Peritoneal carcinomatosis: limits of diagnosis and the case for liquid biopsy

Material density dual-energy CT images: value added in early diagnosis of peritoneal carcinomatosis : Original research

OBJECTIVE

To assess the value of material density (MD) images generated from a rapid kilovoltage-switching dual-energy CT (rsDECT) in early detection of peritoneal carcinomatosis (PC).

MATERIALS AND METHODS

Thirty patients (60 ± 13 years; 24 women) with PC detected on multiple abdominal DECT scans were included. Four separate DECTs with varying findings of PC from each patient were used for qualitative/quantitative analysis, resulting in a total of 120 DECT scans (n = 30 × 4). Three radiologists independently reviewed DECT images (65 keV alone and 65 keV + MD) for diagnosis of PC (diagnostic confidence, lesion conspicuity, sharpness/delineation and image quality) using a 5-point Likert scale. Quantitative estimation of contrast-to-noise ratio (CNR) was done. Wilcoxon signed-rank test and Odds ratio calculation were used to compare between the two protocols. Inter-observer agreement was evaluated using Kappa coefficient analysis. P values < 0.05 were considered statistically significant.

RESULTS

65 keV + MD images showed a slightly higher sensitivity (89%[95%CI:84,92]) for PC detection compared with 65 keV images alone without statistical significance (84%[95%CI:78,88], p = 0.11) with the experienced reader showing significant improvement (98%[95%CI:93,100] vs. 90%[95%CI:83,94], p = 0.02). On a per-patient basis, use of MD images allowed earlier diagnosis for PC in an additional 13-23% of patients. On sub-group analysis, earlier diagnosis of PC was particularly beneficial in patients with BMI ≤ 29.9 kg/m2. 65 keV + MD images showed higher diagnostic confidence, lesion conspicuity, and lesion sharpness for the experienced reader (p < 0.001). CNR was higher in MD images (1.7 ± 0.5) than 65 keV images (0.1 ± 0.02, p < 0.001). All readers showed moderate interobserver agreement for determining PC by both protocols (κ = 0.58 and κ = 0.47).

CONCLUSION

MD images allow earlier and improved detection of PC with the degree of benefit varying based on reader experience and patient body habitus.

Uncovering the Unknown: Granulomatous Peritonitis After Right Ovarian Cystectomy at a Tertiary Care Center in South India-A Case Report

Background. Granulomatous peritonitis is a rare postoperative complication caused by a delayed hypersensitivity reaction to foreign substances. It can be challenging to diagnose owing to its vague presentations, and its possibility is often overlooked. Tubercular peritonitis and peritoneal carcinomatosis are the 2 crucial differential diagnoses that need to be taken into account. However, making a clinical differentiation between these 2 entities is challenging and necessitates a careful histopathological and microbiological analysis. Case Presentation. In this report, we present the case of a 28-year-old female who developed granulomatous peritonitis following a right ovarian cystectomy. The diagnosis was confirmed by histopathological examination. Conclusion. We must be aware of this rare entity, which, if left untreated, could have serious consequences, and consider its possibility in cases where the patient complains of abdominal pain after any abdominal procedure. We hope to provide insights into the importance of histopathological examination in aiding a confirmatory diagnosis of this entity.

Non-Coding RNAs in Peritoneal Carcinomatosis: From Bench to Bedside

Peritoneal carcinomatosis represents an advanced stage of tumors within the peritoneal cavity. Once considered an incurable terminal cancer metastasis, contemporary medicine is on the hunt for certain potentially curative options alongside the present day's palliative disease management. However, for most patients, peritoneal carcinomatosis continues to pose a fatal late-stage prognosis with a grim future outlook. Over the past two decades, non-coding RNAs have garnered significant attention due to their undeniable significance in regulating cellular processes across all levels. Disruption of the intricate regulation led by non-coding RNAs has been demonstrated to have a substantial impact on various human diseases, particularly in cancer, including solid tumors originating from the organs of the peritoneal cavity. This review aims to offer a comprehensive overview of the current state of knowledge in the under-researched field of peritoneal carcinomatosis, focusing specifically on the role of non-coding RNAs in the development of this condition and delineating potential avenues for future research.

Impact of Molecular Status on Cytoreductive Surgery for Peritoneal Metastases from Colorectal Cancer

Colorectal cancer peritoneal metastases (CRC-PM) are present in 5 to 15% of instances of CRC, and the overall survival (OS) of patients with CRC-PM is much lower than that of patients with other isolated metastatic locations. In recent years, the introduction of cytoreductive surgery (CRS) in conjunction with hyperthermic intraperitoneal chemotherapy has resulted in a significant improvement in CRC-PM patients' OS. Despite this, a significant proportion of CRS patients continue to suffer complications of grades III to V or even die during the perioperative period. Early diagnosis, optimization of patient selection criteria, and refining of individualized combination therapy are necessary for these patients. In this review, we evaluate studies examining the relationship between molecular status and CRS in CRC-PM. Our objective is to gain a comprehensive understanding of how the altered molecular status of CRC-PM impacts CRS, which could increase the likelihood of tailored therapy in the future.

Peritoneal Carcinosis: What the Radiologist Needs to Know

Peritoneal carcinosis is a condition characterized by the spread of cancer cells to the peritoneum, which is the thin membrane that lines the abdominal cavity. It is a serious condition that can result from many different types of cancer, including ovarian, colon, stomach, pancreatic, and appendix cancer. The diagnosis and quantification of lesions in peritoneal carcinosis are critical in the management of patients with the condition, and imaging plays a central role in this process. Radiologists play a vital role in the multidisciplinary management of patients with peritoneal carcinosis. They need to have a thorough understanding of the pathophysiology of the condition, the underlying neoplasms, and the typical imaging findings. In addition, they need to be aware of the differential diagnoses and the advantages and disadvantages of the various imaging methods available. Imaging plays a central role in the diagnosis and quantification of lesions, and radiologists play a critical role in this process. Ultrasound, computed tomography, magnetic resonance, and PET/CT scans are used to diagnose peritoneal carcinosis. Each imaging procedure has advantages and disadvantages, and particular imaging techniques are recommended based on patient conditions. Our aim is to provide knowledge to radiologists regarding appropriate techniques, imaging findings, differential diagnoses, and treatment options. With the advent of AI in oncology, the future of precision medicine appears promising, and the interconnection between structured reporting and AI is likely to improve diagnostic accuracy and treatment outcomes for patients with peritoneal carcinosis.

Immunotherapy for Peritoneal Carcinomatosis: Challenges and Prospective Outcomes

Peritoneal metastasis, also known as peritoneal carcinomatosis (PC), is a refractory cancer that is typically resistant to conventional therapies. The typical treatment for PC is a combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Recently, research in this area has seen significant advances, particularly in immunotherapy as an alternative therapy for PC, which is very encouraging. Catumaxomab is a trifunctional antibody intraperitoneal (IP) immunotherapy authorized in Europe that can be used to diminish malignant ascites by targeting EpCAM. Intraperitoneal (IP) immunotherapy breaks immunological tolerance to treat peritoneal illness. Increasing T-cell responses and vaccination against tumor-associated antigens are two methods of treatment. CAR-T cells, vaccine-based therapeutics, dendritic cells (DCs) in combination with pro-inflammatory cytokines and NKs, adoptive cell transfer, and immune checkpoint inhibitors are promising treatments for PC. Carcinoembryonic antigen-expressing tumors are suppressed by IP administration of CAR-T cells. This reaction was strengthened by anti-PD-L1 or anti-Gr1. When paired with CD137 co-stimulatory signaling, CAR-T cells for folate receptor cancers made it easier for T-cell tumors to find their way to and stay alive in the body.

Survival and complications of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy in patients with intra-abdominal malignancies: A meta-analysis of randomized controlled trials

Background: Peritoneal metastasis (PM) is an advanced stage of intra-abdominal malignancy with a very poor prognosis. In recent years, hyperthermic intraperitoneal chemotherapy (HIPEC) combined with cytoreductive surgery (CRS) has been utilized as an active treatment in the prevention and treatment of PM, with encouraging results. However, compared with CRS alone, the results of the CRS plus HIPEC strategy in the treatment of patients with intra-abdominal malignancies are still controversial. This study sought to determine the impact of HIPEC + CRS on patient survival and adverse events (AEs) by reviewing randomized controlled trials (RCTs) for all types of intra-abdominal malignancies.

Methods: A PubMed, Embase, Cochrane Library, Web of Science and Clinical Trials.gov search extracted all RCTs until 12 October 2022, examining the CRS + HIPEC vs. CRS alone strategies in the treatment of various types of intra-abdominal malignancies. The outcomes included overall survival (OS), disease-free survival (DFS), relapse-free survival (RFS), progression-free survival (PFS) and AEs. The dichotomous data were pooled and reported as odds ratios (ORs) with 95% confidence intervals (CIs). The survival outcome data were pooled using hazard ratios (HRs) and corresponding 95% CIs. The Cochrane Collaboration’s Risk of Bias Tool was used to assess the risk of bias in the included studies.

Results: A total of 12 RCTs were included in this meta-analysis, including 873 patients in the CRS + HIPEC group and 878 patients in the CRS alone group. The studies included 3 (617 patients) on colorectal cancer, 4 (416 patients) on gastric cancer, and 5 (718 patients) on ovarian cancer. Our analysis showed no difference in OS between the CRS + HIPEC and CRS alone groups (HR: 0.79, 95% CI 0.62–1.01). Subgroup analysis showed that CRS + HIPEC improved the OS of gastric cancer patients (HR: 0.49, 95% CI 0.32–0.76) compared with CRS alone. However, CRS + HIPEC did not significantly improve the OS of colorectal cancer (HR: 1.06, 95% CI 0.81–1.38) and ovarian cancer (HR: 0.82, 95% CI 0.62–1.07) patients. In addition, there was no significant difference in DFS/RFS (HR: 0.78, 95% CI 0.57–1.07) or PFS (HR: 1.03, 95% CI 0.77–1.38) between the two groups. Compared with CRS alone, CRS with HIPEC had greater nephrotoxicity (OR: 0.45, 95% CI 0.21–0.98), while other AEs did not differ significantly between the two groups.

Conclusion: Our results suggest that CRS + HIPEC may improve OS in gastric cancer patients compared with CRS alone, but we did not observe a benefit for DFS/RFS. For patients with ovarian and colorectal cancers, our results suggest that HIPEC + CRS does not appear to improve survival outcomes. In addition, CRS + HIPEC has higher nephrotoxicity than CRS alone. More evidence from RCTs is needed to evaluate whether the use of CRS + HIPEC is an appropriate option.

Exosomal proteins as a source of biomarkers in colon cancer-derived peritoneal carcinomatosis - A pilot study

PURPOSE

Peritoneal carcinomatosis (PC), metastasized from colorectal cancer (CRC), remains a highly lethal disease. Outcomes of PC is significantly influenced by the amount of intra-abdominal tumor burden and therefore diagnostic tests that facilitate earlier diagnosis could improve PC treatment and patient outcomes.

EXPERIMENTAL DESIGN

Using mass-spectrometry-based proteomics, we characterized the protein features of circulating exosomes in the context of CRC PC, CRC with liver metastasis, and primary CRC limited to the colon. We profiled exosomes isolated from patient plasma to identify exosome-associated protein cargoes released by these cancer types.

RESULTS

Analysis of the resulting data identified metastasis-specific exosome protein signatures. Bioinformatic analyses confirmed enrichment of proteins annotated to vesicle-associated processes and intracellular compartments, as well as representation of cancer hallmark functions and processes.

CONCLUSION AND CLINICAL RELEVANCE

This research yielded distinct protein profiles for the CRC patient groups and suggests the utility of plasma exosome proteomic analysis for a better understanding of PC development and metastasis.

Circulating Tumor DNA is Unreliable to Detect Somatic Gene Alterations in Gastrointestinal Peritoneal Carcinomatosis

INTRODUCTION

Tumor agnostic circulating tumor DNA (ctDNA) is routinely used to guide treatment decisions in gastrointestinal (GI) cancers, especially metastatic cancers. The amount of ctDNA detected in plasma is affected by stage, tumor burden, and tumor vascularization. We hypothesized that peritoneal carcinomatosis (PC) is associated with lower ctDNA levels than other metastatic sites in GI cancers due to the plasma-peritoneal barrier.

METHODS

We conducted a retrospective analysis of patients with stage II-IV GI cancers treated at our institution between 2015 and 2020 with available panel-based ctDNA results (Guardant 360^TM). ctDNA analysis was performed on early and pretreatment samples. We compared the reported maximum variant allele frequency (mVAF) of somatic mutations across metastatic sites.

RESULTS

Of the 279 patients with GI cancers (colorectal, upper GI, pancreaticobiliary), 212 had stage IV disease (PC: n = 61; visceral metastases: n = 138; other metastases: n = 13). Mean mVAF increased with increasing stages of disease (stage II: 3.6 ± 7; stage III: 6.4 ± 10; stage IV: 28.0 ± 51; p < 0.01). Among patients with stage IV disease, PC was associated with lower ctDNA levels independent of primary tumor site (PC only: 12.1%; PC+ visceral metastases: 26.8%; and visceral metastases only: 35.0%; p < 0.01). In a subset of patients (n = 27, matched pair analysis of genomic alterations (GAs) showed fewer GAs were detected in plasma compared with tissue.

CONCLUSIONS

PC of GI origin is associated with significantly lower ctDNA levels compared with visceral metastasis. Caution is warranted when interpreting ctDNA results from patients with PC due to lower sensitivity for detecting actionable mutations.

Intracavitary adoptive transfer of IL-12 mRNA-engineered tumor-specific CD8+ T cells eradicates peritoneal metastases in mouse models

Previous studies have shown that local delivery of tumor antigen-specific CD8⁺ T lymphocytes engineered to transiently express single-chain IL-12 mRNA is highly efficacious. Peritoneal dissemination of cancer is a frequent and often fatal patient condition usually diagnosed when the tumor burden is too large and hence uncontrollable with current treatment options. In this study, we have modeled intracavitary adoptive T cell therapy with OVA-specific OT-I T cells electroporated with IL-12 mRNA to treat B16-OVA and PANC02-OVA tumor spread in the peritoneal cavity. Tumor localization in the omentum and the effects of local T-cell encounter with the tumor antigens were monitored, the gene expression profile evaluated, and the phenotypic reprogramming of several immune subsets was characterized. Intraperitoneal administration of T cells promoted homing to the omentum more effectively than intravenous administration. Transient IL-12 expression was responsible for a favorable reprogramming of the tumor immune microenvironment, longer persistence of transferred T lymphocytes in vivo, and the development of immunity to endogenous antigens following primary tumor eradication. The efficacy of the strategy was at least in part recapitulated with the adoptive transfer of lower affinity transgenic TCR-bearing PMEL-1 T lymphocytes to treat the aggressive intraperitoneally disseminated B16-F10 tumor. Locoregional adoptive transfer of transiently IL-12-armored T cells appears to offer promising therapeutic advantages in terms of anti-tumor efficacy to treat peritoneal carcinomatosis.

Supramolecular Loading of DNA Hydrogels with Dye-Drug Conjugates for Real-Time Photoacoustic Monitoring of Chemotherapy

A longstanding problem with conventional cancer therapy is the nonspecific distribution of chemotherapeutics. Monitoring drug release in vivo via noninvasive bioimaging can thus have value, but it is difficult to distinguish loaded from released drug in live tissue. Here, this work describes an injectable supramolecular hydrogel that allows slow and trackable release of doxorubicin (Dox) via photoacoustic (PA) tomography. Dox is covalently linked with photoacoustic methylene blue (MB) to monitor Dox before, during, and after release from the hydrogel carrier. The conjugate (MB-Dox) possesses an IC50 of 161.4 × 10-9  m against human ovarian carcinoma (SKOV3) cells and loads into a DNA-clad hydrogel with 91.3% loading efficiency due to MB-Dox's inherent intramolecular affinity to DNA. The hydrogel is biodegradable by nuclease digestion, which causes gradual release of MB-Dox. This release rate is tunable based on the wt% of the hydrogel. This hydrogel maintains distinct PA contrast on the order of days when injected in vivo and demonstrates activatable PA spectral shifts   during hydrogel degradation. The released and loaded payload can be imaged relative to live tissue via PA and ultrasound signal being overlaid in real-time. The hydrogel slowed the rate of the murine intraperitoneal tumor growth 72.2% more than free Dox.

Omentum: Friend or foe in ovarian cancer immunotherapy?

Ovarian cancer often spreads out of the ovary before a patient is diagnosed and is the deadliest gynecological malignancy. The aggressiveness of ovarian cancer is determined by the progression in the form of peritoneal carcinomatosis, a stage with a poor prognosis and an untreatable condition in most patients. One of the first tumor nests or the origin of metastasis in the peritoneal cavity is the omentum. The omentum contains immune aggregates, called milky spots, embedded in adipose tissue, which support tumor growth by various mechanisms, including immunosuppressive immune cells and metabolic functions. In this sense, the abundance of blood vessels, omental resident macrophages, and chemokines, among other factors, are known to promote invasiveness, proliferation and resistance to cancer therapies. As a result, surgical practice employed in advanced-stage ovarian cancer almost constantly includes omentectomy. Paradoxically, the omentum is considered the "abdominal policeman" that contributes to peritoneal immunity by capturing antigens and pathogens from the peritoneal cavity and promoting effective immune responses against microbes. Why immunosurveillance against the metastatic tumor does not take place in the omentum? Could omental immune responses be activated with immunotherapeutic interventions? The omentum has largely been ignored in cancer immunology and immunotherapy, and the potential translational implications of this in ovarian cancer are still unclear. Here, we focus on the dual role of the omentum in ovarian cancer: its role in antitumor immune responses versus its activities fostering cancer progression.

A Review of the Clinical Implications of Cachexia, Sarcopenia, and BMI in Patients with Peritoneal Carcinomatosis Receiving Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

Simple Summary

Patients with peritoneal carcinomatosis from varying cancers may be affected by weight loss and decreased muscle mass, the hallmarks of cachexia. These patients can undergo surgical management via cytoreductive surgery and hyperthermic intraperitoneal chemotherapy to improve their overall survival. Here, we review the current literature investigating the impact of sarcopenia, cachexia, and body mass index on outcomes in a patient population that undergo surgical treatment. The results vary across the studies suggesting that further investigation is necessary to better understand the impact of these entities on postoperative outcomes and survival.

Abstract

Peritoneal carcinomatosis (PC) is the dissemination of cancer throughout the peritoneal cavity. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is the surgical treatment of choice in highly selected patients. The aim of this narrative review was to assess the impact of cachexia, sarcopenia, and body mass index (BMI) on patient outcomes for patients undergoing CRS and HIPEC for peritoneal carcinomatosis. A narrative review was performed and articles pertaining to cachexia, sarcopenia, BMI, peritoneal carcinomatosis, and CRS/HIPEC were reviewed and selected. In total, 3041 articles were screened and seven original studies met the inclusion criteria. In summary, obesity was found to not be a contraindication to surgery, but the impact of BMI was variable across the spectrum. Decreased skeletal muscle mass was found to be associated with poorer postoperative outcomes in three studies and with worse overall survival in two. With limited data, evaluating the impact of BMI, sarcopenia, and cachexia on patients with PC undergoing CRS and HIPEC was difficult as most studies included heterogeneous cancer patient populations; thus, postoperative outcomes and survival were inconsistent across studies. More research is needed to better understand its impact and to better generalize the results for each cancer subset treated with CRS and HIPEC across diverse patient populations.

Development of the PERI-Gastric (PEritoneal Recurrence Index) and PERI-Gram (Peritoneal Recurrence Index NomoGRAM) for predicting the risk of metachronous peritoneal carcinomatosis after gastrectomy with curative intent for gastric cancer

BACKGROUND

A model that quantifies the risk of peritoneal recurrence would be a useful tool for improving decision-making in patients undergoing curative-aim gastrectomy for gastric cancer (GC).

METHODS

Five Italian centers participated in this study. Two risk scores were created according to the two most widely used pathologic classifications of GC (the Lauren classification and the presence of signet-ring-cell features). The risk scores (the PERI-Gastric 1 and 2) were based on the results of multivariable logistic regressions and presented as nomograms (the PERI-Gram 1 and 2). Discrimination was assessed with the area under the curve (AUC) of receiver operating curves. Calibration graphs were constructed by plotting the actual versus the predicted rate of peritoneal recurrence. Internal validation was performed with a bootstrap resampling method (1000 iterations).

RESULTS

The models were developed based on a population of 645 patients (selected from 1580 patients treated from 1998 to 2018). In the PERI-Gastric 1, significant variables were linitis plastica, stump GC, pT3-4, pN2-3 and the Lauren diffuse histotype, while in the PERI-Gastric 2, significant variables were linitis plastica, stump GC, pT3-4, pN2-3 and the presence of signet-ring cells. The AUC was 0,828 (0.778-0.877) for the PERI-Gastric 1 and 0,805 (0.755-0.855) for the PERI-Gastric 2. After bootstrap resampling, the PERI-Gastric 1 had a mean AUC of 0.775 (0.721-0.830) and a 95%CI estimate for the calibration slope of 0.852-1.505 and the PERI-Gastric 2 a mean AUC of 0.749 (0.693-0.805) and a 95%CI estimate for the slope of 0.777-1.351. The models are available at www.perigastric.org .

CONCLUSIONS

We developed the PERI-Gastric and the PERI-Gram as instruments to determine the risk of peritoneal recurrence after curative-aim gastrectomy. These models could direct the administration of prophylactic intraperitoneal treatments.

Metastatic Mucinous Adenocarcinoma of Gastrointestinal Origin: A Rare Presentation of Peritoneal Carcinomatosis in a Woman

Peritoneal carcinomatosis is most commonly a rare late-stage manifestation of disseminated ovarian cancer. Women with peritoneal carcinomatosis with no obvious primary tumor are presumptively treated for ovarian cancer. However, less frequently, gastrointestinal cancer disseminates to the peritoneum, which would confer other treatment options. Herein, we present a case of a 68-year-old woman who was managed for peritoneal carcinomatosis of metastatic mucinous adenocarcinoma of lower gastrointestinal origin.

Multimodal treatment in oligometastatic gastric cancer

Gastric cancer is generally diagnosed at an advanced stage, especially in countries without screening programs. Previously, the metastatic stage was synonymous with palliative management, and surgical indications were only for symptomatic relief. However, this therapeutic option is associated with poor prognosis. A subgroup of patients with limited metastatic disease could benefit from intensive treatment. A combination of chemotherapy, immunotherapy, and targeted therapy could help either maintain a resectable state for oligometastatic disease or diminish the metastasis size to obtain a complete resection configuration. This latter strategy is known as conversion therapy and has growing evidence with favorable outcomes. Oncosurgical approach of metastatic disease could prolong survival in selected patients. The challenge for the surgeon and oncologist is to identify these specific patients to offer the best multimodal management. We review in this article the actual evidence for the treatment of oligometastatic gastric cancer with curative intent.

Effect of HIPEC on Peritoneal Recurrence in Peritoneal Metastasis Treated With Cytoreductive Surgery: A Systematic Review

BACKGROUND

Peritoneal metastasis (PM) is a late-stage manifestation of intra-abdominal malignancies. The current standard of care indicates that cure can only be achieved with cytoreductive surgery (CRS) which is often indicated with concurrent adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC). However, the utility of HIPEC within subsets of PM is not fully understood. We seek to compare the effectiveness of HIPEC in improving peritoneal recurrence rates in PM of different origins.

METHODS

We conducted a systematic review of trials on the PubMed, EMBASE, and Cochrane databases, last searched in August 2021. Biases were assessed using the Cochrane Collaboration's tool for assessing the risk of bias in randomized trials as well as the Methodological Index for Non-Randomized Studies (MINORS) framework.

RESULTS

7 gastric PM studies, 3 ovarian PM studies, and 3 colorectal PM studies were included. Recurrence-free survival was improved in the HIPEC + CRS cohort in 5 gastric trials but only 1 ovarian trial and none of colorectal origin.

DISCUSSION

Our findings indicate decent effectiveness of HIPEC in gastric PM, but limited utility in ovarian and colorectal PM. Limitations in the current literature are attributed to the paucity of data available, a lack of homogeneity and consideration of novel and personalised treatment regimens. We implore for further studies to be conducted with a focus on patient selection and stratification, and suggest a reframing of approach towards modern molecular and targeted therapeutic options in future studies of HIPEC.

SYSTEMATIC REVIEW REGISTRATION

https://www.researchregistry.com/browse-the-registry#registryofsystematicreviewsmeta-analyses/registryofsystematicreviewsmeta-analysesdetails/60c1ffff0c1b78001e8efbe3/, identifier reviewregistry1166.

Hepatic bridge and round ligament of the liver during cytoreductive surgery: a retrospective cohort

PURPOSE

The hepatic bridge as an anatomical variation may lead to recurrence and treatment failure in cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) by constituting an obscure region during surgery. This report aimed to highlight the relationship between the hepatic bridge and various prognostic factors in peritoneal carcinomatosis.

METHODS

Data of 101 patients who underwent CRS/HIPEC for peritoneal carcinomatosis in a single centre were retrospectively reviewed. Demographic characteristics, primary origin of peritoneal carcinomatosis, classification of hepatic bridge, Peritoneal Cancer Index (PCI) score, and completeness of cytoreduction (CC) score were analysed.

RESULTS

The tumour was proven histopathologically in 18 (28.6%) of 63 patients who underwent distal round ligament (DRL) resection. The PCI score was found to be significantly higher in patients with tumour in DRL compared to the ones without tumour (p < 0.001). The median PCI score of patients with implant positive DRL was 18 (12-20) and this score was 3 (2-6) for patients with implant negative DRL (p < 0.001). The ROC curve concerning the risk of an implant penetrating the round ligament revealed the optimal cut-off value of PCI at 10 with 88.9% sensitivity and 79.3% specificity.

CONCLUSION

The round ligament should be removed, regardless of the PCI score, as a standard in mucinous adenocarcinoma of the appendix and malignant peritoneal mesothelioma. DRL should be removed when PCI is equal or higher than 10 for PC due to colorectal and ovarian cancers.

Disparities in the Management of Peritoneal Surface Malignancies

Peritoneal surface malignancies are a group of aggressive cancers involving the peritoneum. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy can improve outcomes and survival in select patients. Despite significant advancements in care, racial disparities in peritoneal malignancy outcomes persist and may have even worsened over time. Poor adherence to guideline-recommended therapy introduces wide variability in patient care and often results in fewer options and suboptimal treatment of vulnerable populations. This review explores biological, sociodemographic, and environmental factors that contribute to disparities in peritoneal malignancy outcomes.

Perianesthesia Care of the Oncologic Patients Undergoing Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy: A Retrospective Study

PURPOSE

This study was to understand the perianesthesia care for patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS  + HIPEC).

METHOD

This is a retrospective study.

DESIGN

The perioperative electronic medical records of 189 CRS  + HIPEC surgical cases at a hospital of Western Pennsylvania from 2012 to 2018 were analyzed to study the characteristics of perianesthesia care for CRS  + HIPEC surgery.

FINDINGS

The patients' median age was 57 (range 21-83) years, and 60% were men. The mean anesthesia time was 10.47 ± 2.54 hours. Most tumors were appendix or colorectal in origin, and the mean peritoneal cancer index score was 16.19 ± 8.76. The mean estimated blood loss was 623 ± 582 mL. The mean total intravenous crystalloid administered was 8,377 ± 4,100 mL. Fifty-two patients received packed red blood cells during surgery. Postoperatively, 100% of the patients were transferred to the intensive care unit. A majority (52%) of patients were extubated in the operating room. Median lengths of hospital and intensive care unit stays were 13 and 2 days, respectively. A majority (73%) of patients had 1 or more postoperative complications and 29% of patients experienced major postoperative complications (Clavien-Dindo grade III or higher) during the hospital stay. Prolonged hospitalization was owing to gastrointestinal dysfunctions and respiratory failure related to atelectasis and pleural effusion.

CONCLUSIONS

CRS  + HIPEC is a major surgery with numerous challenges to the perianesthesia care team regarding hemodynamic adjustment, pain control, and postoperative complications, which demand training and future studies from the perianesthesia care team.

The clinicopathologic significance of Tks5 expression of peritoneal mesothelial cells in gastric cancer patients

Background

Gastric cancer (GC) patients frequently develop peritoneal metastasis. Recently, it has been reported that peritoneal mesothelial cells (PMCs) activated by GC cells acquire a migratory capacity and promote GC cell invasion. The invasiveness of PMCs reportedly depends on the activity of Tks5, an adaptor protein required for invadopodia formation. However, the relationship between clinicopathologic features and Tks5 expression in PMCs has been poorly documented. In this study, we evaluated the clinicopathologic significance of the Tks5 expression of PMCs in GC patients.

Materials and methods

A total of 110 GC patients who underwent gastrectomy were enrolled in this study. Tks5 expressions in PMCs from the greater omentum, lesser omentum and retroperitoneum were evaluated by immunohistochemistry. We analyzed the correlation between Tks5 expressions in PMCs and the patients’ clinicopathologic features.

Results

Tks5 expression was found in 71 (64.5%) of the 110 patients, while 39 (35.5%) were Tks5-negative. Tks5 positivity was significantly (p = 0.038) associated with a greater tumor depth (i.e., T3/4 compared with T1/T2). Peritoneal recurrence was found in 12 of 98 cases within 3 years of surgery. The 3-year peritoneal recurrence-free survival (PRFS) rate in Tks5-positive cases was significantly poorer than that in Tks5-negative cases (80.1% vs 97.4%, p = 0.024). Multivariate analysis revealed that Tks5 positivity and lymph node metastasis were independent factors for PRFS.

Conclusion

Tks5 is frequently expressed in PMCs in advanced-stage gastric cancer. Tks5 might be a useful predictor for peritoneal recurrence in GC patients.

Mouse Models of Peritoneal Carcinomatosis to Develop Clinical Applications

Simple Summary

Peritoneal carcinomatosis mouse models as a platform to test, improve and/or predict the appropriate therapeutic interventions in patients are crucial to providing medical advances. Here, we overview reported mouse models to explore peritoneal carcinomatosis in translational biomedical research.

Abstract

Peritoneal carcinomatosis of primary tumors originating in gastrointestinal (e.g., colorectal cancer, gastric cancer) or gynecologic (e.g., ovarian cancer) malignancies is a widespread type of tumor dissemination in the peritoneal cavity for which few therapeutic options are available. Therefore, reliable preclinical models are crucial for research and development of efficacious treatments for this condition. To date, a number of animal models have attempted to reproduce as accurately as possible the complexity of the tumor microenvironment of human peritoneal carcinomatosis. These include: Syngeneic tumor cell lines, human xenografts, patient-derived xenografts, genetically induced tumors, and 3D scaffold biomimetics. Each experimental model has its own strengths and limitations, all of which can influence the subsequent translational results concerning anticancer and immunomodulatory drugs under exploration. This review highlights the current status of peritoneal carcinomatosis mouse models for preclinical development of anticancer drugs or immunotherapeutic agents.

Monitoring of mitochondrial oxygenation during perioperative blood loss

One of the challenges in the management of acute blood loss is to differentiate whether blood transfusion is required or not. The sole use of haemoglobin values might lead to unnecessary transfusion in individual cases. The suggestion is that mitochondrial oxygen tension can be used as an additional monitoring technique to determine when blood transfusion is required. In this case report, we report mitochondrial oxygen measurements in a patient with perioperative blood loss requiring blood transfusion.

Enhanced intraperitoneal delivery of charged, aerosolized curcumin nanoparticles by electrostatic precipitation

Aims: To investigate the potential of curcumin-loaded polylactic-co-glycolic acid nanoparticles (CUR-PLGA-NPs), alone and with electrostatic precipitation, for improving tissue uptake during pressurized intraperitoneal aerosol chemotherapy (PIPAC). Methods: Positively and negatively charged CUR-PLGA-NPs were delivered as PIPAC into inverted bovine urinary bladders ex vivo. The experiment was repeated with the additional use of electrostatic precipitation pressurized intraperitoneal aerosol chemotherapy (electrostatic PIPAC). Results: Positively charged CUR-PLGA-NPs increased depth of tissue penetration by 81.5% and tissue concentration by 80%. Electrostatic precipitation further improved the uptake of positively charged CUR-PLGA-NPs by 41.8%. Conclusion: The combination of positive charge and electrostatic precipitation have significant potential to improve tissue uptake of nanoparticles during intraperitoneal chemotherapy.

Diffusion-Weighted Magnetic Resonance Imaging as a Noninvasive Parameter for Differentiating Benign and Malignant Intraperitoneal Collections

Background and Objective: The imaging differentiation of benign from malignant intraperitoneal collections (IPCs) relies on the tumoral morphological modifications of the peritoneum, which are not always advocating for malignancy. We aimed to assess ascitic fluid with the apparent diffusion coefficient (ADC) to determine non-invasive, stand-alone, differentiation criteria for benign and malignant intraperitoneal effusions. Materials and Methods: Sixty-one patients with known IPCs who underwent magnetic resonance examinations for reasons such as tumor staging, undetermined abdominal mass and disease follow up were retrospectively included in this study. All subjects had a final diagnosis of the fluid based on pathological examinations, which were divided into benign (n = 37) and malignant (n = 24) IPCs groups. ADC values were measured separately by two radiologists, and the average values were used for comparing the two groups by consuming the independent samples t-test. The receiver operating characteristic analysis was performed to test the ADC values' diagnostic ability to distinguish malignant from benign collections. Results: The differentiation between benign and malignant IPCs based on ADC values was statistically significant (p = 0.0034). The mean ADC values were higher for the benign (3.543 × 10^-3 mm²/s) than for the malignant group (3.057 × 10^-3 mm²/s). The optimum ADC cutoff point for the diagnosis of malignant ascites was <3.241 × 10^-3 mm²/s, with a sensitivity of 77.78% and a specificity of 80%. Conclusions: ADC represents a noninvasive and reproducible imaging parameter that may help to assess intraperitoneal collections. Although successful in distinguishing malignant from benign IPCs, further research must be conducted in order to certify if the difference in ADC values is a consequence of the physical characteristics of the ascitic fluids or their appurtenance to a certain histopathological group.

Efficacy of ascitic fluid cell block for diagnosing primary ovarian, peritoneal, and tubal cancer in patients with peritoneal carcinomatosis with ascites

OBJECTIVE

To compare the efficacy of ascitic fluid cell block (ACB) with that of core needle biopsy (CNB) or the CA125/CEA ratio in diagnosing primary tubo-ovarian cancer in female patients with peritoneal carcinomatosis (PC) with ascites.

METHODS

This retrospective study examined female patients with PC with ascites who had available results for ACB, peritoneal tumor CNB, and the CA125/CEA ratio. Several measures of the accuracy of ACB and the CA125/CEA ratio were calculated and compared, with CNB as the reference standard.

RESULTS

Of 81 patients with available results, 57 were clinically diagnosed with primary tubo-ovarian cancer. Overall, 52, 47, and 64 patients were diagnosed via CNB, ACB, and CA125/CEA ratio > 25, respectively. CNB and ACB identified the cancer origin in 91.4% and 82.7% cases, respectively. The concordance ratio of the immunohistochemical findings between ACB and CNB was 93.6%. Two patients with inconclusive CNB results were diagnosed with primary tubo-ovarian cancer via ACB. The sensitivity, specificity, positive predictive value, negative predictive value, and positive likelihood ratio were 86.5%, 93.1%, 95.7%, 79.4%, and 12.5, respectively, for ACB and 94.2%, 48.3%, 76.6%, 82.4%, and 1.82, respectively, for CA125/CEA ratio > 25.

CONCLUSIONS

ACB is not inferior to CNB in diagnosing primary tubo-ovarian cancer; the two methods complement each other. ACB can substitute CNB in diagnosing primary tubo-ovarian cancer in selected PC patients. ACB is superior to a CA125/CEA ratio of >25 in diagnosing primary tubo-ovarian cancer. ACB is effective, reliable, and convenient for diagnosing primary tubo-ovarian cancer in PC patients with ascites.

Influence of peritoneal carcinomatosis on perioperative outcome in palliative gastric bypass for malignant gastric outlet obstruction - a retrospective cohort study

Background

Malignant gastric outlet obstruction (GOO) is commonly associated with the presence of peritoneal carcinomatosis (PC) and preferably treated by surgical gastrojejunostomy (GJJ) in patients with good performance. Here, we aim to investigate the role of PC as a risk factor for perioperative morbidity and mortality in patients with GOO undergoing GJJ.

Methods

Perioperative data of 72 patients with malignant GOO who underwent palliative GJJ at our institution between 2010 and 2019 were collected within an institutional database.

To compare perioperative outcomes of patients with and without PC, extensive group analyses were carried out.

Results

A set of 39 (54.2%) patients was histologically diagnosed with concomitant PC while the remaining 33 (45.8%) patients showed no clinical signs of PC. In-house mortality due to surgical complications was significantly higher in patients with PC (9/39, 23.1%) than in patients without PC (2/33, 6.1%, p = .046). Considerable differences were observed in terms of surgical complications such as anastomotic leakage rates (2.8% vs. 0%, p = .187), delayed gastric emptying (33.3% vs. 15.2%, p = .076), paralytic ileus (23.1% vs. 9.1%, p = .113), and pneumonia (17.9% vs. 12.1%, p = .493) without reaching the level of statistical significance.

Conclusions

PC is an important predictor of perioperative morbidity and mortality patients undergoing GJJ for malignant GOO.

Review of the Application of Nanovesicles and the Human Interstitial Fluid in Gastrointestinal Premalignant Lesion Detection, Diagnosis, Prognosis and Therapy

Premalignant lesions arise from cells that abnormally proliferate and have a tendency to become cancerous. Developing methods to specifically target and remove these premalignant lesions is imperative to the prevention of malignant progression into gastrointestinal (GI) tumors. However, accurate detection and diagnosis of GI precancerous lesions is challenging, as these lesions show little or no structural change. Thus, this prevents early intervention and reduces the success rate of therapy. In this review, we performed a systematic analysis of the technological advancements in the combined application of nanovesicles (NVs) and the human interstitial fluid (HIF) to specifically target GI premalignant lesions. NVs, which include quantum dots (QDs), are small membranous vehicles of a nanometer diameter that are widely used as drug delivery vectors, therapeutic effectors and diagnostic sensors. HIF is the fluid that is present in human interstitial tissues (HITs) in which signaling molecules and agents travel and can be found throughout the body. HIF is exploited by tumor cells for their invasion, migration and spread. Because the HITs span the entire submucosa of the gastrointestinal tract, they have been increasingly targeted in GI tumor therapy. The challenges involved in the combined application of NVs and HIF in the detection, diagnosis, prognosis and therapy of GI premalignant lesions are also discussed.

Overall clinical and trichoscopic analysis performed in patients who underwent pressurized intraperitoneal aerosol chemotherapy (PIPAC) treatment for peritoneal carcinomatosis - initial trial preliminary report

Introduction

Cutaneous adverse events are among the remaining problematic issues of current oncology. The term peritoneal carcinomatosis (PC) refers to the advanced cancer stage. The innovative treatment of PC includes the use of pressurized intraperitoneal aerosol chemotherapy (PIPAC).

Aim

To present a preliminary report from an initial trial aimed at an overall clinical and trichoscopic analysis performed in patients who underwent PIPAC treatment due to PC.

Material and methods

For all steps of this study we obtained the consent of the local bioethics commission #KB 196/2018. Three different hair assessment methods were used in our study: 1) general clinical and patient self-feeling assessment; 2) hair pull test; 3) and trichoscopic analysis.

Results

No hair or scalp disorders were noted in the observation period. In the self-feeling test assessment the vast majority recognized their hair as being of comparable quality or even better in quality compared to previous forms of chemotherapy they had undergone. In all patients we observed a reduction of hair loss in the pull test in the hospitalization period. In trichoscopic analysis we found all determinants and signs of hair disorders in the assessed group.

Conclusions

The PIPAC is safe and is not a burdensome or aggressive form of therapy, especially according to the very important factors influencing the potential quality of hair and hair loss. The authors, however, realize that to obtain comprehensive results and evaluate this novel and promising method we need to perform more research without any limitations like those in our study.

A Case of Advanced Gastric Cancer with Peritoneal Metastasis Treated Successfully with Nivolumab

Peritoneal metastasis (PM) is detected in 14% of gastric cancers at the time of initial diagnosis, with a median survival time of 4 months. A 66-year-old woman diagnosed with cT4a(SE) N2M1(LYN) cStage IV was treated with three lines of chemotherapy for a year. During the third line of chemotherapy, computed tomography (CT) scan revealed a large amount of ascites, periportal collar sign, and bilateral ureteral stenosis owing to PM. The tumor biomarkers (CEA and CA 19-9) remained elevated similar to the initial levels. The patient was administered 3 mg/kg nivolumab intravenously biweekly as the fourth line of chemotherapy. Three months after the nivolumab treatment, gastroscopy revealed an extreme reduction of the tumor size, while CT scan revealed the absence of ascites and a well-controlled tumor. There was no immune-related adverse event with nivolumab during and after the treatment, and performance status improved to 0. The patient has been alive for about 2.5 years since her first visit with her sixth line of chemotherapy (docetaxel). We report a case of advanced gastric cancer with PM that was treated successfully with nivolumab.

Identification of DNA mutations in gastric washes from gastric adenocarcinoma patients: Possible implications for liquid biopsies and patient follow-up

Whereas cancer patients have benefited from liquid biopsies, the scenario for gastric adenocarcinoma (GAC) is still dismal. We used next-generation deep sequencing of TP53-a highly mutated and informative gene in GAC-to assess mutations in tumor biopsies, plasma (PL) and stomach fluids (gastric wash-GW). We evaluated their potential to reveal tumor-derived mutations, useful for monitoring mutational dynamics at diagnosis, progression and treatment. Exon-capture libraries were constructed from 46 patients including tumor biopsies, GW and PL pre and post-treatment (196 samples), with high vertical coverage >8,000×. At diagnosis, we detected TP53 mutations in 15/46 biopsies (32.6%), 7/46 GW- (15.2%) and 6/46 PL-samples (13%). Biopsies and GW were concordant in 38/46 cases (82.6%) for the presence/absence of mutations and, furthermore, four GW-exclusive mutations were identified, suggesting tumor heterogeneity. Considering the combined analysis of GW and PL, TP53 mutations found in biopsies were also identified in 9/15 (60%) of cases, the highest detection level reported for GAC. Our study indicates that GW could be useful to track DNA alterations, especially if anchored to a comprehensive gene-panel designed for this malignancy.

Clinical value of combined detection of miR-1202 and miR-195 in early diagnosis of cervical cancer

The clinical value of the combined detection of miR-1202 and miR-195 in the early diagnosis of cervical cancer was studied. A retrospective analysis of 70 cervical cancer patients treated in the The Third Affiliated Hospital of Kunming Medical University and Yunnan Cancer Hospital from October 2015 to December 2017 was performed, and the lesion tissues were used as the experimental group. Normal cervical tissues from another 67 healthy females confirmed by physical examination at the same period were selected as the control group. The FIGO staging criteria were used for staging of the cervical cancer patients, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method was used for the detection of the expression of miR-1202 and miR-195 in different tissues, and the receiver operating curve (ROC) was used for the analysis of the application values of miR-1202 and miR-195 diagnosis alone and their combined diagnosis in early cervical cancer patients. The levels of miR-1202 and miR-195 in the experimental group were lower than those in the control group (P<0.05). The differences were significant in the different stages of cervical cancer tissues (P<0.05). The later the staging of cervical cancer tissues were, the lower the levels of miR-1202 and miR-195 were. The sensitivities and area under the curve (AUC) values of miR-1202 and miR-195 in the combined diagnosis of early cervical cancer were significantly higher than those of miR-1202 and miR-195 alone. The expression levels of miR-1202 and miR-195 in the cervical cancer patients are different in different stages. Guiding clinical treatment and prognosis according to the results of combined detection is beneficial for the development of treatment for cervical cancer patients and for prognostic judgement, worthy of popularization and application.

Circulating tumor DNA: clinical roles in diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL), the most common non-Hodgkin lymphoma (NHL), is a clinically and molecularly heterogeneous malignant lymphoproliferative disease. In the era of personalized medicine, genetic information is critical to early diagnosis, aiding risk stratification, directing therapeutic option, and monitoring disease relapse. However, lacking a circulating disease with most DLBCL cases hampers the acquisition of tumor genomic landscapes and disease dynamics. Circulating tumor DNA (ctDNA) is a novel noninvasive, real-time, and tumor-specific biomarker, reliably reflecting the comprehensive tumor genetic profiles, thus holds great promise in individualized medicine, including precise diagnosis and prognosis, response monitoring, and relapse detection of DLBCL. Here, we reviewed the recent advances of ctDNA in DLBCL and discussed its clinical values at different time points during the disease courses by comparing with the current routine methods in clinical practice. Collectively, we anticipated that ctDNA will ultimately be integrated into the management of DLBCL to facilitate precision medicine.

Plasma exosomes as novel biomarker for the early diagnosis of gastric cancer

Exosomes are lipid bilayer vesicles of endocytic origin ranging from 30 to 100 nm in size, and contain various nucleic acid molecules such as DNA, mRNA, miRNA, lncRNA and multiple proteins, which could be transferred into target cells. Recent study indicated that exosomes as information carriers between cells has introduced us to a new previously unknown biological communication system. Increasing evidences show that exosomes play a crucial role in gastric cancer because they are potential to influence normal cellular physiology and promote various states of the cancer. In this review, we focus on the latest findings on exosomes in the plasma of gastric cancer patients, mainly summarizing the functions of miRNAs, lncRNAs and multiple proteins in diagnosis, prognosis, and in establishing treatment regimens against gastric cancer. Furtherly, potential functions of exosomes as novel diagnostic biomarkers for gastric cancer are discussed extensively. Exosomes are believed to be a non-invasive disease biomarker with a dual capability to provide insights into the early diagnosis for gastric cancer.

Integrated treatment using intraperitoneal radioimmunotherapy and positron emission tomography-guided surgery with 64Cu-labeled cetuximab to treat early- and late-phase peritoneal dissemination in human gastrointestinal cancer xenografts

Peritoneal dissemination is a common cause of death from gastrointestinal cancers and is difficult to treat using current therapeutic options, particularly late-phase disease. Here, we investigated the feasibility of integrated therapy using ⁶⁴Cu-intraperitoneal radioimmunotherapy (ipRIT), alone or in combination with positron emission tomography (PET)-guided surgery using a theranostic agent (⁶⁴Cu-labeled anti-epidermal growth factor receptor antibody cetuximab) to treat early- and late-phase peritoneal dissemination in mouse models. In this study, we utilized the OpenPET system, which has open space for conducting surgery while monitoring objects at high resolution in real time, as a novel approach to make PET-guided surgery feasible. ⁶⁴Cu-ipRIT with cetuximab inhibited tumor growth and prolonged survival with little toxicity in mice with early-phase peritoneal dissemination of small lesions. For late-phase peritoneal dissemination, a combination of ⁶⁴Cu-ipRIT for down-staging and subsequent OpenPET-guided surgery for resecting large tumor masses effectively prolonged survival. OpenPET clearly detected tumors (≥3 mm in size) behind other organs in the peritoneal cavity and was useful for confirming the presence or absence of residual tumors during an operation. These findings suggest that integrated ⁶⁴Cu therapy can serve as a novel treatment strategy for peritoneal dissemination.

Preoperative Circulating Tumor DNA in Patients with Peritoneal Carcinomatosis is an Independent Predictor of Progression-Free Survival

BACKGROUND

Next-generation sequencing (NGS) is a useful tool for detecting genomic alterations in circulating tumor DNA (ctDNA). To date, most ctDNA tests have been performed on patients with widely metastatic disease. Patients with peritoneal carcinomatosis (metastases) present unique prognostic and therapeutic challenges. We therefore explored preoperative ctDNA in patients with peritoneal metastases undergoing surgery.

METHODS

Patients referred for surgical resection of peritoneal metastases underwent preoperative blood-derived ctDNA analysis (clinical-grade NGS [68-73 genes]). ctDNA was quantified as the percentage of altered circulating cell-free DNA (% cfDNA).

RESULTS

Eighty patients had ctDNA testing: 46 (57.5%) women; median age 55.5 years. The following diagnoses were included: 59 patients (73.8%), appendix cancer; 11 (13.8%), colorectal; five (6.3%), peritoneal mesothelioma; two (2.5%), small bowel; one (1.3%) each of cholangiocarcinoma, ovarian, and testicular cancer. Thirty-one patients (38.8%) had detectable preoperative ctDNA alterations, most frequently in the following genes: TP53 (25.8% of all alterations detected) and KRAS (11.3%). Among 15 patients with tissue DNA NGS, 33.3% also had ctDNA alterations (overall concordance = 96.7%). Patients with high ctDNA quantities (≥ 0.25% cfDNA, n = 25) had a shorter progression-free survival (PFS) than those with lower ctDNA quantities (n = 55; 7.8 vs. 15.0 months; hazard ratio 3.23, 95% confidence interval 1.43-7.28, p = 0.005 univariate, p = 0.044 multivariate).

CONCLUSIONS

A significant proportion of patients with peritoneal metastases referred for surgical intervention have detectable ctDNA alterations preoperatively. Patients with high levels of ctDNA have a worse prognosis independent of histologic grade.

Exosome-mediated peritoneal dissemination in gastric cancer and its clinical applications

The prognosis of patients with peritoneal dissemination from gastric cancer is poor, and the underlying molecular mechanism remains unclear. Exosomes, as macromolecular phospholipid bilayer vesicles comprising of proteins, nucleic acids and lipids, serve as mediators of cell-cell communication. Gastric cancer tumor-derived exosomes may be involved in the pathological process of peritoneal dissemination by mediating crosstalk between cancer cells and mesothelial cells, to result in the induction of enhanced tumor growth, migratory, adhesive and invasive abilities, peritoneal fibrosis and apoptosis, mesothelial-to-mesenchymal transition, angiogenesis and chemoresistance. The present review focuses on previous studies addressing the exosome-dependent molecular transfer in peritoneal dissemination in gastric cancer and the potential clinical applications.

[Surgical treatment of peritoneal metastases of colorectal cancer]

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) may significantly improve overall survival in selected patients with peritoneal metastases of colorectal cancer. For good oncological results complete macroscopic cytoreduction is crucial; furthermore, a linear correlation between peritoneal tumor load, as determined by the peritoneal cancer index (PCI) and overall survival has been demonstrated; therefore, surgical treatment should be initiated as early as possible. Synchronous resection of up to three liver metastases may be performed safely and with good results and no influence on the morbidity. With respect to intraperitoneal chemotherapy, mitomycin C and oxaliplatin are most commonly used and may be regarded as equal; however, for perioperative chemotherapy study results are so far inconclusive with some trials hinting at decreased overall survival following neoadjuvant chemotherapy. Adjuvant therapy is likely to improve overall survival if at least 6 cycles are applied. Early detection of peritoneal metastases is difficult at present but might be facilitated in the future by the use of liquid biopsies, which may detect circulating free tumor-specific DNA or RNA. In the meantime, planned second-look laparotomy should be considered for patients at high risk of peritoneal recurrence. In addition, several international studies are currently evaluating the concept of adjuvant or prophylactic HIPEC. The CRS and HIPEC may be repeated in cases of recurrence and should be considered in suitable patients, applying the same criteria as for primary CRS and HIPEC. A recurrence-free interval of >2 years is associated with a significantly better prognosis.