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

A nomogram prediction model of pseudomyxoma peritonei established based on new prognostic factors of HE stained pathological images analysis

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare clinical malignant syndrome, and its rarity causes a lack of pathology research. This study aims to quantitatively analyze HE-stained pathological images (PIs), and develop a new predictive model integrating digital pathological parameters with clinical information.

METHODS

Ninety-two PMP patients with complete clinic-pathological information, were included. QuPath was used for PIs quantitative feature analysis at tissue-, cell-, and nucleus-level. The correlations between overall survival (OS) and general clinicopathological characteristics, and PIs features were analyzed. A nomogram was established based on independent prognostic factors and evaluated.

RESULTS

Among the 92 PMP patients, there were 34 (37.0%) females and 58 (63.0%) males, with a median age of 57 (range: 31-76). A total of 449 HE stained images were obtained for QuPath analysis, which extracted 40 pathological parameters at three levels. Kaplan-Meier survival analysis revealed eight clinicopathological characteristics and 20 PIs features significantly associated with OS (p < 0.05). Partial least squares regression was used to screen the multicollinearity features and synthesize four new features. Multivariate survival analysis identified the following five independent prognostic factors: preoperative CA199, completeness of cytoreduction, histopathological type, component one at tissue-level, and tumor nuclei circularity variance. A nomogram was established with internal validation C-index 0.795 and calibration plots indicating improved prediction performance.

CONCLUSIONS

The quantitative analysis of HE-stained PIs could extract the new prognostic information on PMP. A nomogram established by five independent prognosticators is the first model integrating digital pathological information with clinical data for improved clinical outcome prediction.

Optimal peritoneal cancer index cutoff point for predicting surgical resectability of pseudomyxoma peritonei in treatment-naive patients

BACKGROUND

The peritoneal cancer index (PCI) has been used to predict surgical outcomes for pseudomyxoma peritonei (PMP). The present study aimed to establish the optimal cutoff point for PCI to predict surgical resectability of PMP.

METHODS

A total of 366 PMP patients were included. The patients were divided into low-grade and high-grade groups. Based on the completeness of the cytoreduction (CC) score, both low-grade and high-grade PMP patients were further divided into complete cytoreductive surgery (CRS) and maximal tumor debulking (MTD) subgroups. The ability to predict surgical resectability of total and selected PCI (regions 2 + 9 to 12) was analyzed through receiver operating characteristic (ROC) curves.

RESULTS

Both total and selected PCI demonstrated excellent discriminative ability in predicting surgical resectability for low-grade PMP patients (n = 266), with the ROC-AUC of 0.940 (95% CI: 0.904-0.965) and 0.927 (95% CI: 0.889-0.955). The corresponding optimal cutoff point was 21 and 5, respectively. For high-grade PMP patients (n = 100), both total and selected PCI exhibited good performance in predicting surgical resectability, with the ROC-AUC of 0.894 (95% CI: 0.816-0.946) and 0.888 (95% CI: 0.810-0.943); correspondingly, the optimal cutoff point was 25 and 8, respectively. The discriminative ability between total and selected PCI in predicting surgical resectability did not show a statistical difference.

CONCLUSIONS

Both total and selected PCI exhibited good performance and similarity in predicting complete surgical resection for both low-grade and high-grade PMP patients. However, the selected PCI was simpler and time-saving in clinical practice. In the future, new imaging techniques or predictive models may be developed to better predict PCI preoperatively, which might assist in confirming whether complete surgical resection can be achieved.

Bland-Altman agreement analysis between CT predicted and surgical peritoneal cancer index in pseudomyxoma peritonei of appendiceal origin

Peritoneal cancer index (PCI) is the surgical variable most commonly used to quantify the extent of peritoneal metastases for pseudomyxoma peritonei (PMP) patients. The present study aimed to investigate the agreement between CT predicted and surgical PCI by the Bland-Altman method for PMP of appendiceal origin. A total of 167 PMP patients of appendiceal origin were included between 2016 and 2021. Bland-Altman analysis was performed for both total PCI and selected PCI (regions 2 + 9-12). After the Bland-Altman plot was drawn, the mean bias and its 95% limit of agreements (LoAs) was quantified. Besides, the correlation coefficients between CT-PCI and surgical PCI were also been calculated. The Bland-Altman plot showed the mean bias ± SD between total CT-PCI and surgical PCI as 0.431 ± 3.005, with the LoAs from - 5.459 to 6.321. There were nine points of difference in total PCI exceeded the 95% LoAs, with the rate of 5.39% (9/167). As for selected CT-PCI, Bland-Altman plot showed the mean bias ± SD between selected CT-PCI and surgical PCI as - 0.287 ± 1.955, with the LoAs from - 4.118 to 3.544. There were ten points of difference in selected PCI exceeded the 95% LoAs, with the rate of 5.99% (10/167). The Spearman's rank correlation coefficient between total CT-PCI and surgical PCI was 0.911, P < 0.001, as for selected CT-PCI and surgical PCI, the coefficient was 0.909, P < 0.001. Although there was a strong correlation for both total and selected CT-PCI with surgical PCI, however, the agreement is still not good in Bland-Altman analysis, which suggested that CT-PCI cannot predict surgical PCI accurately even in professional PMP treatment centers. In brief explanation, CT makes it difficult to distinguish the borderline between tumor tissue and mucus and to detect tumor lesions in the small intestine regions, which caused overestimation or underestimation by CT-PCI. In the future, a multiple linear regression model based on CT-PCI might accurately predict surgical PCI preoperatively.

Prognostic value of the ascites characteristics in pseudomyxoma peritonei originating from the appendix

Background

Pseudomyxoma peritonei (PMP) is a rare disease, with the overall survival (OS) influenced by many factors. To date, no ascites characteristics have been reported to predict OS of patients with PMP. The present study therefore aims to describe the ascites characteristics for PMP and identify prognostic factors for survival.

Methods

Between June 2010 and June 2020, 473 PMP patients who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy were included in a retrospective study. Survival analysis was performed with the Kaplan-Meier method by the log-rank test and a Cox proportional hazards model. Associations between categorical variables were analyzed using the chi-squared test.

Results

Among all included patients, 61% were women. The median OS was 47 months (range, 4-124 months) at the last follow-up in December 2020. Ascites characteristics can be divided into light blood ascites, "Jelly" mucus ascites, and faint yellow and clear ascites. Multivariate Cox analysis showed that the degree of radical surgery, ascites characteristics, and pathological grade were independently associated with OS in PMP patients. The chi-squared test documented that faint yellow "Jelly" ascites were related to low-grade PMP and light blood ascites were associated with high-grade PMP (P < 0.01).

Conclusions

Light blood ascites, incomplete cytoreduction surgery, and high-grade histopathology may predict poor OS in appendix-derived PMP.

Preoperative plasma D-Dimer level is correlated with peritoneal cancer index of patients with pseudomyxoma peritonei

PURPOSE

Accurate assessment of preoperative tumor burden contribute to formulate a scientific surgical plan for patients with pseudomyxoma peritonei (PMP). Present study aimed to assess whether the preoperative plasma D-Dimer level could reflect tumor burden for PMP patients.

METHODS

A total of 253 PMP patients were included between June 1, 2013 and March 1, 2022. According to the peritoneal cancer index (PCI), all participants were divided into extensive (PCI ≥ 28) and none-extensive (PCI < 28) subgroups. The D-Dimer and tumor markers were compared between the two subgroups. The correlation between the abovementioned biomarkers and PCI will be calculated, and further compared with each other. Two-sided P value less than 0.05 is considered statistically significant.

RESULTS

The level of D-Dimer (ng/ml) between extensive and none-extensive subgroup were 600 (328, 1268) vs. 339 (128, 598), Z = -5.425, p < 0.001. The Spearman correlation between D-Dimer, carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA 125), CA 19 - 9 and PCI were 0.487, 0.509, 0.469, and 0.499, respectively (all p < 0.001). The correlation coefficients were compared with each other according to Meng, Rosenthal and Rubin's method, however, there was no significant difference.

CONCLUSION

Preoperative plasma D-Dimer could moderately reflect tumor burden for PMP. In the future, a multivariate prediction model will be developed to help surgeons to formulate a more precise surgical plan for the PMP patients.

Survival prediction by Bayesian network modeling for pseudomyxoma peritonei after cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy

OBJECTIVES

To establish a survival prognostic model for pseudomyxoma peritonei (PMP) treated with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) based on Bayesian network (BN).

METHODS

453 PMP patients were included from the database at our center. The dataset was divided into a training set to establish BN model and a testing set to perform internal validation at a ratio of 8:2. From the training set, univariate and multivariate analyses were performed to identify independent prognostic factors for BN model construction. The confusion matrix, receiver operating characteristic (ROC) curve and the area under curve (AUC) were used to evaluate the performance of the BN model.

RESULTS

The univariate and multivariate analyses identified 7 independent prognostic factors: gender, previous operation history, histological grading, lymphatic metastasis, peritoneal cancer index, completeness of cytoreduction and splenectomy (all p < 0.05). Based on independent factors, the BN model of training set was established. After internal validation, the accuracy and AUC of the BN model were 70.3% and 73.5%, respectively.

CONCLUSION

The BN model provides a reasonable level of predictive performance for PMP patients undergoing CRS + HIPEC.

Prognostic prediction of preoperative nutritional status in low-grade appendiceal mucinous neoplasms

To describe the preoperative nutritional status of Low-grade Appendiceal Mucinous Neoplasms (LAMNs) and identify prognostic factors for survival. Medical records from 165 patients with LAMNs who attended the Aerospace Center Hospital, Beijing, China between January 2017, and December 2018 were retrospectively reviewed. Survival analysis was performed with the Kaplan-Meier method, the log-rank test, and a Cox proportional hazards model. Among 165 patients, 59 (36%) were male and 106 (64%) were female. Patient's median age was 58 years (range 20 to 78 years). Univariate analysis indicated that gender, weight loss, prior surgical score (PSS), red blood cell, albumin, peritoneal cancer index (PCI), completeness of cytoreduction (CCR), and hyperthermic intraperitoneal chemotherapy (HIPEC) were related to prognosis. Multivariate analysis showed that PSS, CCR and HIPEC were independent predictors of prognosis. The preoperative nutritional status of patients plays an important role in predicting prognosis. Patients can benefit from a complete cytoreductive surgery (CCRS) and HIPEC in an experienced institution for the first medical treatment.