Immunotherapy for Peritoneal Carcinomatosis: Challenges and Prospective Outcomes

ED diagnosis of peritoneal carcinomatosis

PURPOSE

The goal of our study was to better characterize new CT diagnoses of peritoneal carcinomatosis (PC) in the ED, and to evaluate how to best identify the primary lesion. Prompt identification of the source of the carcinomatosis may allow for the patient to receive early initial care from the correct clinical service.

METHODS

All new CT cases of PC-like appearance identified on CT in the ED from January 2017 through July 2020. Each report and corresponding medical record were manually reviewed. Patient demographics, presence/absence of intravenous contrast, source organ predicted by the radiologist in the CT scan report, pathologic diagnosis, and amount of ascites were tabulated. Chi-tests were used to test the statistical significance of differences between groups.

RESULTS

Of the 131 CT cases of new PC-like appearance which received workup, 108 cases had pathologically proven PC and 23 cases had no underlying malignancy yielding a positive predictive value for actual PC of 82%. The most common cause of new PC in women was gynecological (66%), and in men was of GI tract origin (57%). Concordance between radiologist prediction and final pathology was higher with intravenous contrast (58%) compared to without contrast (40%); although this difference was not statistically significant (p = 0.19). A moderate or large amount of ascites was found in more than half of GYN primaries and in adenocarcinoma of unknown primary and there was a statistically significant difference in amount of ascites between cancer primaries (p = 0.01).

CONCLUSION

A PC-like appearance on CT in the ED will likely be in patients with known malignancy, but of the new cases, there is a high PPV for it to represent new peritoneal carcinomatosis. Gynecological and GI malignancies are the most common cause in women and men, respectively, and this may help in focusing the radiologist's search pattern. Usage of intravenous contrast may help in identifying a primary lesion, and the presence of high-volume ascites should suggest a GYN primary or adenocarcinoma of unknown primary when there is no other obvious primary lesion.

Resiquimod-loaded cationic liposomes cure mice with peritoneal carcinomatosis and induce specific anti-tumor immunity

Peritoneal carcinomatosis (PC) is characterized by a high recurrence rate and mortality following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC), primarily due to incomplete cancer elimination. To enhance the standard of care for PC, we developed two cationic liposomal formulations aimed at localizing a toll-like receptor agonist, resiquimod (R848), in the peritoneal cavity to activate the immune system locally to specifically eradicate residual tumor cells. These formulations effectively extended R848 retention in the peritoneum by >10-fold, resulting in up to a 2-fold increase in interferon α (IFN-α) induction in the peritoneal fluid, without increasing the plasma levels. In a CT26 colon cancer model with peritoneal metastases, these liposomal R848 formulations, when combined with oxaliplatin (OXA)-an agent used in HIPEC that induces immunogenic cell death-increased tumor infiltration of effector immune cells, including DCs, CD4, and CD8 T cells. This led to the complete elimination of PC in 60-70% of the mice, while the control mice reached humane endpoints by 30 days. The cured mice developed specific antitumor immunity, as re-challenging them with the same tumor cells did not result in tumor establishment. However, inoculation with a different tumor line led to tumor development. Additionally, exposing CT26 tumor antigens to the splenocytes isolated from the cured mice induced the expansion of CD4 and CD8 T cells and the release of IFN-γ, demonstrating long-term immune memory to the specific tumor. The anti-tumor efficacy of these liposomal R848 formulations was mediated via CD8 T cells with different levels of involvement of CD4 and B cells, and the combination with an anti-PD-1 antibody achieved a cure rate of 90%.

Survival Difference of Endometrial Cancer Patients with Peritoneal Metastasis Receiving Cytoreductive Surgery (CRS) with and without Hyperthermic Intraperitoneal Chemotherapy (HIPEC): A Systematic Review and Meta-Analysis

Although several studies have been completed to investigate the effect of cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) in endometrial cancer with peritoneal metastasis (ECPM), a direct comparison was not performed previously. A meta-analysis was performed to investigate the suspected additional survival benefits of CRS plus HIPEC over CRS only. Twenty-one and ten studies with a total number of 1116 and 152 cases investigating CRS only and CRS plus HIPEC were identified, respectively. When all articles were analyzed, the 1-year survival rate was 17.60% higher for CRS plus HIPEC (82.28% vs. 64.68%; p = 0.0102). The same tendency was observed for the 2-year (56.07% vs. 36.95%; difference: 19.12%; p = 0.0014), but not for the 5-year (21.88% vs. 16.45%; difference: 5.43%; p = 0.3918) survival rates. The same clinical significance, but statistically less strong observations, could be made if only the studies published after 2010 were investigated (1-year survival rate: 12.08% and p = 0.0648; 2-year survival rate: 10.90% and p = 0.0988). CRS remains one of the core elements of ECPM treatment, but the addition of HIPEC to CRS can increase the positive clinical outcome, especially in the first 2 years.

Characterizing the Immune Environment in Peritoneal Carcinomatosis: Insights for Novel Immunotherapy Strategies

BACKGROUND OR PURPOSE

Carcinomatosis, a distinct pattern of metastatic cancer in the peritoneal cavity, poses challenges for treatment and has limited therapeutic options. Understanding the immune environment of peritoneal surface malignancies is crucial for developing effective immunotherapeutic approaches. This study characterizes soluble immune mediators in the peritoneal fluid of patients with and without carcinomatosis to identify targets for novel treatment strategies.

PATIENTS AND METHODS

Serum and peritoneal fluid samples were collected from surgical patients, and a multianalyte analysis was performed using the Luminex platform. Patient characteristics, tumor sites, and sample collection details were recorded. Soluble immune mediator levels were measured and compared between peritoneal fluid and serum samples and among clinical subgroups. Statistical analysis was conducted to assess differences in analyte concentrations and correlations between samples.

RESULTS

There were 39 patients included in the study, with varying surgical indications. Significant differences were observed in soluble immune mediator levels between peritoneal fluid and serum, with peritoneal fluid exhibiting lower concentrations. Carcinomatosis was associated with elevated levels of proinflammatory mediators, including IL-6 and IL-8, while adaptive immune response markers were low in peritoneal fluid.

CONCLUSIONS

The peritoneal immune microenvironment in carcinomatosis favors innate immunity, presenting a challenging environment for effective antitumor response. High levels of proinflammatory mediators suggest potential targets for intervention, such as the IL-6 axis, FGF2, IL-8, and CCL2; these could be explored as potential mitigators of malignant ascites and enhance anti-tumor immune responses. These findings provide valuable insights for developing immunotherapy strategies and improving outcomes in patients with peritoneal carcinomatosis.

Peritoneal Carcinomatosis of Malignant Gynecological Origin: A Systematic Review of Imaging Assessment

This systematic review, conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, aims to comprehensively assess the current state of the art of imaging modalities for the evaluation of peritoneal carcinomatosis arising from malignant gynecological origins, with a focus on ovarian and endometrial cancers. A systematic search of relevant databases was performed, adhering to predetermined inclusion and exclusion criteria. Studies reporting the use of computed tomography (CT), magnetic resonance imaging (MRI), fluorodeoxyglucose (FDG) positron emission tomography (PET), PET/CT, and PET/MRI in the assessment of peritoneal carcinomatosis from gynecological malignancies were included. The review encompasses an overview of selected studies, highlighting the strengths and limitations of each imaging modality in diagnosing and characterizing peritoneal carcinomatosis. Overall, a wide variability in the reported accuracy of different imaging techniques emerges from literature, mainly due to the type of the study, technical issues, and patient characteristics. Although a meta-analysis could not be performed due to a scarcity of data, this systematic review provides valuable insights into the several imaging approaches used in peritoneal carcinomatosis of gynecological origin. The findings aim to inform clinical decision making and guide future research endeavors in this critical aspect of gynecological oncology.

The quest for nanoparticle-powered vaccines in cancer immunotherapy

Despite recent advancements in cancer treatment, this disease still poses a serious threat to public health. Vaccines play an important role in preventing illness by preparing the body's adaptive and innate immune responses to combat diseases. As our understanding of malignancies and their connection to the immune system improves, there has been a growing interest in priming the immune system to fight malignancies more effectively and comprehensively. One promising approach involves utilizing nanoparticle systems for antigen delivery, which has been shown to potentiate immune responses as vaccines and/or adjuvants. In this review, we comprehensively summarized the immunological mechanisms of cancer vaccines while focusing specifically on the recent applications of various types of nanoparticles in the field of cancer immunotherapy. By exploring these recent breakthroughs, we hope to identify significant challenges and obstacles in making nanoparticle-based vaccines and adjuvants feasible for clinical application. This review serves to assess recent breakthroughs in nanoparticle-based cancer vaccinations and shed light on their prospects and potential barriers. By doing so, we aim to inspire future immunotherapies for cancer that harness the potential of nanotechnology to deliver more effective and targeted treatments.

Amplifying Curcumin's Antitumor Potential: A Heat-Driven Approach for Colorectal Cancer Treatment

Introduction

Peritoneal metastases from colorectal cancer (CRC) present a significant clinical challenge with poor prognosis, often unresponsive to systemic chemotherapy. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment approach for select patients. The use of curcumin, a natural compound with antitumor properties, in HIPEC is of interest due to its lower side effects compared to conventional drugs and potential for increased efficacy through direct delivery to the peritoneal cavity.

Methods

An in vitro hyperthermic model was developed to simulate clinical HIPEC conditions. Three colon cancer cell lines (SK-CO-1, COLO205, SNU-C1) representing different genetic mutations (p53, KRAS, BRAF) were treated with either curcumin (25 µM) or mitomycin-C (1 µM) for 1, 2, or 3 hours. Post-treatment, cells were incubated at 37°C (normothermia) or 42°C (hyperthermia). Cell viability and proliferation were assessed at 24, 48 and 72 hours post-treatment using Annexin V/PI, MTT assay, trypan blue exclusion, and Hoffman microscopy.

Results

Hyperthermia significantly enhanced the antitumor efficacy of curcumin, evidenced by a two-fold reduction in cell viability compared to normothermia across all cell lines. In the SNU-C1 cell line, which harbors a p53 mutation, mitomycin-C failed to significantly impact cell viability, unlike curcumin, suggesting mutation-specific differences in treatment response.

Discussion

The findings indicate that hyperthermia augments the antitumor effects of curcumin in vitro, supporting the hypothesis that curcumin could be a more effective HIPEC agent than traditional drugs like mitomycin-C. Mutation-associated differences in response to treatments were observed, particularly in p53 mutant cells. While further studies are needed, these preliminary results suggest that curcumin in HIPEC could represent a novel therapeutic strategy for CRC patients with peritoneal metastases. This approach may offer improved outcomes with fewer side effects, particularly in genetically distinct CRC subtypes.

Nano-immunotherapy: overcoming delivery challenge of immune checkpoint therapy

Immune checkpoint (ICP) molecules expressed on tumor cells can suppress immune responses against tumors. ICP therapy promotes anti-tumor immune responses by targeting inhibitory and stimulatory pathways of immune cells like T cells and dendritic cells (DC). The investigation into the combination therapies through novel immune checkpoint inhibitors (ICIs) has been limited due to immune-related adverse events (irAEs), low response rate, and lack of optimal strategy for combinatorial cancer immunotherapy (IMT). Nanoparticles (NPs) have emerged as powerful tools to promote multidisciplinary cooperation. The feasibility and efficacy of targeted delivery of ICIs using NPs overcome the primary barrier, improve therapeutic efficacy, and provide a rationale for more clinical investigations. Likewise, NPs can conjugate or encapsulate ICIs, including antibodies, RNAs, and small molecule inhibitors. Therefore, combining the drug delivery system (DDS) with ICP therapy could provide a profitable immunotherapeutic strategy for cancer treatment. This article reviews the significant NPs with controlled DDS using current data from clinical and pre-clinical trials on mono- and combination IMT to overcome ICP therapeutic limitations.