Pseudomyxoma Peritonei Patients Research Articles

Radiomics analysis based on CT\u2019s greater omental caking for predicting pathological grading of pseudomyxoma peritonei

The objective of this study was to predict the preoperative pathological grading and survival period of Pseudomyxoma peritonei (PMP) by establishing models, including a radiomics model with greater omental caking as the imaging observation index, a clinical model including clinical indexes, and a combined model of these two. A total of 88 PMP patients were selected. Clinical data of patients, including age, sex, preoperative serum tumor markers [CEA, CA125, and CA199], survival time, and preoperative computed tomography (CT) images were analyzed. Three models (clinical model, radiomics model and combined model) were used to predict PMP pathological grading. The models’ diagnostic efficiency was compared and analyzed by building the receiver operating characteristic (ROC) curve. Simultaneously, the impact of PMP’s different pathological grades was evaluated. The results showed that the radiomics model based on the CT’s greater omental caking, an area under the ROC curve ([AUC] = 0.878), and the combined model (AUC = 0.899) had diagnostic power for determining PMP pathological grading. The imaging radiomics model based on CT greater omental caking can be used to predict PMP pathological grading, which is important in the treatment selection method and prognosis assessment.

Tumor-stroma ratio as a new prognosticator for pseudomyxoma peritonei: a comprehensive clinicopathological and immunohistochemical study

BackgroundAs a rare clinical tumor syndrome with an indolent clinical course and lack of pathognomonic symptoms, pseudomyxoma peritonei (PMP) is usually diagnosed at an advanced stage. In-depth pathological analysis is essential to assess tumor biological behaviors, assist treatment decision, and predict the clinical prognosis of PMP. The tumor-stroma ratio (TSR) is a promising prognostic parameter based on the tumor and stroma. This study explored the relationship between TSR and the pathological characteristics and prognosis of PMP.MethodsPMP patients with complete data who underwent cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy were enrolled. The TSR of postoperative pathological images was quantitatively analyzed by Image-Pro Plus. Then the relationship between TSR and the clinicopathological characteristics, immunohistochemical characteristics and prognosis of PMP was analyzed.ResultsAmong the 50 PMP patients included, there were 27 males (54.0%) and 23 females (46.0%), with a median age of 55 (range: 31–76) years. 25 (50.0%) patients were diagnosed with low-grade PMP (LG-PMP), and 25 (50.0%) were diagnosed with high-grade PMP (HG-PMP). There were 4 (8.0%) patients with vascular tumor emboli, 3 (6.0%) patients with nerve invasion, and 5 (10.0%) patients with lymph node metastasis. The immunohistochemical results showed that the Ki67 label index was < 25% in 18 cases (36.0%), 25 - 50% in 18 cases (36.0%) and > 50% in 14 cases (28.0%). The range of TSR was 2 - 24% (median: 8%). The cutoff value of TSR was 10% based on the receiver operating characteristic (ROC) curve and X-Tile analysis. There were 31 (62.0%) cases with TSR < 10% and 19 (38.0%) cases with TSR ≥ 10%. The TSR was closely related to histopathological type (P < 0.001) and Ki67 label index (P < 0.001). Univariate analysis showed that preoperative carcinoembryonic antigen (CEA), preoperative carbohydrate antigen 19–9, pathological type, vascular tumor emboli and TSR influenced the prognosis of PMP patients (P < 0.05). Multivariate analysis showed that preoperative CEA, vascular tumor emboli and the TSR were independent prognostic factors.ConclusionsThe TSR could be a new independent prognosticator for PMP.

Nomogram to predict overall survival of patients with pseudomyxoma peritonei of appendiceal origin: A retrospective cohort study.

Pseudomyxoma peritonei (PMP) is a rare disease, with the rate of overall survival (OS) influenced by many factors. The present study aimed to define independent predictors and establish a nomogram for individual risk prediction in PMP patients. One hundred forty-seven PMP patients were consecutively included between June 1, 2013, and November 22, 2019. The log-rank test was used to compare the OS rate between groups; subsequently, variables with p < .10 were subjected to multivariate Cox modeling for defining independent prediction indicators. Finally, a nomogram was established based on independent prognosticators and assessed for internal validation. Multivariate Cox analysis showed that D-dimer level, carbohydrate antigen (CA) 125 level, CA 19-9 level, degree of radical surgery, and histological grade were all independently associated with OS in PMP patients. A nomogram was plotted and underwent internal validation. The discrimination ability of the nomogram revealed a good predictive ability as indicated by the C-index value (0.825), and calibration plots confirmed good consistency between the predicted and observed survival probabilities. Five independent prognostic factors for predicting the survival of PMP patients were identified, and the nomogram based on these independent indicators showed a reasonable discrimination ability for individual risk prediction.

Ultrasound for Preoperatively Predicting Pathology Grade, Complete Cytoreduction Possibility, and Survival Outcomes of Pseudomyxoma Peritonei.

ObjectivesThis study aimed to investigate the value of using ultrasound (US) preoperatively for predicting pathological classification, complete cytoreduction possibility, and survival rate of patients with pseudomyxoma peritonei (PMP).MethodsWe retrospectively studied PMP patients who were scheduled for cytoreductive surgery between May 2009 and October 2019. US examination was performed before surgery. Factors related to high-grade pathology and poor completeness of cytoreduction (CC) score were identified. Associations between ultrasound characteristics and the survival status were also examined to identify independent predictive factors.ResultsPMP patients with clear ascites, abdominal lymph nodes, omental cake, abdominal mass, portal infiltration, and mesenteric involvement visible on US were considered to have high-grade pathology. Various US features were shown to be independent prognostic markers for inadequate cytoreduction in PMP patients. Portal infiltration and mesenteric involvement were significant prognostic factors for lower survival rates (hazard ratio = 3.092, 3.932, respectively). A visual nomogram including these factors was constructed to predict survival rates. The consistency index was 0.777, which reflected relatively high accuracy.ConclusionsPreoperative US has the potential to predict pathological grade and resectability of PMP. Portal infiltration and mesenteric involvement were independent predictors of poor clinical outcomes in PMP patients. Furthermore, a simple-to-use nomogram derived from our study data may be a helpful visual tool in clinical practice to predict 1-, 2-, and 3-year survival rates for PMP patients.

Nomogram to Predict Incomplete Cytoreduction for Pseudomyxoma Peritonei.

The completeness of cytoreduction is one of the most important prognostic factors for patients with pseudomyxoma peritonei (PMP). To date, no nomograms have been established to predict incomplete cytoreduction (IC) for patients with PMP. The current study therefore proposed a nomogram to predict individual IC risk for PMP patients. Between 1 June 2013, and 22 November 2019, 144 consecutive PMP patients who underwent cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) for the first time in our center were included in a retrospective study. Possible predictors of cytoreducibility were analyzed using logistic regression modeling to predict IC for PMP patients. A nomogram was developed based on the multivariate analysis and further investigated for internal validation. After CRS, the 144 participants were divided into complete CRS (CCRS) (n = 46) and IC (n = 98) subgroups. Four independent predictors (sex, disease duration, anemia, and carbohydrate antigen 19-9 (CA 199)) were included in the prediction model. Then, a nomogram predicting IC was established based on the aforementioned variables, which demonstrated good predictive accuracy (C-index, 0.837; 95 % confidence interval [CI], 0.764-0.894). The predicted probability was close to the actual observed outcome according to the calibration plot. The current work led to the development of a nomogram capable of predicting IC for PMP patients who demonstrated good performance. Risk stratification by the established nomogram had ability to optimize individual IC prediction and help physicians to establish meticulous preoperative plans.

Enhanced recovery after surgery promotes the postoperative recovery of lung and gastrointestinal function of pseudomyxoma peritonei.

Pseudomyxoma peritonei (PMP) is a rare low-grade malignant tumor, which is difficult to operate with many postoperative complications. In recent years, enhanced recovery after surgery (ERAS) has been greatly developed in the perioperative management of surgical diseases, and it plays an important role in improving the postoperative prognosis of surgical patients. This study was conducted to explore the application of ERAS in the perioperative management of PMP patients, and to study the effect of ERAS on postoperative respiratory and digestive tract complications. We retrospectively analyzed clinical data of patients with PMP from January 2014 to December 2018. These patients were treated with surgery in our center and they were divided into an observation group and a control group. The patients in the control group didn't perform ERAS in perioperative period, and patients in the observation group was performed ERAS. Then, we analyzed and compared the postoperative pulmonary complications (PPC) and gastrointestinal function between the 2 groups. There was no significant difference in the incidence of atelectasis, pleural effusion, pulmonary infection and acute respiratory distress syndrome (ARDS) between the two groups, but the total incidence of PPC in the observation group was significantly lower than that in the control group (P=0.032). The incidence of postoperative gastrointestinal dysfunction (PGID) in the observation group was significantly lower than that in the control group (P=0.025), and the postoperative first exhaust time, first defecation time, oral feeding time, and albumin level in the observation group were all better than those in the control group (all P<0.05). ERAS can significantly reduce the incidence of postoperative PPC and PGID in the PMP patients and improve their postoperative recovery.

Managing Recurrent Pseudomyxoma Peritonei in 430 Patients After Complete Cytoreduction and HIPEC: A Dilemma for Patients and Surgeons.

Epithelial appendiceal neoplasms are uncommon peritoneal malignancies causing a spectrum of disease including pseudomyxoma peritonei (PMP). The optimal management is cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Despite complete CRS (CCRS), recurrence develops in almost 45% of patients. No consensus exists for the optimal treatment of recurrent disease, with treatment strategies including repeat CRS, watch-and-wait, and palliative chemotherapy. This report aims to describe evolving management strategies for a large cohort with recurrence after CCRS. This retrospective study analyzed a prospective database of patients with recurrence after CCRS for appendiceal neoplasms from 1994 to 2017 who had long-term follow-up evaluation with tumor markers and computed tomography (CT). Overall, 430 (37.6%) of 1145 PMP patients experienced recurrence at a median of 19 months. Of these 430 patients 145 (33.7%) underwent repeat CRS, 119 (27.7%) had a watch-and-wait approach, and 119 (27.7%) had palliative chemotherapy. The patients with recurrence had a median overall survival (OS) of 39 months, a 3-year survival of 74.6%, a 5-year survival of 57.4%, and a 10-year survival of 36.5%. In the multivariate analysis, the patients who had recurrence within 1 year after primary CRS (hazard ratio [HR], 3.55), symptoms at recurrence (HR, 3.08), a high grade of disease or adenocarcinoma pathology (HR, 2.94), signet ring cells (HR, 1.91), extraperitoneal metastatic disease (HR, 1.71), or male gender (HR, 1.61) had worse OS. The OS was longer for the patients who had repeat CRS (HR, 0.41). The patients who underwent repeat CCRS had a 3-year OS of 87.5%, a 5-year OS of 78.1%, and a 10-year OS of 67.9%. Dilemmas persist around the optimal management of patients with recurrence after CRS and HIPEC for appendiceal tumors. Selected patients benefit from repeat CRS, particularly those with favorable tumor biology and focal disease.

Two-step cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei with high peritoneal carcinomatosis index

BackgroundComplete cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is the only curative treatment for pseudomyxoma peritonei (PMP) arising from the appendix. High peritoneal carcinomatosis index (PCI) is associated with an increased risk of surgical complications. The objective of this study was to present the results of a planned two-step surgical strategy to decrease postoperative morbidity and improve resectability of patients with very high PCI.MethodsAll consecutive patients who underwent a planned two-step surgical approach for PMP between January 2012 and March 2020 were retrospectively included. This approach was offered for patients with low-grade PMP with PCI > 28 for which feasibility of a complete CRS in one operation was uncertain. The first surgery included a complete CRS of the inframesocolic compartment and omentectomy. HIPEC was delivered at the second surgery, after complete CRS of the supramesocolic compartment. Postoperative morbidity was assessed using the Clavien-Dindo classification and survival results were also collected.ResultsEight patients underwent the two-step approach. The median PCI was 33 (29–39) and the median time between the two procedures was 111 days (90–212 days). One patient was deemed unresectable at the second surgery. The rate of major morbidity was 0% for the first step and 25% for the second step, with no mortality. Median follow-up was 53.8 months (3–73 months).ConclusionA two-step surgical management for low-grade PMP patients with very high PCI is safe and feasible, with acceptable postoperative morbidity and no compromise on oncological outcomes.

Evaluation of the significance of pseudomyxoma peritonei patients based on the Peritoneal Surface Oncology Group International (PSOGI) classification

Pseudomyxoma peritonei (PMP) is a rare disease characterized by mucinous ascites and deposits on the peritoneal surfaces. The study aimed to assess PMP patients according to the Peritoneal Surface Oncology Group International (PSOGI) classification, as a part of standardization of this rare disease. This retrospective study analyzed PMP patients who underwent surgery between January 2007 and December 2017. All histologic slides were re-evaluated and the clinical data were collected. According to the PSOGI, PMP was retrospectively classified into three categories: low-grade (LG-PMP), high-grade (HG-PMP), and signet-ring cells (SRC-PMP). The extent of peritoneal involvement was quantified by the peritoneal cancer index (PCI). The completeness of cytoreduction (CCR) was dichotomized as complete or incomplete. Fifty-seven patients were included in this study, consisted of 39 patients with LG-PMP (74.0%), 14 with HG-PMP (20.8%), and 4 with SRC-PMP (5.2%). There was no operative mortality and major complications occurred in 24 patients (31.2%). The 5-year overall survival was 56.2%±8.1% for LG-PMP, 37.5%±12.1% for HG-PMP, and 25.0%±21.7% for SRC-PMP. Concerning CCR, the 5-year overall (complete: 59.5%±8.4% vs. incomplete: 12.7%±8.1%, p=0.001) and disease-free survival (complete: 38.6%±8.9% vs. incomplete: 7.7%±6.8%, p=0.001) were significantly different. In a multivariable analysis, PSOGI classification and CCR independently correlated with survival (p=0.011 and 0.018, respectively). The PSOGI classification provides prognostic stratification, hopefully requiring further validation including every single case of PMP established as a standard criteria.

Role of Epithelial-Mesenchymal Plasticity in Pseudomyxoma Peritonei: Implications for Locoregional Treatments.

The mechanisms by which neoplastic cells disseminate from the primary tumor to metastatic sites, so-called metastatic organotropism, remain poorly understood. Epithelial–mesenchymal transition (EMT) plays a role in cancer development and progression by converting static epithelial cells into the migratory and microenvironment-interacting mesenchymal cells, and by the modulation of chemoresistance and stemness of tumor cells. Several findings highlight that pathways involved in EMT and its reverse process (mesenchymal–epithelial transition, MET), now collectively called epithelial–mesenchymal plasticity (EMP), play a role in peritoneal metastases. So far, the relevance of factors linked to EMP in a unique peritoneal malignancy such as pseudomyxoma peritonei (PMP) has not been fully elucidated. In this review, we focus on the role of epithelial–mesenchymal dynamics in the metastatic process involving mucinous neoplastic dissemination in the peritoneum. In particular, we discuss the role of expression profiles and phenotypic transitions found in PMP in light of the recent concept of EMP. A better understanding of EMP-associated mechanisms driving peritoneal metastasis will help to provide a more targeted approach for PMP patients selected for locoregional interventions involving cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

Neoadjuvant Intraperitoneal Chemotherapy in Patients with Pseudomyxoma Peritonei-A Novel Treatment Approach.

Neoadjuvant intravenous chemotherapy in patients with pseudomyxoma peritonei (PMP) has not shown convincing results. The effectiveness of neoadjuvant intraperitoneal (IP) chemotherapy has never been reported. This prospective, non-randomized phase II study included patients with PMP treated between May 2017 and December 2018, who were not considered suitable for primary cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The majority of patients were treated with laparoscopic HIPEC (oxaliplatin 200 mg/m2, 60 min, 43 °C). IP chemotherapy was started 2 weeks after docetaxel 40 mg/m2 + cisplatin 40 mg/m2, accompanied by oral S1 (tegafur, gimeracil, and oteracil) (50 mg/m2) for 14 days, followed by one week rest. Clinical parameters and complications were recorded. In total, 22/27 patients qualified for CRS and HIPEC after neoadjuvant treatment. A complete cytoreduction (Completeness of cytoreduction Score 0/1) could be achieved in 54.5%. The postoperative morbidity rate was 13.6% and mortality was rate 4.5%. In total, 20/22 patients had major pathological tumor responses. The mean drop in CEA was 28.2% and in the peritoneal carcinomatosis index (PCI) was 2.6. Positive or suspicious cytology turned negative in 69.2% of patients. Thus, for PMP patients who were not amenable for primary surgery, the majority received complete cytoreduction after treatment with neoadjuvant IP chemotherapy, with satisfying tumor regression and with low complication rates. The oncological benefit in terms of survival with this new treatment regimen needs to be proven.

Clinicopathological Characteristics of Pseudomyxoma Peritonei Originated from Ovaries.

ObjectiveThis study aims to demonstrate clinicopathological characteristics and immunohistopathological phenotypes of pseudomyxoma peritonei (PMP) originated from ovaries.MethodsThe primary origin of PMP was explored by reviewing H&E sections retrospectively and performing a series of immunohistochemical staining on CK7, CK20, CDX2, CEA, Villin, SATB2, CA125, ER, PR, and MUC.ResultsAmong 310 PMP patients, a few originated from extra-appendix, whereas eight cases were of ovarian origin (2.6%), including three teratoma-associated ovarian mucinous tumors and five primary ovarian mucinous tumors with spontaneous or iatrogenic rupture, respectively. Most peritoneal metastases were acellular mucin or low-grade mucinous carcinoma peritonei (6/8, 75%), while the rest were high-grade mucinous carcinoma peritonei (2/8, 25%). Tumors were positive for CK20, CDX2, CEA, and Villin. SATB2 was specifically diffuse positive in teratoma-associated ovarian mucinous tumors, and negative in primary ovarian mucinous tumors. Differential expression of MUC was observed in these tumors.ConclusionPMP of ovarian origin is extremely rare. The precise diagnosis requires serial sections of the appendix or suspicious tissue to exclude appendiceal mucinous neoplasms, as well as comprehensive analysis of clinical features, surgical findings, histopathological characteristics, and immunohistochemistry on specific biomarkers.

Development and validation of prognostic nomograms for pseudomyxoma peritonei patients after surgery: A population-based study.

Background:The aim of study was to develop and validate nomograms for predicting overall survival (OS) and cancer-specific survival (CSS) of patients with pseudomyxoma peritonei (PMP) and compare the predictive accuracy with the American Joint Committee on Cancer (AJCC) staging system.Methods:Data of 4959 PMP patients who underwent surgical resection were collected between 2004 and 2015 from the Surveillance Epidemiology and End Results (SEER) database. All included patients were divided into training (n = 3307) and validation (n = 1652) cohorts. The Kaplan–Meier method and Cox proportional hazard model were applied. Nomograms were validated by discrimination and calibration. Finally, concordance index (C-index) was used to compare the predictive performance of nomograms with that of the AJCC staging system.Results:According to the univariate and multivariate analyses of training sets, both nomograms for predicting OS and CSS combining age, grade, location, N stage, M stage, and chemotherapy were identified. Nomograms predicting OS also incorporated T stage and the number of lymph nodes removed (LNR). The calibration curves showed good consistency between predicted and actual observed survival. Moreover, C-index values demonstrated that the nomograms predicting both OS and CSS were superior to the AJCC staging system in both cohorts.Conclusion:We successfully developed and validated prognostic nomograms for predicting OS and CSS in PMP patients. Two nomograms were more accurate and applicable than the AJCC staging system for predicting patient survival, which may help clinicians stratify patients into different risk groups, tailor individualized treatment, and accurately predict patient survival in PMP.

Improved Outcome Prediction for Appendiceal Pseudomyxoma Peritonei by Integration of Cancer Cell and Stromal Transcriptional Profiles.

In recent years, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have substantially improved the clinical outcome of pseudomyxoma peritonei (PMP) originating from mucinous appendiceal cancer. However, current histopathological grading of appendiceal PMP frequently fails in predicting disease outcome. We recently observed that the integration of cancer cell transcriptional traits with those of cancer-associated fibroblasts (CAFs) improves prognostic prediction for tumors of the large intestine. We therefore generated global expression profiles on a consecutive series of 24 PMP patients treated with CRS plus HIPEC. Multiple lesions were profiled for nine patients. We then used expression data to stratify the samples by a previously published “high-risk appendiceal cancer” (HRAC) signature and by a CAF signature that we previously developed for colorectal cancer, or by a combination of both. The prognostic value of the HRAC signature was confirmed in our cohort and further improved by integration of the CAF signature. Classification of cases profiled for multiple lesions revealed the existence of outlier samples and highlighted the need of profiling multiple PMP lesions to select representative samples for optimal performances. The integrated predictor was subsequently validated in an independent PMP cohort. These results provide new insights into PMP biology, revealing a previously unrecognized prognostic role of the stromal component and supporting integration of standard pathological grade with the HRAC and CAF transcriptional signatures to better predict disease outcome.

The perioperative safety of cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei

Objective: This study was to investigate the perioperative safety of cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) for pseudomyxoma peritonei (PMP), and analyze the risk factors of serious adverse events (SAEs). Methods: The occurrences of perioperative SAEs were retrospectively analyzed in 254 PMP patients treated with CRS plus HIPEC. Univariate and multivariate analysis were performed to identify independent risk factors. Results: Among the 272 CRS plus HIPEC procedures for 254 PMP patients, a total of 93 (34.2%) perioperative SAEs occurred, including 26 in infection, 22 in digestive system, 17 in respiratory system, 15 in cardiovascular system, 8 in hematological system, and 4 in urinary system. In terms of severity, the vast majority was grade Ⅲ with 76 cases, followed by grade Ⅳ with 13 cases and grade Ⅴ with 4 cases. Univariate analysis revealed 3 risk factors of perioperative SAEs: HIPEC regimen (P=0.020), intraoperative red blood cell transfusion volume (P=0.004), and intraoperative blood loss volume (P=0.002). Multivariate analysis by logistic regression model analysis revealed that intraoperative red blood cell transfusion volume was an independent risk factor for perioperative SAEs (OR=1.160, P=0.001). Conclusion: In conclusion, the perioperative safety of CRS plus HIPEC was acceptable. Moreover, intraoperative blood loss volume and red blood cell transfusion volume are expected to be reduced in order to prevent SAEs for PMP patients.

Clinical evaluation of tumor-stroma ratio in pseudomyxoma peritonei from the appendix

To evaluate the effect of tumor-stroma ratio (TSR) on disease progression and prognosis of pseudomyxoma peritonei (PMP) from the appendix. The study included 30 PMP patients with complete individual patient data, who underwent cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) in Beijing Shijitan Hospital. Image-Pro Plus was used to quantitatively analyze the proportion of tumor and stromal areas in hematoxylin-eosin staining pathological images, from which TSR was derived. Correlation studies were conducted to evaluate the relationships between TSR and clinicopathological features, immunohistochemical characteristics, and prognosis of PMP. Among 30 PMP patients, there were 16 males (53.3%) and 14 females (46.7%), with the mean age of (54.9±2.3) years. There were 15 cases (50.0%) of low-grade mucinous carcinoma peritonei (LMCP) and high-grade mucinous carcinoma peritonei (HMCP), respectively, with vascular tumor emboli occurring in 4 cases (13.3%), nerve invasion occurring in 3 cases (10.0%), and lymphatic metastasis occurring in 4 cases (13.3%). The median peritoneal cancer index (PCI) score was 36 (range: 3-39). The median TSR was 8% (range: 2%-24%), with TSR≤10% in 19 cases (63.3%) and TSR>10% in 11 cases (36.7%). Immunohistochemistry showed that 16 cases (53.3%) had Ki67 label index ≤ 50% and 14 cases (46.7%) > 50%. The mutation rate of p53 was 56.7% and the loss rate of MMR protein was 11.8%. In addition, the expression rates of MUC2, MUC5AC, CDX2, CK7, and CK20 were 66.7%, 100.0%, 82.6%, 56.0%, and 92.3%, respectively. There were significant correlations between TSR and histopathological types, nerve invasion, Ki67 label index, and p53 mutation (P<0.05 for all). At the end of the last follow-up, 21 patients (70.0%) died and 9 patients (30.0%) survived, including 6 patients survived with tumor. The median overall survival (OS) was 12.7 months (95%CI: 10.4-11.5 months), and the 1-, 2-, and 3-year survival rates were 60.5%, 32.3%, and 27.7%, respectively. The median OS was 19.4 months (95%CI: 3.0-35.9 months) in the TSR≤10% group, versus 12.6 months (95%CI: 0.7-24.5 months) in the TSR>10% group (χ2=3.996, P=0.046). TSR is correlated with histopathological types, tumor proliferation, invasion behaviors and prognosis of PMP, thus could be a new prognostic indicator for PMP.

Pseudomyxoma peritonei: visceral scalloping on CT is a predictor of recurrence after complete cytoreductive surgery.

Pseudomyxoma peritonei (PMP) is characterized by peritoneal dissemination of gelatinous ascites following rupture of a mucinous tumor. Treatment by cytoreductive surgery (CRS) has improved its prognosis. Although visceral scalloping, notably liver scalloping, on computed tomography (CT) is a typical feature of PMP, its prognostic value remains unknown. We aimed to investigate the efficacy of liver scalloping in predicting recurrence in PMP patients. Among 159 consecutive patients with PMP who had contrast-enhanced CT between September 2012 and December 2018, 64 treatment-naïve patients who subsequently underwent CRS with complete resection (i.e., completeness of cytoreduction score (CC)-0 or CC-1), were included in analysis. Presence of liver scalloping and maximum thickness of mucin deposition at the liver surface were evaluated on CT. Disease-free survival (DFS) was determined based on the combination of postoperative CT features and tumor marker values. Median follow-up was 24.3months. CT revealed liver scalloping in 40/64 (63.4%) patients. Kaplan-Meier analysis showed significantly shorter DFS in patients with scalloping than in those without (p = 0.001; hazard ratio, 4.3). In patients with scalloping, greater mucin deposition (thickness ≥ 20mm) significantly correlated with poorer DFS (p = 0.042). In multivariate Cox proportional hazards regression including CC status, pathologic type, and tumor markers, the presence of scalloping independently and significantly correlated with DFS (p = 0.031). Liver scalloping was an independent predictor even after adjusting for clinical covariates. The presence of liver scalloping can lead to a high recurrence rate after CRS. • The presence of liver scalloping is a prognostic factor independent of histological grade and tumor markers. • Greater mucin deposition (thickness ≥ 20mm at the liver surface) is associated with higher recurrence rates in patients with liver scalloping.

Perioperative safety after cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei from appendiceal origin: Experience on 254 patients from a single center

ObjectiveCytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is a standard treatment for pseudomyxoma peritonei (PMP) recommended by Peritoneal Surface Oncology Group International (PSOGI). The study is to analyze the incidence of perioperative serious adverse events (SAEs) of CRS + HIPEC to treat PMP patients, and identify the risk factors, for guiding the prevention of SAEs. MethodsThis is a retrospective study on the PMP database established at our center. The clinicopathological features, treatment details and SAEs information on the PMP patients are systematically established in this database. The incidence, organ system distribution and severity of perioperative SAEs are analyzed. Univariate and multivariate analyses are performed to identify the independent risk factors. ResultsAmong the 272 CRS + HIPEC procedures for 254 PMP patients, there are 93 (34.2%) SAEs. Six systems are involved in the SAEs, including infections (9.6%), digestive system (8.1%), respiratory system (6.3%), cardiovascular system (5.5%), hematological system (2.9%), and urinary system (1.5%), in terms of frequency. In terms of severity, the majority is grade III SAEs (27.9%), followed by grade IV SAEs (4.8%) and grade V SAEs (1.5%). Univariate analysis reveals 4 risk factors for perioperative SAEs: HIPEC regimens (P = 0.020), PCI (P = 0.025), intraoperative red blood cell transfusion volume (P = 0.004), and intraoperative blood loss volume (P = 0.002). Multivariate and logistic regression model analysis identifies only one independent risk factor for perioperative SAEs: intraoperative blood loss volume (P = 0.001, OR = 0.344, 95%CI: 0.182–0.649). ConclusionsPMP patients treated by CRS + HIPEC at experienced centers could have acceptable safety. Improving the surgical techniques and developing the integrated hemostasis techniques are essential to reduce intraoperative blood loss and decrease SAEs rate.

Pathological prognostic factors of pseudomyxoma peritonei: comprehensive clinicopathological analysis of 155 cases

Pseudomyxoma peritonei (PMP) is an extremely rare malignancy, characterized by extensive peritoneal implantation and colloidal ascites. This study was to explore the pathological prognostic factors of PMP. Specimens from 155 PMP patients were analyzed by H&E and immunohistochemistry. Parameters included primary tumor location, histological grade, lymph node metastasis, tumor emboli in the blood and lymph vessels, perineural invasion, Ki67 labeling index, p53, mismatch repair (MMR) gene mutations, MUC1, MUC2, MUC5AC, and MUC6. Clinicopathological and follow-up data were subjected to univariate and multivariate analyses. The patients included 63.2% (n = 98) low-grade mucinous carcinoma peritonei, 31.6% (n = 49) high-grade mucinous carcinoma peritonei and 5.2% (n = 8) high-grade mucinous carcinoma peritonei with signet ring cells. There were 9.7% (n = 15) with lymph node metastasis; 11.6% (n = 18) with angiolymphatic invasion; 6.3% (n = 8) with defective MMR (dMMR); 35.5% (n = 55) with Ki67 labeling index ≥ 50%; 36.1% (n = 56) with p53 mutation. For PMP from appendiceal origin (n = 140), univariate analysis identified 10 potential prognostic factors. But Multivariate analysis identified only histologic grade was the independent prognostic factor for OS. Mortality risk of high-grade peritoneal mucinous carcinoma or high-grade peritoneal mucinous carcinoma with signet ring cells was 7.056 times (P < .0001, 95% CI: 2.701-18.435) or 27.224 times (P < .0001, 95% CI: 6.207-119.408), respectively, higher than low-grade. For PMP from the appendiceal origin, histological grade could be the only independent prognostic factor.

Complete pathologic response after two-stage cytoreductive surgery with HIPEC for bulky pseudomyxoma peritonei: proof of concept

Introduction Pseudomyxoma peritonei (PMP) is a rare disease characterized by the progressive accumulation of mucinous ascites and peritoneal implants. The optimal treatment for PMP includes the association of complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC). For patients with a large burdensome disease, the completeness of cytoreduction sometimes requires maximal effort surgery. The aim of this article is to provide proof of concept for two stage cytoreductive surgery (CRS) in this category of patients. Methods and materials A two stage CRS and HIPEC with oxaliplatin was proposed for patients with bulky PMP including important involvement of the serosal surfaces of the bowel or colon who had an impaired nutritional status. The residual disease at the end of the first stage was less than 5 mm of thickness on several implants. Clinical, surgical and histopathological variables were analyzed. Results All eight patients completed the two-stage strategy. Mortality was nil. One Clavien Dindo grade 3 event occurred in each stage. After a median follow up of 29.5 months, all patients were alive and free of recurrence. All of the patients had histopathological complete response on the specimens obtained from the residual sites during the second stage surgery. Conclusions Two-stage surgical strategy is feasible for bulky PMP patients and it is associated with little high-grade morbidity and enhanced visceral sparing.