Malignant Peritoneal Mesothelioma: An In-Depth and Up-to-Date Review of Pathogenesis, Diagnosis, Management and Future Directions

Malignant peritoneal mesothelioma (MPM) is an extremely rare malignancy usually confined to the abdominal cavity. With an aggressive natural history, morbidity and mortality are consequences of progressive locoregional effects within the peritoneal cavity. The first reported case was in the early 20th century, however, due to the rare nature of the disease and a large gap in understanding of the clinicopathological effects, the next reported MPM cases were only published half a decade later. Since then, there has been exponential growth in our understanding of the disease, however, there are no prospective data and a paucity of literature regarding management. Traditionally, patients were treated with systemic therapy and the outcomes were very poor, with a median survival of less than one year. However, with the advent of cytoreductive surgery and locoregional chemotherapy, there have been significant improvements in survival. Even more recently, with an improved understanding of the molecular pathogenesis of MPM, there have been reports of improved outcomes with novel therapies. Given the disastrous natural history of MPM, the limited data, and the lack of universal treatment guidelines, an in-depth review of the past, present, and future of MPM is critical to improve treatment regimens and, subsequently, patient outcomes.

Cytoreductive Surgery and HIPEC for Malignant Peritoneal Mesothelioma: Outcomes and Survival From an Australian Centre

BACKGROUND/AIM

The aim of the study was to determine outcomes and overall survival (OS) in patients undergoing cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) for malignant peritoneal mesothelioma (MPM).

PATIENTS AND METHODS

This was a retrospective cohort study from a prospectively maintained database of patients that underwent CRS/HIPEC for MPM from April 1999 to December 2021.

RESULTS

A total of 81 patients were identified with MPM. Median OS was 53 months with a 1-, 3- and 5-year OS of 76%, 55% and 49% respectively. Multivariate analysis identified lymph node status, PCI and CC score as statistically significant prognostic factors that impact survival. Median OS for PCI 0-20 was 103 months vs. 33 months for PCI 21-39 (p=0.005). Median OS for CC0, CC1 and CC2 were 104, 30 and 2.7 months respectively (p<0.001). Hazard ratio for node-positive disease over node-negative was 2.14 (95% CI=1.07-4.31, p<0.033). Grade III/IV complication rate was 43.2% and mortality 4.9%.

CONCLUSION

CRS/HIPEC remains the gold standard for treating patients with MPM with excellent patient OS. Lymph node status, PCI and CC score were independent prognostic factors that affect OS.

Acute Kidney Injury Following Hyperthermic Intraperitoneal Chemotherapy With Cisplatin

BACKGROUND/AIM

Cisplatin increases the risk of acute kidney injury (AKI) during systemic chemotherapy. However, little is known about its risk of inducing AKI when used during intraperitoneal chemotherapy. This study aimed to determine the incidence of AKI in patients undergoing cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) with cisplatin.

PATIENTS AND METHODS

A retrospective analysis of patients who received cisplatin-based HIPEC from November 2008 to March 2018 was undertaken to determine the incidence of AKI.

RESULTS

A total of 111 patients were identified. The incidence of AKI was 15.3% (17/111). Univariate analysis showed increased peritoneal cancer index (PCI), low intraoperative and post-operative urine output were significantly associated with the development of AKI. Multivariate analyses did not identify any significant predictors factors for AKI.

CONCLUSION

Cisplatin-based HIPEC is associated with AKI. At our centre, the incidence of AKI was 15.3%. Risk factors that may influence its development include high PCI and low perioperative diuresis.

Impact of signet ring cells on overall survival in peritoneal disseminated appendix cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

INTRODUCTION

To determine the effect of signet ring cell (SRC) histopathology in appendix cancer with peritoneal dissemination on overall survival (OS) in patients undergoing cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC).

MATERIALS AND METHODS

Retrospective cohort study from a prospectively maintained database of patients that underwent CRS/HIPEC for appendix cancer from April 1999 to December 2019.

RESULTS

255 patients were identified. 174 had high-grade disease with no SRC component, 35 with a low count of SRC and 46 with a high count of SRC. Median OS without SRC was 93.8 months vs 58.2 months for low count SRC and 23.7 months for high count SRC (P < 0.001). 5-year OS was 60% for patients with no SRC, 35.5% and 10% in those with low count and high count SRC respectively. On multivariate analysis, presence of SRC and complete cytoreduction score were identified as independent factors that affect OS.

CONCLUSION

The presence of SRC in appendix cancer with peritoneal dissemination is associated with worse OS when compared to an absence of SRC in patients undergoing CRS/HIPEC.

Repeat cytoreductive surgery with or without intraperitoneal chemotherapy for recurrent epithelial appendiceal neoplasms

Background

With recurrence rates after primary cytoreductive surgery (CRS) in excess of 50 per cent, repeat CRS is being performed increasingly, but survival outcomes have not been reported widely. This study examined the outcomes following repeat CRS for appendiceal cancer with peritoneal surface malignancy (PSM), and evaluated its feasibility and safety.

Methods

A retrospective cohort of patients who had surgery between 1996 and 2018 were analysed. Patients who underwent a single CRS procedure with or without heated intraperitoneal chemotherapy (HIPEC) were compared with those who had multiple procedures with or without HIPEC. Perioperative morbidity and survival outcomes were analysed.

Results

Some 462 patients were reviewed, 102 of whom had repeat procedures. For high‐grade tumours, patients who had a single CRS procedure had significantly reduced overall survival (OS) compared with those who had repeat CRS (55·6 versus 90·7 months respectively; P = 0·016). For low‐grade tumours, there was no difference in OS (P = 0·153). When patients who had a single procedure were compared with those who had multiple procedures, there was no significant difference in major morbidity (P = 0·441) or in‐hospital mortality (P = 0·080). For multiple procedures, no differences were found in major morbidity (P = 0·262) or in‐hospital mortality (P = 0·502) when the first procedure was compared with the second. For low‐grade cancers, the peritoneal carcinomatosis index was a significant prognostic factor for OS (hazard ratio (HR) 1·11, 95 per cent c.i. 1·05 to 1·17; P < 0·001), whereas for high‐grade cancers repeat CRS (HR 0·57, 0·33 to 0·95; P = 0·033), complete cytoreduction score (HR 1·55, 1·01 to 2·40; P = 0·046) and presence of signet ring cells (HR 2·77, 1·78 to 4·30; P < 0·001) were all significant indicators of long‐term survival.

Conclusion

In selected patients presenting with PSM from epithelial appendiceal neoplasms, repeat CRS performed in high‐volume centres could provide survival benefits.