MPM, a malignancy arising from the lining of the abdominal cavity, remains a therapeutic challenge and has a historically poor prognosis. Predominantly linked to asbestos exposure, its epidemiology suggests a changing pattern, with a subset of patients presenting without any known exposure to this carcinogen. This shift necessitates re-examination of the disease's risk factors and pathogenesis.
The demographic distribution within our study, notably a female majority and a prevalence of patients under the age of 50, raises questions about the typical profile of mesothelioma patients and suggests that other environmental or genetic factors may contribute to disease development. The absence of asbestos exposure in our patient cohort is particularly striking and aligns with emerging research suggesting alternative etiological pathways.(20) The limited size of the sample could have influenced the outcomes.
Traditionally, the treatment of MPM involves systemic chemotherapy and palliative care, with limited success in improving patient survival. (21) However, the advent of cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has revolutionized the treatment landscape, offering the potential for extended survival in selected patients. (13)
HIPEC involves the circulation of heated chemical agents within the peritoneal cavity postcytoreduction, aiming to eliminate residual microscopic disease. The rationale for hyperthermia is twofold: it enhances the cytotoxicity of chemotherapeutic agents and facilitates deeper penetration into tissues. (22) Studies have demonstrated that HIPEC combined with complete cytoreduction can lead to median survival rates that significantly exceed those achieved with traditional therapies. (23)
Despite these promising developments, the administration of HIPEC remains complex, with considerable debate regarding its indications, optimal timing, and patient selection criteria. The procedure is associated with significant morbidity and requires careful patient evaluation and management by a multidisciplinary team. (24)
The administration of neoadjuvant chemotherapy in our study was reserved, and only 13.33% (n = 2) of patients received this treatment. This percentage is comparatively low when juxtaposed with other studies, where neoadjuvant chemotherapy is more commonly used as a part of multimodal treatment.(5) The rationale behind this conservative approach to neoadjuvant chemotherapy in our cohort could be multifaceted and potentially influenced by factors such as the timing of presentation, the burden of disease, and the perceived responsiveness of the tumor to systemic therapy.
In our series, epithelial mesothelioma was the most common histological subtype (66.67%), which is associated with a better prognosis than are the sarcomatoid and mixed subtypes.(25) The distribution of subtypes in our study aligns with the established literature that also reports that epithelioids are the most common subtype of peritoneal mesothelioma. Among our patients, 26.67% (n = 4) had the mixed subtype, followed by the sarcomatoid subtype (n = 1).
When addressing the clinical management outcomes detailed in the provided data, it is essential to consider the peritoneal cancer index (PCI) and the completeness of cytoreduction (CC), both of which are well-established prognostic indicators for MPM. Our cohort presented a mean PCI of 14.0, which is a pivotal finding considering that a higher PCI is correlated with poorer outcomes, as indicated in studies where cytoreductive surgery combined with HIPEC was evaluated. (5) The fact that 60% of our patients had a PCI above the mean might reflect an advanced disease stage at presentation and could influence survival outcomes, despite the aggressive treatment approach adopted.
Our cohort achieved a CC0 rate of 40%, which compares favourably with the published literature. For instance, Sugarbaker and colleagues reported CC0 rates varying from approximately 40–50% in selected patient groups undergoing CRS and HIPEC, confirming the importance of complete cytoreduction in improving outcomes.(6) Other studies have reported CC0 rates ranging between 30–60%, with higher rates associated with specialized centers that frequently perform these complex treatments.(5, 23) The CC1 and CC2 rates, representing minimal and more extensive residual disease, respectively, were 33.33% and 26.67%. These findings underscore the inherent challenges in achieving complete cytoreduction and align with broader clinical experience, where complete macroscopic clearance is not always feasible due to tumor spread and patient factors.(26)
The universal application of HIPEC in our cohort reinforces its role as a cornerstone in the current standard of care for MPM, as it has been shown to improve survival in patients who underwent complete cytoreductive surgery.(23) The high rate of adjuvant chemotherapy usage (60%) further exemplifies the aggressive therapeutic strategy employed in our center, although the impact on survival remains to be conclusively determined.
The surgical procedures, ranging from total resection to organ-specific resection and lymph node dissection, reflect the tailored approach to the extent of disease, aiming to achieve the best possible cytoreductive outcomes. However, the relatively extensive surgeries performed may contribute to variability in postoperative recovery and morbidity, factors that require careful preoperative assessment.
When interpreting the operative and postoperative data of MPM patients in our study, surgical management was considered to be appropriate, as reflected by the mean blood loss and operative duration. The average blood loss of 577 ml, though significant, is within acceptable limits for major abdominal surgeries, and the mean operative time of 350 minutes indicates the complexity and extent of the procedures performed, such as peritonectomy and organ resections. These operative parameters are consistent with those of other specialized centers performing similar extensive cytoreductive surgeries. (27)
A median ICU stay of 1 day and a hospital stay of 8 days are indicative of an efficient postoperative care protocol, optimizing patient recovery and resource utilization. These durations are comparable to or better than those reported in larger series, where the complexity of the surgery can lead to longer ICU and hospital stays.(5) The relatively short ICU stay also suggested a high level of surgical and anaesthetic expertise, as well as effective postoperative management protocols.
Postoperative complications occur in a pattern that is not uncommon in high-risk abdominal surgeries. The spectrum of complications observed, ranging from mild (grade I) to more severe (grade IV), provides a real-world snapshot of the potential risks associated with aggressive surgical management of MPM. Notably, the incidences of Grade III and IV complications, as well as single-stage mortality, underscore the necessity of careful patient selection and the inherent risks of the disease and its treatment.
The overall median survival of 27.0 months, with 1- and 3-year survival rates of 86.7% and 33.3%, respectively, offers a meaningful addition to the literature on MPM, which generally reports a median survival ranging from 12 to 27 months.(23) On univariate analysis, only histological subtype emerged as a predictive factor for overall survival, while PCI and CC were not significant. This could be attributed to the small sample size of our study.
The limitations of this study include its retrospective nature, reliance on data from a single center, limited sample size, and absence of Ki67 reporting in the histopathological analysis.