Risk factors and prognosis of malignant peritoneal mesothelioma with paraneoplastic syndrome.

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is a rare and highly aggressive tumor. Its clinical manifestations are diverse, and the symptoms are not specific. Some patients will develop paraneoplastic syndrome (PS) during the disease course. This study aims to analyze the risk factors of PS in patients with MPM and their impacts on prognosis. METHODS: The clinical data of MPM patients who underwent cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) at our center from June 2015 to May 2023 were retrospectively analyzed. MPM patients were divided into PS group and non-PS group according to the diagnostic criteria. Univariate and multivariate analyses were performed to explore the risk factors of PS in MPM patients, and to analyze the impact of PS on prognosis. RESULTS: There were 146 MPM patients in this study, including 60 patients (41.1%) with PS and 86 patients (58.9%) without PS. The highest incidence of PS was thrombocytosis (33.6%), followed by neoplastic fever (9.6%). Univariate analysis revealed 8 factors (P < 0.05) with statistically significant differences between the two groups: prior surgical scores, targeted therapy history, Karnofsky performance status score, preoperative carbohydrate antigen (CA) 125 level, vascular tumor embolus, peritoneal cancer index, completeness of cytoreduction (CC) score and intraoperative ascites. Multivariate analysis identified 3 independent factors associated with PS: preoperative CA 125 level, vascular tumor embolus, and CC score. Survival analysis demonstrated that MPM patients with PS had worse prognosis, although PS was not an independent prognostic factor. CONCLUSIONS: PS is not rare in patients with MPM, and is independently associated with preoperative CA 125 level, vascular tumor embolus and CC score. PS often indicates advanced disease and poor prognosis.

Whole-Exome Sequencing Identifies Mutation Profile and Mutation Signature-Based Clustering Associated with Prognosis in Appendiceal Pseudomyxoma Peritonei.

Pseudomyxoma peritonei (PMP) is a rare malignant clinical syndrome with little known about the global mutation profile. In this study, whole-exome sequencing (WES) was performed in 49 appendiceal PMP to investigate mutation profiles and mutation signatures. A total of 4,020 somatic mutations were detected, with a median mutation number of 56 (1-402). Tumor mutation burden (TMB) was generally low (median 1.55 mutations/Mb, 0.12-11.26 mutations/Mb). Mutations were mainly enriched in the function of cancer-related axonogenesis, extracellular matrix-related processes, calcium signaling pathway, and cAMP signaling pathway. Mutations in FCGBP, RBFOX1, SPEG, RTK-RAS, PI3K-AKT, and focal adhesion pathways were associated with high-grade mucinous carcinoma peritonei. These findings revealed distinct mutation profile in appendiceal PMP. Ten mutation signatures were identified, dividing patients into mutation signature cluster (MSC) 1 (N = 28, 57.1%) and MSC 2 (N = 21, 42.9%) groups. MSC (P = 0.007) was one of the four independent factors associated with 3-year survival. TMB (P = 0.003) and microsatellite instability (P = 0.002) were independent factors associated with MSC 2 grouping. Taken together, our findings provided a broader view in the understanding of molecular pathologic mechanism in appendiceal PMP and may be critical to developing an individualized approach to appendiceal PMP treatment. IMPLICATIONS: This work describes exhaustive mutation profile of PMP based on WES data and derives ten mutation signatures, which divides patients into two clusters and serve as an independent prognostic factor associated with 3-year survival.

Long-term survival in patients with PMP: a single-institutional retrospective study from China.

BACKGROUND: As the standard treatment for pseudomyxoma peritonei (PMP), cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) can significantly prolong the survival of PMP patients, and some patients can even achieve long-term survival (LTS) or clinical cure. The purpose of this study was to analyze the clinicopathological and treatment features of PMP patients with LTS and to explore the survival benefit factors of PMP patients. METHODS: The clinicopathological and prognostic data of PMP patients who received CRS + HIPEC at our center from December 2004 to May 2023 were retrospectively analyzed. PMP patients were divided into LTS group (≥ 10 years) and short-term survival (STS) group (< 5 years) according to the length of natural history. Univariate and multivariate analyses were performed to explore the beneficial factors of PMP patients with LTS. RESULTS: A total of 609 patients with PMP received CRS + HIPEC treatment at our center. Two-hundred one patients with PMP were included in the study after screening, including 39 patients (19.4%) in the LTS group and 162 patients (80.6%) in the STS group. In STS group and LTS group, median overall survival based on natural history was 29.2 (2.4-59.9) vs. 138.9 (120.3-416.7) months. Univariate analysis revealed 8 factors (P < 0.05) with statistically significant differences between the two groups: gender, chemotherapy history, previous surgical score, Karnofsky Performance Status score, pathological diagnosis, lymphatic metastasis, peritoneal cancer index, and completeness of cytoreduction (CC). Multivariate analysis identified only two factors independently associated with LTS of PMP patients: CC and pathological diagnosis. CONCLUSION: Complete CRS and pathological features are two key factors affecting LTS in PMP patients.

Etiological analysis of infection after CRS + HIPEC in patients with PMP.

BACKGROUND: Cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) is the standard treatment for pseudomyxoma peritonei (PMP). It can significantly prolong the survival of patients, but at the same time may increase the risk of postoperative infection. METHOD: Patients with PMP who underwent CRS + HIPEC at our center were retrospectively analyzed. According to PMP patients, basic clinical data and relevant information of postoperative infection, we analyzed the common sites of postoperative infection, results of microbial culture and the antibiotics sensitivity. Univariate and multivariate analysis were performed to explore infection-related risk factors. RESULT: Among the 482 patients with PMP, 82 (17.0%) patients were infected after CRS + HIPEC. The most common postoperative infection was central venous catheter (CVC) infection (8.1%), followed by abdominal-pelvic infection (5.2%). There were 29 kinds of microbes isolated from the culture (the most common was Staphylococcus epidermidis), including 13 kinds of Gram-positive bacteria, 12 kinds of Gram-negative bacteria, and 4 kinds of funguses. All the antibiotics sensitivity results showed that the most sensitive antibiotics were vancomycin to Gram-positive bacteria (98.4%), levofloxacin to Gram-negative bacteria (68.5%), and fluconazole to fungus (83.3%). Univariate and multivariate analysis revealed the infection independent risk factors as follow: intraoperative blood loss ≥ 350 mL (P = 0.019), ascites volume ≥ 300 mL (P = 0.008). CONCLUSION: PMP patients may have increased infection risk after CRS + HIPEC, especially CVC, abdominal-pelvic and pulmonary infections. The microbial spectrum and antibiotics sensitivity results could help clinicians to take prompt prophylactic and therapeutic approaches against postoperative infection for PMP patients.

Establishment of a Bayesian network model to predict the survival of malignant peritoneal mesothelioma patients after cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy.

OBJECTIVES: To establish a Bayesian network (BN) model to predict the survival of patients with malignant peritoneal mesothelioma (MPM) treated with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: The clinicopathological data of 154 MPM patients treated with CRS + HIPEC at our hospital from April 2015 to November 2022 were retrospectively analyzed. They were randomly divided into two groups in a 7:3 ratio. Survival analysis was conducted on the training set and a BN model was established. The accuracy of the model was validated using a confusion matrix of the testing set. The receiver operating characteristic (ROC) curve and area under the curve were used to evaluate the overall performance of the BN model. RESULTS: Survival analysis of 107 patients (69.5%) in the training set found ten factors affecting patient prognosis: age, Karnofsky performance score, surgical history, ascites volume, peritoneal cancer index, organ resections, red blood cell transfusion, pathological types, lymphatic metastasis, and Ki-67 index (all p < 0.05). The BN model was successfully established after the above factors were included, and the BN model structure was adjusted according to previous research and clinical experience. The results of confusion matrix obtained by internal validation of 47 cases in the testing set showed that the accuracy of BN model was 72.7%, and the area under ROC was 0.74. CONCLUSIONS: The BN model was established successfully with good overall performance and can be used as a clinical decision reference.

Effect of standardized fluid management on cardiac function after CRS + HIPEC in patients with PMP: a single-center case-control study.

OBJECTIVE: To investigate the effects of standardized fluid management (SFM) on cardiac function in patients with pseudomyxoma peritonei (PMP) after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). METHOD: Patients with PMP who underwent CRS + HIPEC at our center were retrospectively analyzed. The patients were divided into control and study groups according to whether SFM was applied after CRS + HIPEC. We compared the preoperative and postoperative cardiac and renal function parameters, daily fluid volume three days after CRS, and cardiovascular-related adverse events. Univariate and multivariate analyses were performed to identify the indicators affecting clinical prognosis. RESULT: Among the 104 patients, 42 (40.4%) were in the control group and 62 (59.6%) in the study group. There were no statistically significant differences between the two groups in the main clinicopathological characteristics, preoperative cardiac and renal function parameters, and CRS + HIPEC-related indicators. The incidences of cardiac troponin I (CTNI) > upper limit of normal (ULN), >2 × ULN, >3 × ULN, serum creatinine > ULN, and blood urea nitrogen > ULN were higher in the control group than in the study group (p < 0.05). The median daily fluid volume of the control group was higher than that of the study group 3 days after CRS (p < 0.05). Postoperative CTNI > 2 × ULN was an independent risk factor for serious circulatory adverse events. Survival analysis revealed pathological grading, completeness of cytoreduction score, and postoperative CTNI > ULN as independent prognostic factors. CONCLUSIONS: SFM after CRS + HIPEC in patients with PMP may reduce cardiovascular adverse events risk and improve clinical outcomes.

Loss of NPM2 expression is a potential immunohistochemical marker for malignant peritoneal mesothelioma: a single-center study of 92 cases.

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is a rare malignant tumor with a high mortality rate and extremely poor prognosis. In-depth pathological analysis is essential to assess tumor biological behaviors and explore potential therapeutic targets of MPM. Nucleoplasmin 2 (NPM2) is a molecular chaperone that binds histones and may play a key role in the development and progression of tumors. This study aimed to analyze the correlation between the expression level of NPM2 and the main clinicopathological characteristics and prognosis of MPM. METHODS: Ninety-two postoperative specimens from MPM patients following cytoreductive surgery were collected. Postoperative specimens were stained with immunohistochemistry. The expression level of NPM2 was quantitatively analyzed by QuPath-0.3.2 software. Univariate and multivariate analyses were conducted to investigate the correlation between NPM2 expression and other conventional clinicopathological characteristics. RESULTS: Among the 92 MPM patients, there were 47 males (48.9%) and 45 females (51.1%), with a median age of 56 (range: 24-73). There were 70 (76.0%) cases with loss of NPM2 protein expression, 11 (12.0%) cases with low expression, and 11 (12.0%) cases with high expression. Univariate analysis showed that NPM2 protein expression level (negative vs. low expression vs. high expression) was negatively correlated with the following three clinicopathological factors: completeness of cytoreduction (CC) score, vascular tumor emboli, and serious adverse events (SAEs) (all P < 0.05). Multivariate analysis showed that NPM2 protein expression level (negative vs. low expression vs. high expression) was independently negatively correlated with the following two clinicopathological factors: CC score [odds ratio (OR) = 0.317, 95% CI: 0.317-0.959, P = 0.042] and vascular tumor emboli (OR = 0.092, 95% CI = 0.011-0.770, P = 0.028). Survival analysis showed that loss of NPM2 protein expression (negative vs. positive) was associated with poor prognosis of MPM. CONCLUSIONS: Loss of NPM2 expression is a potential immunohistochemical marker for MPM.

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

Objective: To 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. Methods: 27 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. Results: The 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%. Conclusions: Apatinib is effective in treating refractory DMPM, with promising efficacy and acceptable safety.

NPM2 in malignant peritoneal mesothelioma: from basic tumor biology to clinical medicine.

BACKGROUND: This review systematically summarizes gene biology features and protein structure of nucleoplasmin2 (NPM2) and the relationship between NPM2 and malignant peritoneal mesothelioma (MPM), in order to explore the molecular pathological mechanism of MPM and explore new therapeutic targets. METHODS: NCBI PubMed database was used for the literature search. NCBI Gene and Protein databases, Ensembl Genome Browser, UniProt, and RCSB PDB database were used for gene and protein review. Three online tools (Consurf, DoGSiteScorer, and ZdockServer), the GEPIA database, and the Cancer Genome Atlas were used to analyze bioinformatics characteristics for NPM2 protein. RESULTS: The main structural domains of NPM2 protein include the N-terminal core region, acidic region, and motif and disordered region. The N-terminal core region, involved in histone binding, is the most conserved domain in the nucleoplasmin (NPM) family. NPM2 with a large acidic tract in its C-terminal tail (NPM2-A2) is able to bind histones and form large complexes. Bioinformatics results indicated that NPM2 expression was correlated with the pathology of multiple tumors. Among mesothelioma patients, 5-year survival of patients with low-NPM2-expression was significantly higher than that of the high-NPM2-expression patients. NPM2 can facilitate the formation of histone deacetylation. NPM2 may promote histone deacetylation and inhibit the related-gene transcription, thus leading to abnormal proliferation, invasion, and metastasis of MPM. CONCLUSION: NPM2 may play a key role in the development and progression of MPM.