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.

Laparoscopic versus open approach for interval cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) in advanced epithelial ovarian cancer: a matched comparative study.

BACKGROUND: The use of the laparoscopic approach for the treatment of carcinomatosis from epithelial ovarian cancer (EOC) is controversial. The aim of this study was to compare the short-term outcomes of both laparoscopic and open approach for interval CRS+HIPEC in a matched cohort of patients with advanced EOC. METHODS: A retrospective analysis of a prospectively maintained database including 254 patients treated with interval CRS-HIPEC between January 2016 and December 2021 was performed. Patients with primary disease and limited carcinomatosis (PCI ≤ 10) were selected. A comparative analysis of patients treated by either open (O-CRS-HIPEC) or the laparoscopic (L-CRS-HIPEC) approach was conducted. Overall survival (OS), disease-free survival (DFS), and perioperative outcomes were analysed. RESULTS: Fifty-three patients were finally selected and enrolled into two comparable groups in this study. Of these, 14 patients were treated by interval L-CRS-HIPEC and 39 by interval O-CRS-HIPEC. The L-CRS-HIPEC group had a shorter hospital stay (5.6 ± 1.9 vs. 9.7 ± 9.8 days; p < 0.001) and a shorter time to return to systemic chemotherapy (4.3 ± 1.9 vs. 10.3 ± 16.8 weeks; p = 0.003). There were no significant differences in postoperative complications between both groups. The 2-year OS and DFS was 100% and 62% in the L-CRS-HIPEC group versus 92% and 60% in the O-CRS-HIPEC group, respectively (p = 0.96; p = 0.786). CONCLUSION: This study suggests that the use of interval L-CRS-HIPEC for primary advanced EOC is associated with shorter hospital stay and return to systemic treatment while obtaining similar oncological results compared to the open approach. Further prospective research is needed to recommend this new approach for these strictly selected patients.

Learning curve for minimal invasive cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) procedures.

PURPOSE: The benefits of the minimally invasive approach for performing cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (L-CRS + HIPEC) have been described previously, associating an early recovery with similar oncologic outcomes in patients with limited peritoneal carcinomatosis. Currently, no studies are focusing on the learning curve for this emerging procedure. This study aimed to evaluate the L-CRS + HIPEC learning curve and its knock-on effect on the perioperative outcomes. METHODS: We identified all consecutive unselected patients who underwent L-CRS + HIPEC by a single surgeon between April 2016 and January 2022 (n = 51). Patients who underwent risk-reducing CRS + HIPEC (PCI = 0) or initial conversion due to an intraoperative PCI > 10 were excluded from the final analysis. To evaluate the learning curve, perioperative data were analysed using the cumulative sum (CUSUM) analysis. RESULTS: Twenty-six patients were included in the final analysis. Major morbidity occurred in one patient (3.8%). The difficulty of the L-CRS + HIPEC procedures was categorised as low in 23.1% (n = 6), intermediate in 19.2% (n = 5), and advanced in 57.7% (n = 15). The mean length of hospital stay was 5.4 ± 1.5 days. No patient had a conversion to open surgery. The learning curve was divided into two distinct phases: the learning phase (1-14) and the consolidation phase (15-26). A significant decrease in the operative time (375 ± 103.1 vs 239.2 ± 63.6 min) was observed with no differences in complexity, the number of peritonectomy procedures, or morbidity. CONCLUSION: L-CRS + HIPEC is a complex procedure that must be performed in a high-volume and experienced oncologic unit, requiring a learning curve to achieve the consolidation condition, which could be established after 14 procedures.

Intraoperative metabolic changes associated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) causes considerable hemodynamic, respiratory, and metabolic changes during the perioperative period. OBJECTIVES: To evaluate metabolic changes associated with this procedure. Understanding perioperative factors and their association with morbidity may improve the perioperative management of patients undergoing this treatment. METHODS: A retrospective review of a prospectively maintained database was performed. All consecutive unselected patients who underwent CRS plus HIPEC between January 2018 and December 2020 (n = 219) were included. RESULTS: The mean age was 58 ± 11.7 years and 167 (76.3%) were female. The most frequent histology diagnosis was serous ovarian carcinoma 49.3% (n = 108) and colon carcinoma 36.1% (n = 79). Mean peritoneal cancer index was 14.07 ± 10.47. There were significant variations in pH, lactic acid, sodium, potassium, glycemia, bicarbonate, excess bases, and temperature (p < 0.05) between the pre-HIPEC and post-HIPEC periods. The closed HIPEC technique resulted in higher levels of temperature than the open technique (p < 0.05). Age, potassium level post-HIPEC potassium level, and pre-HIPEC glycemia were identified as prognostic factors for morbidity in multivariate analysis. CONCLUSION: The administration of HIPEC after CRS causes significant changes in internal homeostasis. Although the closed technique causes a greater increase in temperature, it is not related to higher morbidity rates. The patient's age, post-HIPEC potassium level, and pre-HIPEC glycemia are predictive factors for morbidity.

A Proposal for Modification of the PSOGI Classification According to the Ki-67 Proliferation Index in Pseudomyxoma Peritonei.

BACKGROUND: Pseudomyxoma peritonei (PMP) is a rare malignancy, classified according to the Peritoneal Surface Oncology Group International (PSOGI) classification, whose response to treatment remains highly heterogeneous within the high-grade (HG) category. Molecular profiling of PMP cases might help to better categorize patients and predict treatment responses. METHODS: We studied the Ki-67 proliferation rate and P53 overexpression in tissue samples from our historical cohort of HG-PMP patients. We established as cut-off levels the third quartile of each marker to perform univariate and multivariate Cox regression survival analyses. According to these results, the HG-PMP category was divided into subcategories and a new survival analysis was performed. RESULTS: A total of 90/117 patients with PMP undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) were selected for secondary analysis. The survival analysis of the HG-PMP category for preoperative variables showed that a proliferation index defined by Ki-67 >15% is a bad prognostic factor, with a hazard ratio (HR) of 3.20 (95% confidence interval [CI] 1.24-8.25). Accordingly, the HG-PMP group was divided using the Ki-67 15% cut-off. The new PSOGI/Ki-67 variable was an independent prognostic factor for overall survival (OS), with an HR of 3.74 (95% CI 1.88-7.47), and disease-free survival (DFS), with an HR of 4.184 (95% CI 1.79-9.75). The estimated 5-year OS rate was 100%, 70% and 24% for the LG-PMP, HG-PMP ≤15% and HG-PMP >15% groups, respectively (p = 0.0001), while the 5-year DFS rate was 90%, 44% and 0%, respectively (p = 0.0001). CONCLUSION: Division of the HG-PMP category of the PSOGI classification, according to the Ki-67 proliferation index, provides two well-defined subcategories, with significant differences in terms of OS and DFS, and hence high prognostic value.

GECOP-MMC: phase IV randomized clinical trial to evaluate the efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) with mytomicin-C after complete surgical cytoreduction in patients with colon cancer peritoneal metastases.

BACKGROUND: The French PRODIGE 7 trial, published on January 2021, has raised doubts about the specific survival benefit provided by HIPEC with oxaliplatin 460 mg/m2 (30 minutes) for the treatment of peritoneal metastases from colorectal cancer. However, several methodological flaws have been identified in PRODIGE 7, specially the HIPEC protocol or the choice of overall survival as the main endpoint, so its results have not been assumed as definitive, emphasizing the need for further research on HIPEC. It seems that the HIPEC protocol with high-dose mytomicin-C (35 mg/m2) is the preferred regime to evaluate in future clinical studies. METHODS: GECOP-MMC is a prospective, open-label, randomized, multicenter phase IV clinical trial that aims to evaluate the effectiveness of HIPEC with high-dose mytomicin-C in preventing the development of peritoneal recurrence in patients with limited peritoneal metastasis from colon cancer (not rectal), after complete surgical cytoreduction. This study will be performed in 31 Spanish HIPEC centres, starting in March 2022. Additional international recruiting centres are under consideration. Two hundred sixteen patients with PCI ≤ 20, in which complete cytoreduction (CCS 0) has been obtained, will be randomized intraoperatively to arm 1 (with HIPEC) or arm 2 (without HIPEC). We will stratified randomization by surgical PCI (1-10; 11-15; 16-20). Patients in both arms will be treated with personalized systemic chemotherapy. Primary endpoint is peritoneal recurrence-free survival at 3 years. An ancillary study will evaluate the correlation between surgical and pathological PCI, comparing their respective prognostic values. DISCUSSION: HIPEC with high-dose mytomicin-C, in patients with limited (PCI ≤ 20) and completely resected (CCS 0) peritoneal metastases, is assumed to reduce the expected risk of peritoneal recurrence from 50 to 30% at 3 years. TRIAL REGISTRATION: EudraCT number: 2019-004679-37; Clinicaltrials.gov: NCT05250648 (registration date 02/22/2022, ).

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.

Secondary surgical cytoreduction needs to be assessed taking into account surgical technique, completeness of cytoreduction, and extent of disease.

Recent evidence suggested that secondary surgical cytoreduction followed by chemotherapy does not result in longer overall survival in patients with platinum-sensitive recurrent ovarian cancer.This statement is based on a phase III multicenter, randomized clinical trial that lacks a description of the surgical protocol, the surgical technique, and the surgical variables. In a study that evaluates surgical cytoreduction, it is mandatory to assess the grade of cytoreductive surgery achieved (Sugarbaker PH, Langenbeck's Arch Surg 384:576-87, 1999), the extent of disease using PCI (Peritoneal Cancer Index), the technique itself, and the existence of a multidisciplinary approach with extensive upper abdominal procedures in experienced centers (Ren et al, BMC Cancer 15:1-12, 2015). There is evidence proving that the quality of cytoreduction (Al Rawahi et al, Cochrane Database Syst Rev 2013, 2013), the measurement of the amount of disease by PCI (Elzarkaa et al, J Gynecol Oncol 29, 2018), and a multidisciplinary approach with supramesocolic procedures (Ren et al, BMC Cancer 15:1-12, 2015) impact overall survival.This study fails to compare chemotherapy with secondary cytoreductive surgery since, due to the lack of variables, we can assess neither the performed surgery nor its criteria. This study should not be taken into account to recommend chemotherapy alone over a surgical approach in this group of patients.

Residual tumour less than 0.25 centimetres and positive lymph nodes are risk factors for early relapse in recurrent ovarian peritoneal carcinomatosis treated with cytoreductive surgery, HIPEC and systemic chemotherapy.

AIM: The cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has showed promising results for the survival in patients with recurrent ovarian carcinomatosis, however, some of them will recur within the first year. The aim of this study is focussed on identifying the risk factors to develop the recurrence within the first year after an optimal CRS-HIPEC in patients with recurrent ovarian carcinomatosis. METHODS: A total of 100 patients with peritoneal carcinomatosis from recurrent ovarian cancer treated by CRS + HIPEC were selected for analysis. Multivariate logistic regression analysis was performed to evaluate the relationship between the variables and the early recurrence. RESULTS: The mean follow-up was 42.5 months. The mean age was 56.2 years. Early recurrence was observed in the 36%. The group early recurrence presented a higher rate of optimal cytoreductions CC1 (16.2% vs. 3.5%), lymph nodes (32.5% vs. 15%) and the use of hemoderivates (40.5% vs. 33%). Others parameters as Peritoneal Cancer Index, major morbidity? 3, re-operations rate and time to adjuvant chemotherapy were similar in both groups. The five years OS was 58%, for the non-early recurrence was higher than the early recurrence group (64% vs. 41%). In the multivariate analysis, CC-1 (OR 5.73; 1.16-32.04) and positive lymph nodes (OR 2.26; 1.01-4.32) proved to be independent factors for the early recurrence. CONCLUSION: The combination of both (CC1 and positive lymph nodes) makes that the indication of CRS and HIPEC should be individualised. However, the major morbidity, stage IV and the time to the adjuvant treatment were not associated with an early recurrence, so that, a major aggressiveness is recommended to achieve a CC0.

Progress in the management of primary and recurrent ovarian carcinomatosis with peritonectomy procedure and HIPEC in a high volume centre.

INTRODUCTION: The treatment of advanced primary or recurrent ephitelial ovarian cancer still remains an open and a critical question. The addition of HIPEC to cytoreductive surgery has shown improving overall survival rates. The aim of our study is to describe the progress in its management in our Unit and what we have learned after more than 350 HIPEC procedures. METHODS: From 1997 to 2016 we conducted a retrospective analysis from a prospective database. We described and analyzed 4 cut-points, 1997-2004, 2009, 2012 and 2016. RESULTS: From 1997 to September 2016, 358 patients have been operated in our Unit by CRS with peritonectomy procedures plus HIPEC for stage IIIc and IV ovarian cancer. The HIPEC procedures rate was 4,7 HIPEC per years in the first years up to 35 HIPEC/year in last era. Mean age was 56,7 years (28-78). Median PCI was 15,8. (range 3-36). R0-cytoreduction was 95%. Severe morbidity and mortality were observed in 15 % and 2%, respectively. The 3 y OS was 77% in primary and 79% in recurrent ovarian cancer. The stage IV was not a risk factor for survival. R1 cytoreduction and positive lymph nodes were risk factors in multivariate analysis. CONCLUSION: The addition of HIPEC to CRS improves overall survival rates for primary and recurrent ovarian cancer. This therapeutic strategy was incorporated twenty years ago for a few teams in the world and today there is an emerging and strong evidence that could consider it as an standard treatment for the ovarian carcinomatosis.

Long-term survival with peritoneal mucinous carcinomatosis from intraductal mucinous papillary pancreatic carcinoma treated with complete cytoreduction and hyperthermic intraperitoneal chemotherapy.

Traditionally, peritoneal carcinomatosis (PC) was regarded as an untreatable condition; however, the introduction of locoregional therapies combining cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) approximately two decades ago has changed this view. There is controversy, however, when a PC arises from pancreatic cancer. We have reported on an extraordinary case of an aggressive pseudomixoma peritonei arising from an invasive intraductal papillary mucinous neoplasm (IPMN) treated with complete cytoreduction and HIPEC. This combination of treatments has not been previously described. Moreover, a very long-term disease-free survival of up to 70 months has been achieved by this combined approach. This approach may provide some optimism for considerable life extension in selected patients who present with an aggressive peritoneal mucinous carcinomatosis of pancreatic origin considered suitable only for palliative care.

Altered CELF4 splicing factor enhances pancreatic neuroendocrine tumors aggressiveness influencing mTOR and everolimus response.

Pancreatic neuroendocrine tumors (PanNETs) comprise a heterogeneous group of tumors with growing incidence. Recent molecular analyses provided a precise picture of their genomic and epigenomic landscape. Splicing dysregulation is increasingly regarded as a novel cancer hallmark influencing key tumor features. We have previously demonstrated that splicing machinery is markedly dysregulated in PanNETs. Here, we aimed to elucidate the molecular and functional implications of CUGBP ELAV-like family member 4 (CELF4), one of the most altered splicing factors in PanNETs. CELF4 expression was determined in 20 PanNETs, comparing tumor and non-tumoral adjacent tissue. An RNA sequencing (RNA-seq) dataset was analyzed to explore CELF4-linked interrelations among clinical features, gene expression, and splicing events. Two PanNET cell lines were employed to assess CELF4 function in vitro and in vivo. PanNETs display markedly upregulated CELF4 expression, which is closely associated with malignancy features, altered expression of key tumor players, and distinct splicing event profiles. Modulation of CELF4 influenced proliferation in vitro and reduced in vivo xenograft tumor growth. Interestingly, functional assays and RNA-seq analysis revealed that CELF4 silencing altered mTOR signaling pathway, enhancing the effect of everolimus. We demonstrate that CELF4 is dysregulated in PanNETs, where it influences tumor development and aggressiveness, likely by modulating the mTOR pathway, suggesting its potential as therapeutic target.