Analysis of Treatment Strategies and Outcomes in Malignant Peritoneal Mesothelioma: Insights From a Multi-Center Study

BACKGROUND

This study aimed to evaluate the demographic," clinicopathologic, and prognostic characteristics of malignant peritoneal mesothelioma (MPeM), as well as the treatment options for the rare and heterogeneous MPeM population.

METHODS

A retrospective multi-center observational cohort study was conducted to evaluate patients with MPeM. Due to the heterogeneity of the study population, the study divided them into two main groups in terms of treatments, follow-up periods, and prognostic features. The first group comprised the patients who underwent cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), and the second group included the patients with metastatic disease for whom curative intent surgery was not possible. The patients' diagnostic procedures and treatments were identified from medical records. Patients older than 18 years old were included in the study regardless of asbestos exposure. Well-differentiated papillary and multicystic mesothelioma histologic types were not included in the study.

RESULTS

The study evaluated 118 patients from five centers. Survival times, prognosis, and treatment responses were analyzed in both groups. The study showed that CRS-HIPEC was associated with longer overall survival (OS) and progression-free survival (PFS). Perioperative therapy was evaluated in subgroup analyses of this population and shown to provide survival benefits. The patients treated with chemotherapy (metastatic and medically inoperable patients and those for whom complete cytoreduction was not achievable) had a poorer prognosis than the surgery group. The study showed that life expectancy decreased significantly for the patients not suitable to undergo surgery for any reason.

CONCLUSIONS

According to data from experienced centers, CRS-HIPEC is a treatment option recognized as effective, cost-effective, and safe, with better OS and PFS , as well as low morbidity and mortality rates similar to those in the literature. In addition, the platinum-pemetrexed combination continues to be an effective and acceptable treatment option for metastatic patients, those who are medically inoperable, and those for whom complete or near-complete cytoreduction is not achievable.

Diffuse malignant peritoneal mesothelioma: A review

Diffuse malignant peritoneal mesothelioma (DMPM) is an unusual and life-threatening locally invasive tumor. The morbidity and mortality of the disease are associated with progressive local effects in the abdominal cavity, such as abdominal distention, painful sensations, and early saturation with reduced oral intake, which eventually lead to intestinal obstruction and cachexia. Computed tomography (CT) has been widely used as a first-line diagnostic tool for DMPM. In addition, the most sensitive immunohistochemical markers of DMPM include WT 1, D2-40, and calmodulin. This paradigm has altered with the advancements in the immunohistochemical analysis of BRCA1-Associated Protein 1 (BAP1) the lack of BAP1 expression shows the diagnosis of malignancy. DMPM is resistant to conventional chemotherapies. Therefore, the gold standard for the treatment of DMPM is the combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The overexpression of the phosphatidylinositol 3-kinase (PI3K)/AKT serine/threonine kinase 1 (AKT)/mammalian target of rapamycin (mTOR) signaling pathway drives the malignant phenotype of DMPM, thereby showing promising potential for the treatment of DMPM. The coordinated activities among multiple RTKs are directly involved in the biological processes of DMPM, suggesting that the combined inhibition of the PI3K and mTOR signaling pathways might be an effective measure. This treatment strategy can be easily implemented in clinical practice. However, the combined inhibition of ERBB1(HER1)/ERBB2 (HER2) and ERBB3 (HER3) requires further investigations. Thus, based on these, the discovery of novel targeted therapies might be crucial to improving the prognosis of DMPM patients.

Pathology of Malignant Pleural Mesothelioma

Despite multiple diagnostic toolkits, the diagnosis of diffuse malignant pleural mesothelioma relies primarily on proper histologic assessment. The definitive diagnosis of diffuse malignant pleural mesothelioma is based on the pathologic assessment of tumor tissue, which can be obtained from core biopsy sampling, pleurectomy, or other more extensive resections, such as extrapleural pneumonectomy. Given its rarity and overlapping microscopic features with other conditions, the histologic diagnosis of diffuse malignant pleural mesothelioma is challenging. This review discusses the pathologic features and the differential diagnosis of diffuse malignant pleural mesothelioma, including select diagnostic pitfalls.

The Application of Immunohistochemical Biomarkers in Urologic Surgical Pathology

Context

Tumors of the genitourinary tract can be diagnostically challenging, particularly in core biopsies and cystoscopic biopsies with limited material. Immunohistochemistry is a valuable tool to use when morphology alone is insufficient for diagnosis.

Objectives

To review tumors and benign lesions of the kidney, urinary bladder, prostate gland, testis, and paratesticular structures with an emphasis on difficult differential diagnoses, as well as staining patterns in normal tissue. Recommended immunohistochemical stain panels are discussed that can assist in the diagnostic workup.

Data Sources

Review of current literature.

Conclusions

Immunohistochemistry is a valuable tool, assisting in the diagnosis of problematic tumors and benign lesions of the genitourinary tract.

A rare cause of heart failure with preserved ejection fraction: primary pericardial mesothelioma masquerading as pericardial constriction

We present a case of a 30-year-old woman with a history of HIV and hepatitis C who sought medical attention because of severe oedema of the lower limbs and abdomen. CT of the chest showed a thickened pericardium, and cardiac catheterisation demonstrated constrictive physiology. She underwent pericardiectomy, but the procedure was unsuccessful because the pericardium was densely adherent to the myocardium. After consultation with several pathologists, she was diagnosed with primary pericardial mesothelioma (PPM), an exceedingly rare cardiac tumour with a fatal prognosis. She died within 3 months of presentation. The details of the case as well as pertinent literature are reviewed.