Pseudomyxoma peritonei treated by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: results from a single centre

Breaking the Mucin Barrier: A New Affinity Chromatography-Mass Spectrometry Approach to Unveil Potential Cell Markers and Pathways Altered in Pseudomyxoma Peritonei

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare peritoneal mucinous carcinomatosis with largely unknown underlying molecular mechanisms. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is the only therapeutic option; however, despite its use, recurrence with a fatal outcome is common. The lack of molecular characterisation of PMP and other mucinous tumours is mainly due to the physicochemical properties of mucin.

RESULTS

This manuscript describes the first protocol capable of breaking the mucin barrier and isolating proteins from mucinous tumours. Briefly, mucinous tumour samples were homogenised and subjected to liquid chromatography using two specific columns to reduce mainly glycoproteins, albumins and immunoglobulin G. The protein fractions were then subjected to mass spectrometry analysis and the proteomic profile obtained was analysed using various bioinformatic tools. Thus, we present here the first proteome analysed in PMP and identified a distinct mucin isoform profile in soft compared to hard mucin tumour tissues as well as key biological processes/pathways altered in mucinous tumours. Importantly, this protocol also allowed us to identify MUC13 as a potential tumour cell marker in PMP.

CONCLUSIONS

In sum, our results demonstrate that this protein isolation protocol from mucin will have a high impact, allowing the oncology research community to more rapidly advance in the knowledge of PMP and other mucinous neoplasms, as well as develop new and effective therapeutic strategies.

From the Ronnett to the PSOGI Classification System for Pseudomyxoma Peritonei: A Validation Study

BACKGROUND

Several classifications have been used for pseudomyxoma peritonei (PMP), and among these, the Ronnett classification is the most commonly used. However, a new consensual Peritoneal Surface Oncology Group International (PSOGI) classification has recently been proposed. Nonetheless, to date, the ability of the PSOGI classification to predict survival based on its different disease histologic categories has not been validated.

METHODS

This study enrolled 117 patients with PMP who had undergone cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) between 1997 and 2020. Cox proportional hazards regression models and time-dependent curve receiver operating characteristic (ROC) analyses were used to assess the predictive capacity of both classification systems for the overall survival (OS) and disease-free survival (DFS) of these patients.

RESULTS

Significant differences in the 5-year OS rate were found for the different histologic grades according to each of the classifications. The completeness of cytoreduction score (CCS) was identified as a factor that predicted patient OS prognosis (p = 0.006). According to the time-dependent ROC curves at the "100" time point, adjusted by the CCS and DFS, the capacity to predict OS was optimal and achieved an area under the curve (AUC) of about 69% for OS and approximately 62% for DFS.

CONCLUSIONS

Both the Ronnett and PSOGI classifications were able to predict survival optimally for this patient cohort. However, when the classifications were adjusted by the CCS, the predictive availability for OS was better with the PSOGI classification than with the Ronnett classification.

Outcome of patients with aggressive pseudomyxoma peritonei treated by cytoreductive surgery and intraperitoneal chemotherapy

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare disease with an incidence rate of approximately 1 per million a year. During the past few years, there has been a survival benefit for these patients treated by complete cytoreduction and perioperative chemotherapy. Better survival rates were found in the adenomucinosis group than the carcinomatosis group. The purpose of our study was to analyze the outcome and the prognosis factors of only high-grade PMP.

METHODS

We selected 38 patients from a prospective database of 59 with high-grade PMP from appendiceal origin who were treated by cytoreduction surgery and HIPEC at the Hospital University Reina Sofia (Cordoba, Spain) between 1998 and July 2012. Clinical, surgical, analytical, radiological, and histological data were obtained prospectively. Survival curves were calculated using the Kaplan-Meier method, a univariate analysis was performed and the log rank-test was used to analyze the effects of several clinical and pathologic factors on overall survival (OS) and disease-free survival (DFS).

RESULTS

Median follow-up time was 32 months (range, 2-170). Median age at diagnosis was 57 years (range, 32-77). In 89.5 % of patients, optimal cytoreduction CC-0 (57.9 %) and CC-1 (31.6 %) was achieved. In the remaining 10.5 %, cytoreduction was classified as CC-2. The median PCI score was 21 (range, 4-38). Morbidity complications ≥ Grade 3 in the CTCAE v 3.0 classification was 18.4 %. One patient died 45 days postsurgery. Median OS at the end of follow-up was 36 months (range, 9-83); overall 5-year survival rate was 58.7 %. In the univariate analysis for OS, significant values were obtained for lymph-node involvement and suboptimal cytoreduction. The 5-year OS was 64.5 % when an optimal cytoreduction was achieved. Median DFS was 36 months (17-54); 3-year DFS rate was 49.1 %. Neoadjuvant therapy did not affect the survival of these patients; there was no difference in the 5-year OS (43 % vs. 75 %, p = 0.068).

CONCLUSIONS

In aggressive PMP, cytoreduction with peritonectomy procedure plus HIPEC is a safe procedure that suggests an improvement to the survival rates. Because optimal cytoreduction is a primary prognostic factor for survival rates, this procedure would have to be performed in an experienced center with a low morbidity. Neoadjuvant chemotherapy has not demonstrated benefits in these patients and further research will be required.

Pseudomyxoma peritonei of 92 Chinese patients: Clinical characteristics, pathological classification and prognostic factors

AIM: To assess the clinicopathologic features and its relationship with prognosis of pseudomyxoma peritonei (PMP) in Chinese patients.

METHODS: The clinicopathologic features and follow-up data of 92 patients with PMP were reviewed and retrospectively analyzed. The cases were categorized into three groups: disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA), and peritoneal mucinous carcinomatosis with intermediate or discordant features (PMCA-I/D). The log-rank test was used to analyze survival for each group and various clinicopathological parameters. Multivariate Cox proportional-hazard models were constructed to determine the important factors associated with survival.

RESULTS: The median age at diagnosis was 51.9 years (range: 22-76 years). The median follow up was 124 mo. The 3-, 5- and 10-year survival rates were 74.0%, 67.4% and 49.1%, respectively. There were 49 (53.2%) patients with DPAM, 26 (28.3%) with PMCA-I and 17 (18.5%) with PMCA. Patients with DPAM, PMCA-I/D and PMCA exhibited statistically significant difference in survival (P = 0.001). The 3 year survival for DPAM, PMCAI/D and PMCA was 97.0%, 80.0% and 67.0%, respectively; the 5 year survival was 80.0%, 67.0% and 50.0%, respectively; and the 10 year survival was 65.0%, 28.0% and 14.0%, respectively. Survival rate was significantly lowest in patients < 40 age years of age (P = 0.011). Appendiceal tumor and extra-ovarian parenchymal organ involvement were significantly related to overall survival. Patients with appendiceal mucinous adenocarcinoma (MACA) showed the significantly poorer prognosis (P = 0.011). Multivariate analysis showed that pathological classification, age, appendiceal tumor were significant related to overall survival.

CONCLUSION: The clinical process “PMP” should be pathologically classified into DPAM, PMCA and PMCA-I/D. Pathological classification, age, appendiceal MACA are survival independent predictors in Chinese patients with PMP.