the cationic liposome-conjugated RNAi molecule targeting thymidylate synthase, on peritoneal disseminated ovarian cancer xenograft model

Introduction

Peritoneal disseminated ovarian cancer is one of the most difficult cancers to treat with conventional anti-cancer drugs and the treatment options are very limited, although an intraperitoneal (ip) paclitaxel has shown some clinical benefit. Therefore, treatment of peritoneal disseminated ovarian cancer is a highly unmet medical need and it is urgent to develop a new ip delivered drug regulating the fast DNA synthesis.

Methods

We developed a unique RNAi molecule consisting of shRNA against the thymidylate synthase (TS) and a cationic liposome (DFP-10825) and tested its antitumor activity and PK profile in peritoneally disseminated human ovarian cancer ascites models by the luciferase gene-transfected SCID mice. DFP-10825 alone, paclitaxel alone or combination with DFP-10825 and paclitaxel were administered in an ip route to the tumor-bearing mice. The TS expression level was measured by conventional RT-PCR. The anti-tumor activity and host survival benefit by DFP-10825 treatment on tumor-bearing mice were observed as resulting from the specific TS mRNA knock-down in tumors.

Results

DFP-10825 alone significantly suppressed the growth of SKOV3-luc tumore ascites cells and further extended the survival time of these tumor-bearing mice. Combination with the ip paclitaxel augmented the antitumor efficacy of DFP-10825 and significantly prolonged the survival time in the tumor-bearing mice. Short-hairpin RNA for TS (TS shRNA) levels derived from DFP-10825 in the ascetic fluid were maintained at a nM range across 24 hours but not detected in the plasma, suggesting that TS shRNA is relatively stable in the peritoneal cavity, to be able to exert its anti-tumor activity, but not in blood stream, indicating little or no systemic effect.

Conclusion

Collectively, the ip delivery of DFP-10825, TS shRNA conjugated with cationic liposome, shows a favorable antitumor activity without systemic adverse events via the stable localization of TS shRNA for a sufficient time and concentration in the peritoneal cavity of the peritoneally disseminated human ovarian cancer-bearing mice.

Hyperthermic Intraperitoneal Perfusion Chemotherapy and Cytoreductive Surgery for Controlling Malignant Ascites From Ovarian Cancer

BACKGROUND

Malignant ascites, a complication often seen in patients with ovarian cancer (OC), is difficult to treat, but hyperthermic intraperitoneal chemotherapy (HIPEC) has a good efficacy.

OBJECTIVE

The aim of this study was to assess the efficacy of cytoreductive surgery (CRS) combined with HIPEC for controlling malignant ascites from OC.

MATERIALS AND METHODS

From December 2009 until December 2014, 53 patients with OC and malignant ascites were treated with CRS and HIPEC. Patients in good health condition were treated with CRS followed by HIPEC (CRS + HIPEC), and patients in poor health condition were treated initially with B-mode ultrasound-guided HIPEC followed by delayed CRS upon improvement of their health condition (HIPEC + delayed CRS). Resolution of ascites, complete CRS, overall survival, and disease-free survival were analyzed.

RESULTS

All patients showed ascites regression. The total objective remission rate was 100%, even for patients in the poor condition group before CRS. Complete CRS was successful in 30 (88.23%) of 34 patients in the good condition group, and 17 (89.47%) of 19 patients in the poor condition group (P > 0.05). Median disease-free survival and median overall survival were 21 and 39 months in the good condition group, and 22 and 38 months in the poor condition group, respectively (P > 0.05).

CONCLUSIONS

Hyperthermic intraperitoneal chemotherapy is effective at controlling ascites in patients with OC, even for patients in poor condition before CRS, or when complete CRS is not feasible. Furthermore, the regression of ascites appears not to be dependent on complete resection.

Nanoparticle as a novel tool in hyperthermic intraperitoneal and pressurized intraperitoneal aerosol chemotheprapy to treat patients with peritoneal carcinomatosis

The treatment of peritoneal surface malignances has changed considerably over the last thirty years. Unfortunately, the palliative is the only current treatment for peritoneal carcinomatosis (PC). Two primary intraperitoneal chemotherapeutic methods are used. The first is combination of cytoreductive surgery (CRS) and Hyperthermic IntraPEritoneal Chemotherapy (HIPEC), which has become the gold standard for many cases of PC. The second is Pressurized IntraPeritoneal Aerosol Chemotheprapy (PIPAC), which is promising direction to minimally invasive as safedrug delivery. These methods were improved through multicenter studies and clinical trials that yield important insights and solutions. Major method development has been made through nanomedicine, specifically nanoparticles. Here, we are presenting the latest advances of nanoparticles and their application to precision diagnostics and improved treatment strategies for PC. These advances will likely develop both HIPEC and PIPAC methods that used for in vitro and in vivo studies. Several benefits of using nanoparticles will be discussed including: 1) Nanoparticles as drug delivery systems; 2) Nanoparticles and Near Infrred (NIR) Irradiation; 3) use of nanoparticles in perioperative diagnostic and individualized treatment planning; 4) use of nanoparticles as anticancer dressing's, hydrogels and as active beeds for optimal reccurence prevention; and 5) finally the curent in vitro and in vivo studies and clinical trials of nanoparticles. The current review highlighted use of nanoparticles as novel tools in improving drug delivery to be effective for treatment patients with peritoneal carcinomatosis.

Targeting of p32 in peritoneal carcinomatosis with intraperitoneal linTT1 peptide-guided pro-apoptotic nanoparticles

Gastrointestinal and gynecological malignancies disseminate in the peritoneal cavity - a condition known as peritoneal carcinomatosis (PC). Intraperitoneal (IP) administration can be used to improve therapeutic index of anticancer drugs used for PC treatment. Activity of IP anticancer drugs can be further potentiated by encapsulation in nanocarriers and/or affinity targeting with tumor-specific affinity ligands, such as tumor homing peptides. Here we evaluated a novel tumor penetrating peptide, linTT1 (AKRGARSTA), as a PC targeting ligand for nanoparticles. We first demonstrated that the primary homing receptor for linTT1, p32 (or gC1qR), is expressed on the cell surface of peritoneal carcinoma cell lines of gastric (MKN-45P), ovarian (SKOV-3), and colon (CT-26) origin, and that peritoneal tumors in mice and clinical peritoneal carcinoma explants express p32 protein accessible from the IP space. Iron oxide nanoworms (NWs) functionalized with the linTT1 peptide were taken up and routed to mitochondria in cultured PC cells. NWs functionalized with linTT1 peptide in tandem with a pro-apoptotic [D(KLAKLAK)2] peptide showed p32-dependent cytotoxicity in MKN-45P, SKOV-3, and CT-26 cells. Upon IP administration in mice bearing MKN-45P, SKOV-3, and CT-26 tumors, linTT1-functionalized NWs showed robust homing and penetration into malignant lesions, whereas only a background accumulation was seen in control tissues. In tumors, the linTT1-NW accumulation was seen predominantly in CD31-positive blood vessels, in LYVE-1-positive lymphatic structures, and in CD11b-positive tumor macrophages. Experimental therapy of mice bearing peritoneal MKN-45P xenografts and CT-26 syngeneic tumors with IP linTT1-D(KLAKLAK)2-NWs resulted in significant reduction of weight of peritoneal tumors and significant decrease in the number of metastatic tumor nodules, whereas treatment with untargeted D(KLAKLAK)2-NWs had no effect. Our data show that targeting of p32 with linTT1 tumor-penetrating peptide improves tumor selectivity and antitumor efficacy of IP pro-apoptotic NWs. P32-directed intraperitoneal targeting of other anticancer agents and nanoparticles using peptides and other affinity ligands may represent a general strategy to increase their therapeutic index.

Optimal drug delivery for intraperitoneal paclitaxel (PTX) in murine model

Background

Repeated intraperitoneal (IP) administration of paclitaxel (PTX) with concurrent systemic chemotherapy is clinically effective for the treatment of peritoneal metastases (PM) from gastric cancer. However, it is unclear how biochemical modifications may affect the pharmacokinetics and bioavailability of IP administered PTX.

Methods

In a xenograft PM model using human gastric cancer cells, MKN45, fluorescein-conjugated PTX (OG-PTX) was given IP and the intra-tumor distribution of PTX examined with fluorescein microscopy.

Results

After IP injection, PTX was seen to directly infiltrate up to several hundred micrometers from the surface of the PM. Co-injection with 5 % non-animal stabilized hyaluronic acid increased PTX infiltration and suppressed the development of PM more efficiently than PTX alone. PTX solubilized with amphiphilic polymer composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) and n-butyl methacrylate (BMA) efficiently formed a micellar formation 50-100 nm in diameter. IP injection of the nanomicellar PTX (PTX-30W) also showed significantly enhanced tumor infiltration and further inhibition of the growth of PM compared with PTX solubilized with Cremophor-ethanol (PTX-Cre). Finally, IP administration of NK105, another nanomicellar PTX, inhibited the growth of subcutaneous tumors as well as PM, compared with conventional PTX-Cre in the same murine model.

Conclusions

PTX administered IP directly infiltrates PM and are thus a useful strategy for the treatment of PM. Drug modification with nanotechnology may further enhance penetration of PM resulting in improved clinical efficacy.

Cytomorphological changes induced by intraperitoneal chemotherapy present important diagnostic pitfalls in peritoneal fluid cytology

OBJECTIVE

Intraperitoneal chemotherapy (IP ChT) is an emerging modality in the treatment of advanced gastric adenocarcinoma with peritoneal disease. Cytological evaluation of peritoneal fluid specimens from patients undergoing IP ChT is important in clinical management. However, direct intraperitoneal exposure to chemotherapeutic agents induces cytomorphological changes in benign constituents of peritoneal fluid, presenting particular challenges to accurate cytological interpretation. These morphological changes have not been well characterised in the literature. We systematically reviewed the cytomorphological features in immunocytochemically-confirmed positive and negative IP ChT peritoneal fluid samples to elucidate the degree of morphological overlap between malignant and reactive cells.

METHODS

We reviewed 39 peritoneal fluid samples of patients treated with IP ChT, and scored specific cytomorphological parameters of both benign and malignant cells with the aid of relevant immunocytochemical interrogation.

RESULTS

The present findings show a significant degree of morphological overlap between reactive and malignant cells. Abnormal, "exploding" mitotic figures, nuclear membrane irregularities, multi-nucleation and cytoplasmic vacuolation were commonly observed in negative fluid specimens. The most helpful feature that favoured malignant cells was the increased nuclear-to-cytoplasmic ratio. A background inflammatory milieu of eosinophils and/or neutrophils was seen in 45-58% of post IP ChT peritoneal fluid specimens. The presence of pseudoparakeratotic cells, a novel observation in post IP ChT fluid specimens is also described.

CONCLUSIONS

The extent of reactive cytomorphological anomalies arising from treatment with IP ChT poses unique diagnostic challenges and may prompt a malignant or 'atypical' diagnosis in benign reactive samples.

Recent achievements in colorectal cancer diagnostic and therapy by the use of nanoparticles

Colorectal cancer is a major public health issue, being the third most common cancer in men and the second in women. It is one of the leading causes of cancer deaths. Nanomedicine is an emerging field of interest, many of its aspects being linked to cancer research. Chemotherapy has a well-established role in colorectal cancer management, unfortunately being limited by inability to have a selective distribution, by multidrug resistance and adverse effects. Researches carried out in recent years about nanotechnologies aimed, among others, to resolve the issues mentioned above. Targeted and localized delivery of the chemotherapeutic drugs, using nanoparticles, with selective destruction of cancerous cells would minimize the toxicity on healthy tissues. Also, the use of nanomaterials as contrast agent could improve sensitivity and specificity of diagnosis. The purpose of this review is to highlight the recent achievements of cancer research by use of nanomaterials, in the idea of finding the ideal composite, capable to simultaneous diagnostic and treat cancer.

Complications after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for treatment of peritoneal carcinomatosis: Risk factors for ICU admission and morbidity prognostic score

BACKGROUND AND OBJECTIVES

For patients suffering from peritoneal carcinomatosis, cytoreductive surgery and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is the only curative option. We focused on severe complications in the postoperative course of HIPEC.

METHODS

We studied perioperative data from patients who underwent HIPEC between January 2010 and August 2011. Our primary objective was to identify perioperative risk factors for ICU admission. Our secondary objective was to identify patient that may be re-admitted to the ICU thanks to a prognostic score.

RESULTS

122 patients underwent HIPEC. 32 presented severe adverse events (26.2%) and 7 died (5.7%). Reasons for ICU admission were septic shock in 28.1% of patients, hemorrhagic shock for 21.9%, hemodynamic instability for 15.6%, respiratory causes for 6.2% and post-operative acidosis for 6.2%. Vasopressors were required for 34% and 40.6% were mechanically ventilated.

CONCLUSION

Peritoneal cancer index, diaphragmatic peritonectomy, the need of vasopressive therapy, total volume of fluid leakage collected in drains and total volume of fluid therapy administered at day 1 reported on ideal body weight were the 5 significant variables that we combined to build a morbidity prognostic score. One patient over 4 is likely to present severe complications. A predictive morbidity score provide informative data for clinicians.

State-of-the-art methods in clinical diagnosis and treatment of peritoneal metastasis of gastric cancer

Gastric cancer is one of the most common malignant tumors and presents a very high mortality. The main reason for this situation is metastasis after curative resection, with the most common type being peritoneal metastasis, which accounts for more than 50% of all cases. Once peritoneal carcinomatosis (PC) happens, the pathological stage is stage IV and there is a grim prognosis. Accordingly, early effective prevention and treatment of PC have extremely important clinical significance for the improvement of the prognosis of patients with gastric cancer. This article describes the pathogenesis, clinical diagnosis using serum biomarkers and image examinations, as well as multimodality treatment of peritoneal metastasis of gastric cancer by neoadjuvant intraperitoneal-systemic chemotherapy (NIPS), cytoreductive surgery+hyperthermic intraperitoneal chemotherapy (CRS+HIPEC), early postoperative intraperitoneal chemotherapy (EPIC), extensive intraoperative peritoneal lavage (EIPL), molecular targeting therapy, and usage of drug delivery systems.

Long noncoding RNA aberrant expression profiles after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy of AGC ascertained by microarray analysis

Long noncoding RNAs (lncRNAs) have been shown to be involved in the development and progression of advanced gastric cancer (AGC). However, the roles of lncRNAs in advanced gastric cancer during the process of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are not well understood. A high-throughput microarray analysis was performed to compare the expression profiles of lncRNAs and messenger RNAs (mRNAs) in AGC serum samples during the process of CRS + HIPEC. Several potentially AGC-associated lncRNAs were verified by real-time quantitative reverse transcription polymerase chain reaction (PCR) analysis. Using abundant and varied probes, we were able to assess 33,045 lncRNAs and 30,215 mRNAs in our microarray. We found that 566 lncRNAs were differentially expressed (2-fold change) in AGC serum samples, indicating the significantly up- or downregulated lncRNAs play important roles in AGC during the process of CRS + HIPEC. Quantitative PCR results further verified that eight lncRNAs were aberrantly expressed in AGC serum samples after CRS + HIEC compared with matched serum sample before CRS + HIPEC. Among them, BC031243 and RP11-356I2.2 were the most aberrantly expressed lncRNAs, as estimated by quantitative PCR in six pairs of AGC serum samples. Our study demonstrated the expression patterns of lncRNAs in AGC serums before and after CRS + HIPEC by microarray. These results revealed that lncRNAs were differentially expressed during the process of CRS + HIPEC, suggesting that they might play key roles in tumor development.

Clinical significance of cytological status of peritoneal lavage fluid during intraperitoneal chemotherapy for gastric cancer with overt peritoneal dissemination

BACKGROUND

A positive cytology of peritoneal lavage fluid (CY1) is a poor prognostic factor in patients with gastric cancer (GC). We have recently reported that CY1 often changes to negative (CY0) following combination chemotherapy including intraperitoneal (IP) paclitaxel (PTX), which results in marked prolongation of survival in GC patients with peritoneal dissemination (P1).

METHODS

A total of 95 P1 GC patients who received combination chemotherapy with S-1 and intravenous and IP PTX were enrolled. Peritoneal lavage fluid was periodically examined cytologically at the start of every cycle of chemotherapy, and the impact of CY status on patient outcome was retrospectively evaluated.

RESULTS

Seventy-three (76.8%) of 95 patients were diagnosed as CY1 before initial treatment. Median survival time (MST) of the CY1 group was significantly shorter than that of the CY0 group (19.1 vs. 32.5 months, P = 0.033). Cytological status changed from CY1 to CY0 in 68 (93.2%) of 73 CY1 patients during the whole treatment period and MST of patients who showed a negative change was significantly longer than that of the unchanged group (20.0 vs. 13.0 months, P = 0.0017). In 64 patients who achieved CY0 by IP PTX regimen, the median time to achieve CY0 was 1.4 months, and patients who achieved a negative change within 1 month showed a particularly good outcome (MST = 26.1 months).

CONCLUSIONS

Periodic cytological examination of peritoneal lavage fluid is clinically useful to evaluate the efficacy of treatment as well as to predict the outcome of patients with P1 GC.