Under the Hood: Understanding the Features of Mucin in Pseudomyxoma Peritonei.

Pseudomyxoma peritonei (PMP) is a rare malignant growth characterized by the production of mucin and the potential for peritoneal relapse. This study aimed to investigate the immunohistochemical and biological characteristics of mucin in patients with cellular and acellular PMP. We prospectively analyzed mucin specimens obtained from our patient cohort and described the composition and type of mucin present in each sample. A metagenomic analysis of the samples was performed to investigate the bacterial composition of the PMP microbiome. Secreted mucins 2 and 5AC and membrane-associated mucin-1 were the primary components of mucin in both cellular and acellular tumor specimens. The metagenomic study revealed a predominance of the phylum Proteobacteria and the genus Pseudomonas. Notably, Pseudomonas plecoglossicida, a species not previously reported in the human microbiome, was found to be the most abundant organism in the mucin of pseudomyxoma peritonei. Our findings suggest that the presence of MUC-2 and mucin colonization by Pseudomonas are characteristic features of both cellular and acellular disease. These results may have significant implications for the diagnosis and treatment of this rare entity.

Understanding CAR T cell therapy and its role in ovarian cancer and peritoneal carcinomatosis from ovarian cancer.

Ovarian cancer is the seventh most common cancer worldwide in women and the most lethal gynecologic malignancy due to the lack of accurate screening tools for early detection and late symptom onset. The absence of early-onset symptoms often delays diagnosis until the disease has progressed to advanced stages, frequently when there is peritoneal involvement. Although ovarian cancer is a heterogeneous malignancy with different histopathologic types, treatment for advanced tumors is usually based on chemotherapy and cytoreduction surgery. CAR T cells have shown promise for the treatment of hematological malignancies, though their role in treating solid tumors remains unclear. Outcomes are less favorable owing to the low capacity of CAR T cells to migrate to the tumor site, the influence of the protective tumor microenvironment, and the heterogeneity of surface antigens on tumor cells. Despite these results, CAR T cells have been proposed as a treatment approach for peritoneal carcinomatosis from colorectal and gastric origin. Local intraperitoneal administration of CAR T cells has been found to be superior to systemic administration, as this route is associated with increased tumor reduction, a more durable effect, protection against local relapse and distant metastases, and fewer systemic adverse effects. In this article we review the application of CAR T cells for the treatment of ovarian cancer and peritoneal carcinomatosis from ovarian cancer.

The Role of Shared Decision-Making in Personalised Medicine: Opening the Debate.

Surgeons and cancer patients are starting to open the debate on how personalised medicine could use shared decision-making (SDM) to balance the personal and clinical components and thus improve the quality and value of care. Personalised precision medicine (PPM) has traditionally focused on the use of genomic information when prescribing treatments, which are usually pharmaceutical. However, the knowledge base is considerably scarcer in terms of how clinicians can individualise the information they provide patients about the consequences of different treatments, and in doing so involve them in the decision-making process. To achieve this, the ethical implications of SDM must be addressed from both sides. This paper explores the medical characteristics, the SDM implications in severe and fragile patients, potential risks, and observed benefits within this healthcare approach through four clinical cases. Findings shed light on current needs for clinician and patient training and tools related to SDM in PPM, and also remarks on the way in which this shift in healthcare settings is taking place to include the human component together with the biological and technological advances when designing care processes in colorectal cancer.

Necrotizing fasciitis as a complication of late anastomotic leak after anterior resection for rectal cancer.

BACKGROUND: Anastomotic leak is a serious complication of rectal cancer surgery that leads to increased morbidity and mortality. Its incidence is 3-21%, usually appearing 5-7 days after surgery, although there are cases of late presentation as chronic anastomotic fistulas or sinuses. CASE REPORT: We present three cases of patients who underwent anterior resection for rectal cancer and developed necrotizing fasciitis due to late anastomotic leaks. CONCLUSIONS: We believe that early and resolutive surgical treatment is recommended for chronic anastomotic fistulas or sinuses, even when asymptomatic, because of the associated risk of necrotizing fasciitis.

ANTECEDENTES: La dehiscencia anastomótica es una complicación grave de la cirugía del cáncer de recto que conlleva un aumento de la morbimortalidad. Su incidencia se sitúa en un 3-21%, manifestándose habitualmente alrededor del quinto a séptimo días de posoperatorio, si bien existen casos de presentación tardía en forma de fístulas o sinus anastomóticos crónicos. CASOS CLÍNICOS: Presentamos tres casos de pacientes intervenidos mediante resección anterior por cáncer de recto que desarrollaron fascitis necrotizante secundaria a dehiscencia anastomótica tardía. CONCLUSIONES: Creemos recomendable el tratamiento quirúrgico resolutivo y precoz de las fístulas y sinus anastomóticos crónicos, incluso asintomáticos, por el potencial riesgo de fascitis necrotizante que suponen.

Liquid biopsy in peritoneal fluid and plasma as a prognostic factor in advanced colorectal and appendiceal tumors after complete cytoreduction and hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Positive cytology has been identified as an independent negative prognostic factor in patients with peritoneal metastases (PM) of colorectal origin. Liquid biopsy in plasma may detect increasing levels of circulating tumor DNA (ctDNA) and could help predict systemic relapse in patients with colorectal cancer, but little is known about the role of liquid biopsy in peritoneal fluid. The aim of this study was to evaluate the prognostic value of peritoneal fluid and plasma liquid biopsy in patients undergoing complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CC-HIPEC). METHODS: A longitudinal prospective study was designed in patients with KRAS-mutated colorectal or appendiceal primary tumor, including PM of colorectal origin, pseudomyxoma peritonei and patients at high risk of developing PM (selected for second-look surgery). Eleven patients were recruited according to inclusion and exclusion criteria. ctDNA from plasma and peritoneal fluid before and after HIPEC was studied by droplet digital PCR looking for KRAS mutation. A close follow-up was scheduled (mean of 28.5 months) to monitor for systemic and peritoneal recurrences. RESULTS: All patients with positive plasma postHIPEC had systemic relapse and four patients died as a result, while those with negative plasma postHIPEC did not relapse. Patients with negative peritoneal ctDNA after CC-HIPEC did not present peritoneal relapse. Of six patients with positive peritoneal ctDNA postHIPEC, two presented peritoneal recurrence and four systemic relapses. CONCLUSIONS: Treatment with CC-HIPEC does not always neutralize ctDNA in peritoneal fluid, and its persistence after treatment may predict adverse outcome. Despite being a proof of concept, an adequate correlation between liquid biopsy in plasma and peritoneal fluid with both systemic and peritoneal relapse has been observed.