Diffuse Malignant Peritoneal Mesothelioma Research Articles

Abstract 4642: Fatty acid synthase as a novel prognostic biomarker and a potential therapeutic target in diffuse malignant peritoneal mesothelioma

Abstract Diffuse malignant peritoneal mesothelioma (DMPM) is a rare and locally aggressive tumor with a dismal prognosis. The availability of new therapies and biomarkers for patients’ selection is still an urgent need. Altered lipid metabolism, which has been reported in several tumors, has not yet been studied in DMPM. By comparatively analyzing gene expression profiles of tumors form relapsed (n=18) and non-relapsed (n=18) DMPM patients, we initially found that fatty acid synthase (FASN) was up-modulated in relapsed tumors, with a significant linear correlation between FASN expression and shorter patient relapse-free survival (RFS), suggesting a potential role of FASN in DMPM progression. The prognostic significance of FASN was further assessed in a cohort of 80 DMPM patients who underwent cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy. Our results indicated that high FASN staining was significantly associated with reduced RFS (hazard ration (HR): 1.930; p=0.014) and Overall Survival (OS) (HR: 1.854; p=0.032) as assessed by immunohistochemistry in tissues microarray samples. The prognostic value of FASN, along with Ki67 staining and patient age, was also maintained in multivariate analysis in terms of both RFS (HR: 2.240; p=0.007) and OS (HR: 2.246; p=0.014). To validate FASN as a therapeutic target, we investigated the cytotoxic effects of non-selective (orlistat) and selective (cerulenin and C75) FASN inhibitors on patient-derived DMPM cell lines, both as single agents and in combination with selinexor -a selective inhibitor of the exportin chromosome maintenance protein. FASN pharmacological inhibition in DMPM cells resulted in a significant reduction of cell proliferation, especially upon C75 exposure. In combination experiments, we observed a synergistic activity of FASN inhibitors and selinexor, as determined by Chou and Talalay method. Through western blotting and flow cytometry analysis, we gained further insight into the mechanisms by which FASN inhibitors and selinexor synergize to reduce DMPM cell proliferation. Compared to single agents, the combined treatments resulted in increased apoptosis response and cell cycle impairment, as indicated by caspase-dependent apoptosis activation and cell accumulation in the G2-phase. Overall, our results support the relevance of FASN as a prognostic biomarker for DMPM patients and underscore its potential as a novel therapeutic target. Citation Format: Valentina Doldi, Silvia Martini, Chiara Maura Ciniselli, Alessia Beretta, Marcello Deraco, Shigeki Kusamura, Dario Baratti, Paolo Gandellini, Paolo Verderio, Nadia Zaffaroni. Fatty acid synthase as a novel prognostic biomarker and a potential therapeutic target in diffuse malignant peritoneal mesothelioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4642.

Abstract 2995: The ectopic expression of miR-380-5p interferes with the aggressive traits of diffuse malignant peritoneal mesothelima cells

Abstract Telomerase activity (TA) and the alternative lengthening of telomere (ALT) pathway are two telomere maintenance mechanisms (TMM) yet identified in human cancers. Although the activation of either TMM seems to be equivalent in supporting tumor cell immortalization (a hallmark of cancer), the contribution of TA and ALT to tumor progression and aggressiveness may be different. Mounting evidence suggests that cancer cell aggressiveness could be associated with a TA↔ALT shift that would allow the acquisition of distinct aggressive traits. We previously showed that an ALT-like phenotype emerged in diffuse malignant peritoneal mesothelioma (DMPM) cells upon miR-380-5p-dependent inhibition of TA (Cimino-Reale G, et al. J Hematol Oncol. 2017). To analyze the transcriptomic changes associated with the emergence of such a phenotype, gene expression profiling was carried out. Results showed that 3331 genes were differentially expressed (FDR<0.05, adjusted for multiple hypothesis testing) in miR-380-5p- vs. preNeg-transfected DMPM cells, out of which 1673 genes were up-regulated and 1658 genes down-regulated. To get biological meaning about the molecular events occurring upon miR-380-5p reconstitution, Gene Set Enrichment Analysis was performed. Results showed a positive enrichment of 188 gene sets, restricted for an FDR < 0.05, out of which signatures related to DNA replication, DNA recombination and telomere maintenance via recombination were present. Conversely, only 1 gene set (GO: positive regulation of blood vessel endothelial cell migration) was negatively enriched at significant level. Notably, among the leading edge genes, PTGS2, which encodes for cyclooxygenase-2 (COX-2) and represents a predicted target of miR-380-5p (miRWalk), was the most significantly down-regulated gene (FDR< 0.000001; log(fold-change): -2.15). Notably, a complete abrogation of PTGS2 expression levels and COX-2 protein amounts was observed in miR-380-5p- compared to preNeg-transfected cells upon validation by qRT-PCR and western blotting, respectively. This evidence was paralleled by reduced amounts of phospho-FAK (focal adhesion kinase) and impaired migrating/invading capabilities of cells ectopically expressing miR-380-5p. Moreover, a reduction of Vimentin and a slight increase in P-Cadherin protein levels were also observed in cells ectopically expressing miR-380-5p, likely indicating the occurrence of a reverse-EMT program. Finally, a pronounced increase in the sensitivity to Cisplatin and Doxorubicin was also appreciable in miR-380-5p- vs. preNeg-transfected cells, suggesting that miRNA-mediated induction of a reverse-EMT may, at least in part, contribute to improve the response of DMPM cells to chemotherapeutic drugs. Citation Format: Stefano Percio, Lorenzo Di Pietro, Eisa Naghshineh, Marcello Deraco, Nadia Zaffaroni, Marco Folini. The ectopic expression of miR-380-5p interferes with the aggressive traits of diffuse malignant peritoneal mesothelima cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2995.

Nationwide ten-year treatment evaluation in French centers for 924 patients with diffuse malignant peritoneal mesothelioma

Nationwide ten-year treatment evaluation in French centers for 924 patients with diffuse malignant peritoneal mesothelioma

ASO Author Reflections: Perioperative Systemic Chemotherapy in Diffuse Malignant Peritoneal Mesothelioma treated with CRS-HIPEC.

ASO Author Reflections: Perioperative Systemic Chemotherapy in Diffuse Malignant Peritoneal Mesothelioma treated with CRS-HIPEC.

Impact of Perioperative Systemic Chemotherapy on Survival for Patients Who have Diffuse Malignant Peritoneal Mesothelioma Treated with CRS-HIPEC.

The available data on the role of perioperative systemic chemotherapy (SC) for diffuse malignant peritoneal mesothelioma (DMPM) patients undergoing (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is heterogeneous and unstandardized. This study aimed to evaluate the impact of SC on the survival outcomes of DMPM patients undergoing CRS-HIPEC and to identify prognostic factors that affect the decision to administer SC. Patients who underwent CRS-HIPEC in the National Cancer Institute Milan (1995-2020) were retrospectively analyzed using propensity score-matching of known covariates. The patients were grouped into three groups: group A (neoadjuvant chemotherapy [NACT] and no-SC), group B (no-SC and adjuvant chemotherapy [ACT]), and group C (NACT and ACT). Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meir method, and prognostic factors were calculated using the Cox-regression method. After a median follow-up period of 45 months (95% confidence interval [CI], 6.348-83.652 months) for group A, 115 months (95% CI, 44.379-185.621 months) for group B, and 88 months (95% CI, 3.296-172.704 months) for group C, the study analyzed 154 DMPM patients consisting of matched group A (NACT: 60 + no-SC: 52 = 112), group B (ACT: 38 + no-SC: 38 = 76), and group C (NACT: 31 + ACT: 31 = 62). The patients undergoing ACT had better 5-year OS and PFS than the patients undergoing NACT. In the multivariate analysis, ACT was significantly associated with improved OS by 48% (hazard ratio [HR], 0.52; 95% CI, 0.280-0.965, p = 0.038). For PFS, the association of ACT did not reach statistical significance (HR, 0.531; 95% CI, 0.266-1.058; p = 0.072). The optimum treatment sequence for DMPM is CRS-HIPEC followed by adjuvant chemotherapy for high-risk patients. Upfront surgery appears preferable to NACT for patients amenable to complete CRS.

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

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

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

BackgroundDiagnosis 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.MethodsSeventy 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.ResultsThe 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.ConclusionsCD74, 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.

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 250mg/m2 over 90min, 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 50mg/m2 plus doxorubicin 15mg/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 90min. A harmonization of protocols and further comparative studies are needed to optimize HIPEC regimen choice.

Correlation of serum-soluble mesothelin-related protein, HMGB1 and CA125 in diffuse malignant peritoneal mesothelioma and their combined measurement for prognosis

Diagnosis of diffuse malignant peritoneal mesothelioma (DMPM) is challenging due to the lack of efficient biomarkers for early-stage DMPM. This study was designed to characterize three serum-soluble mesothelium-related proteins, including soluble mesothelin-related protein (SMRP), high mobility group box 1 (HMGB1), and cancer antigen 125 (CA125) in diagnosing DMPM. Serum samples of DMPM patients and healthy controls were collected and an enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of HMGB1, CA125, and SMRP. Correlations between these three serum proteins were examined and the diagnostic values of the biomarkers were assessed by receiver operating curve (ROC) analysis. The combined expression levels of the three markers were also analyzed in terms of predicting patient survival. Higher levels of CA125, SMRP, and HMGB1 was found to be a prominent characteristic of DMPM patients (with > two-fold higher for all levels in DMPM patients compared to control patients, all p < .001), particularly for those with higher-stage DMPM (stage III-IV) compared with lower-stage DMPM (stage I-II) (all p < .05). HMGB1, CA125, and SMRP were all significantly inter-correlated with each other (all p < .05), the combination of the three serum markers had high sensitivity and specificity for diagnosing DMPM. Combined values of the three markers demonstrated a high AUC of 0.85, sensitivity of 78.95%, specificity of 82.75% for identifying DMPM. The combined level of the three markers also demonstrated a significant positive correlation with poor survival of DMPM patients (p = .022). CA125, SMRP, and HMGB1 are potentially valuable diagnostic biomarkers to facilitate the diagnosis of DMPM.

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).

Diffuse malignant peritoneal mesothelioma: A review.

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

Cytoreductive surgery and intraperitoneal hyperthermic chemotherapy for malignant peritoneal mesothelioma.

The aim of this study is to evaluate the results of treatment of diffuse malignant peritoneal mesothelioma (DMPM) by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) at a single center. We conducted a retrospective single-center observational cohort study of consecutive patients with DMPM treated by CRS-HIPEC at the Department of Surgery I of the University Hospital in Olomouc, Czech Republic. Data on a total of 16 patients were processed. The study group of 16 patients had six (37.5 %) women. The mean age was approximately 62 years. Complete cytoreduction was achieved in all patients (100 %) (CC0: 75 %, CC1: 25 %). All patients underwent a closed form of HIPEC with cisplatin and doxorubicin for 90 min. The mean hospital stay was 13.5 days, including 4.38 days in the ICU (13.5 ± 5.07 and 4.38 ± 1.49, respectively). Major postoperative complications (CD grades 3-4) occurred in four patients (25 %). In-hospital mortality was 6.25 %. In the study group, the median overall survival was 20 months, and the median disease-free survival was 10.3 months. Also under the conditions at our specialized center, CRS-HIPEC is considered as an effective, affordable, and safe therapy with OS, DFS, morbidity, and mortality rates comparable to those reported in the literature (Tab. 5, Fig. 2, Ref. 28). Text in PDF www.elis.sk Keywords: cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, malignant mesothelioma, cisplatin, doxorubicin.

A single-center retrospective cohort study of perioperative systemic chemotherapy in diffuse malignant peritoneal mesothelioma.

BackgroundDiffuse malignant peritoneal mesothelioma (DMPM) is a rare variant of malignant mesothelioma, representing 10–15% of malignant mesothelioma cases. The preferred therapeutic approach is cytoreductive surgery (CRS) accompanied by hyperthermic intraperitoneal chemotherapy (HIPEC); the role of systemic chemotherapy is not well established. While some limited retrospective studies report worse outcomes with neoadjuvant chemotherapy, our institution has favored the use of neoadjuvant chemotherapy for symptom relief and surgical optimization. The aim of our study was to assess the outcomes of patients receiving neoadjuvant chemotherapy, compared to those receiving adjuvant or no perioperative chemotherapy.Patients and methodsWe conducted a single-center retrospective cohort study of treatment-naïve, non-papillary DMPM patients seen at our institution between 1/1/2009 and 9/1/2019. We explored the effect of type of systemic therapy on clinical outcomes and estimated median overall survival (mOS) using Kaplan-Meier curves. Hazard ratios (HR) calculated by Cox proportional hazard model were used to estimate effect of the exposures on overall survival.Results47 patients were identified with DMPM (median age at diagnosis 61.2 years, 76.6% epithelioid histology, 74.5% white race, 55.3% known asbestos exposure). CRS was performed in 53.2% of patients (25/47); 76.0% of surgical patients received HIPEC (19/25). The majority received systemic chemotherapy (37/47, 78.7%); among patients receiving both CRS and chemotherapy, neoadjuvant chemotherapy was more common than adjuvant chemotherapy (12 neoadjuvant, 8 adjuvant). Overall mOS was 84.1 months. Among neoadjuvant patients, 10/12 underwent surgery, and 2 were lost to follow-up; the majority (9/10) had clinically stable or improved disease during the pre-operative period. There were numerical more issues with chemotherapy with the adjuvant patients (4/8: 2 switches in platinum agent, 2 patients stopped therapy) than with the neoadjuvant patients (2/10: 1 switch in platinum agent, 1 delay due to peri-procedural symptoms). Neoadjuvant chemotherapy was not associated with worse mOS compared to adjuvant chemotherapy (mOS NR vs 95.1 mo, HR 0.89, 95% CI 0.18–4.5, p = 0.89).ConclusionsWhen used preferentially, the use of neoadjuvant chemotherapy in DMPM patients was not associated with worse outcomes compared to adjuvant chemotherapy. It was well-tolerated and did not prevent surgical intervention.

CT Differentiation of Diffuse Malignant Peritoneal Mesothelioma, Tuberculous Peritonitis, and Peritoneal Carcinomatosis

Objective: To investigate the significance of computed tomography findings in diffuse malignant peritoneal mesothelioma (DMPeM), tuberculous peritonitis (TBP), and peritoneal carcinomatosis (PC) to differentiate the three diseases. Methods: The clinical manifestation and computed tomography scans of 147 patients with diffuse malignant peritoneal mesothelioma (n = 60), tuberculous peritonitis (n = 32), and peritoneal carcinomatosis (n = 55) were retrospectively reviewed, while taking into account of ascites, pleural plaques, viscera infiltration; abnormalities in the peritoneum; involvement of the mesentery and omentum; as well as the presence and location of enlarged lymph nodes. Results: There was no significant difference among all three groups in terms of clinical manifestation, peritoneum, omentum, and mesentery involvement, ascites, as well as the presence and location of enlarged lymph nodes. The study found that 95% of DMPeM patients had been exposed to asbestos in the past. The patients showed significant differences in the following aspects: (1) irregular peritoneum thickening, caked omentum thickening, pleural plaques, visceral infiltration, and asbestos exposure were more common in peritoneal mesothelioma patients; (2) nodular peritoneum thickening and visceral metastasis were more common in patients with peritoneal carcinomatosis; (3) smooth peritoneal thickening, pleural effusion, and extraperitoneal tuberculosis were more common in patients with tuberculous peritonitis. Conclusion: A combination of computed tomography findings could improve our ability in differentiating the three diseases.

Efficacy and Adverse Events of Apatinib Salvage Treatment for Refractory Diffuse Malignant Peritoneal Mesothelioma: A Pilot Study

ObjectiveTo investigate the clinical efficacy and adverse events (AEs) of apatinib salvage treatment for diffuse malignant peritoneal mesothelioma (DMPM) that has failed to respond to the recommended treatments.Methods27 patients with refractory DMPM were treated with apatinib at our center from April 2014 to October 2020, at the initial dose of 250 mg/d. The dose was reduced to 125 mg/d when serious adverse events (SAEs) occurred. 28-day was set as a treatment cycle. The frequency of follow up was once every 28 days. The efficacy evaluation was conducted according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria and the serum tumor markers before and after apatinib treatment. The safety assessment was performed with the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. The primary endpoints were objective response rate (ORR) and disease control rate (DCR), and the secondary endpoints were AEs.ResultsThe 27 patients completed a median treatment-cycle of 15.0, ranging from 5.1 to 39.4 cycles. At the median follow-up of 14.3 (4.8-51.8) months, median overall survival (OS) was 59.4 months, median apatinib-treatment-related survival (ATRS) was 14.0 (4.8-36.8) months. Complete response (CR) was observed in 0 case (0.0%), partial response (PR) in 4 cases (14.8%), stable disease (SD) in 12 cases (44.4%), and progression disease (PD) in 11 cases (40.7%). The ORR was 14.8%, and DCR was 59.3%. The median serum CA125 values before and after apatinib treatment were 32.9 (7.0-4592.4) U/mL and 29.7 (6.1-4327.4) U/mL, respectively (P=0.009). The common AEs were hypertension (6/27; 22.2%), hand-foot syndrome (5/27; 18.5%), albuminuria (4/27; 14.8%), anemia (4/27; 14.8%), leukopenia (4/27; 14.8%), rash (2/27; 7.4%), fatigue (2/27; 7.4%), oral ulcers (2/27; 7.4%), hoarseness (2/27; 7.4%), nausea/vomiting (2/27; 7.4%), diarrhea (2/27; 7.4%), headache (1/27; 3.7%), and fever (1/27; 3.7%). The incidence rate of grade III/IV AEs was 16.2%.ConclusionsApatinib is effective in treating refractory DMPM, with promising efficacy and acceptable safety.

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

This single-center study evaluated cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) for diffuse malignant peritoneal mesothelioma (DMPM). 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 60min or 90min 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. The median follow-up was 5.0years (95%-CI 4.6-5.5). The median age was 59.2years (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 60min and 14 patients (16.7%) received it for 90min. 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 38.4months (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. In well-selected patients with DMPM, prolonged survival is achievable with CRS and HIPEC in specialized centers.

Improved Survival and Quality of Life Through an Integrative, Multidisciplinary Oncological Approach: Pathophysiological Analysis of Four Clinical Cancer Cases and Review of the Literature.

Objectives: According to the National Cancer Institute, the integrative medicine (IM) approach to medical care combines standard medicine with complementary and alternative medicine practices that have proved safe and effective. Methods: We describe the clinical cases of four patients with malignant pleural mesothelioma (MPM), diffuse malignant peritoneal mesothelioma (DMPM), intrahepatic cholangiocarcinoma, and breast cancer (BC) who received supportive treatment (ST) according to an IM approach after the failure of standard cancer treatments or the appearance of serious adverse events caused by antiblastic chemotherapy. The critical role of complementary drugs in reducing the side effects of cancer treatments and normalizing the white cell count is especially apparent in the case of the patient with metastatic BC, who experienced prolonged neutropenia. Results: The IM approach was well-tolerated and had no adverse side effects. It improved the quality of life (QoL) of all patients and in two cases extended overall survival. Conclusion: The extended clinical and instrumental response to IM of the patients with malignant mesothelioma and the improved health-related QoL and good tolerance of the ST demonstrated in all cases support the value of this approach in patients whose cancer therapies have failed but who show a good performance status. Our data require confirmation in a well-designed prospective clinical trial.

Clinical activity of pembrolizumab monotherapy in diffuse malignant peritoneal mesothelioma.

8557 Background: Among patients with malignant mesothelioma, pembrolizumab has demonstrated activity in diffuse pleural mesothelioma (DPM), with limited data available for those with diffuse malignant peritoneal mesothelioma (DMPM). DMPM represents a clinically distinct entity from DPM and disease specific outcomes data is needed. We present real world data on the efficacy of pembrolizumab in DMPM. Methods: In this retrospective study, we identified patients with DMPM treated with pembrolizumab at two tertiary care cancer centers between 1/1/2009 and 1/1/2021. Clinicopathologic features were annotated. Median progression free survival (mPFS) and median overall survival (mOS) were calculated using Kaplan-Meier curves. Best overall response rate (BOR) was determined using RECIST 1.1 criteria. Association of partial response with disease characteristics was evaluated using Fisher’s exact test. Results: We identified 24 patients with DMPM who received pembrolizumab (median age 62 years, 63% never smokers, 58% female, 75% had epithelioid histology). All patients received systemic chemotherapy prior to pembrolizumab (median prior lines of therapy: 3). BOR was 17% (3 partial responses, 10 stable disease, 5 progressive disease, 6 lost to follow-up). With a median follow up time of 29.2 months, mPFS was 4.9 months and mOS 20.9 months from pembrolizumab initiation. Three patients experienced PFS of &gt; 2 years. Among the 14 patients who underwent next generation sequencing of tumor tissue, there were 8 somatic BAP1 alterations. Among the 17 patients tested for PDL1, 6 had positive PDL1 expression (1-80%). There was no association between partial response and presence of a BAP1 somatic alteration (p = 0.453), PDL1 positivity (p = 0.7) or non-epithelioid histology (p = 0.55). Conclusions: Pembrolizumab is active in a PDL1 unselected cohort of patients with DMPM. The overall response rate of 17% and mPFS of 4.9 months in this 75% epithelioid histology cohort warrants further investigation to identify those most likely to respond to immunotherapy, especially among epithelioid histology.

5-hmC loss is another useful tool in addition to BAP1 and MTAP immunostains to distinguish diffuse malignant peritoneal mesothelioma from reactive mesothelial hyperplasia in peritoneal cytology cell-blocks and biopsies.

The differentiation between reactive mesothelial hyperplasia (RMH) and diffuse malignant peritoneal mesothelioma (DMPM) is challenging especially when applied on peritoneal small samples. The use of BRCA-associated protein 1 (BAP1) and methylthioadenosine phosphorylase (MTAP) immunostains is familiar to identify malignant mesothelial proliferation. Recently, nuclear 5-hydroxymethylcytosine (5-hmC) was reported to be a new recognition tool of pleural mesothelial malignancy on surgical specimens. However, application of 5-hmC immunostaining has not yet studied in peritoneal specimens from small biopsies or cytology cell-blocks. The aim was to assess the diagnostic accuracy of this new marker combination to distinguish DMPM from RMH in biopsies and cell-blocks. Seventy-five cases were analyzed; among which, 38 were of cytological specimens including 6 RMH and 32 DMPM, and 37 tissue biopsies with 7 RMH and 30 DMPM. BAP1, MTAP, and 5-hmC immunostains were performed on all cases. RMH cases exhibited a retained staining with all immunostains. Among DMPM, BAP1 was lost in 71.8% of cytology cell-blocks and 66.7% of biopsies. MTAP was lost in 40.6% of cytology cell-blocks and 33.3% of biopsies. 5-hmC was lost in 40.6% of cytology cell-blocks and 30% of biopsies. The combination of BAP1, MTAP, and 5-hmC showed the best accuracy in differential diagnosis between RMH and DMPM (sensitivity = 0.84, specificity = 1 in cytology cell-blocks; sensitivity = 0.90, specificity = 1 in biopsy). The best diagnostic combination in peritoneal cytology effusion fluids and biopsies samples provided by BAP1, MTAP, and 5-hmC should be applied on a diagnostic step-wise algorithm by pathologists involved into the management of DMPM, because of their therapeutic implications.