Combined grade and nuclear grade are prognosis predictors of epithelioid malignant peritoneal mesothelioma: a multi-institutional retrospective study

[RENAPE network: Towards more equitable access to care and expertise for patients with rare peritoneal cancers]

Since its creation in 2010, the progressive structuration of the RENAPE network (Réseau national de prise en charge des tumeurs rares du péritoine) supported by the "Institut national du cancer" and the "Direction générale de l'offre de soins", allowed the optimization of the healthcare system involved in the management of the rare cancers of the peritoneum. In this setting, the RENA-PATH group has also been reinforced, notably by its recognized diagnostic expertise in pathology and its interface with the MESOPATH group. Moreover RENAPE and RENA-PATH led to guidelines diffusion through the integration, in 2019, to the ``Thesaurus National de Cancérologie Digestive'' (TNCD) and to post-university medical education programs. The aim of this article is to highlight the missions of the RENAPE and RENA-PATH, notably the equity in terms of expertise, access to the networks and their improvement in the management of peritoneal diseases.

Advances in the management of peritoneal malignancies

Peritoneal surface malignancies (PSMs) are usually associated with a poor prognosis. Nonetheless, in line with advances in the management of most abdominopelvic metastatic diseases, considerable progress has been made over the past decade. An improved understanding of disease biology has led to the more accurate prediction of neoplasia aggressiveness and the treatment response and has been reflected in the proposal of new classification systems. Achieving complete cytoreductive surgery remains the cornerstone of curative-intent treatment of PSMs. Alongside centralization in expert centres, enabling the delivery of multimodal and multidisciplinary strategies, preoperative management is a crucial step in order to select patients who are most likely to benefit from surgery. Depending on the specific PSM, the role of intraperitoneal chemotherapy and of perioperative systemic chemotherapy, in particular, in the neoadjuvant setting, is established in certain scenarios but questioned in several others, although more prospective data are required. In this Review, we describe advances in all aspects of the management of PSMs including disease biology, assessment and improvement of disease resectability, perioperative management, systemic therapy and pre-emptive management, and we speculate on future research directions.

Concurrent alcoholic cirrhosis and malignant peritoneal mesothelioma in a patient: A case report

BACKGROUND

Malignant peritoneal mesothelioma (MPM) originates from the mesothelial and subcutaneous cells of the abdominal cavity. Its diagnose is difficult due to its nonspecific and vague symptoms, and it should be differentiated from alcoholic cirrhosis and liver and pancreatic cancers. Misdiagnosis and missed diagnosis can easily occur when MPM presents with other diseases. To the best of our knowledge, no case of MPM concurrent with alcoholic cirrhosis has been reported.

CASE SUMMARY

A 63-year-old man presented to our hospital with abdominal distension for 20days. He had a history of alcohol consumption for nearly 30 years and no history of special drug use or toxic exposure. After treatment for alcoholic cirrhosis in a community hospital, his symptoms did not improve significantly. The patient underwent exploratory laparotomy and surgical resection. Pathologic examination showed an epithelioid MPM. He was treated with chemotherapy and intraperitoneal hyperthermic perfusion after surgery. Currently, he is in a stable condition and tumor recurrence has not occurred.

CONCLUSION

Misdiagnosis and missed diagnosis of MPM can easily occur because of its insidious onset. Therefore, there is a need to understand. MPM in clinical practice, make the correct diagnosis, and provide timely and effective treatment.

B cells and tertiary lymphoid structures as determinants of tumour immune contexture and clinical outcome

B cells are a major component of the tumour microenvironment, where they are predominantly associated with tertiary lymphoid structures (TLS). In germinal centres within mature TLS, B cell clones are selectively activated and amplified, and undergo antibody class switching and somatic hypermutation. Subsequently, these B cell clones differentiate into plasma cells that can produce IgG or IgA antibodies targeting tumour-associated antigens. In tumours without mature TLS, B cells are either scarce or differentiate into regulatory cells that produce immunosuppressive cytokines. Indeed, different tumours vary considerably in their TLS and B cell content. Notably, tumours with mature TLS, a high density of B cells and plasma cells, as well as the presence of antibodies to tumour-associated antigens are typically associated with favourable clinical outcomes and responses to immunotherapy compared with those lacking these characteristics. However, polyclonal B cell activation can also result in the formation of immune complexes that trigger the production of pro-inflammatory cytokines by macrophages and neutrophils. In complement-rich tumours, IgG antibodies can also activate the complement cascade, resulting in the production of anaphylatoxins that sustain tumour-promoting inflammation and angiogenesis. Herein, we review the phenotypic heterogeneity of intratumoural B cells and the importance of TLS in their generation as well as the potential of B cells and TLS as prognostic and predictive biomarkers. We also discuss novel therapeutic approaches that are being explored with the aim of increasing mature TLS formation, B cell differentiation and anti-tumour antibody production within tumours.