Elevated tumour markers prior to complete tumour removal in patients with pseudomyxoma peritonei predict early recurrence

Recurrence after cytoreductive surgery and HIPEC for pseudomyxoma peritonei: A single-center retrospective cohort study

BACKGROUND AND AIMS

Pseudomyxoma peritonei (PMP) is a rare disease characterized by progressive build-up of mucinous deposits inside the abdominal cavity. The aim of this study was to investigate the effect of disease recurrence on overall survival in patients with PMP after cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

One-hundred thirty-two consecutive PMP patients treated with CRS + HIPEC at Helsinki University Hospital between 2008 and 2017 were included. The impact of clinicopathological and treatment-related characteristics on recurrence and overall survival was evaluated.

RESULTS

The median follow-up time in the study was 5.04 (range = 0.05-11.60) years. In 121 (91.7%) patients, the disease was classified as low grade and 11 (8.3%) had high-grade disease. In the low-grade group, 26 (21.5%) patients developed a recurrence during follow-up compared to 6 (54.5%) patients in the high-grade group. In the low-grade group, cumulative survival was 98.2%, 91.4%, and 91.4% at 3, 6, and 8 years, respectively. In the high-grade group, cumulative survival was 90.0% and 78.8% at 3 and 6 years, respectively. In patients with recurrent disease, the cumulative survival was 100%, 84.6%, and 84.6% at 3, 6, and 8 years in the low-grade category and 80.0% and 60.0% at 3 and 6 years in the high-grade category, respectively. In the low-grade group, a statistically significant correlation with recurrence but not with overall survival was identified with peritoneal cancer index (PCI), carcinoembryonic antigen (CEA), and the number of affected regions.

CONCLUSION

The recurrence of low-grade PMP does not significantly affect overall survival of patients. Disease extent may not be a prognostic indicator after curative CRS and HIPEC in low-grade PMP.

[Surgical treatment for recurrent intra-abdominal mucinous neoplasms]

BACKGROUND

The gold standard in the treatment of mucinous intra-abdominal neoplasms is cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). Despite complete cytoreduction up to 45% of patients develop recurrences.

METHOD

A search and analysis of the current literature were carried out.

RESULTS

There is still controversy regarding the best treatment strategy for patients with recurrent pseudomyxoma peritonei (PMP) after CRS and HIPEC. The clinical management of these patients depends on many factors, such as the site and volume of recurrence, histological subtype and symptoms. Treatment options range from repeated surgery with curative intent with or without HIPEC to watch and wait strategies. In selected patients redo surgery is feasible and safe with low morbidity and mortality. Iterative complete CRS can result in a median 5‑year overall survival of more than 80%. Debulking surgery leads to a prolonged survival and to symptom control fora period with of nearly 2 years.

CONCLUSION

Repeated complete cytoreduction of recurrent PMP can result in long-term survival. Tumor debulking surgery may be particularly beneficial for symptomatic patients.

Determining a minimum data set for reporting clinical and radiologic data for pseudomyxoma peritonei

Objectives

Pseudomyxoma peritonei (PMP) is a rare cancer currently affecting over 11,736 patients across Europe. Since PMP is so uncommon, collaboration between scientific centers is key to discovering the mechanisms behind the disease, efficient treatments, and targets pointing to a cure. To date, no consensus has been reached on the minimum data that should be collected during PMP research studies. This issue has become more important as biobanking becomes the norm. This paper begins the discussion around a minimum data set that should be collected by researchers through a review of available clinical trial reports in order to facilitate collaborative efforts within the PMP research community.

Content

A review of articles from PubMed, CenterWatch, ClinicalTrials.gov and MedRxiv was undertaken, and clinical trials reporting PMP results selected.

Summary

There is a core set of data that researchers report, including age and sex, overall survival, peritoneal cancer index (PCI) score, and completeness of cytoreduction, but after this, reports become variable.

Outlook

Since PMP is a rare disease, it is important that reports include as large of a number of standardised data points as possible. Our research indicates that there is still much ground to cover before this becomes a reality.

Radiomics analysis based on CT's 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.

Prognostic Impact of Pathology, Cytoreduction, and Tumor Markers in Pseudomyxoma Peritonei

INTRODUCTION

The pathologic classification of pseudomyxoma peritonei is controversial. This study aimed to standardize the histopathological evaluation of pseudomyxoma peritonei and identify the clinicopathological factors associated with survival.

METHODS

A pathologic review was performed to systematize the pathology report and verify the relationship between clinical features and survival. Terminology was based on the World Health Organization and Peritoneal Surface Oncology Group International definitions. Preoperative serum levels of carcinoembryonic antigen, CA19-9, and CA-125 were evaluated to determine their association with overall survival (OS) and ability to predict CC0-1 cytoreduction.

RESULTS

Among 109 patients with carcinomas resulting from primary appendiceal neoplasms, 72 had pseudomyxoma peritonei of appendiceal origin and underwent debulking surgery. CC0-1 cytoreduction and CC2-3 cytoreduction were achieved in 61% and 39% of patients, respectively. Patients in the CC0-1 and CC2-3 groups had an OS of 122.80 and 32.92 mo, respectively. The histologic grade was associated with CC0-1 cytoreduction; however, it did not influence OS. Patients with CC0-1 cytoreduction, acellular mucin, and low-grade lesions had better disease-free survival. Higher preoperative CA19-9 levels were associated with poor OS. Normal carcinoembryonic antigen values were associated with 100% sensitivity for predicting CC0-1. CA19-9 levels of 625 U/mL were associated with a low possibility of predicting CC0-1.

CONCLUSIONS

Histologic grades are associated with disease-free survival when CC0-1 cytoreduction is achieved. Normal preoperative CA19-9 levels were associated with a better OS. CC0-1 cytoreduction is the main determinant of longer survival.

Overall Survival is More Closely Associated with Peritoneal than Primary Appendiceal Pathological Grade in Pseudomyxoma Peritonei with Discordant Pathology

BACKGROUND

The WHO classification of mucinous appendix neoplasms and pseudomyxoma peritonei (PMP) describes low- and high-grade histology and is of prognostic importance. The metastatic peritoneal disease grade can occasionally be different from the primary appendix tumor. This analysis aimed to report outcomes from a high-volume center in patients with pathological discordance.

METHODS

This was a retrospective analysis of prospective data of patients treated by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for PMP at a single institution between January 2016 and December 2020. Reporting was by pathologists with a special interest in peritoneal malignancy. Discordant pathology was classified as a low-grade primary appendix tumor with high-grade peritoneal disease, or a high-grade primary appendix tumor with low-grade peritoneal disease. Outcomes analyzed were overall and recurrence-free survival, and Kaplan-Meier survival curves and the log-rank test were used to analyze the outcomes.

RESULTS

Between 2016 and 2020, 830 patients underwent CRS and HIPEC for PMP, of whom 37 (4.4%) had discordant pathology. The primary appendix tumors were low-grade in 23 patients and high-grade in 14 patients. The median Peritoneal Cancer Index (PCI) was significantly higher in patients with a low-grade primary tumor (31 vs. 16; p = 0.001), while complete cytoreduction (CC0/1) was achieved in 31/37 (83.8%) patients. The median follow-up was 19 months. Overall survival was worse in those with high-grade peritoneal disease (p = 0.029), whereas recurrence-free survival was similar in both groups (p = 0.075).

CONCLUSION

In PMP with pathological discordance, the peritoneal disease grade influences prognosis and survival.

Nomogram to Predict Incomplete Cytoreduction for Pseudomyxoma Peritonei

BACKGROUNDS

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

The mutational landscape and prognostic indicators of pseudomyxoma peritonei originating from the ovary

Pseudomyxoma peritonei (PMP) is a rare disorder with unique pathological and genetic changes. Although several studies have reported the clinical features and mutational changes of PMP that originates from the appendix, few studies on PMP originating from the ovary have been reported due to its extreme rarity. In order to characterize the somatic mutational landscape and to investigate the prognosis predicting factors of ovary-originating PMP, we examined 830 cases of PMP and identified 16 patients with PMP that originated from the ovary. Whole-exome sequencing (WES) was performed on 12 cases using formalin-fixed, paraffin-embedded (FFPE) tissue samples. We found that 25% (3/12) of the patients carried mutations in cancer driver genes, including TP53, ATM and SETD2, and 16.7% (2/12) of the patients carried mutations in cancer driver genes, including ATRX, EP300, FGFR2, KRAS, NOCR1 and RB1. The MUC16 (58.33%), BSN (41.67%), PCNT (41.67%), PPP2R5A (41.67%), PRSS36 (41.67%), PTPRK (41.67%) and SBF1 (41.67%) genes presented the highest mutational frequencies. The PI3K-Akt signaling pathway, human papillomavirus infection pathway, cell skeleton, cell adhesion, and extracellular matrix and membrane proteins were the major pathways or functions that were affected. Patients were followed up to 174 months (median: 48.26 months). The 5-year OS rate for all patients was 71.2% and the median OS was not reached. PTPRK mutations, presurgical CA199 level, completeness of cytoreduction (CCR) and peritoneal cancer index (PCI) were identified as potential predictive factors for patient survival. In conclusion, the mutational landscape for ovary-originating PMP was revealed and exhibited unique features distinct from appendix-originating PMP. PTPRK, CA199, CCR and PCI may predict patient survival.

Severe Erosive Esophagitis Secondary to Gastric Outlet Obstruction Related to Pseudomyxoma Peritonei

Pseudomyxoma peritonei (PMP) is a rare clinical condition characterized by a mucin-producing tumor. PMP tumor cells migrate to abdominal and pelvic sites, eventually enveloping intra-abdominal organs and compressing the gastrointestinal tract. Patients with PMP are often asymptomatic in early stages of the disease, but in later stages develop symptoms including abdominal pain, acute abdomen, increased abdominal girth, vomiting, and bowel obstruction. Nonspecific symptoms combined with a relatively modest accuracy of imaging modalities frequently lead to delay in PMP diagnosis and treatment, thereby increasing morbidity. We present a case demonstrating severe erosive esophagitis as a result of PMP-associated gastric antrum compression.

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.

Appendiceal tumours and pseudomyxoma peritonei: Literature review with PSOGI/EURACAN clinical practice guidelines for diagnosis and treatment

Pseudomyxoma Peritonei (PMP) is a rare peritoneal malignancy, most commonly originating from a perforated epithelial tumour of the appendix. Given its rarity, randomized controlled trials on treatment strategies are lacking, nor likely to be performed in the foreseeable future. However, many questions regarding the management of appendiceal tumours, especially when accompanied by PMP, remain unanswered. This consensus statement was initiated by members of the Peritoneal Surface Oncology Group International (PSOGI) Executive Committee as part of a global advisory role in the management of uncommon peritoneal malignancies. The manuscript concerns an overview and analysis of the literature on mucinous appendiceal tumours with, or without, PMP. Recommendations are provided based on three Delphi voting rounds with GRADE-based questions amongst a panel of 80 worldwide PMP experts.

Preoperative Risk Score for Predicting Incomplete Cytoreduction: A 12-Institution Study from the US HIPEC Collaborative

BACKGROUND

For patients with peritoneal carcinomatosis undergoing cytoreductive surgery with heated intraperitoneal chemotherapy (CRS/HIPEC), incomplete cytoreduction (CCR2/3) confers morbidity without survival benefit. The aim of this study is to identify preoperative factors which predict CCR2/3.

METHODS

All patients who underwent curative-intent CRS/HIPEC of low/high-grade appendiceal, colorectal, or peritoneal mesothelioma cancers in the 12-institution US HIPEC Collaborative from 2000 to 2017 were included (n = 2027). The primary aim is to create an incomplete-cytoreduction risk score (ICRS) to predict CCR2/3 CRS utilizing preoperative data. ICRS was created from a randomly selected cohort of 50% of patients (derivation cohort) and verified on the remaining patients (validation cohort).

RESULTS

Within our derivation cohort (n = 998), histology was low-grade appendiceal neoplasms in 30%, high-grade appendiceal tumor in 41%, colorectal tumor in 22%, and peritoneal mesothelioma in 8%. CCR0/1 was achieved in 816 patients and CCR 2/3 in 116 patients. On multivariable analysis, preoperative factors associated with incomplete cytoreduction were male gender [odds ratio (OR) 3.4, p = 0.007], presence of ascites (OR 2.8, p = 0.028), cancer antigen (CA)-125 ≥ 40 U/mL (OR 3.4, p = 0.012), and carcinoembryonic antigen (CEA) ≥ 4.2 ng/mL (OR 3.2, p = 0.029). Each preoperative factor was assigned a score of 0 or 1 to form an ICRS from 0 to 4. Scores were grouped as zero (0), low (1-2), or high (3-4). Incidence of CCR2/3 progressively increased by risk group from 1.6% in zero to 13% in low and 39% in high. When ICRS was applied to the validation cohort (n = 1029), this relationship was maintained.

CONCLUSION

The incomplete cytoreduction risk score incorporates preoperative factors to accurately stratify the risk of CCR2/3 resection in CRS/HIPEC. This score should not be used in isolation, however, to exclude patients from surgery.

Factors influencing long-term survival after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei originating from appendiceal neoplasms

Background

Pseudomyxoma peritonei (PMP) is a rare disease, most commonly of appendiceal origin. Treatment consists of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS–HIPEC). The aim of this study was to identify prognostic factors for recurrence and survival.

Methods

This was an observational study using a prospectively designed database containing consecutive patients with PMP originating from the appendix, undergoing CRS–HIPEC at a tertiary referral centre between 1996 and 2015. Histopathological slides were reassessed. Cox regression was used for multivariable analyses.

Results

Of 225 patients identified, 36 (16·0 per cent) were diagnosed with acellular mucin, 149 (66·2 per cent) had disseminated peritoneal adenomucinosis (DPAM) and 40 (17·8 per cent) had peritoneal mucinous carcinomatosis (PMCA). The 5‐year overall survival (OS) rates were 93, 69·8 and 55 per cent respectively. Recurrence was observed in 120 patients (53·3 per cent), 39 of whom (17·3 per cent) were treated with a second CRS–HIPEC procedure. Factors independently associated with poor disease‐free survival were six or seven affected regions (hazard ratio (HR) 6·01, 95 per cent c.i. 2·04 to 17·73), incomplete cytoreduction (R2a resection: HR 1·67, 1·05 to 2·65; R2b resection: HR 2·00, 1·07 to 3·73), and more than threefold raised carcinoembryonic antigen (CEA) and/or carbohydrate antigen (CA) 19‐9 level (HR 2·31, 1·30 to 4·11). Factors independently associated with poorer OS were male sex (HR 1·74, 1·09 to 2·77), incomplete cytoreduction (R2a resection: HR 1·87, 1·14 to 3·08; R2b resection: HR 2·28, 1·19 to 4·34), and more than threefold raised CEA and/or CA19‐9 level (HR 2·89, 1·36 to 6·16).

Conclusion

CEA and CA19‐9 levels raised more than threefold above the upper limit identify patients with PMP of appendiceal origin and poorer survival.

Pseudomyxoma pleurii and peritonei secondary to sigmoid colon adenocarcinoma: a rare clinico-pathologico-radiological presentation

Pseudomyxoma peritonei (PMP) is a rare condition resulting from mucin-producing tumors that have disseminated into intraperitoneal implants and mucinous ascites. The extra-abdominal spread of PMP is exceptionally rare, with few reported cases in the medical literature. Pseudomyxoma pleurii is an infrequently encountered clinical syndrome characterized by transdiaphragmatic pleural extension and spread of PMP. The disease is highly fatal. We hereby report a case of 58 years old woman who presented with an abdominal distension and shortness of breath of 2 months duration. Histopathology confirmed the diagnosis of large mucin-producing rectosigmoid adenomatous polypoid lesion with malignant transformation and PMP that had spread to the right pleural space. PMP from colon tumor is uncommon and its transdiaphragmatic pleural extension is very unusual complicated by management challenge and high mortality rate.

Pseudomyxoma peritonei: natural history and treatment

Pseudomyxoma peritonei (PMP) is an uncommon disease characterised by mucinous ascites, classically originating from a ruptured low grade mucinous neoplasm of the appendix. The natural history of PMP revolves around the "redistribution phenomenon", whereby mucinous tumour cells accumulate at specific sites with relative sparing of the motile small bowel and to a lesser extent other parts of the gastrointestinal tract. Peritoneal tumour accumulates due to gravity and at the sites of peritoneal fluid absorption, namely, the greater and lesser omentum and the under-surface of the diaphragm, particularly on the right. The optimal treatment is complete macroscopic tumour excision termed cytoreductive surgery (CRS) combined with Hyperthermic Intra-Peritoneal Chemotherapy (HIPEC). Total operating time for complete CRS and HIPEC for extensive PMP is around 10 h and generally involves bilateral parietal and diaphragmatic peritonectomies, right hemicolectomy, radical greater omentectomy with splenectomy, cholecystectomy and liver capsulectomy, a pelvic peritonectomy with, or without, rectosigmoid resection and bilateral salpingo-oophorectomy with hysterectomy in females. A unique feature of low grade PMP, which differs from other peritoneal malignancies, includes slow disease progression, which may be asymptomatic until advanced stages. Additionally, very extensive disease with a high "PCI" (Peritoneal Carcinomatosis Index) may still be amenable to complete excision and cure. In cases where complete tumour removal is not feasible, maximum tumour debulking can still result in long-term survival in PMP. PMP is challenging, complex but nevertheless the most rewarding peritoneal malignancy amenable to cure by CRS and HIPEC.

Outcomes of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal mesothelioma and predictors of survival

BACKGROUND

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) benefits selected patients with peritoneal mesothelioma. We present the outcomes of this treatment strategy in a UK peritoneal malignancy national referral centre.

METHODS

Observational retrospective analysis of data prospectively collected in a dedicated peritoneal malignancy database between March 1998 and January 2016.

RESULTS

Of 1586 patients treated for peritoneal malignancy, 76 (4.8%) underwent surgery for peritoneal mesothelioma. Median age was 49 years (range 21-73 years). 34 patients (45%) were female. Of the 76 patients, 39 (51%) had low grade histological subtypes (mostly multicystic mesothelioma), and 37 (49%) had diffuse malignant peritoneal mesothelioma (DMPM; mostly epithelioid mesothelioma). Complete cytoreduction was achieved in 52 patients (68%) and maximal tumour debulking (MTD) was performed in 20 patients (26%); the remaining 4 patients (5%) underwent a laparotomy with biopsy only. HIPEC was administered in 67 patients (88%). Median overall (OS) and disease-free survival (DFS) after CRS was 97.8 (80.2-115.4) and 58.8 (47.4-70.3) months, respectively. After complete cytoreduction, 100% overall survival was observed amongst patients with low-grade disease. Ki-67 proliferation index was significantly associated with survival outcomes after complete cytoreduction for DMPM and was an independent predictor of decreased survival.

CONCLUSION

With adequate patient selection (guided by histological classification and Ki-67 proliferation index) and complete cytoreduction with HIPEC, satisfactory outcomes can be achieved in selected patients with peritoneal mesothelioma.

Preserving fertility in pseudomyxoma peritonei, a novel approach

Background

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is the gold standard treatment for patients with pseudomyxoma peritonei (PMP) but involves routine bilateral salpingo-oophorectomy. Young women wishing to maintain fertility may be reluctant to pursue this. An alternative strategy in women with low-grade PMP has been explored in the form of laparoscopic evacuation of pelvic and ovarian mucin with resection of the appendiceal tumour.

Methods

Between January 2012 and January 2015, four young women (aged 28-35 years) with PMP seeking to maintain fertility underwent laparoscopy, appendicectomy and pelvic mucinous evacuation and washout. Data regarding intra-operative and histopathological findings were collected. Endpoints were fertility-related outcomes and oncological follow-up.

Results

Infertility was a presenting symptom in three of the four women. All four had significant pelvic mucinous disease on radiological imaging and were offered CRS and HIPEC as definitive treatment, but chose laparoscopy with appendicectomy and copious irrigation and washout of the pelvis with stripping of mucinous disease off the ovarian surfaces. Postoperative histology demonstrated a low-grade appendiceal mucinous neoplasm (LAMN) in all patients with acellular mucin or low-grade mucinous carcinoma peritonei in the peritoneal cavity. All patients successfully conceived subsequently and gave birth to healthy babies. After 12-29 months follow-up, all women are well with no radiological or laparoscopic evidence of disease recurrence.

Conclusions

In patients with low-grade PMP, initial therapeutic laparoscopy can restore fertility, whilst providing short- to medium-term disease control. This modality in young women wishing to have children appears to be a feasible alternative to immediate CRS and HIPEC.

Pathophysiology and classification of pseudomyxoma peritonei

Background: The term pseudomyxoma peritonei (PMP) was first described in 1884 and there has been much debate since then over the term. A recent consensus of world experts agreed that PMP should be thought of as a clinical entity characterised by the presence of mucinous ascites, omental cake, peritoneal implants and possibly ovarian involvement. It generally originates from mucinous appendiceal tumours. Content: This review details the clinical presentation of this unusual condition, presents the new classification system and how this relates to outcome. The pathophysiology of this disease is also explored with a special reference to the relationship of the disease to tumour markers. Summary: A classification system has been agreed upon by the leading experts in PMP which is now divided into low and high grade mucinous carcinomatosis peritonei. This distinction correlates with clinical outcome as does the presence of raised tumour markers preoperatively. Outlook: Research needs to be focused on understanding the factors associated with poor prognosis through well designed multi-centred prospective studies. This will allow us to identify patients with bad tumour biology so that targeted treatment based on likely prognosis may then become a reality.

Elevated tumour markers are normalized in most patients with pseudomyxoma peritonei 7 days after complete tumour removal

AIM

Elevation of the preoperative tumour markers in pseudomyxoma peritonei (PMP) is common and is a risk factor for recurrence. There has, however, been no documentation of the effect of complete tumour removal on tumour markers levels after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The aim of the study was to compare the tumour markers 7 days after surgery in patients with elevated preoperative levels.

METHOD

This was an observational prospective study of patients with PMP of appendiceal origin treated in one of the UK National Referral Centres for this condition. Thirty patients [median age = 61 (range: 31-74) years; six men] with an elevated preoperative level of carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA-125) and/or carbohydrate antigen 19-9 (CA19-9) underwent repeated estimation, 7 days after CRS and HIPEC for PMP.

RESULTS

The median preoperative CEA level of 12 μg/l fell to 0.75 μg/l postoperatively (P < 0.0001), CA-125 fell from 45 to 31 kU/l (P = 0.183) and CA19-9 fell from 134 to 37 kU/l (P = 0.003). The CEA was raised in 22 (73%) of 30 patients preoperatively and in two (7%) of 30 patients 7 days after surgery (P < 0.0001). The corresponding data for CA-125 were 18 (60%) and 13 (43%) (P = 0.196) and for CA19-9 they were 24 (80%) and 16 (53%) (P = 0.028).

CONCLUSION

This is the first documentation of a reduction or normalization of CEA 7 days after CRS, but not for CA19-9 or CA-125. This may indicate completeness of surgical resection and could aid selection for adjuvant therapy and predict prognosis. Long-term follow-up is, however, necessary to determine the significance of this observation.

Histologic and Immunohistochemical Alterations Associated with Cytoreductive Surgery and Heated Intraperitoneal Chemotherapy

BACKGROUND

Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) are used to treat peritoneal carcinomatosis from a variety of primary tumor sites. Little is known about the in vivo effects of CRS and HIPEC.

METHODS

We examined tumor and non-neoplastic peritoneal tissue samples from 38 patients undergoing CRS and HIPEC for appendiceal or colorectal carcinomatosis, using conventional histologic analysis and immunohistochemical analysis for markers of early DNA damage (phosphorylated H2AX, γH2AX) and early necrosis (extracellular HMGB1). Findings were correlated with clinicopathologic features and oncologic outcome.

RESULTS

Histologic findings corresponding with CRS and HIPEC included extensive submesothelial inflammatory infiltrate, endothelial activation, mesothelial karyolysis and surface fibrin deposition. Endothelial activation in submesothelial vessels exhibited high specificity for samples obtained following HIPEC relative to samples obtained following CRS but prior to HIPEC. Mesothelial nuclear γH2AX staining and submesothelial extracellular HMGB1 staining increased progressively following CRS and HIPEC, consistent with DNA damage and necrosis. No significant increase in tumor staining for markers was seen with CRS or HIPEC. Submesothelial HMGB1 staining was associated with increased progression-free survival on univariate analysis.

CONCLUSIONS

The immediate histologic effects of CRS and HIPEC are defined and provide evidence that DNA damage and early steps of necrosis are underway in mesothelial tissues at the conclusion of the procedure. Further research will be necessary to investigate the impact of these findings on long-term oncologic outcome, and may provide insight into the downstream effects of CRS and HIPEC that could facilitate refinement of regional therapeutic regimens for carcinomatosis.

Feasibility of radical cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei of appendiceal origin

BACKGROUND AND AIMS

We analyzed the feasibility of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with pseudomyxoma peritonei.

MATERIAL AND METHODS

A prospective database comprised 90 consecutive patients with demonstrable pseudomyxoma peritonei collected during 48 months. These patients, referred to our unit for consideration for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, received both cytoreductive surgery and hyperthermic intraperitoneal chemotherapy if possible. We evaluated the factors associated with a successful procedure.

RESULTS

Hyperthermic intraperitoneal chemotherapy was successfully delivered to 56 of 90 patients (62%) with demonstrable pseudomyxoma peritonei. Tumor morphology of low grade (p = 0.013), age under 65 years (p = 0.004), and serum carcinoembryonic antigen level under 5.0 µg/L (p = 0.003) were associated with successful administration of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Mean peritoneal cancer index was lower (18.9 vs 32.6, p < 0.001) and age was younger (54.3 vs 61.6, p = 0.003) in patients who underwent hyperthermic intraperitoneal chemotherapy than in patients who did not. Four patients had complete cytoreductive surgery alone, and 20 patients underwent palliative debulking, but 10 were ineligible for this operation.

CONCLUSIONS

Although the combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is currently suggested the standard practice for pseudomyxoma peritonei, not all patients are eligible for this protocol. In this study, hyperthermic intraperitoneal chemotherapy was suitable for 62% of patients with pseudomyxoma peritonei of appendiceal origin.

Secreted mucins in pseudomyxoma peritonei: pathophysiological significance and potential therapeutic prospects

Pseudomyxoma peritonei (PMP, ORPHA26790) is a clinical syndrome characterized by progressive dissemination of mucinous tumors and mucinous ascites in the abdomen and pelvis. PMP is a rare disease with an estimated incidence of 1-2 out of a million. Clinically, PMP usually presents with a variety of unspecific signs and symptoms, including abdominal pain and distention, ascites or even bowel obstruction. It is also diagnosed incidentally at surgical or non-surgical investigations of the abdominopelvic viscera. PMP is a neoplastic disease originating from a primary mucinous tumor of the appendix with a distinctive pattern of the peritoneal spread. Computed tomography and histopathology are the most reliable diagnostic modalities. The differential diagnosis of the disease includes secondary peritoneal carcinomatoses and some rare peritoneal conditions. Optimal elimination of mucin and the mucin-secreting tumor comprises the current standard of care for PMP offered in specialized centers as visceral resections and peritonectomy combined with intraperitoneal chemotherapy. This multidisciplinary approach has reportedly provided a median survival rate of 16.3 years, a median progression-free survival rate of 8.2 years and 10- and 15-year survival rates of 63% and 59%, respectively. Despite its indolent, bland nature as a neoplasm, PMP is a debilitating condition that severely impacts quality of life. It tends to be diagnosed at advanced stages and frequently recurs after treatment. Being ignored in research, however, PMP remains a challenging, enigmatic entity. Clinicopathological features of the PMP syndrome and its morbid complications closely correspond with the multifocal distribution of the secreted mucin collections and mucin-secreting implants. Novel strategies are thus required to facilitate macroscopic, as well as microscopic, elimination of mucin and its source as the key components of the disease. In this regard, MUC2, MUC5AC and MUC5B have been found as the secreted mucins of relevance in PMP. Development of mucin-targeted therapies could be a promising avenue for future research which is addressed in this article.

Pre-operative tumour marker status predicts recurrence and survival after complete cytoreduction and hyperthermic intraperitoneal chemotherapy for appendiceal Pseudomyxoma Peritonei: Analysis of 519 patients

BACKGROUND

Cytoreductive surgery (CRS) combined with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is the optimal treatment for Pseudomyxoma Peritonei (PMP). Despite treatment, disease often recurs and may not be amenable to further CRS. Clinical experience suggests a spectrum of disease which may correlate with tumour marker levels. The aim of this study was to analyse the influence of markers on recurrence and survival.

METHODS

The details of all patients undergoing surgery for PMP of appendiceal origin at a national centre for peritoneal malignancy were recorded in a dedicated prospective database. The data on all patients who had CRS and HIPEC between March 1994 and January 2012 was analysed and recurrence and survival correlated with pre-operative levels of CEA, CA-125 and CA19-9.

RESULTS

Overall, 519 (69%) of 752 consecutive patients, underwent complete CRS and HIPEC. The median (range) age was 56 (20-82) years with 342/519 (66%) females. The mean overall (OS) and disease free survival (DFS) in the 131/519 patients who had normal preoperative tumour markers was 168 (128-207) and 125 (114-136) months respectively, significantly higher when compared with the 109/519 (21%) who had all three tumour markers elevated (OS of 65 (42-88) and DFS of 55 (41-70) months respectively) (P = 0.002).

CONCLUSIONS

Elevated tumour markers predict an increased risk of recurrence and reduced survival after complete CRS. This may reflect cell biology in low grade tumours and is an independent prognostic feature. Further analysis may help to select patients for post-operative chemotherapy, second look procedures or stratification of follow up.

Aggressive pseudomyxoma peritonei: a case report with an unusual clinical presentation

Introduction. Pseudomyxoma peritonei (PMP) is an uncommon surgical entity. We report a case of aggressive disease with an unusual clinical presentation and we analyze current data on diagnosis and management of PMP. Case Presentation. A 71-year-old male patient presented with intermittent diarrhea and loss of appetite during the last two months, without any other classic symptoms of PMP. The clinical examination was misleading due to patient's obesity. The radiological evaluation revealed ascites of the abdomen and possible mucocele of the appendix, whereas the laboratory exams showed high values of specific tumour markers. The patient underwent an exploratory laparotomy for definite diagnosis. Biopsies and immunohistochemical examination confirmed the diagnosis of an aggressive and extended peritoneal mucinous carcinomatosis (PMCA). The patient was programmed for adjuvant systematic chemotherapy, which was not completed due to progression of the disease. Conclusions. Progressed PMP can present with unspecific symptoms that mislead diagnosis. Cytoreductive surgery in combination with systematic chemotherapy could be appropriate for aggressive PMCA, even with an unfavourable prognosis.

Carbohydrate antigen 19-9 (CA 19-9) is an independent prognostic indicator in pseudomyxoma peritonei post cytoreductive surgery and perioperative intraperitoneal chemotherapy

INTRODUCTION

Pseudomyxoma peritonei (PMP) is characteristically divided into two histopathological subtypes; disseminated peritoneal adenomucinosis (DPAM) and peritoneal mucinous carcinomatosis (PMCA). The latter is associated with a worse prognosis. However, even within the DPAM group, there is a considerable variation in outcome. In this study we investigate the role of baseline serum tumor markers CA 19-9, CEA and CA-125 in further stratifying survival.

METHODS

Over 16 years, 218 patients with PMP were treated with cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy (PIC) at our institution. A CA-125 level of >35 U/L, CA 19-9 of >40 U/mL and CEA of >3 ng/mL were considered positive or elevated outside the laboratory reference range. The impact of clinicopathologic and treatment-related variables on overall survival (OS) was analyzed with the Kaplan Meier method. Survival curves were compared using the log-rank test. Variables deemed significant by univariate analyses were entered into multivariate analysis using the Cox proportional hazards model.

RESULTS

Within the DPAM group, the 5-year survival of patients who were CA 19-9 positive versus those with normal values were 58% and 90% respectively (P<0.001). Other variables found to negatively impact on OS in univariate analyses were completeness of cytoreduction (CC) score 2/3 (P<0.001), peritoneal cancer index (PCI) >25 (P<0.001) and male gender (P=0.017). In the Cox regression model, only CA 19-9 positivity was found to be an independent prognostic factor for OS (P=0.034). In addition to marker positivity, the absolute level of CA 19-9 was also prognostically significant. In patients with CA 19-9>1,000 U/mL, the 5-year survival was 23%, in contrast to 90% in patients with CA 19-9<100 U/mL (P<0.001). In the PMCA cohort, only CC-score was found to be associated with OS (P<0.001).

CONCLUSIONS

Our study provides relevant prognostic information for the DPAM subtype in staging and prioritizing surgery; as even in apparently indolent disease, some patients have poorer survival. CA 19-9 elevation may also be useful in identifying patients who would potentially benefit from adjuvant therapy and/or closer post-operative surveillance. The potential role of CA 19-9 in mediating tumor cell adhesion and disease progression in PMP should be further investigated to deepen our understanding of the disease's inherent biological behavior. If a true relationship exists, CA 19-9 may be a conceivable target for immunotherapy.

Inflammatory markers in blood and serum tumor markers predict survival in patients with epithelial appendiceal neoplasms undergoing surgical cytoreduction and intraperitoneal chemotherapy

BACKGROUND

The study examines the role inflammatory and tumor markers as biomarkers to preoperatively predict outcome in patients with epithelial appendiceal neoplasm undergoing cytoreduction and intraperitoneal chemotherapy.

METHODS

Associations between baseline variables, tumor markers [CEA (carcinoembyronic antigen], CA125, CA199), inflammatory markers including neutrophils-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and C-reactive protein (CRP) with progression-free survival (PFS) and overall survival (OS) were examined in patients undergoing surgical cytoreduction and intraperitoneal chemotherapy for epithelial appendiceal neoplasm.

RESULTS

A total of 174 patients with epithelial appendiceal neoplasm (low-grade pseudomyxoma, n = 117; appendiceal cancer, n = 57) underwent cytoreduction. On univariate analysis, all 3 inflammatory and tumor markers predicted for both PFS and OS, respectively; NLR ≤ 2.6 (P = 0.01, P = 0.002), PLR ≤ 166 (P = 0.006, P = 0.016), CRP ≤ 12.5 (P = 0.001, P = 0.008), CEA (P < 0.001, P = 0.001), CA125 (P = 0.004, P < 0.001), CA199 (P < 0.001, P < 0.001). On multivariate analysis, there were no independent predictors of OS. PFS was independently associated with the presence of lymph node metastasis (P = 0.02), CA199 > 37 (P = 0.003), and a CRP > 12.5 (P = 0.013). A higher peritoneal cancer index (PCI > 24) was associated with elevation in CEA > 12, CA125 > 39, CA199 > 37, PLR > 166 and CRP > 12. The tumor histologic subtype was associated with CA 199 levels.

CONCLUSIONS

The results from this investigation suggest that preoperative inflammatory markers in blood and serologic tumor markers may predict outcomes and are associated with tumor biology in patients with epithelial appendiceal neoplasm undergoing cytoreduction and intraperitoneal chemotherapy treatment.

Significance of serum tumor marker levels in peritoneal carcinomatosis of appendiceal origin

BACKGROUND

The significance of tumor markers in patients with appendiceal carcinomatosis is poorly defined. We determined preoperative and postoperative tumor marker levels in patients undergoing cytoreductive surgery (CRS) and heated intraperitoneal chemoperfusion (HIPEC) and examined their association with clinicopathologic features and survival.

METHODS

A total of 176 patients undergoing attempted CRS/HIPEC for appendiceal carcinomatosis had at least 1 tumor marker measured. Marker levels were correlated with tumor characteristics and oncologic outcomes. Kaplan-Meier curves and multivariate Cox regression models were used to identify prognostic factors affecting progression and survival.

RESULTS

At least 1 marker was elevated prior to CRS/HIPEC in 70 % of patients (CEA, 54.1 %; CA19-9, 47.7 %; CA-125, 47.2 %). Among patients with elevated preoperative marker levels, normalization occurred postoperatively in 79.4 % for CEA, 92.3 % for CA19-9, and 60 % for CA-125. Absolute preoperative tumor marker levels correlated with peritoneal carcinomatosis index (PCI) (p < .0002), and the number of elevated markers was associated with PCI and progression-free survival (PFS). Elevated postoperative CEA level was associated with decreased PFS (median, 13 vs 36 months, p = .0008). On multivariate Cox regression analysis, elevated preoperative CA19-9 was associated with shorter PFS (hazard ratio [HR] 2.9, 95 % confidence interval [95 % CI] 1.5-5.3, p = .0008), whereas elevated CA-125 was associated with shorter overall survival (HR 2.6, 95 % CI 1.3-5.4, p = .01).

CONCLUSIONS

Most patients with appendiceal carcinomatosis will have at least 1 elevated tumor marker and will normalize following CRS/HIPEC, allowing for ongoing surveillance. CA19-9 is a promising biomarker for early progression following CRS/HIPEC, whereas CA-125 is associated with shorter survival.

Pseudomyxoma peritonei: disseminated peritoneal adenomucinosis variant

Pseudomyxoma peritonei (PMP) is a rare disease and even after advances in its understanding and management it often has a protracted course and multiple recurrences despite aggressive surgery and intraperitoneal chemotherapy. The current preferred treatment of ultraradical surgery and hyperthermic intraperitoneal chemotherapy is associated with considerable morbidity and significant mortality. With better understanding we know that the prognosis of the disease is dependent on the degree of total excision of the disease and type of histology. The authors propose the need to be selective in applying aggressive treatment regimens in all patients with PMP regardless of factors like age, low malignant variants and expected morbidities. Our patient had a good outcome with a conservative approach. However, large studies are needed before reaching a conclusion.

Pseudomyxoma peritonei

Pseudomyxoma peritonei (PMP) is an uncommon “borderline malignancy” generally arising from a perforated appendiceal epithelial tumour. Optimal treatment involves a combination of cytoreductive surgery (CRS) with heated intraperitoneal chemotherapy (HIPEC). Controversy persists regarding the pathological classification and its prognostic value. Computed tomography scanning is the optimal preoperative staging technique. Tumour marker elevations correlate with worse prognosis and increased recurrence rates. Following CRS with HIPEC, 5-year survival ranges from 62.5% to 100% for low grade, and 0%-65% for high grade disease. Treatment related morbidity and mortality ranges from 12 to 67.6%, and 0 to 9%, respectively. Surgery and HIPEC are the optimal treatment for PMP which is at best a “borderline” peritoneal malignancy.

Pseudomyxoma peritonei: biological features are the dominant prognostic determinants after complete cytoreduction and hyperthermic intraperitoneal chemotherapy

OBJECTIVE

To investigate outcome and prognostic factors in patients with pesudomyxoma peritonei (PMP) treated by complete cytoreduction and hyperthermic intraperitoneal chemotherapy.

BACKGROUND

After comprehensive treatment, prognosis of PMP is predominantly dependent on the completeness of cytoreduction. Once complete cytoreduction is achieved, additional factors predicting long-term outcome are still poorly understood.

METHODS

From a prospective database, we selected 102 patients undergoing complete cytoreduction (residual tumor nodules < or =2.5 mm) and closed-abdomen hyperthermic intraperitoneal chemotherapy with mitomycin-C and cisplatin. Previously, 22 patients had systemic chemotherapy. PMP was histologically classified into disseminated peritoneal adenomucinosis, peritoneal mucinous carcinomatosis (PMCA), and intermediate/discordant group. Twenty-one patient-, tumor-, and treatment-related variables were assessed by multivariate analysis with respect to overall (OS) and progression-free (PFS) survival. The following immunohistochemical markers were tested: cytokeratin (CK)-7, CK-20, CDX-2, MUC-2, and MUC-5AC.

RESULTS

Operative mortality was 1%. Seventy-eight patients were diagnosed with disseminated peritoneal adenomucinosis, 24 with PMCA, none with intermediate/discordant group. For the overall series, median follow-up, 5-year OS, and PFS were 45 months (range 1-110), 84.4%, and 48.3%, respectively. In most cases, CK20, CDX-2, and MUC-2 were diffusely positive, whereas CK-7 and MUC-5AC were variably expressed. At multivariate analysis, previous systemic chemotherapy and PMCA correlated to both worse OS and PFS, elevated serum CA125 only to worse PFS. CK20, CDX-2, and MUC-2 expression correlated to prognosis at univariate analysis.

CONCLUSIONS

After complete cytoreduction and hyperthermic intraperitoneal chemotherapy, prognosis of PMP is primarily dependent on pathologic and biologic features. MUC-2, CK-20, and CDX-2 may be related to the disease biology. Understanding PMP molecular basis may facilitate personalized treatment.

Consensus statement on the loco-regional treatment of appendiceal mucinous neoplasms with peritoneal dissemination (pseudomyxoma peritonei)

Pseudomyxoma peritonei (PMP) is a rare condition mostly originating from low malignant potential mucinous tumours of the appendix. Although this disease process is minimally invasive and rarely causes haematogenous or lymphatic metastases, expectation of long-term survival are limited with no prospect of cure. Recently, the combined approach of cytoreductive surgery (CRS) and perioperative loco-regional chemotherapy (PLC) has been proposed as the standard of treatment for the disease. The present paper summarizes the available literature data and the main features of the comprehensive loco-regional treatment of PMP. The controversial issues concerning the indications and technical methodology in PMP management were discussed through a web-based voting system by internationally known experts. Results were presented for further evaluation during a dedicated session of "The Fifth International Workshop on Peritoneal Surface Malignancy (Milan, Italy, December 4-6, 2006)". The experts agreed that multiple prospective trials support a benefit of the procedure in terms of improved survival, as compared with historical controls. Concerning the main controversial methodological questions, there was an high grade of consistency among the experts and agreement with the findings of the literature.

Retrospective multicenter study of a clinicopathologic analysis of pseudomyxoma peritonei associated with ovarian tumors (KGOG 3005)

The purpose of this study is to assess clinicopathologic features of pseudomyxoma peritonei (PMP) that has ovarian pathology and its relationship with the prognosis. From 1995 to 2004, the clinical records and follow-up data of 35 patients with PMP, which had primarily originated from the ovary, were collected from 11 institutes of gynecologic oncology in Korea and retrospectively analyzed. All patients had ovarian lesion histologically confirmed with PMP. The mean age at diagnosis was 53.7 years (range: 16-82 years). There were 25 (71.4%) patients with disseminated peritoneal adenomucinosis, 5 (14.3%) with peritoneal mucinous carcinomatosis with intermediate group, and 5 (14.3%) with peritoneal mucinous carcinomatosis. The clinical stages at diagnosis were IA in 2 patients, IIIB in 4, IIIC in 23, IV in 1, and unknown in 5. In preoperative tumor markers, the positive rates were 72% (CA125), 47.4% (CA19-9), and 84.6% (CEA). Thirty-four patients underwent surgical staging or cytoreduction, and then 27 patients (77%) received adjuvant chemotherapy that was given to patients in a nonuniform fashion. The 5-year survival for 35 patients was 87%. Survival rate was significantly lower in patients >50 years of age (P = 0.002). Our data showed that age of the patient is the only significant prognostic factor in PMP that has ovarian lesion.

Pseudomyxoma peritonei--two novel orthotopic mouse models portray the PMCA-I histopathologic subtype

Background

Pseudomyxoma peritonei (PMP) is a rare malignant disease, most commonly originating from appendiceal lesions and characterized by accumulation of mucinous tumor tissue in the peritoneal cavity. Since the disease is infrequent, the task of carrying out studies of treatment efficacy and disease biology in the clinical setting is challenging, warranting the development of relevant in vitro and in vivo PMP models.

Methods

Human tumor tissue was implanted in the peritoneal cavity of nude mice to establish two orthotopic models exhibiting noninvasive intraperitoneal growth without metastasis development.

Results

Xenograft tissues have retained essential properties of the original human tumors, such as macro- and microscopic growth patterns, mucin production as well as expression of carcinoembryonal antigen, cytokeratins 20 and 7 and the proliferation marker pKi67. Upon microscopic examination, the human tumors were categorized as the PMCA-I (peritoneal mucinous carcinomatosis of intermediate features) subtype, which was conserved through 14 examined passages in mice, for the first time modeling this particular histopathologic category.

Conclusion

In conclusion, two novel orthotopic models of human PMP have been established that consistently portray a distinct histopathologic subtype and reflect essential human tumor properties. Xenografts can easily and reproducibly be transferred to new generations of mice with acceptable passage periods, rendering the models as attractive tools for further studies of PMP biology and treatment.

Prognostic Value of Circulating Tumor Markers in Patients with Pseudomyxoma Peritonei Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

Encouraging results have been recently reported in selected patients affected by pseudomyxoma peritonei (PMP) treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The selection factors predicting clinical outcome are still a matter of clinical investigation. We assessed the prognostic reliability of serum tumor markers in a large series of patients with PMP undergoing CRS and HIPEC.

METHODS

Sixty-two patients with PMP were operated on at a single institution with the intent of performing adequate CRS (residual tumor nodules </=2.5mm) and HIPEC. Baseline and serial marker measurements were prospectively collected and tested by multivariate analysis with respect to adequate cytoreduction, overall (OS) and progression-free (PFS) survival, along with the following variables: age, sex, performance status, prior surgical score, histological subtype, prior systemic chemotherapy, disease extent, completeness of cytoreduction.

RESULTS

Baseline diagnostic sensitivity was 72.6% for CEA, 58.1% for CA19.9, 58.7% for CA125, 36.1% for CA15.3. Fifty-three patients underwent adequate CRS and HIPEC; gross residual tumor was left after surgery in nine. Adequate CRS was performed in 19/27 patients with elevated and in 19/19 with normal baseline CA125 (P = .0140). The other markers were unable to predict the completeness of CRS by univariate analysis. Baseline elevated CA19.9 was an independent predictor of reduced PFS; inadequate CRS and aggressive histology were independent prognostic factors for both reduced OS and PFS.

CONCLUSION

Normal CA125 correlated to the likelihood to achieve adequate CRS, which is a significant prognostic factor for PMP. Increased baseline CA19.9 was an independent predictor of worse PFS after CRS and HIPEC.

Early results of surgery in 123 patients with pseudomyxoma peritonei from a perforated appendiceal neoplasm

PURPOSE

Epithelial appendiceal tumors are uncommon but can present as an emergency simulating appendicitis, or unexpectedly at laparotomy, laparoscopy, or on cross-sectional imaging. Occult rupture with features of pseudomyxoma peritonei may be encountered. We report the operative findings, pathologic assessment, and early outcomes in 123 consecutive patients with a perforated appendiceal neoplasm presenting as pseudomyxoma peritonei.

METHODS

From March 1994 to March 2004, 292 patients were referred to a peritoneal malignancy surgical treatment center. Complete tumor removal (cytoreduction) was attempted in selected patients and, if achieved, surgery was combined with intraoperative, intraperitoneal mitomycin C (10 mg/m(2)).

RESULTS

In total, 123 patients (52 males; 41 percent) underwent laparotomy for a perforated appendiceal malignancy presenting as pseudomyxoma peritonei. The median age was 52 (range 30-77) years. Complete cytoreduction was achieved in 83 of 123 patients (67 percent), major palliative resection in 34 patients (28 percent), and 6 patients (5 percent) were inoperable. Postoperative mortality was 6 of 123 patients (5 percent). Kaplan-Meier analysis of the 83 patients who had complete tumor removal predicted 75 percent disease-free survival at five years.

CONCLUSIONS

A perforated appendiceal epithelial tumor most frequently presents as pseudomyxoma peritonei. This treatment strategy, involving surgery and intraperitoneal chemotherapy, can result in good outcomes in this rare and otherwise fatal disease.

Pseudomyxoma peritonei

Pseudomyxoma peritonei (PMP) is a rare condition, which is known for its high mortality when not treated properly. The first step to improve prognosis of these patients is to recognize this clinical syndrome preferably in an early stage. Knowledge of pathogenesis and common diagnostic tools is essential in this regard. Treatment strategy for PMP should pursue complete cytoreduction and prevention of recurrence or progression. Combined modality treatment, consisting of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy, seems very efficient in this regard. This approach is currently carried out in many centers throughout the world with promising results and seems to win ground as the standard treatment approach.

Controversial origin of Pseudomyxoma peritonei

Pseudomyxoma peritonei describes the accumulation of mucinous material in the abdominal cavity. The main diagnostic problem appears when the primary site of origin could be appendix or ovary. In this paper describe clinicopathological features and biological markers that support appendiceal origin.

Pseudomyxoma peritonei--a revisit: report of 2 cases and literature review

Background

Pseudomyxoma peritonei (PMP) is a rare, chronic, relapsing, diagnostically challenging and poorly understood disease characterized by disseminated mucinous ascites and peritoneal implants.

Case presentation

We report two cases of PMP that represent the two biological variants of disseminated peritoneal adenomucinosis (DPAM) – the benign variant and the peritoneal mucinous carcinomatosis (PMCA) – the malignant variant, both of which were characterized by multiple relapses and progression of the disease despite aggressive management.

Conclusion

Even with a better understanding and recent advances in the management of these cases, PMP remains an enigmatic disease with a protracted clinical course characterized by multiple recurrences despite surgery and/or chemotherapy. Recognition of PMP as a delayed consequence years later should alert all surgeons to be extremely vigilant when treating mucinous neoplasms of the appendix, with special care being directed towards adequate excision and thorough debridement at the initial diagnosis.

Management of an unexpected appendiceal neoplasm

BACKGROUND

Appendiceal neoplasms are rare and most present unexpectedly as acute appendicitis. The classification and management are confusing, and there are few substantial reports in the literature.

METHODS

A systematic literature review was performed to access relevant publications on the presentation, pathology and management of appendiceal tumours.

RESULTS

Appendiceal tumours account for 0.4 to 1 per cent of all gastrointestinal tract malignancies and are found in 0.7 to 1.7 per cent of appendicectomy specimens. Carcinoid tumours are most common. Most are cured by simple appendicectomy if the tumour is less than 2 cm in size and does not involve the resection margin or mesoappendix. Epithelial tumours may present with, or in time develop, pseudomyxoma peritonei, the optimal management of which involves complete tumour resection and intraperitoneal chemotherapy, usually available only in specialized centres.

CONCLUSION

Suggested algorithms for the management of unexpected appendiceal tumours are provided. Recommendations are made for follow-up of patients with a perforated appendiceal epithelial tumour.