Treatment factors associated with long-term survival after cytoreductive surgery and regional chemotherapy for patients with malignant peritoneal mesothelioma

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.

Diagnosis and treatment of malignant retroperitoneal mesothelioma: A case report

RATIONALE

Malignant peritoneal mesothelioma (MPM) is a rare clinical disease. Although there are several reports describing intraperitoneal mesothelioma of the lung, liver, and intestine, retroperitoneal mesothelioma is, to our knowledge, very rare and rarely reported. In recent years, our best clinical protocols for the treatment and diagnosis of retroperitoneal mesothelioma have not been proven and the diagnosis and treatment are challenging.

PATIENT CONCERNS

A 37-year-old Chinese woman complained of bilateral low back pain for a month, with obvious symptoms of low back pain on the left side. To treat low back pain, retroperitoneal masses were found during physical examination. The patient consulted a urological specialist for further treatment.

DIAGNOSIS

After the operation, pathological biopsy confirmed retroperitoneal epithelioid diffuse mesothelioma.

INTERVENTIONS

After exclusion of surgical contraindications, the patient underwent laparoscopic retroperitoneal lesion resection under tracheal intubation and general anesthesia, and the operation was successful.

OUTCOMES

On the tenth day after surgery, the patient vital signs were stable, and he was discharged.

LESSONS

Patients with malignant peritoneal mesothelioma may have no typical clinical symptoms, and the diagnosis is based on pathological and immunohistochemical examination. In selected patients, surgical cell reduction and intraoperative intraperitoneal heat chemotherapy have become the first choice of treatment, which can achieve ideal therapeutic effects and prolong survival.

Is extereme cytoreductive surgery beneficial to survival ın malignant peritoneal mesothelioma?

INTRODUCTION

Malign peritoneal mesothelioma (MPM) is an uncommon disease that is difficult to treat. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) are the gold standards for treating MPM. Sometimes extreme cytoreductive surgery (eCRS) is required to achieve complete cytoreduction, which is one of the most important prognostic factors. There is limited information in the literature about the contribution of eCRS in patients with MPM. In this study, we aimed to investigate the impact of eCRS on survival and perioperative outcomes.

METHODS

The Department of Surgical Oncology at Cumhuriyet University database was retrospectively reviewed for MPM patients who underwent CRS-HIPEC between January 2004 and December 2018. Patients who underwent CRS-HIPEC were divided into eCRS and less extensive CRS (leCRS) groups. A resection of ≥5 organs or ≥3 small bowel anastomoses were defined as eCRS. Both groups were compared regarding survival, demographic information, and perioperative outcomes.

RESULTS

A total of 31 patients were included. eCRS-HIPEC was used in 15 patients. Complete cytoreduction (CC score 0/1) was achieved in all 31 patients. Compared to leCRS, the eCRS group had a longer median length of stay, longer intensive care unit stay, a higher median peritoneal cancer index (PCI), higher intraoperative blood loss, more frequent occurrence of any complication, and a longer operative time (all p values < 0.001). Clavien Dindo 3-4 complications, ASA, and gender were similar in both groups of patients (p > 0.05). It was found that there was no significant difference between the OS of the eCRS and leCRS groups (37.5 vs. 42.8 months, p = 0.895).

CONCLUSIONS

Rates of serious complications and morbidity are similar in patients undergoing eCRS compared to leCRS. In patients with high PCI and multiorgan involvement, complete cytoreduction can be achieved by performing eCRS, and survival results equivalent to those with low PCI can be achieved.

Organoids derived from patients provide a new opportunity for research and individualized treatment of malignant peritoneal mesothelioma

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is an extremely rare and highly invasive tumor. Due to the lack of accurate models that reflect the biological characteristics of primary tumors, studying MPM remains challenging and is associated with an exceedingly unfavorable prognosis. This study was aimed to establish a new potential preclinical model for MPM using patient-derived MPM organoids (MPMOs) and to comprehensively evaluate the practicality of this model in medical research and its feasibility in guiding individualized patient treatment.

METHODS

MPMOs were constructed using tumor tissue from MPM patients. Histopathological analysis and whole genome sequencing (WGS) were employed to determine the ability of MPMOs to replicate the original tumor's genetic and histological characteristics. The subcutaneous and orthotopic xenograft models were employed to assess the feasibility of establishing an in vivo model of MPM. MPMOs were also used to conduct drug screening and compare the results with retrospective analysis of patients after treatment, in order to evaluate the potential of MPMOs in predicting the effectiveness of drugs in MPM patients.

RESULTS

We successfully established a culture method for human MPM organoids using tumor tissue from MPM patients and provided a comprehensive description of the necessary medium components for MPMOs. Pathological examination and WGS revealed that MPMOs accurately represented the histological characteristics and genomic heterogeneity of the original tumors. In terms of application, the success rate of creating subcutaneous and orthotopic xenograft models using MPMOs was 88% and 100% respectively. Drug sensitivity assays demonstrated that MPMOs have different medication responses, and these differences were compatible with the real situation of the patients.

CONCLUSION

This study presents a method for generating human MPM organoids, which can serve as a valuable research tool and contribute to the advancement of MPM research. Additionally, these organoids can be utilized as a means to evaluate the effectiveness of drug treatments for MPM patients, offering a model for personalized treatment approaches.

2022 PSOGI Consensus on HIPEC Regimens for Peritoneal Malignancies: Diffuse Malignant Peritoneal Mesothelioma

BACKGROUND

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare and aggressive primary peritoneal disease, with recommended treatment, in eligible patients, of a combination of complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). As treatment is multimodal, there is a wide heterogeneity of HIPEC protocols precluding clear comparisons. Standardization at an international level is required.

METHODS

The Peritoneal Surface Oncology Group International (PSOGI) designated a steering committee to produce consensus recommendations for HIPEC regimens, adapted to each etiology. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology was used, based on a systematic review focused on main outcomes related to HIPEC regimens in DMPM patients and on the patient, intervention, comparator, and outcome (PICO) method to elaborate main questions. An opinion survey was added. Furthermore, a Delphi process was performed with voting from a panel of international experts.

RESULTS

Eleven questions were elaborated, including two for future research requirements and three to assess the HIPEC regimen preference of the panel. The level of evidence underlying questions was globally low. Overall, 75 (86%) and 67 (77%) of the 87 invited experts completed the vote at the first and second round, respectively. HIPEC following complete CRS was strongly supported by 88% of voters with no need to plan comparative studies with CRS alone for 61.2% of voters. Bi-drug regimens appeared to be preferred to mono-drug ones and cisplatin was globally favored. The opinion survey confirmed the combination of cisplatin and doxorubicin as the recommended regimen.

CONCLUSION

International consensus confirmed the indication of HIPEC following complete CRS in DMPM patients and recommended cisplatin-doxorubicin as the first-line HIPEC regimen.

Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) for peritoneal mesothelioma: Canadian practices and outcomes

INTRODUCTION

Peritoneal mesothelioma (PM) is a rare malignancy originating from the peritoneal lining. Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) is the standard-of-care for patients with isolated PM. Due to a paucity of prospective data there are several different HIPEC protocols. The aims of this study are to describe the CRS and HIPEC protocols for PM and patient outcomes across Canada.

METHODS

A multicenter retrospective study was performed on patients diagnosed and treated for PM with CRS and HIPEC in four major peritoneal disease centers in Canada between 2000 and 2021. Data on patient characteristics, treatment patterns, postoperative morbidity, recurrence, and survival were collected.

RESULTS

A total of 72 patients were identified. Mean age was 52 years (17-75) and 37.5% were male. Epithelioid (70.1%) and multicystic (13%) mesothelioma were the most common subtypes. Twenty-one patients (30%) were treated with neoadjuvant chemotherapy. CRS and HIPEC was performed in 64 patients (91.4%). Of these, the mean PCI was 22 (2-39) and cisplatin+doxorubicin was the most common HIPEC regimen (n = 33, 51.6%). A semi-closed coliseum technique was used in 68.8% of HIPECs and the mean duration of surgery was 486 min (90-1052). Clavien-Dindo III or IV complications occurred in 12 patients (16.9%). With a median follow-up of 24 months (0.2-104.4), we found a 5-year overall survival of 61% and a 5-year recurrence-free survival of 35%.

CONCLUSION

CRS and HIPEC is a safe and effective treatment modality for well-selected patients with PM, with some achieving prolonged survival.

Cisplatin exhibits superiority over MMC as a perfusion agent in a peritoneal mesothelioma patient specific organoid HIPEC platform

Peritoneal mesothelioma (PM) is a rare malignancy with poor prognosis, representing about 10-15% of all mesothelioma cases. Herein we apply PM patient-derived tumor organoids (PTOs) in elucidating personalized HIPEC responses to bypass rarity of disease in generating preclinical data. Specimens were obtained from PM patients undergoing cytoreductive surgery with HIPEC. PTOs were fabricated with tumor cells suspended in ECM-hydrogel and treated with HIPEC regimen parameters. Viability and characterization analyses were performed post-treatment. Treatment efficacy was defined as ≥ 50% viability reduction and p < 0.05 compared to controls. From October 2020 to November 2022, 17 tumors from 7 patients were biofabricated into organoids, with 16/17 (94.1%) sites undergoing comparative 37° and 42° treatments with cisplatin and mitomycin C (MMC). Hyperthermic cisplatin and MMC enhanced cytotoxicity which reduced treatment viability by 25% and 22%, respectively, compared to normothermia. Heated cisplatin displayed the greatest cytotoxicity, with efficacy in 12/16 (75%) tumors and an average viability of 38% (5-68%). Heated MMC demonstrated efficacy in 7/16 (43.8%) tumors with an average treatment viability of 51% (17-92.3%). PTOs fabricated from distinct anatomic sites exhibited site-specific variability in treatment responses. PM PTOs exhibit patient and anatomic location treatment responses suggestive of underlying disease clonality. In PM organoids cisplatin is superior to MMC in HIPEC.

Primary and secondary tumors of the peritoneum: key imaging features and differential diagnosis with surgical and pathological correlation

Peritoneal malignancies represent a diagnostic challenge for abdominal radiologists, oncologists, surgeons and pathologists in multidisciplinary teams, who must address their differential diagnosis, staging and treatment. In this article, we explain the pathophysiology of these processes and lay out the role of different imaging techniques in their evaluation. Then, we review the clinical and epidemiological aspects, the main radiological features and the therapeutic approaches for each primary and secondary peritoneal neoplasm, with surgical and pathological correlation. We further describe other rare peritoneal tumors of uncertain origin and a variety of entities that may mimic peritoneal malignancy. Finally, we summarize the key imaging findings of each peritoneal neoplasm to facilitate an accurate differential diagnosis that may impact patient management.Clinical relevance statementImaging plays an essential role in the evaluation of peritoneal malignancies, assessing their extension, detecting unfavorable sites of involvement and facilitating an accurate differential diagnosis, helping to choose the best therapeutic approach.

Peritoneal Mesothelioma: Systematic Review of Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Protocol Outcomes

Diffuse malignant peritoneal mesothelioma (DMPM) prognosis was improved by the locoregional treatment combining cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). HIPEC is a multiparametric treatment with multiple protocols proposed and reviewed in this work. A systematic review of medical literature was performed according to PRISMA guidelines. The search strategy used "malignant peritoneal mesothelioma" and "HIPEC" as keywords in three databases. Studies were included if reporting precisely the HIPEC regimen and the related outcomes, if comparing regimen, or if reporting national/international guidelines. The GRADE methodology was used to rate the level of evidence. Twenty-eight studies were included in this review: 1 was a meta-analysis, 18 reported cohort outcomes, 4 retrospectively compared HIPEC regimens, and 5 were guidelines. Six HIPEC regimens were found, 4 with one drug (cisplatin, mitomycine-C, carboplatin, oxaliplatin), 2 using two drugs (cisplatin-doxorubicin or cisplatin-mitomycine-C). Cisplatin, up to 250 mg/m2 over 90 min, appeared as the key HIPEC drug with a toxicity profile well controlled by the concomitant intravenous perfusion of sodium thiosulfate. Comparative studies tended to show that a bi-drug regimen led to better long-term oncologic outcomes, with cisplatin 50 mg/m2 plus doxorubicin 15 mg/m2 being safe and more efficient. This late protocol was the most widely used and recommended in 3 out of 4 international guidelines. Cisplatin was the preferred drug for HIPEC in DMPM patients. Most of the time, it was combined with doxorubicin for 90 min. A harmonization of protocols and further comparative studies are needed to optimize HIPEC regimen choice.

Prognostic role of CD74, CD10 and Ki-67 immunohistochemical expression in patients with diffuse malignant peritoneal mesothelioma: a retrospective study

BACKGROUND

Diagnosis and treatment of diffuse malignant peritoneal mesothelioma (DMPM) are still challenging. The aim of the present study was to explore the correlation between CD74, CD10, Ki-67 and clinicopathological parameters, and identify independent prognostic factors of DMPM.

METHODS

Seventy patients with pathologically proven DMPM were retrospectively reviewed. The expression of CD74, CD10 and Ki-67 in peritoneal tissues was detected by immunohistochemical analysis using standard avidin biotin complex (ABC) immunostaining technique. Kaplan-Meier survival analysis and multivariate Cox regression analyses were performed to assess prognostic factors. The nomogram based on the Cox hazards regression model was established. C-index and calibration curve were performed to evaluate the accuracy of nomogram models.

RESULTS

The median age of DMPM was 62.34 years, and the male-to-female ratio was 1: 1.80. CD74 expression was identified in 52 (74.29%) of 70 specimens, CD10 in 34 (48.57%) specimens, and higher Ki-67 in 33(47.14%) specimens. CD74 was negatively associated with asbestos exposure(r = -0.278), Ki-67(r = -0.251) and TNM stage(r = -0.313). All patients were effectively followed up in the survival analysis. Univariate analysis revealed that PCI, TNM stage, treatment, Ki-67, CD74 and ECOG PS were associated with DMPM prognosis. CD74 (HR = 0.65, 95%Cl:0.46-0.91, P = 0.014), Ki-67(HR = 2.09, 95%Cl:1.18-3.73, P = 0.012),TNM stage (HR = 1.89, 95%Cl:1.16-3.09, P = 0.011), ECOG PS(HR = 2.12, 95%Cl:1.06-4.25, P = 0.034), systemic chemotherapy (HR = 0.41, 95%Cl:0.21-0.82, P = 0.011) and intraperitoneal chemotherapy (HR = 0.34, 95%Cl:0.16-0.71, P = 0.004) were independent predictors by multivariate Cox analysis. The C‑index of the nomogram for predicting overall survival (OS) was 0.81. The OS calibration curve showed good agreement between nomogram-predicted and observed survival.

CONCLUSIONS

CD74, Ki-67, TNM stage, ECOG PS and treatment were independent factors affecting prognosis of DMPM. Reasonable chemotherapy treatment might improve the prognosis of patients. The proposed nomogram was a visual tool to effectively predict the OS of DMPM patients.

Peritoneal Mesothelioma in a High Volume Peritoneal Surface Malignancies Unit

Diffuse malignant peritoneal mesothelioma (PM) is a rare neoplasm, traditionally associated with a poor prognosis. There are other varieties of PM that are even less frequent and of uncertain malignancy. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has achieved prolonged survival in selected patients. The aim of this study is to analyze the patients with PM assessed in our center. Clinicopathological characteristics, diagnostic procedures and survival results from patients with PM appraised at our unit, according to the applied treatment, were analyzed. Seventeen patients were assessed between 2007 and 2019. Three cases had multicystic PM that were treated with complete CRS + HIPEC; all patients are alive and free of disease after a long follow-up. Three other cases had biphasic PM; a curative treatment could be performed in none of them, and their survival was minimal (<6 moths). Lastly, 11 cases with epithelioid PM were treated. Two cases were considered unresectable at laparoscopy (PCI 39); one of them had a long survival (67 months) with three iterative laparoscopic palliatives HIPECs for refractory ascites. The other nine cases were treated with curative CRS + HIPEC, with a median PCI of 14 (range 4–25), and a median overall survival (OS) of 58 months, with a 5-year OS of 47.4%. In conclusion, CRS + HIPEC, when possible, appears to be the optimal treatment for patients with PM. Knowledge of this therapeutic option is crucial, both to offer it to patients and to avoid delays in their referral to appropriate centers for treatment.

Cytoreduction and HIPEC for Gastric Carcinomatosis: Multi-institutional Analysis of Two Phase II Clinical Trials

INTRODUCTION

There are no approved locoregional therapies for peritoneal carcinomatosis from gastric adenocarcinoma (GA). Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) represents a potential treatment for advanced GA with isolated peritoneal metastasis.

PATIENTS AND METHODS

Two separate single-institution phase II, single-arm studies evaluating CRS-HIPEC using cisplatin with mitomycin C (NIH: NCT03092518, MDACC: NCT02891447) in patients with GA and confirmed peritoneal metastasis were analyzed. The primary endpoint of each trial was overall survival (OS). Clinical, pathologic, and treatment variables were analyzed for association with outcomes.

RESULTS

Over 4 years, 41 patients with peritoneal carcinomatosis from GA underwent CRS-HIPEC. All patients had synchronous peritoneal metastasis and received systemic chemotherapy as front-line therapy. A total of 23 patients also received laparoscopic HIPEC prior to open CRS-HIPEC. The majority (63%, n = 26) were male, and median PCI score at CRS-HIPEC was 2. Median OS was 24.9 months from diagnosis and 14.4 months from CRS-HIPEC. Three-year OS was 25% from diagnosis and 22% from CRS-HIPEC. Median RFS was 7.4 months. The rate of 30-day Clavien-Dindo grade ≥ 3 complications was 32%; specifically, the rate of anastomotic leak was 22%. Multivariable analysis identified the number of pathologically positive lymph nodes as an independent predictor of postoperative OS.

CONCLUSIONS

In patients with gastric adenocarcinoma and isolated peritoneal metastasis treated with CRS-HIPEC, 3-year OS was 22% from CRS-HIPEC, and complications were common. The number of pathologic lymph node metastases was inversely correlated with overall survival. Further investigation of CRS-HIPEC for GA should include patient selection based on response to systemic chemotherapy or incorporate novel intraperitoneal treatment strategies.

Diagnostic and Therapeutic Pathway in Diffuse Malignant Peritoneal Mesothelioma

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare form of mesothelioma that carries a very poor prognosis. The 5-year overall survival is about 20% (±5.9). Survival is optimal for patients suitable for cytoreductive surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC), with a median OS ranging from 34 to 92 months. However, selecting patients for surgery remains a complex task and requires a careful preoperative workup, rational analysis of prognostic profiles, and risk prediction models. Systemic chemotherapy could be offered: (1) in the adjuvant setting for high-risk patients; (2) for patients not eligible for CRS; and (3) for those with recurrent disease. It mainly includes the combination of Platin compound with Pemetrexed or immunotherapy. The biology of DMPM is still largely unknown. However, progress has been made on some fronts, such as telomere maintenance mechanisms, deregulation of apoptosis, tyrosine kinase pathways, and mutation of BRCA1-associated protein 1 (BAP1). Future perspectives should include translational research to improve our understanding of the disease biology to identify druggable targets. We should also clear the role of immune checkpoint inhibitors and investigate new locoregional technologies, such as pressurized intraperitoneal aerosol chemotherapy (PIPAC) or normothermic intraperitoneal chemotherapy (NIPEC).

The contemporary management of peritoneal metastasis: A journey from the cold past of treatment futility to a warm present and a bright future

Peritoneal metastasis (PM) is often regarded as a less frequent pattern of spread; however, collectively across all spectra of primary tumors, the consequences of PM impact a large population of patients annually. Unlike other modes of metastasis, symptoms at presentation or during the treatment course are common, representing an additional challenge in the management of PM. Early efforts with chemotherapy and incomplete surgical interventions transiently improved symptoms, but durable symptom control and survival extension were rare, which established a perspective of treatment futility for PM through most of the 20th century. Notably, the continued development of better systemic therapy combinations, optimization of cytoreductive surgery (CRS), and rigorous investigation of combining regional therapy-specifically hyperthermic intraperitoneal chemotherapy-with CRS, have resulted in more effective multimodal treatment options for patients with PM. In this article, the authors provide a comprehensive review of the data establishing the contemporary approach for tumors with a high frequency of PM, including appendix, colorectal, mesothelioma, and gastric cancers. The authors also explore the emerging role of adding hyperthermic intraperitoneal chemotherapy to the well established paradigm of CRS and systemic therapy for advanced ovarian cancer, as well as the recent clinical trials identifying the efficacy of poly(adenosine diphosphate ribose) polymerase maintenance therapy. Finally, recent data are included that explore the role of precision medicine technology in PM management that, in the future, may help further improve patient selection, identify the best systemic therapy regimens, detect actionable mutations, and identify new targets for drug development.

miR-550a-3p is a prognostic biomarker and exerts tumor-suppressive functions by targeting HSP90AA1 in diffuse malignant peritoneal mesothelioma

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare and rapidly lethal tumor, poorly responsive to conventional treatments. In this regards, the identification of molecular alterations underlying DMPM onset and progression might be exploited to develop novel therapeutic strategies. Here, we focused on miR-550a-3p, which we found downregulated in 45 DMPM clinical samples compared to normal tissues and whose expression levels were associated with patient outcome. Through a gain-of-function approach using miRNA mimics in 3 DMPM cell lines, we demonstrated the tumor-suppressive role of miR-550a-3p. Specifically, miRNA ectopic expression impaired cell proliferation and invasiveness, enhanced the apoptotic response, and reduced the growth of DMPM xenografts in mice. Antiproliferative and proapoptotic effects were also observed in prostate and ovarian cancer cell lines following miR-550a-3p ectopic expression. miR-550a-3p effects were mediated, at least in part, by the direct inhibition of HSP90AA1 and the consequent downregulation of its target proteins, the levels of which were rescued upon disruption of miRNA-HSP90AA1 mRNA pairing, partially abrogating miR-550a-3p-induced cellular effects. Our results show that miR-550a-3p reconstitution affects several tumor traits, thus suggesting this approach as a potential novel therapeutic strategy for DMPM.

Ten-year single-center experience with treatment of primary diffuse malignant peritoneal mesothelioma (DMPM) by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC)

PURPOSE

This single-center study evaluated cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) for diffuse malignant peritoneal mesothelioma (DMPM).

METHODS

Prospectively collected data from a single institution data registry was retrospectively investigated. Eighty-four patients with primary malignant peritoneal mesothelioma underwent CRS and HIPEC with cisplatin and doxorubicin either for 60 min or 90 min of duration from 2011 to 2021. The primary endpoint was overall survival. The secondary endpoint was the evaluation of prognostic factors for overall survival. The tertiary endpoint was to assess the effect of neoadjuvant chemotherapy on survival.

RESULTS

The median follow-up was 5.0 years (95%-CI 4.6-5.5). The median age was 59.2 years (IQR: 47-66). Eighty-two patients (97.6%) had epithelioid tumors. The median peritoneal cancer index was 18.0 (IQR: 13-27). Sixty-six patients (78.6%) had complete or near-complete cytoreduction (CCR 0 or CCR 1). Seventy patients (83.3%) received HIPEC for 60 min and 14 patients (16.7%) received it for 90 min. Twenty-two patients (26.2%) had grade 3 to 4 complications. Acute kidney injury (AKI) stage I-III occurred in 30 (35.7%) patients. Three patients (3.6%) died perioperatively. The overall median survival was 38.4 months (95%-CI 23.6-54.3), and the 5-year survival rate was 42%. Survival was independently associated with age, female gender, and thrombocytosis. Preoperative chemotherapy did not emerge as an adverse prognostic factor.

CONCLUSION

In well-selected patients with DMPM, prolonged survival is achievable with CRS and HIPEC in specialized centers.

Clinical-pathological characteristics and prognostic factors for malignant peritoneal mesothelioma in the elderly

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare disease characterized by atypical symptoms, difficult diagnosis, variable course and poor prognosis, and it develops mainly in elderly individuals. The authors aimed to identify the clinical-pathological characteristics, prognosis, and prognostic factors in elderly MPM patients.

METHODS

From the National Cancer Institute Surveillance Epidemiology End Results (SEER) database, 1492 patients with MPM from 1975 to 2016 were selected and divided into the elderly group (≥ 65) and the adult group (< 65). We compared the clinical-pathological characteristics and treatment methods of the elderly group (N = 665) and the adult group (N = 827). At the same time, we analysed specific selected clinicopathological parameters and prognostic factors for elderly MPM patients.

RESULTS

Compared with the adult group, the elderly group had higher percentages of male patients (P = 0.017) and white patients (P = 0.043) and lower proportions of insured patients (P < 0.001) married patients (P < 0.001), patients with peritoneal tumours (P = 0.006) and patients who underwent surgery (P < 0.001) and chemotherapy (P < 0.001). There was a significant difference in the differentiation grade between the two groups (P = 0.003). Elderly patients had a shorter median survival time than adult patients (6 months vs. 19 months). Uninsured (hazard ratio (HR): 5.187, P = 0.005), sarcomatoid type (HR 3.913, P < 0.001), poorly differentiated (HR 3.900, P < 0.001), distant metastasis (HR 1.735, P = 0.001), no cancer-directed surgery (HR 1.733, P < 0.001), and no chemotherapy (HR 1.532, P < 0.001) were independently associated with poorer prognosis in elderly MPM patients.

CONCLUSION

Compared with adult patients, elderly MPM patients had a higher male ratio, poor differentiation and relatively conservative treatment. The cancer-specific survival (CSS) rate of elderly MPM patients was significantly lower than that of adult patients. Insurance status, histology type, differentiation grade, stage, surgery status, and chemotherapy status were all independent prognostic factors for elderly MPM patients.

Ultra-high drug loading improves nanoparticle efficacy against peritoneal mesothelioma

Peritoneal mesothelioma is an aggressive disease with a median survival of under three years, due to a lack of effective treatment options. Mesothelioma is traditionally considered a "chemoresistant" tumor; however, low intratumoral drug levels coupled with the inability to administer high systemic doses suggests that therapeutic resistance may be due to poor drug delivery rather than inherent biology. While patient survival may improve with repetitive local intraperitoneal infusions of chemotherapy throughout the perioperative period, these regimens carry associated toxicities and significant peri-operative morbidity. To circumvent these issues, we describe ultra-high drug loaded nanoparticles (NPs) composed of a unique poly(1,2-glycerol carbonate)-graft-succinate-paclitaxel (PGC-PTX + PTX) conjugate. PGC-PTX + PTX NPs are cytotoxic, localize to tumor in vivo, and improve survival in a murine model of human peritoneal mesothelioma after a single intraperitoneal (IP) injection compared to multiple weekly doses of the clinically utilized formulation PTX-C/E. Given their unique pharmacokinetics, a second intraperitoneal dose of PGC-PTX + PTX NPs one month later more than doubles the overall survival compared to the clinical control (122 versus 58 days). These results validate the clinical potential of prolonged local paclitaxel to treat intracavitary malignancies such as mesothelioma using a tailored polymer-mediated nanoparticle formulation.

Splicing deregulation, microRNA and Notch aberrations: fighting the three-headed dog to overcome drug resistance in malignant mesothelioma

INTRODUCTION

Malignant mesothelioma (MMe) is an aggressive rare cancer of the mesothelium, associated with asbestos exposure. MMe is currently an incurable disease at all stages mainly due to resistance to treatments. It is therefore necessary to elucidate key mechanisms underlying chemoresistance, in an effort to exploit them as novel therapeutic targets.

AREAS COVERED

Chemoresistance is frequently elicited by microRNA (miRNA) alterations and splicing deregulations. Indeed, several miRNAs, such as miR-29c, have been shown to exert oncogenic or oncosuppressive activity. Alterations in the splicing machinery might also be involved in chemoresistance. Moreover, the Notch signaling pathway, often deregulated in MMe, plays a key role in cancer stem cells formation and self-renewal, leading to drug resistance and relapses.

EXPERT OPINION

The prognosis of MMe in patients varies among different tumors and patient characteristics, and novel biomarkers and therapies are warranted. This work aims at giving an overview of MMe, with a special focus on state-of-the-art treatments and new therapeutic strategies against vulnerabilities emerging from studies on epigenetics factors. Besides, this review is also the first to discuss the interplay between miRNAs and alternative splicing as well as the role of Notch as new promising frontiers to overcome drug resistance in MMe.

Treatment of Patients with Malignant Peritoneal Mesothelioma

Malignant peritoneal mesothelioma is a rare malignancy arising from the serosa of the peritoneal cavity. It is diagnosed based on suspicious findings on cross sectional imaging and a tissue biopsy showing confirmatory histologic and immunohistochemical features. The disease is hallmarked by its propensity to progress mainly in the peritoneal cavity. In selected patients, surgical cytoreduction and hyperthermic intra-operative peritoneal chemotherapy has become the initial preferred treatment and is associated with provide prolonged in many patients. Systemic chemotherapy using a couplet of cisplatin or gemcitabine with pemetrexed has modest response rates and duration of response. Expression of PD-L1 has been demonstrated in peritoneal mesothelioma tumors and there has been significant interest in the use of check point blockade targeted against PD-L1 in this clinical setting. Future clinical research using a combination of check point blockade with surgical cytoreduction is a high clinical priority.

Primary and metastatic peritoneal surface malignancies

Peritoneal surface malignancies comprise a heterogeneous group of primary tumours, including peritoneal mesothelioma, and peritoneal metastases of other tumours, including ovarian, gastric, colorectal, appendicular or pancreatic cancers. The pathophysiology of peritoneal malignancy is complex and not fully understood. The two main hypotheses are the transformation of mesothelial cells (peritoneal primary tumour) and shedding of cells from a primary tumour with implantation of cells in the peritoneal cavity (peritoneal metastasis). Diagnosis is challenging and often requires modern imaging and interventional techniques, including surgical exploration. In the past decade, new treatments and multimodal strategies helped to improve patient survival and quality of life and the premise that peritoneal malignancies are fatal diseases has been dismissed as management strategies, including complete cytoreductive surgery embedded in perioperative systemic chemotherapy, can provide cure in selected patients. Furthermore, intraperitoneal chemotherapy has become an important part of combination treatments. Improving locoregional treatment delivery to enhance penetration to tumour nodules and reduce systemic uptake is one of the most active research areas. The current main challenges involve not only offering the best treatment option and developing intraperitoneal therapies that are equivalent to current systemic therapies but also defining the optimal treatment sequence according to primary tumour, disease extent and patient preferences. New imaging modalities, less invasive surgery, nanomedicines and targeted therapies are the basis for a new era of intraperitoneal therapy and are beginning to show encouraging outcomes.

Communicating imaging findings in peritoneal mesothelioma: the impact of 'PAUSE' on surgical decision-making

The peritoneal cavity is the second commonest site of mesothelioma after the pleural cavity. There are five histological types of peritoneal mesothelioma with variable symptomatology, clinical presentation and prognosis. Cystic mesothelioma is a borderline malignant neoplasm with a favourable prognosis, well-differentiated papillary mesothelioma is generally a low-grade malignancy, and all other varieties such as epithelioid, sarcomatoid and biphasic mesothelioma are highly malignant types of peritoneal mesothelioma with poor prognosis. Malignant peritoneal mesothelioma was considered inevitably fatal prior to the introduction of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in selected cases where long-term survival and cure could be achieved. However, the survival benefits following CRS and HIPEC mainly depend on completeness of cytoreduction, which come at the cost of high morbidity and potential mortality. Using the acronym 'PAUSE', we aimed at describing the key imaging findings that impact surgical decision-making in patients with peritoneal mesothelioma. PAUSE stands for peritoneal cancer index, ascites and abdominal wall disease, unfavourable sites of involvement, small bowel and mesenteric disease and extraperitoneal disease. Reporting components of 'PAUSE' is crucial for patient selection. Despite limitations of CT in accurately depicting the volume of disease, describing findings in terms of PAUSE plays an important role in excluding patients who might not benefit from CRS and HIPEC.

Osteopontin, GLUT1 and Ki-67 expression in malignant peritoneal mesothelioma: prognostic implications

Background

Malignant peritoneal mesothelioma is the most common primary peritoneal neoplasm. The only universally recognised pathological prognostic factor is histopathological subtype. Prognostic markers based on patient features and clinical stages have been disappointing.

Aims

To assess the prognostic role of several clinicopathological features in a retrospective cohort of 60 patients diagnosed with peritoneal mesothelioma.

Methods

Sixty patients were centrally collected and were immunohistochemically analysed for the expression of osteopontin (OPN), GLUT1 and Ki‐67. Labelling was assessed by two pathologists. Complete clinical information and follow‐up were obtained from patients' records.

Results

OPN expression was identified in 52 (86.6%) of 60 specimens, and GLUT1 in 39 (65%) of 60 specimens. Univariate Cox regression analysis showed that a lower peritoneal carcinomatosis index (PCI), tumour‐directed treatment (chemotherapy or surgery alone or in any combination), lower Ki‐67, GLUT1 and lower OPN expression had a statistically significant positive effect on overall survival (OS). PCI (hazard ratio (HR) = 1.032 (95% confidence interval (CI): 1.000–1.067); P = 0.054) and tumour‐directed treatment (HR = 0.211 (95% CI: 0.104–0.430); P < 0.001), Ki‐67 (HR = 22.326 (95% CI: 3.523–141.498); P = 0.003) and OPN (HR = 7.268 (95% CI: 1.771–29.811); P = 0.009) retained independent prognostic significance in the multivariate analysis, all with a positive effect on OS with the exception of GLUT1.

Conclusions

OPN, Ki‐67, treatment and PCI were independent indicators for OS, and a higher level of OPN expression correlated significantly with poorer OS.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) with cisplatin in pediatric patients with peritoneal mesothelioma: a single institution experience and long term follow up

INTRODUCTION

Malignant peritoneal mesothelioma (MPM) is a lethal cancer, with approximately 2% of diagnoses occurring in patients less than 40 years of age. The purpose of this study is to report the only long-term follow up and survival of pediatric patients with MPM after multi-modality therapy including cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

We retrospectively investigated a prospectively maintained database including patients <21 years old who underwent CRS and HIPEC from 1994 through 2014. Follow-up information was available through 2019 and is included in this report.

RESULTS

Seven young patients underwent CRS and HIPEC. Final histology was epithelioid in all patients. Three patients had received neo-adjuvant systemic chemotherapy. At the time of the operation Peritoneal Cancer Index ranged from 6 to 25. Completeness of cytoreduction score after CRS was 0 in 4 patients, 1 in two patients, and 2 in one patient. Post-operative complications included acute kidney injury (n = 1), hyperbilirubinemia (n = 1), bilateral pleural effusions (n = 1) and pneumothorax requiring chest tube placement (n = 1). At last available follow-up, 71% of patients (n = 5) were alive with minimal or no evaluable disease. The remaining two patients had passed away from their disease at 14 and 26 months, respectively, following CRS and HIPEC. Overall survival ranged between 14 and 281 months.

CONCLUSION

Our surgical experience shows that CRS and HIPEC is a feasible and safe treatment option in pediatric patients, potentially improving overall survival.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in the management of peritoneal surface malignancies - An evidence-based review

BACKGROUND

Traditionally, peritoneal surface malignancies (PSM) were considered terminal diseases because of their advanced nature, therefore, systemic chemotherapy was given with palliative intent only. As a result, very poor survival outcomes were observed. But with the introduction of complete Cytoreductive surgery (CRS) and Hyperthermic intraperitoneal chemotherapy (HIPEC), the scenario has changed dramatically.

METHODOLOGY

An objective electronic database search was performed in Pubmed, NLM Catalog, Google scholar, Bookshelf, and Pubmed Central published in the time period from 2000 till 2020. All the randomized studies were included. In the absence of randomized studies, both prospective and retrospective studies were included. The outcomes of HIPEC were measured in terms of median survival, disease-free survival, overall survival, complications and drug toxicities.

RESULTS

CRS and HIPEC are considered the standard of care for PMP and MPM even in the absence of level 1 evidence due to lack of an effective alternative treatment. In colorectal and gastric cancer, several phase-three trials are showing overall survival benefit in selected cases while there is a prophylactic and palliative role of HIPEC in gastric cancer. Three reported phase 3 trials showed positive results in ovarian cancer. In peritoneal sarcomatosis, the role of HIPEC is yet to be proven.

CONCLUSION

The patient selection is the key to the successful outcomes after HIPEC. HIPEC should be performed by the experienced surgeons in specialized centres with a strong critical care and intensive care support to reduce the morbidity and mortality. Ongoing trials and future directions will prove to be an indispensable arm in the oncological armamentarium.

Clinicopathological characteristics of primary peritoneal epithelioid mesothelioma of clear cell type: A case report

RATIONALE

Primary peritoneal epithelioid mesothelioma of clear cell type is an extremely rare entity composed of clear cytoplasm. It is challenging to diagnose because of the morphological resemblance to clear cell tumor.

PATIENTS CONCERNS

A 69-year-old male patient had swollen lymph nodes in the right inguinal region for 7 months and was constipated for 1 month.

DIAGNOSIS

The patient was diagnosed as peritoneal epithelioid mesothelioma of clear cell type based on computed tomography scan, pathology, immunohistochemistry, special staining and whole-exome sequencing. This patient harbored VHL gene alteration in exon 1 and homologous recombination defect (with a score of 45). This finding indicated that this patient might be sensitive to platinum-based therapy and Poly ADP-ribose Polymerase (PARP) inhibitor. This patient carried no microsatellite instability, a low level of tumor mutation burden, and a high extent of intratumoral heterogeneity. Eighteen neoantigens were detected.

INTERVENTIONS

The patient received surgery-based multidisciplinary treatment by integrating cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). HIPEC was administered with docetaxel 120 mg plus cisplatin 120 mg, at 43°C, for 60 minutes. After operation, the patient received intravenous (IV) chemotherapy with docetaxel 60 mg, pemetrexed 750 mg and cisplatin 100 mg, and then intraperitoneal (IP) chemotherapy with docetaxel 40 mg. The patient received interventional therapy of hepatic artery embolization for 5 times.

OUTCOMES

Regular follow-up was performed until Oct 14, 2020. The patient died 31.6 months later owing to incomplete intestinal obstruction.

LESSONS

Primary peritoneal epithelioid mesothelioma of clear cell type needs to be differentiated from a variety of clear cell tumors. This disease is characterized by specific genetic alteration. Whole-exome sequencing contributes to guide individualized therapy. CRS-HIPEC helps achieve long-term overall survival.

Malignant peritoneal mesothelioma: prognostic significance of clinical and pathologic parameters and validation of a nuclear-grading system in a multi-institutional series of 225 cases

Malignant peritoneal mesothelioma historically carried a grim prognosis, but outcomes have improved substantially in recent decades. The prognostic significance of clinical, morphologic, and immunophenotypic features remains ill-defined. This multi-institutional cohort comprises 225 malignant peritoneal mesotheliomas, which were assessed for 21 clinical, morphologic, and immunohistochemical parameters. For epithelioid mesotheliomas, combining nuclear pleomorphism and mitotic index yielded a composite nuclear grade, using a previously standardized grading system. Correlation of clinical, morphologic, and immunohistochemical parameters with overall and disease-free survival was examined by univariate and multivariate analyses. On univariate analysis, longer overall survival was significantly associated with diagnosis after 2000 (P = 0.0001), age <60 years (P = 0.0001), ECOG performance status 0 or 1 (P = 0.01), absence of radiographic lymph-node metastasis (P = 0.04), cytoreduction surgery (P < 0.0001), hyperthermic intraperitoneal chemotherapy (P = 0.0001), peritoneal carcinomatosis index <27 (P = 0.01), absence of necrosis (P = 0.007), and epithelioid histotype (P < 0.0001). Among epithelioid malignant mesotheliomas only, longer overall survival was further associated with female sex (P = 0.03), tubulopapillary architecture (P = 0.005), low nuclear pleomorphism (P < 0.0001), low mitotic index (P = 0.0007), and low composite nuclear grade (P < 0.0001). On multivariate analyses, the low composite nuclear grade was independently associated with longer overall and disease-free survival (P < 0.0001). Our data further clarify the interactions of clinical and pathologic features in peritoneal mesothelioma prognosis and validate the prognostic significance of a standardized nuclear-grading system in epithelioid malignant mesothelioma of the peritoneum.

The Role of Hyperthermic Intraperitoneal Chemotherapy for Non-colorectal Peritoneal Surface Malignancies

BACKGROUND

Peritoneal carcinomatosis, from a variety of gastrointestinal and gynecological malignancies, has been historically challenging to treat and there remains a wide range of biologic aggressiveness in these patients. Malignancies commonly associated with PC include those of colorectal, appendiceal, gastric, ovarian, sarcoma, small intestinal, and primary peritoneal origin among others. Advances in our understanding of this unique disease process have led to significant interest in cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) as an emerging treatment option. The goal of CRS-HIPEC is to remove all visible macroscopic disease while preserving organ function, and then treat microscopic disease through perfusion of the peritoneal cavity with heated chemotherapy.

PURPOSE

Although recent reviews have focused on the management of peritoneal carcinomatosis secondary to colorectal cancer given the publication of several recent randomized controlled trials, the purpose of the current review is to summarize the evidence on CRS-HIPEC for non-colorectal peritoneal surface malignancies, including appendiceal neoplasms, malignant peritoneal mesothelioma, gastric cancer, and ovarian cancer.

RESULTS

While retrospective studies have clarified the importance of prognostic factors such as the peritoneal carcinomatosis index, completeness of cytoreduction, histopathological characteristics, and lymph node positivity, the lack of convincing level 1 evidence for the use of CRS-HIPEC has led to it remaining a highly controversial topic.

CONCLUSION

The decision to utilize CRS-HIPEC should involve a multidisciplinary team approach and evaluation of prognostic factors to balance the short-term morbidity of the operation with maximum long-term benefits. Large, multi-institutional groups and ongoing trials hold promise for clarifying the role of CRS-HIPEC in peritoneal surface malignancies.

Role of immunohistochemistry in gynec oncopathology including specific diagnostic scenarios with associated treatment implications

Over the years, immunohistochemistry has emerged as a powerful tool for a more precise diagnosis of certain tumors in gynecologic oncopathology and resolving certain diagnostic dilemmas with significant treatment implications. Certain specific immunohistochemical (IHC) markers have been useful in the more correct identification of rare tumors, characterized by specific molecular signatures. Immunohistochemistry has also been useful in the identification of underlying genetic events, characterizing various tumors, as well as precancerous lesions. This review will focus upon the judicious application of various IHC antibody markers in gynec oncopathology, including authors' experience during "sign-outs" and especially during interaction with other oncology colleagues within the institutional disease management group. The updated references were retrieved from PubMed.

In-Hospital Mortality and Complication Rates According to Health Insurance Data in Patients Undergoing Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Surface Malignancies in Germany

BACKGROUND

Morbidity and in-hospital mortality rates of patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in Germany are not known.

METHODS

From 2009 to 2018 all patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in Germany were retrospectively analyzed regarding morbidity and in-hospital mortality rates according to nationwide hospital billing data based on diagnosis-related groups (DRG). The "failure to rescue" (FTR) index, characterizing patients who died after severe but potentially manageable complications, was calculated.

RESULTS

In total, 8463 patients were included and analyzed. Female sex predominated (1.5:1). Colonic origin of peritoneal metastasis was highest throughout all years, reaching its highest level in 2017 (55%; n = 563) and its lowest level in 2012 (40%; n = 349). Median length of hospital stay reached its maximum in 2017 at 23.9 days and its minimum in 2010 at 22.0 days. Analysis of the total FTR index showed a noticeable improvement over the years, reaching its lowest values in 2017 (9.8%) and 2018 (8.8%). The FTR index for sepsis, peritonitis, and pulmonary complications significantly improved over time. Of the 8463 included patients, 290 died during hospital stay, reflecting an in-hospital mortality rate of 3.4%.

CONCLUSION

In-hospital mortality after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is reasonably low compared with other surgical procedures. The improvement in the FTR index reflects efforts to centralize treatment at specialized high-volume centers.

CRS/HIPEC with Major Organ Resection in Peritoneal Mesothelioma Does not Impact Major Complications or Overall Survival: A Retrospective Cohort Study of the US HIPEC Collaborative

INTRODUCTION

CRS/HIPEC is thought to confer a survival advantage for patients with malignant peritoneal mesothelioma (MPM). However, the impact of nonperitoneal organ resection is not clearly defined. We evaluated the impact of major organ resection (MOR) on postoperative outcomes and overall survival (OS).

PATIENTS AND METHODS

The US HIPEC collaborative database (2000-2017) was reviewed for MPM patients who underwent CRS/HIPEC. MOR was defined as total or partial resection of diaphragm, stomach, spleen, pancreas, small bowel, colon, rectum, kidney, ureter, bladder, and/or uterus. MOR was categorized as 0, 1, or 2+ organs.

RESULTS

A total of 174 patients were identified. Median PCI was 16 (3-39). The distribution of patients with MOR-0, MOR-1, and MOR-2+ was 94, 45, and 35 patients, respectively. MOR-1 and MOR-2+ groups had a higher frequency of any complication compared with MOR-0 (57.8%, 74.3%, and 48.9%, respectively, p = 0.035), but Clavien 3/4 complications were similar. Median length of stay was slightly higher in the MOR-1 and MOR-2+ groups (10 and 11 days) compared with the MOR-0 cohort (9 days, p = 0.005). Incomplete cytoreduction, ASA class 4, and male gender were associated with increased mortality on unadjusted analysis; however, their impact on OS was attenuated on multivariable analysis. MOR was not associated with OS based on these data (MOR-1: HR 1.67, 95% CI 0.59-4.74; MOR-2+ : HR 0.77, 95% CI 0.22-2.69).

CONCLUSIONS

MOR was not associated with an increase in major complications or worse OS in patients undergoing CRS/HIPEC for MPM and should be considered, if necessary, to achieve complete cytoreduction for MPM patients.

Peritoneal Cancers and Hyperthermic Intraperitoneal Chemotherapy

Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy is an aggressive, potentially curative approach used to treat locoregional disease associated with primary and secondary malignancies of the peritoneum. It involves resection of all macroscopic disease larger than 2.5 mm, followed by instillation of hyperthermic chemotherapy directly into the peritoneum for higher drug exposure to microscopic disease. In select patients with primary peritoneal mesothelioma, pseudomyxoma peritonei, colorectal adenocarcinoma, appendiceal adenocarcinoma, or ovarian cancer, with no extra-abdominal metastasis and limited involvement of the peritoneum, the procedure can be performed to increase overall survival.

Survivin expression as an independent predictor of overall survival in malignant peritoneal mesothelioma

Malignant peritoneal mesothelioma (MPeM) is an incurable cancer strongly associated with asbestos exposure and characterised by poor prognosis. The aim of the present study was to elucidate the prognostic and predictive value of CD146 and survivin expression in MPeM. Diagnostic biopsies from 60 patients with MPeM were collected and analysed for CD146, survivin and Ki-67 expression using immunohistochemistry. Complete clinical and follow-up information was obtained from patients' records. CD146 was expressed in 31/60 MPeM specimens and survivin in 34/60 specimens, with both expression levels being significantly associated with the Ki-67 labelling index (Ki-67LI). Kaplan-Meier and univariate Cox regression analyses revealed that a lower peritoneal cancer index (PCI), tumour-directed treatment, stage I, lower Ki-67LI and lower CD146 and survivin expression had a statistically positive effect on overall survival (OS). Cox regression analysis revealed that PCI [hazard ratio (HR)=1.99; 95% CI, 1.04–3.83; P=0.038], survivin (HR=1.47; 95% CI, 1.03–2.10; P=0.034) and treatment protocol including intraperitoneal chemotherapy (HR=0.28; 95% CI, 0.14–0.57; P=0.013) and systemic chemotherapy (HR=0.13; 95% CI, 0.04–0.42; P=0.013) retained independent prognostic significance for OS. All of these were included in the nomogram. Calibration curves showed good agreement between nomogram-predicted and observed survival. The C-index of the nomogram for predicting OS was 0.77. A lower PCI, intraperitoneal chemotherapy, systemic chemotherapy and a lower level of survivin were powerful prognostic markers in patients with MPeM. The proposed nomogram provides individual survival prediction for patients with MPeM.

Peritoneal mesothelioma

Malignant peritoneal mesothelioma (MPM) is a rare and lethal disease of the peritoneal lining, with high variability in biologic aggressiveness. Morbidity and mortality of the disease are related to progressive locoregional effects within the abdominal cavity, such as distention, pain, early satiety, and decreased oral intake that can ultimately lead to bowel obstruction and cachexia. The standard of care for patients with resectable disease remains cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), with potential survival outcomes greater than 5 years in appropriately selected patients. Patients with inoperable MPM can be offered systemic treatment, although the disease is usually refractory to standard chemotherapic regimens. Patients with MPM should be treated at high volume centers with strong consideration for inclusion in tumor registries and clinical trials. In 2020, research will continue to explore promising genetic and immunologic targets and focus on refinement of surgical methods to optimize CRS-HIPEC approaches.

Clinical and surgical outcomes of patients with peritoneal mesothelioma discussed at a monthly national multidisciplinary team video-conference meeting

Background

Peritoneal mesothelioma (PM) is a rare primary neoplasm of the peritoneum with an increasing incidence worldwide. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promise as a treatment strategy. A national PM multidisciplinary team (national PM MDT) video‐conference meeting was established in the UK and Ireland in March 2016, aiming to plan optimal treatment, record outcomes and provide evidence for the benefits of centralization. This article reports on the activities and outcomes of the first 2·5 years.

Methods

Between March 2016 and December 2018, patients with PM, referred to peritoneal malignancy centres in Basingstoke, Birmingham, Manchester and Dublin, were discussed by the national PM MDT via video‐conference. The MDT was composed of surgeons, radiologists, specialist nurses and pathologists. Patients were considered for CRS and HIPEC if considered fit for surgery and if radiological imaging suggested that complete surgical cytoreduction could be achieved. Morbidity and mortality following surgery were analysed. Survival analysis following MDT discussion was conducted.

Results

A total of 155 patients (M : F ratio 0·96) with a mean(s.d.) age of 57(17) years were discussed. To date, 22 (14·2 per cent) have had CRS and HIPEC; the median Peritoneal Cancer Index for the surgical group was 17·0. Complete cytoreduction was achieved in 19 patients. Clavien–Dindo grade I–II complications occurred in 16 patients; there was no grade III–IV morbidity or 30‐day in‐hospital mortality. The median follow‐up for the whole cohort was 18·7 months, and the 2‐year survival rate from time of first review at the national PM MDT was 68·3 per cent.

Conclusion

The centralized national PM MDT was effective at selecting patients suitable for CRS and HIPEC, reporting a good outcome from patient selection.

Two-Stage Cytoreductive Surgery and Intraperitoneal Chemotherapy for Diffuse Malignant Peritoneal Mesothelioma: Predictors of Overall Survival in an Intention-to-Treat Series

PURPOSE

Cytoreductive surgery with intraoperative hyperthermic intraperitoneal chemotherapy is standard of care for diffuse malignant peritoneal mesothelioma (DMPM), but there is variability among institutions in the administration of adjuvant chemotherapy. Characterization of the largest series of DMPM patients treated at a single institution and identification of the demographic, disease, and treatment factors associated with overall survival were sought.

PATIENTS AND METHODS

All DMPM patients who underwent initial cytoreductive surgery with the intention to undergo intraperitoneal chemotherapy and a second-look operation from 1995 to 2016 at our institution were retrospectively reviewed. The primary endpoint was overall survival.

RESULTS

A total of 204 DMPM patients underwent initial cytoreduction. Median overall survival was 32 months from initial cytoreduction. Independent baseline prognostic factors of improved overall survival were female sex, age < 60 years, and epithelioid histology. Independent treatment factors associated with improved overall survival were attempted resection at initial operation, residual disease < 0.5 cm at the end of the initial operation, and dwell intraperitoneal chemotherapy.

CONCLUSIONS

Cytoreductive surgery with intraoperative and dwell intraperitoneal chemotherapy is a feasible approach for DMPM. Expanded access to these therapies may offer benefit to a larger population of patients. Demographic and operative parameters associated with overall survival in this large cohort are consistent with previous reports. In the context of this treatment protocol, dwell intraperitoneal chemotherapy is associated with longer overall survival.

Malignant Peritoneal Mesothelioma: Patterns of Care and Survival in the Netherlands: A Population-Based Study

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare and aggressive disease. Recently, focus has shifted toward a more aggressive and multimodal treatment approach. This study aimed to assess the patterns of care and survival for MPM patients in the Netherlands on a nationwide basis.

METHODS

The records of patients with a diagnosis of MPM from 1993 to 2016 were retrieved from the Dutch Cancer Registry. Data regarding diagnosis, staging, treatment, and survival were extracted. Cox regression analyses and Kaplan-Meier survival curves were used to study overall survival.

RESULTS

Between 1993 and 2016, MPM was diagnosed for 566 patients. Overall, the prognosis was very poor (24% 1-year survival). The most common morphologic subtype was the epithelioid subtype (88%), followed by the biphasic (8%) and sarcomatoid (4%) subtypes. Surgical treatment has become more common in recent years, which most likely has resulted in improved survival rates. In this study, improved survival was independently associated with hyperthermic intraperitoneal chemotherapy (hazard ratio [HR], 0.33; 95% confidence interval [CI], 0.21-0.55) and surgery with adjuvant systemic chemotherapy (HR, 0.33; 95% CI, 0.23-0.48). Nonetheless, most patients (67%) do not receive any form of anti-cancer treatment.

CONCLUSION

This study indicated that MPM still is a rare and fatal disease. The survival rates in the Netherlands have improved slightly in the past decade, most likely due to more aggressive treatment approaches and increased use of surgery. However, most patients still do not receive cancer-directed treatment. To improve MPM management, and ultimately survival, care should be centralized in expert medical centers.

Peritoneal mesothelioma in Sweden: A population-based study

The study aim was to report survival and morbidity of all patients in Sweden with peritoneal mesothelioma treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) as well as investigate whether the survival has increased on a population level since this treatment was nationalized 2011. Study data were collected from the Swedish HIPEC registry and the Swedish National Cancer Registry. All patients with peritoneal mesothelioma scheduled for CRS/HIPEC treatment in Sweden January 2011 to March 2018 were retrieved from the Swedish HIPEC registry. Clinicopathological and survival data were collected. For population‐level analysis, all patients with diffuse malignant peritoneal mesothelioma (DMPM) were identified from the Swedish National Cancer Registry and data were retrieved from two separate 5‐year time periods: 1999‐2003 and 2011‐2015. Thirty‐two patients were accepted for CRS/HIPEC. Four were open/close cases. Two‐year survival rate was 84% or 59% when excluding borderline peritoneal mesotheliomas (n = 17). Median overall survival was not reached. Grade III‐IV Clavien‐Dindo events occurred in 22% with no mortality. From the national cancer registry, 102 DMPM cases were retrieved: 40 cases between 1999 and 2003, and 62 cases between 2011 and 2015 (corresponding to an increase from 0.9 to 1.24/million/year, P = .04). Six patients (10%) received CRS/HIPEC in the second period. Median OS increased between periods from 7 to 15 months and 5‐year survival from 14% to 29% (P = .03). Peritoneal mesothelioma of both borderline and DMPM subtypes undergoing CRS/HIPEC have good long‐term survival. The incidence of DMPM in Sweden has increased. Overall survival has increased alongside the introduction of CRS/HIPEC, which may be a contributing factor.

Mesothelioma: Scientific clues for prevention, diagnosis, and therapy

Mesothelioma affects mostly older individuals who have been occupationally exposed to asbestos. The global mesothelioma incidence and mortality rates are unknown, because data are not available from developing countries that continue to use large amounts of asbestos. The incidence rate of mesothelioma has decreased in Australia, the United States, and Western Europe, where the use of asbestos was banned or strictly regulated in the 1970s and 1980s, demonstrating the value of these preventive measures. However, in these same countries, the overall number of deaths from mesothelioma has not decreased as the size of the population and the percentage of old people have increased. Moreover, hotspots of mesothelioma may occur when carcinogenic fibers that are present in the environment are disturbed as rural areas are being developed. Novel immunohistochemical and molecular markers have improved the accuracy of diagnosis; however, about 14% (high-resource countries) to 50% (developing countries) of mesothelioma diagnoses are incorrect, resulting in inadequate treatment and complicating epidemiological studies. The discovery that germline BRCA1-asssociated protein 1 (BAP1) mutations cause mesothelioma and other cancers (BAP1 cancer syndrome) elucidated some of the key pathogenic mechanisms, and treatments targeting these molecular mechanisms and/or modulating the immune response are being tested. The role of surgery in pleural mesothelioma is controversial as it is difficult to predict who will benefit from aggressive management, even when local therapies are added to existing or novel systemic treatments. Treatment outcomes are improving, however, for peritoneal mesothelioma. Multidisciplinary international collaboration will be necessary to improve prevention, early detection, and treatment.

Manejo del mesotelioma peritoneal maligno con citorreducción quirúrgica más quimioterapia hipertérmica intraperitoneal en el Instituto Nacional de Cancerología, Colombia: reporte de un caso y revisión bibliográfica

El mesotelioma peritoneal es una neoplasia que se origina en las células mesoteliales del peritoneo. Históricamente, la supervivencia de los pacientes con mesotelioma peritoneal maligno sin tratamiento, es menor de 12 meses y se considera una neoplasia resistente a la quimioterapia. La citorreducción quirúrgica y la quimioterapia regional administrada como quimioterapia hipertérmica intraperitoneal (Hyperthermic Intraperitoneal Chemotherapy, HIPEC) se asocia con mejor supervivencia a largo plazo. Se presenta el caso de un paciente con antecedentes de exposición al asbesto y con diagnóstico de mesotelioma peritoneal maligno de tipo epitelioide, que fue tratado con cirugía citorreductora más quimioterapia hipertérmica intraperitoneal en el Instituto Nacional de Cancerología con una supervivencia de un año libre de enfermedad.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal mesothelioma: patient selection and special considerations

Malignant peritoneal mesothelioma (MPM) is a rare, aggressive malignancy that typically presents with vague symptoms, ascites, and/or diffuse peritoneal studding. Despite findings of advanced disease within the peritoneal cavity, spread beyond the abdomen is uncommon. Although advances in systemic chemotherapy have been made, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) remain the mainstay of treatment. Median overall survival of approximately 50 months with CRS/HIPEC has been demonstrated, with age, gender, histologic subtype, peritoneal carcinomatosis index, comorbidities, nodal and extra-abdominal metastases, and completeness of cytoreduction all playing a role in prognosis. In patients with refractory malignant ascites and unresectable disease, complete resolution of ascites and improvement in quality of life have been demonstrated with palliative HIPEC. In appropriately selected patients, CRS/HIPEC plays a critical role in the treatment and palliation of MPM.

A Phase II Trial of Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Recurrent Adrenocortical Carcinoma

BACKGROUND

Recurrent adrenocortical carcinoma (ACC) is an aggressive disease with few options offering durable survival benefit. Despite metastasectomy, recurrence is common. Cytoreduction and intraperitoneal chemotherapy have offered improved survival in other advanced cancers. We sought to evaluate the use of cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) for the treatment of recurrent intraperitoneal ACC.

METHODS

A phase II, single institution clinical trial was approved for patients with radiographic evidence of resectable ACC limited to the peritoneum. Patients underwent treatment if optimal cytoreduction was deemed possible at exploratory laparotomy. Primary outcome was intraperitoneal progression-free survival. Secondary outcomes were treatment-related morbidities and overall survival.

RESULTS

Sixty-three patients were evaluated, of whom 11 met eligibility criteria. Nine patients underwent cytoreduction and HIPEC, including one patient who recurred and was re-treated (n = 10 treatments). One patient could not be optimally cytoreduced for HIPEC and therefore did not receive intraperitoneal chemotherapy. There was no perioperative mortality; perioperative comorbidities were limited to Clavien-Dindo grade 2 or 3 and included hematologic, infectious, and neurologic complications. Seven patients experienced disease recurrence and two patients died of disease during follow-up (median 24 mo). Intraperitoneal progression-free survival was 19 mo, and median overall survival has not yet been reached.

CONCLUSIONS

Cytoreduction and HIPEC can be performed safely in selected patients. Patients with recurrent ACC confined to the peritoneal cavity can be considered for regional therapy in experienced hands. However, disease recurrence is common, and other treatment options should be explored.

Malignant Peritoneal Mesothelioma Mimicking Recurrent Diverticulitis

Mesothelioma is an uncommon type of cancer arising from the mesothelial cells that form the lining of several cavities in the body. Exposure to asbestos is the leading known cause of mesothelioma. We present a 73-year-old male with a significant asbestos exposure and a recent history of recurrent diverticulitis who reported persistent left lower quadrant (LLQ) pain despite several courses of empiric antibiotic therapy. A recent computed tomography (CT) performed due to nonresolving symptoms showed possible nodularity of the mesentery and subsequent positron emission tomography (PET) scan demonstrated multiple hypermetabolic mesenteric lesions, notably in the left paracolic gutter. A colonoscopy was subsequently performed which demonstrated severe diverticulosis, but no obvious luminal lesions. The patient underwent an exploratory laparoscopy showing extensive peritoneal carcinomatosis involving all mesenteric surfaces and partial involvement of the right diaphragm. Final pathology revealed malignant epithelial mesothelioma with peritoneal seeding. The patient was referred to oncology and was started on hyperthermic intraperitoneal chemotherapy (HIPEC) and cytoreductive surgery (CRS). Our case highlights a challenging presentation of malignant peritoneal mesothelioma (MPM), which is often initially misdiagnosed due to vague symptoms. Physicians should consider further diagnostic workup for unrelenting LLQ abdominal pain after diverticulitis has been treated.

Morbidity and Mortality Rates Following Cytoreductive Surgery Combined With Hyperthermic Intraperitoneal Chemotherapy Compared With Other High-Risk Surgical Oncology Procedures

IMPORTANCE

Currently, rates of referral of patients with peritoneal metastasis in the United States who qualify for cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) are low, in part because of the misperception of high morbidity and mortality rates. However, patients requiring major gastrointestinal surgical procedures with similar complication rates are routinely referred.

OBJECTIVE

To evaluate the relative safety of CRS/HIPEC.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of 34 114 patients who underwent CRS/HIPEC, right lobe hepatectomy, trisegmental hepatectomy, pancreaticoduodenectomy, and esophagectomy between January 1, 2005, and December 31, 2015, included in the American College of Surgeons National Surgical Quality Improvement Project (NSQIP) database. Data analysis was performed in 2018.

MAIN OUTCOMES AND MEASURES

Data from the NSQIP database were used to compare perioperative and 30-day postoperative morbidity and mortality rates of CRS/HIPEC (1822 patients) with other, well-accepted, high-risk surgical oncology procedures: right lobe hepatectomy (5109 patients), trisegmental hepatectomy (2449 patients), pancreaticoduodenectomy (Whipple) (16 793 patients), and esophagectomy (7941 patients).

RESULTS

For 34 114 patients, median (interquartile range [IQR]) age was 63 (55-71) years and 42% were female. Patients undergoing CRS/HIPEC tended to be younger, with a median age of 57 years, and esophagectomy had the highest median (IQR) American Society of Anesthesiologists classification (3 [3-3]). When compared with CRS/HIPEC, higher complication rates were reported in the following categories: (1) superficial incisional infection in Whipple and esophagectomy (5.4% [95% CI, 4.4%-6.4%] vs 9.7% [95% CI, 9.3%-10.1%] and 7.2% [95% CI, 6.6%-7.8%], respectively; P < .001); (2) deep incisional infection in Whipple (1.7% [95% CI, 1.1%-2.3%] vs 2.7% [95% CI, 2.5%-2.9%]; P < .01); (3) organ space infection in right lobe hepatectomy (7.2% [95% CI, 6.0%-8.4%] vs 9.0% [95% CI, 8.2%-9.8%]; P = .02), trisegmental hepatectomy (12.4% [95% CI, 11.1%-13.7%]; P < .001), and Whipple (12.9% [95% CI, 12.4%-13.4%]; P < .001); and (4) return to the operating room for esophagectomy (6.8% [95% CI, 5.6%-8.0%] vs 14.4% [95% CI, 13.6%-15.2%]; P < .001). Median (IQR) length of hospital stay was lower in CRS/HIPEC (8 [5-11] days) than Whipple (10 [7-15] days) and esophagectomy (10 [8-16] days) (P < .001). Overall 30-day mortality was lower in CRS/HIPEC (1.1%; 95% CI, 0.6%-1.6%) compared with Whipple (2.5%; 95% CI, 2.3%-2.7%), right lobe hepatectomy (2.9%; 95% CI, 2.4%-3.4%), esophagectomy (3.0%; 95% CI, 2.6%-3.4%), and trisegmental hepatectomy (3.9%; 95% CI, 3.1%-4.7%) (P < .001).

CONCLUSIONS AND RELEVANCE

Comparative analysis revealed CRS/HIPEC to be safe, often safer across the spectrum of NSQIP safety metrics when compared with similar-risk oncologic procedures. Patient selection was important in achieving observed outcomes. High complication rates are a misperception from early CRS/HIPEC experience and should no longer deter referral of patients to experienced centers or impede clinical trial development in the United States.