Intraperitoneal immunotherapy to prevent peritoneal carcinomatosis in patients with advanced gastrointestinal malignancies

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.

Multidisciplinary Treatment for Colorectal Peritoneal Metastases: Review of the Literature

Peritoneum is one of the common sites of metastasis in advanced stage colorectal cancer patients. Colorectal cancer patients with peritoneal metastases (PM) are traditionally believed to have poor prognosis, which indicates it is of no value to adopt surgical treatment. With the advancement of surgical techniques, hyperthermic intraperitoneal chemotherapy (HIPEC), and multidisciplinary treatment in recent years, the cognition and treatment strategies of colorectal peritoneal metastases (CPM) have changed dramatically. In terms of prognosis, CPM under the palliative systemic treatment shows an inferior outcome compared with nonperitoneal metastasis. Nevertheless, some CPM patients amenable to the complete peritoneal cytoreductive surgery (CRS) combined with HIPEC may achieve long-term survival. The prognostic factors of CPM comprise peritoneal carcinomatosis index (PCI), completeness of cytoreduction score (CC score), the presence of extraperitoneal metastasis (liver, etc.), Peritoneal Surface Disease Severity Score (PSDSS), Japanese peritoneal staging, and so forth. Taken together, literature data suggest that a multimodality approach combining complete peritoneal CRS plus HIPEC, systemic chemotherapy, and targeted therapy may be the best treatment option for PM from colorectal cancer.

Malignant ascites: A review of prognostic factors, pathophysiology and therapeutic measures

Malignant ascites indicates the presence of malignant cells in the peritoneal cavity and is a grave prognostic sign. While survival in this patient population is poor, averaging about 20 wk from time of diagnosis, quality of life can be improved through palliative procedures. Selecting the appropriate treatment modality remains a careful process, which should take into account potential risks and benefits and the life expectancy of the patient. Traditional therapies, including paracentesis, peritoneovenous shunt placement and diuretics, are successful and effective in varying degrees. After careful review of the patient’s primary tumor origin, tumor biology, tumor stage, patient performance status and comorbidities, surgical debulking and intraperitoneal chemotherapy should be considered if the benefit of therapy outweighs the risk of operation because survival curves can be extended and palliation of symptomatic malignant ascites can be achieved in select patients. In patients with peritoneal carcinomatosis who do not qualify for surgical cytoreduction but suffer from the effects of malignant ascites, intraperitoneal chemotherapy can be safely and effectively administered via laparoscopic techniques. Short operative times, short hospital stays, low complication rates and ultimately symptomatic relief are the advantages of laparoscopically administering heated intraperitoneal chemotherapy, making it not only a valuable treatment modality but also the most successful treatment modality for achieving palliative cure of malignant ascites.

Distinct myeloid suppressor cell subsets correlate with plasma IL-6 and IL-10 and reduced interferon-alpha signaling in CD4⁺ T cells from patients with GI malignancy

Interferon-alpha (IFN-α) promotes anti-tumor immunity through its actions on immune cells. We hypothesized that elevated percentages of myeloid-derived suppressor cells (MDSC) and increased pro-inflammatory cytokines in peripheral blood would be associated with impaired response to IFN-α in patients with gastrointestinal (GI) malignancies. This study evaluated relationships between plasma IL-6, IL-10, circulating MDSC subsets, and IFN-α-induced signal transduction in 40 patients with GI malignancies. Plasma IL-6 and IL-10 were significantly higher in patients versus normal donors. CD33(+)HLADR(-)CD11b(+)CD15(+) and CD33(+)HLADR(-/low)CD14(+) MDSC subsets were also elevated in patients versus normal donors (P < 0.0001). Plasma IL-6 was correlated with CD33(+)HLADR(-)CD15(+) MDSC (P = 0.008) and IL-10 with CD33(+)HLADR(-)CD15(-) MDSC (P = 0.002). The percentage of CD15(+) and CD15(-) but not CD14(+) MDSC subsets were inversely correlated with IFN-α-induced STAT1 phosphorylation in CD4(+) T cells, while co-culture with in vitro generated MDSC led to reduced IFN-α responsiveness in both PBMC and the CD4(+) subset of T cells from normal donors. Exploratory multivariable Cox proportional hazards models revealed that an increased percentage of the CD33(+)HLADR(-)CD15(-) MDSC subset was associated with reduced overall survival (P = 0.049), while an increased percentage of the CD33(+)HLADR(-/low)CD14(+) subset was associated with greater overall survival (P = 0.033). These data provide evidence for a unique relationship between specific cytokines, MDSC subsets, and IFN-α responsiveness in patients with GI malignancies.

The trifunctional antibody catumaxomab in treatment of malignant ascites and peritoneal carcinomatosis

Peritoneal carcinomatosis remains an unsolved medical problem in modern oncologic treatment. Excruciating symptoms such as malignant ascites, ileus, nausea, vomiting, dyspnoea and pain deteriorate the quality of life for affected patients. There is still no effective standard treatment for peritoneal carcinomatosis. The trifunctional antibody catumaxomab (antiepithelial cell adhesion molecule x anti-CD3) is able to direct T lymphocytes and Fcg-receptor-positive accessory cells to epithelial cell adhesion molecule-positive tumor cells. Intraperitoneal catumaxomab therapy was shown to be the first effective therapy against accumulation of malignant ascites in patients with peritoneal carcinomatosis of epithelial cancer, reducing the need of paracentesis and prolonging puncture-free survival. This paper reviews the mode of action of catumaxomab and analyzes different fields of local immunotherapy in patients with peritoneal carcinomatosis. A summary of completed and ongoing studies is included. Catumaxomab is discussed to be an outstanding option for local control and therapy of peritoneal carcinomatosis, which could be an optimal modular therapy in addition to systemic chemotherapy and surgical tumor resection.