The Chicago Consensus on peritoneal surface malignancies: Management of appendiceal neoplasms

Pseudomyxoma peritonei arising from mature ovarian teratoma, a rare entity: Report of six cases and review of current literature

Background

Pseudomyxoma peritonei (PMP) is a clinical syndrome characterised by intraperitoneal accumulation of mucus due to mucinous neoplasia. It is a rare condition affecting 1-2 per million individuals per year. The majority of PMP arises from a ruptured mucinous appendiceal tumour, with infrequent occurrences from other primary gastrointestinal tumours and mucinous ovarian tumours. PMP arising from a mature ovarian teratoma is a rare entity, with limited case reports in the literature. Given the infrequent and sporadic occurrences of these tumours, little is known about the tumour behaviour and prognosis.

Case series and literature review

Herein, we report six cases of PMP arising from a mature ovarian teratoma who were treated with primary cytoreductive surgery (CRS), with one case of recurrence. Literature review identified 21 cases from 12 manuscripts. Nineteen patients were treated with CRS alone, with two patients receiving adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC). Follow up data were variably reported, with no recurrence in 20 patients during their follow up of 5-54 months. One patient reported to have died of disease at 49 months.

Conclusion

Despite the lack of high-quality evidence and limitations of small case series, our review indicates that close surveillance after CRS could be considered as the preferred treatment over more morbid CRS and HIPEC, with HIPEC reserved for patients who recur or progress after CRS.

Efficacy and safety of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy in patients with pancreatic cancer peritoneal metastasis

OBJECTIVES

Pancreatic cancer with peritoneal metastasis presents a challenging prognosis, with limited effective treatment options available. This study aims to evaluate the efficacy and safety of combining cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) as a treatment strategy for this patient group.

METHODS

A retrospective analysis was conducted on patients with peritoneal metastasis of pancreatic cancer who underwent CRS + HIPEC treatment at Beijing Shijitan Hospital from March 2017 to December 2023. The study focused on assessing clinical features, the incidence of sever adverse events (SAEs), and overall survival (OS).

RESULTS

A total of 10 patients were enrolled in this study. The median OS was 24.2 months, suggesting an improvement over traditional therapies. While SAEs were noted, including two cases of severe complications necessitating additional surgical interventions, no perioperative fatalities were recorded. The overall survival time for patients with CC0/1 was not significantly different from that of patients with CC2/3, and no prognostic predictors were identified.

CONCLUSIONS

The combination of CRS and HIPEC appears to be a viable and promising treatment modality for patients with peritoneal metastasis of pancreatic cancer, offering an improved survival rate with manageable safety concerns. Further research is needed to refine patient selection criteria and to explore the long-term benefits of this approach.

The 2022 PSOGI International Consensus on HIPEC Regimens for Peritoneal Malignancies: Pseudomyxoma Peritonei

BACKGROUND

The combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) constitutes the established standard of care for pseudomyxoma peritonei patients. However, the role of HIPEC lacks validation through randomized trials, leading to diverse proposed treatment protocols. This consensus seeks to standardize HIPEC regimens and identify research priorities for enhanced clarity.

METHODS

The steering committee applied the patient, intervention, comparator, and outcome method to formulate crucial clinical questions. Evaluation of evidence followed the Grading of Recommendations, Assessment, Development, and Evaluation system. Consensus on HIPEC regimens and research priorities was sought through a two-round Delphi process involving international experts.

RESULTS

Out of 90 eligible panelists, 71 (79%) participated in both Delphi rounds, resulting in a consensus on six out of seven questions related to HIPEC regimens. An overwhelming 84% positive consensus favored combining HIPEC with CRS, while a 70% weak positive consensus supported HIPEC after incomplete CRS. Specific HIPEC regimens also gained consensus, with 53% supporting Oxaliplatin 200 mg/m2 and 51% favoring the combination of cisplatin (CDDP) associated with mitomycin-C (MMC). High-dose MMC regimens received an 89% positive recommendation. In terms of research priorities, 61% of panelists highlighted the importance of studies comparing HIPEC regimens post CRS. The preferred regimens for such studies were the combination of CDDP/MMC and high-dose MMC.

CONCLUSIONS

The consensus recommends the application of HIPEC following CRS based on the available evidence. The combination of CDDP/MMC and high-dose MMC regimens are endorsed for both current clinical practice and future research efforts.

Beyond boundaries: Feasibility of curved linear array echoendoscope in appendiceal neoplasm detection

We recently read with great interest a study by Zhang et al in the World Journal of Gastroenterology. In our practice, we focus specifically on examining appendiceal mucinous neoplasms (AMNs) with endoscopic ultrasound (EUS) using different scopes. AMNs are rare neoplastic lesions characterized by an accumulation of mucin inside a cystic dilatation of the appendix. Clinically, they can present as nonspecific acute appendicitis. AMNs can turn into a life-threatening condition, termed pseudomyxoma peritonei, in which the ruptured appendix causes accumulation of mucin in the abdomen. Therefore, accurate and rapid diagnosis of AMN is essential. EUS is able to confirm and stage AMNs; although, EUS examination was once limited to the rectal and anal regions due to the conventional oblique-view scopes. With the emergence of new forward-view linear echoendoscopes and instruments like EUS miniprobes and overtubes, the scope of examination is changing. Herein, we discuss the feasibility of using the curved linear array echoendoscopes to examine cecal and appendiceal orifice lesions.

Multi-Institutional Study Evaluating the Role of Circulating Tumor DNA in the Management of Appendiceal Cancers

PURPOSE

Conventional surveillance methods are poorly sensitive for monitoring appendiceal cancers (AC). This study investigated the utility of circulating tumor DNA (ctDNA) in evaluating systemic therapy response and recurrence after surgery for AC.

METHODS

Patients from two specialized centers who underwent tumor-informed ctDNA testing (Signatera) were evaluated to determine the association between systemic therapy and ctDNA detection. In addition, the accuracy of ctDNA detection during surveillance for the diagnosis of recurrence after complete cytoreductive surgery (CRS) for grade 2-3 ACs with peritoneal metastases (PM) was investigated.

RESULTS

In this cohort of 94 patients with AC, most had grade 2-3 tumors (84.0%) and PM (84.0%). Fifty patients completed the assay in the presence of identifiable disease, among which ctDNA was detected in 4 of 7 (57.1%), 10 of 16 (62.5%), and 19 of 27 (70.4%) patients with grade 1, 2, and 3 diseases, respectively. Patients who had recently received systemic chemotherapy had ctDNA detected less frequently (7 of 16 [43.8%] v 26 of 34 [76.5%]; odds ratio, 0.22 [95% CI, 0.06 to 0.82]; P = .02). Among 36 patients with complete CRS for grade 2-3 AC-PM, 16 (44.4%) developed recurrence (median follow-up, 19.6 months). ctDNA detection was associated with shorter recurrence-free survival (median 11.3 months v not reached; hazard ratio, 14.1 [95% CI, 1.7 to 113.8]; P = .01) and showed high accuracy for the detection of recurrence (sensitivity 93.8%, specificity 85.0%). ctDNA was more sensitive than carcinoembryonic antigen (62.5%), CA19-9 (25.0%), and CA125 (18.8%) and was the only elevated biomarker in four (25%) patients with recurrence.

CONCLUSION

This study revealed a reduced ctDNA detection frequency after systemic therapy and accurate recurrence assessment after CRS. These findings underscore the role of ctDNA as a predictive and prognostic biomarker for grade 2-3 AC-PM management.

Active surveillance for low-grade appendiceal mucinous neoplasm (LAMN)

Objectives

Due to the scarcity of low-grade appendiceal mucinous neoplasm (LAMN), there is an absence of systematized guidelines concerning its management, especially after incidental finding on an appendiceal specimen. In this study, we evaluate the active surveillance (AS) strategy adopted for a series of patients diagnosed with LAMN on resection specimens who were considered to have a low risk of pseudomyxoma progression.

Methods

Thirty patients were included between April 2014 and July 2021, with a female majority and a median follow-up period of 3.1 years. The inclusion criteria were as follows: LAMN diagnosis on appendiceal specimens, confirmed in an expert center, limited extra-appendiceal mucin resected and localized around the appendix, normal biology (CEA, CA199, CA125) and normal abdominopelvic MRI. AS included physical exam (trocar scar), biology and MRI, 6 months postoperatively, then yearly for 10 years.

Results

As an initial surgery, 77 % had an appendectomy as their initial intervention, 17 % had a cecectomy, and 6 % had a right colectomy. After follow-up, 87 % of patients showed no sign of disease progression by MRI, while 13 % progressed to PMP. MRI performed in the first postoperative year predicted the disease prognosis in 97 % of patients.

Conclusions

The AS strategy, based on MRI, is a valid option after incidental LAMN diagnosis.

Peritoneal dissemination of appendiceal goblet cell adenocarcinoma mimicking white pus caused by peritonitis following appendicitis: an instructive case report

BACKGROUND

Goblet cell adenocarcinoma is an extremely rare tumor in which the same cells exhibit both mucinous and neuroendocrine differentiation. It is considered more aggressive compared to conventional carcinoids and more likely to cause metastasis.

CASE PRESENTATION

We report a case of goblet cell adenocarcinoma with peritoneal metastases. A 62-year-old man underwent appendectomy for acute appendicitis. Intraoperatively, inflammatory white pus and a small amount of dirty ascites were observed in the lower abdomen with severely inflamed appendix. Histopathological examination of the specimen collected during appendectomy revealed goblet cell adenocarcinoma with a positive surgical margin. One month later, additional ileal resection was planned. Laparoscopic examination revealed disseminated nodules throughout the abdominal cavity. Therefore, the patient underwent resection of the peritoneal nodules. The peritoneal specimens confirmed the histopathological findings. Thus we diagnosed the patient with peritoneal dissemination of appendiceal goblet cell adenocarcinoma.

CONCLUSIONS

In cases wherein white pus is observed during surgery for acute appendicitis, considering the possibility of dissemination, collecting samples for histopathological examination, and initiating early treatment are crucial.

Serum Tumor Markers and Outcomes in Patients With Appendiceal Adenocarcinoma

Importance

Serum tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and cancer antigen 125 (CA125) have been useful in the management of gastrointestinal and gynecological cancers; however, there is limited information regarding their utility in patients with appendiceal adenocarcinoma.

Objective

To assess the association of serum tumor markers (CEA, CA19-9, and CA125) with clinical outcomes and pathologic and molecular features in patients with appendiceal adenocarcinoma.

Design, Setting, and Participants

This is a retrospective cohort study at a single tertiary care comprehensive cancer center. The median (IQR) follow-up time was 52 (21-101) months. Software was used to query the MD Anderson internal patient database to identify patients with a diagnosis of appendiceal adenocarcinoma and at least 1 tumor marker measured at MD Anderson between March 2016 and May 2023. Data were analyzed from January to December 2023.

Main Outcomes and Measures

Association of serum tumor markers with survival in patients with appendiceal adenocarcinoma. Cox proportional hazards regression analyses were also performed to assess associations between clinical factors (serum tumor marker levels, demographics, and patient and disease characteristics) and patient outcomes (overall survival).

Results

A total of 1338 patients with appendiceal adenocarcinoma were included, with a median (range) age at diagnosis of 56.5 (22.3-89.6) years. The majority of the patients had metastatic disease (1080 patients [80.7%]). CEA was elevated in 742 of the patients tested (56%), while CA19-9 and CA125 were elevated in 381 patients (34%) and 312 patients (27%), respectively. Individually, elevation of CEA, CA19-9, or CA125 were associated with worse 5-year survival; elevated vs normal was 81% vs 95% for CEA (hazard ratio [HR], 4.0; 95% CI, 2.9-5.6), 84% vs 92% for CA19-9 (HR, 2.2; 95% CI, 1.4-3.4), and 69% vs 93% for CA125 (HR, 4.6; 95% CI, 2.7-7.8) (P < .001 for all). Quantitative evaluation of tumor markers was associated with outcomes. Patients with highly elevated (top 10th percentile) CEA, CA19-9, or CA125 had markedly worse survival, with 5-year survival rates of 59% for CEA (HR, 9.8; 95% CI, 5.3-18.0), 64% for CA19-9 (HR, 6.0; 95% CI, 3.0-11.7), and 57% for CA125 (HR, 7.6; 95% CI, 3.5-16.5) (P < .001 for all). Although metastatic tumors had higher levels of all tumor markers, when restricting survival analysis to 1080 patients with metastatic disease, elevated CEA, CA19-9, or CA125 were all still associated worse survival (HR for CEA, 3.4; 95% CI, 2.5-4.8; P < .001; HR for CA19-9, 1.8; 95% CI, 1.2-2.7; P = .002; and HR for CA125, 3.9; 95% CI, 2.4-6.4; P < .001). Interestingly, tumor grade was not associated with CEA or CA19-9 level, while CA-125 was slightly higher in high-grade tumors relative to low-grade tumors (mean value, 18.3 vs 15.0; difference, 3.3; 95% CI, 0.9-3.7; P < .001). Multivariable analysis identified an incremental increase in the risk of death with an increase in the number of elevated tumor markers, with an 11-fold increased risk of death in patients with all 3 tumor markers elevated relative to those with none elevated. Somatic mutations in KRAS and GNAS were associated with significantly higher levels of CEA and CA19-9.

Conclusions and Relevance

In this retrospective study of serum tumor markers in patients with appendiceal adenocarcinoma, CEA, CA19-9, and CA125 were associated with overall survival in appendiceal adenocarcinoma. Given their value, all 3 biomarkers should be included in the initial workup of patients with a diagnosis of appendiceal adenocarcinoma.

Building an Efficient Peritoneal Surface Malignancies Program Despite the Lower-Middle-Income Barriers: Ukraine Experience

PURPOSE

Cytoreductive surgery/hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) programs are often limited to centers in developed countries because of extensive requirements. We aimed to analyze efficacy and challenges of CRS/HIPEC centers in lower-middle-income settings in the Ukraine example.

METHODS

A multicenter descriptive study was conducted using data sets (2008-2022) from Kyiv, Lviv, and Odesa centers. Patients with appendiceal neoplasm (AN); colorectal cancer (CRC); malignant peritoneal mesothelioma (MPM); and epithelial ovarian, fallopian tube, and primary peritoneal cancer (EOC) treated with CRS ± HIPEC were included. Overall survival (OS) was analyzed for N ≥ 20 cohorts using the Kaplan-Meier method.

RESULTS

We included 596 patients. At Kyiv and Lviv centers, 37 and 28 patients with AN had completeness of cytoreduction (CC-0/1) rates of 84% and 71%, respectively. Thirty-day major morbidity stood at 24% and 18%, respectively. Median OS was not reached (NR) at both centers. Nineteen patients with CRC from Kyiv, 11 from Lviv, and 156 from Odesa had CC-0/1 rates of 84%, 91%, and 86%, respectively. Thirty-day major complications occurred in 16%, 18%, and 8%, respectively. Median OS in the Odesa cohort was 35 (95% CI, 32 to 38) months. Among 15 Kyiv, five Lviv, and six Odesa patients with MPM, CC-0/1 rates were 67%, 80%, and 100%, respectively, while major complications occurred in 13%, 0%, and 17%, respectively. OS was not analyzed because of small MPM cohorts. At Kyiv, Lviv, and Odesa centers, 91, 40, and 89 patients, respectively, had primary EOC. CC-0/1 rates were 79%, 100%, and 80%, and 30-day major morbidity rates were 23%, 5%, and 6%, respectively. Median OS was NR, 71 (95% CI, 32 to 110), and 67 (95% CI, 61 to 73) months, respectively.

CONCLUSION

CRS/HIPEC programs in lower-middle-income environment can achieve safety and survival that meet global standards. Our discussion highlights common obstacles in such settings and proposes effective overcoming strategies.

Whole-Exome Sequencing Identifies Mutation Profile and Mutation Signature-Based Clustering Associated with Prognosis in Appendiceal Pseudomyxoma Peritonei

Pseudomyxoma peritonei (PMP) is a rare malignant clinical syndrome with little known about the global mutation profile. In this study, whole-exome sequencing (WES) was performed in 49 appendiceal PMP to investigate mutation profiles and mutation signatures. A total of 4,020 somatic mutations were detected, with a median mutation number of 56 (1-402). Tumor mutation burden (TMB) was generally low (median 1.55 mutations/Mb, 0.12-11.26 mutations/Mb). Mutations were mainly enriched in the function of cancer-related axonogenesis, extracellular matrix-related processes, calcium signaling pathway, and cAMP signaling pathway. Mutations in FCGBP, RBFOX1, SPEG, RTK-RAS, PI3K-AKT, and focal adhesion pathways were associated with high-grade mucinous carcinoma peritonei. These findings revealed distinct mutation profile in appendiceal PMP. Ten mutation signatures were identified, dividing patients into mutation signature cluster (MSC) 1 (N = 28, 57.1%) and MSC 2 (N = 21, 42.9%) groups. MSC (P = 0.007) was one of the four independent factors associated with 3-year survival. TMB (P = 0.003) and microsatellite instability (P = 0.002) were independent factors associated with MSC 2 grouping. Taken together, our findings provided a broader view in the understanding of molecular pathologic mechanism in appendiceal PMP and may be critical to developing an individualized approach to appendiceal PMP treatment.

IMPLICATIONS

This work describes exhaustive mutation profile of PMP based on WES data and derives ten mutation signatures, which divides patients into two clusters and serve as an independent prognostic factor associated with 3-year survival.

Taxane-Based Chemotherapy Is Effective in Metastatic Appendiceal Adenocarcinoma

Appendiceal cancer is a rare, orphan disease with no therapies currently approved by the FDA for its treatment. Given the limited data regarding drug efficacy, these tumors have historically been treated with chemotherapy designed for colon cancer. However, an overwhelming body of molecular data has demonstrated that appendiceal adenocarcinoma is a distinct entity with key molecular differences from colon cancer, notably rare APC mutation. Recognizing that APC loss-of-function is thought to contribute to taxane resistance and that taxanes are effective in the treatment of other gastrointestinal tumors, including gastric, esophageal, and small bowel adenocarcinoma, we completed a single-center retrospective study to assess efficacy. In a cohort of 13 patients with metastatic appendiceal adenocarcinoma, treated with taxane chemotherapy the median overall survival was 8.8 months. Of 10 evaluable patients, we observed 3 responses, 4 patients with stable disease, and 3 with progression (30% response rate, 70% disease control rate). The results of this study showing activity of taxane-based chemotherapy in appendiceal adenocarcinoma support further clinical investigation of taxane therapy in this orphan disease.

Progress in the Treatment of Peritoneal Metastatic Cancer and the Application of Therapeutic Nanoagents

Peritoneal metastatic cancer is a cancer caused by the direct growth of cancer cells from the primary site through the bloodstream, lymph, or peritoneum, which is a difficult part of current clinical treatment. In the abdominal cavity of patients with metastatic peritoneal cancer, there are usually nodules of various sizes and malignant ascites. Among them, nodules of different sizes can obstruct intestinal movement and form intestinal obstruction, while malignant ascites can cause abdominal distension and discomfort, and even cause patients to have difficulty in breathing. The pathology and physiology of peritoneal metastatic cancer are complex and not fully understood. The main hypothesis is "seed" and "soil"; i.e., cells from the primary tumor are shed and implanted in the peritoneal cavity (peritoneal metastasis). In the last two decades, the main treatment modalities used clinically are cytoreductive surgery (CRS), systemic chemotherapy, intraperitoneal chemotherapy, and combined treatment, all of which help to improve patient survival and quality of life (QOL). However, the small-molecule chemotherapeutic drugs used clinically still have problems such as rapid drug metabolism and systemic toxicity. With the rapid development of nanotechnology in recent years, therapeutic nanoagents for the treatment of peritoneal metastatic cancer have been gradually developed, which has improved the therapeutic effect and reduced the systemic toxicity of small-molecule chemotherapeutic drugs to a certain extent. In addition, nanomaterials have been developed not only as therapeutic agents but also as imaging agents to guide peritoneal tumor CRS. In this review, we describe the etiology and pathological features of peritoneal metastatic cancer, discuss in detail the clinical treatments that have been used for peritoneal metastatic cancer, and analyze the advantages and disadvantages of the different clinical treatments and the QOL of the treated patients, followed by a discussion focusing on the progress, obstacles, and challenges in the use of therapeutic nanoagents in peritoneal metastatic cancer. Finally, therapeutic nanoagents and therapeutic tools that may be used in the future for the treatment of peritoneal metastatic cancer are prospected.

The Clinical Significance of CEA, CA19-9, and CA125 in Management of Appendiceal Adenocarcinoma

Importance

Serum tumor markers CEA, CA19-9, & CA125 have been useful in the management of gastrointestinal and gynecological cancers, however there is limited information regarding their utility in patients with appendiceal adenocarcinoma.

Objective

Assessing the association of serum tumor markers (CEA, CA19-9, and CA125) with clinical outcomes, pathologic, and molecular features in patients with appendiceal adenocarcinoma.

Design

This is a retrospective study with results reported in 2023. The median follow-up time was 43 months.

Setting

Single tertiary care comprehensive cancer center.

Participants

Under an approved Institutional Review Board protocol, the Palantir Foundry software system was used to query the MD Anderson internal patient database to identify patients with a diagnosis of appendiceal adenocarcinoma and at least one tumor marker measured at MD Anderson between 2016 and 2023.

Results

A total of 1,338 patients with appendiceal adenocarcinoma were included, with a median age of 56.5 years. The majority of the patients had metastatic disease (80.7%). CEA was elevated in more than half of the patients tested (56%), while CA19-9 and CA125 were elevated in 34% and 27%, respectively. Individually, elevation of CEA, CA19-9, or CA125 were associated with worse 5-year survival; 82% vs 95%, 84% vs 92%, and 69% vs 93% elevated vs normal for CEA, CA19-9, and CA125 respectively (all p<0.0001). Quantitative evaluation of tumor markers increased prognostic ability. Patients with highly elevated (top 10th percentile) CEA, CA19-9 or CA125 had markedly worse survival with 5-year survival rates of 59%, 64%, and 57%, respectively (HR vs. normal : 9.8, 6.0, 7.6, all p<0.0001). Although metastatic tumors had higher levels of all tumor markers, when restricting survival analysis to 1080 patients with metastatic disease elevated CEA, CA19-9 or CA125 were all still associated worse survival (HR vs. normal : 3.4, 1.8, 3.9, p<0.0001 for CEA and CA125, p=0.0019 for CA19-9). Interestingly tumor grade was not associated with CEA or CA19-9 level, while CA-125 was slightly higher in high relative to low-grade tumors (18.3 vs. 15.0, p=0.0009). Multivariable analysis identified an incremental increase in the risk of death with an increase in the number of elevated tumor markers, with a 11-fold increased risk of death in patients with all three tumor markers elevated relative to those with none elevated. Mutation in KRAS and GNAS were associated with significantly higher levels of CEA and CA19-9.

Conclusions

These findings demonstrate the utility of measuring CEA, CA19-9, and CA125 in the management of appendiceal adenocarcinoma. Given their prognostic value, all three biomarkers should be included in the initial workup of patients diagnosed with appendiceal adenocarcinoma.

Taxane-based Chemotherapy is Effective in Metastatic Appendiceal Adenocarcinoma

Appendiceal cancer is a rare, orphan disease with no therapies currently approved by the FDA for its treatment. Given the limited data regarding drug efficacy, these tumors have historically been treated with chemotherapy designed for colon cancer. However, an overwhelming body of molecular data has demonstrated that appendiceal adenocarcinoma is a distinct entity with key molecular differences from colon cancer, notably rare APC mutation. Recognizing that APC loss-of-function is thought to contribute to taxane resistance, and that taxanes are effective in the treatment of other gastrointestinal tumors including gastric, esophageal, and small bowel adenocarcinoma, we completed a single-center retrospective study to assess efficacy. In a cohort of 13 patients with metastatic appendiceal adenocarcinoma, treated with taxane chemotherapy the median overall survival was 8.3 months. Of 10 evaluable patients we observed 3 responses, 4 patients with stable disease, and 3 with progression (30% response rate, 70% disease control rate). The results of this study showing activity of taxane-based chemotherapy in appendiceal adenocarcinoma support further clinical investigation of taxane therapy in this orphan disease.

Association of Systemic Chemotherapy Approaches With Outcomes in Appendiceal Peritoneal Metastases

INTRODUCTION

Many patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for appendiceal adenocarcinoma peritoneal metastases (APM) undergo preoperative systemic chemotherapy. The primary aim of this study is to evaluate differences in oncologic outcomes among two popular chemotherapy approaches in patients with APM undergoing CRS-HIPEC.

METHODS

We performed a multicenter retrospective review of patients who underwent CRS-HIPEC for APM due to high or intermediate grade disease between 2013 and 2019. Patients in the total neoadjuvant therapy group (TNT) received 12 cycles of preoperative chemotherapy. Patients in the "sandwich" chemotherapy group (SAND) received six cycles of preoperative chemotherapy with a maximum of six cycles of postoperative chemotherapy. The primary outcomes were overall survival (OS) and recurrence-free survival (RFS) defined as months from date of first treatment or surgery, respectively.

RESULTS

A total of 39 patients were included in this analysis, with 25 (64%) patients in the TNT group and 14 (36%) patients in the SAND group. Patients in the TNT group had a median OS of 62 mo, while median OS in the SAND group was 45 mo (P = 0.01). In addition, patients in the TNT group had significantly longer RFS compared to the SAND group (35 versus 12 mo, P = 0.03). In a multivariable analysis, TNT approach was independently associated with improved OS and RFS.

CONCLUSIONS

In this multicenter retrospective analysis, a TNT approach was associated with improved overall and recurrence-free survival compared to a sandwiched chemotherapy approach in patients undergoing CRS-HIPEC for high or intermediate grade APM.

Mutational profiles and prognostic impact in colorectal and high-grade appendiceal adenocarcinoma with peritoneal metastases

BACKGROUND

Next-generation sequencing (NGS) personalizes cancer treatments. In this study, we analyze outcomes based on NGS testing for colorectal cancer (CRC) and high-grade appendiceal adenocarcinoma (HGA) with peritoneal metastases.

METHODS

Retrospective review of genomic analyses and outcomes in patients with CRC or HGA with peritoneal metastases at a high-volume center from 2012 to 2019.

RESULTS

Ninety-two patients (57 CRC, 35 HGA) were identified. Overall survival was longer for CRC (52.8 vs. 30.5 months, p = 0.03), though rates of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) were similar. Multiple genes were more frequently mutated in CRC, including KRAS (51% vs. 29%, p = 0.04), TP53 (47% vs. 20%, p < 0.01), and APC (46% vs. 6%, p < 0.01). For CRC, multivariate regression showed an increased hazard ratio (HR) with increasing peritoneal cancer index (1.06 [1.01-1.11], p = 0.02) and a decreased HR following CRS/HIPEC (0.30 [0.11-0.80], p = 0.02). PIK3CA mutation associated with significantly increased HR (3.62 [1.06-12.41], p = 0.04), though only in non-CRS/HIPEC patients. Multivariate analysis in the HGA group showed a benefit following CRS/HIPEC (0.18 [0.06-0.61], p = 0.01) and for mucinous disease (0.38 [0.15-0.96], p = 0.04), while there was an increased HR with TP53 mutation (6.89 [2.12-22.44], p < 0.01).

CONCLUSION

CRC and HGA with peritoneal spread have distinct mutational profiles. PIK3CA and TP53 mutations are associated with survival for CRC or HGA with peritoneal metastases, respectively.

Peritoneal metastases from primary appendiceal and colorectal carcinomas demonstrate distinct molecular identities on comprehensive tumor analysis

BACKGROUND AND OBJECTIVES

Published data comparing peritoneal metastases from appendiceal cancers (pAC) and colorectal cancers (pCRC) remain sparse. We compared pAC and pCRC using comprehensive tumor profiling (CTP).

METHODS

CTP was performed, including next-generation sequencing and analysis of copy number variation (CNV), microsatellite instability (MSI) and tumor mutational burden (TMB).

RESULTS

One hundred thirty-six pAC and 348 pCRC samples underwent CTP. The cohorts' age and gender were similar. pCRC demonstrated increased pathogenic variants (PATHs) in APC (48% vs. 3%, p < 0.01), ARID1A (12% vs. 2%, p < 0.01), BRAF (12% vs. 2%, p < 0.01), FBXW7 (7% vs. 2%, p < 0.01), KRAS (52% vs. 41%, p < 0.05), PIK3CA (15% vs. 2%, p < 0.01), and TP53 (53% vs. 23%, p < 0.01), and decreased PATHs in GNAS (8% vs. 31%, p < 0.01). There was no difference in CNV, fusion rate, or MSI. Median TMB was higher in pCRC (5.8 vs. 5.0 mutations per megabase, p = 0.0007). Rates of TMB-high tumors were similar (pAC 2.1% vs. pCRC 9.0%, p = 0.1957). pCRC had significantly more TMB-high tumors at lower thresholds.

CONCLUSIONS

Despite a reduced overall TMB, pAC demonstrated mutations distinct from those seen in pCRC. These may serve as discrete biomarkers for future study.

Which classification system defines best prognosis of mucinous neoplasms of the appendix with peritoneal dissemination: TNM vs PSOGI?

AIMS

Several classification systems are used for pseudomyxoma peritonei. The four-tiered classification system proposed by Peritoneal Surface Oncology Group International (PSOGI) and the two-tiered proposed by the eighth edition of the American Joint Committee on Cancer (AJCC) result from evolution in terminology and pathological insight. The aim is to evaluate the impact of PSOGI and eighth edition of the AJCC classifications on survival.

METHODS

Pathological slides were reviewed from a prospectively maintained database including patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for an appendiceal mucinous neoplasm with peritoneal dissemination between January 2009 and December 2019. Patients were reclassified according to PSOGI and AJCC eighth edition criteria. Survival analysis evaluated the impact of each classification system on overall survival (OS) and disease-free survival (DFS) while the concordance-index evaluated their predictive power.

RESULTS

95 patients were identified; 21.1% were reclassified as acellular mucin, 55.8% as low-grade mucinous carcinoma peritonei, 8.4% as high-grade MCP (HGMCP) and 14 as HGMCP with signet ring cells. Median OS was not reached, 5-year OS and DFS were 86.1% and 51.5%, respectively. Multivariate analysis revealed significant associations with OS (PSOGI: HR 10.2, p=0.039; AJCC: HR 7.7, p=0.002) and DFS (PSOGI: HR 12.7, p=0.001; AJCC: HR 3.7, p<0.001). The predictive capacity of both classification systems was unacceptable for OS and DFS (concordance-index values <0.7).

CONCLUSIONS

Both classification systems behaved similarly when stratifying our series into prognostic groups. The PSOGI classification provides better histopathological description, but histology alone is insufficient for adequate patient prognostication.

A Multicenter Phase 1 Trial Evaluating Nanoliposomal Irinotecan for Heated Intraperitoneal Chemotherapy Combined with Cytoreductive Surgery for Patients with Peritoneal Surface Disease

BACKGROUND

Nanoliposomal irinotecan (nal-IRI) is a promising novel hyperthermic intraperitoneal chemotherapy (HIPEC) agent given its enhanced efficacy against gastrointestinal tumors, safety profile, thermo-synergy, and heat stability. This report describes the first in-human phase 1 clinical trial of nal-IRI during cytoreductive surgery (CRS) and HIPEC.

METHODS

Patients with peritoneal surface disease (PSD) from appendiceal and colorectal neoplasms were enrolled in a 3 + 3 dose-escalation trial using nal-IRI (70-280 mg/m²) during HIPEC for 30 min at 41 ± 1 °C. The primary outcome was safety. The secondary outcomes were pharmacokinetics (PK) and disease-free survival. Adverse events (AEs) categorized as grade 2 or higher were recorded. The serious AEs (SAEs) were mortality, grade ≥ 3 AEs, and dose-limiting toxicity (DLT). Irinotecan and active metabolite SN38 were measured in plasma and peritoneal washings.

RESULTS

The study enrolled 18 patients, who received nal-IRI during HIPEC at 70 mg/m² (n = 3), 140 mg/m² (n = 6), 210 mg/m² (n = 3), and 280 mg/m² (n = 6). No DLT or mortality occurred. The overall morbidity for CRS/HIPEC was 39% (n = 7). Although one patient experienced neutropenia, no AE (n = 131) or SAE (n = 3) was definitively attributable to nal-IRI. At 280 mg/m², plasma irinotecan and SN38 measurements showed maximum concentrations of 0.4 ± 0.6 µg/mL and 3.0 ± 2.4 ng/mL, a median time to maximum concentration of 24.5 and 26 h, and areas under the curve of 22.6 h*µg/mL and 168 h*ng/mL, respectively. At the 6-month follow-up visit, 83% (n = 15) of the patients remained disease-free.

CONCLUSIONS

In this phase 1 HIPEC trial (NCT04088786), nal-IRI was observed to be safe, and PK profiling showed low systemic absorption overall. These data support future studies testing the efficacy of nal-IRI in CRS/HIPEC.

Comprehensive Treatment Algorithms of the Swiss Peritoneal Cancer Group for Peritoneal Cancer of Gastrointestinal Origin

Peritoneal cancer (PC) is a dire finding, yet in selected patients, long-term survival is possible. Complete cytoreductive surgery (CRS) together with combination immunochemotherapy is essential to achieve cure. Hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC) are increasingly added to the multimodal treatment. The Swiss Peritoneal Cancer Group (SPCG) is an interdisciplinary group of expert clinicians. It has developed comprehensive treatment algorithms for patients with PC from pseudomyxoma peritonei, peritoneal mesothelioma, gastric, and colorectal origin. They include multimodal neoadjuvant treatment, surgical resection, and palliative care. The indication for and results of CRS HIPEC and PIPAC are discussed in light of the current literature. Institutional volume and clinical expertise required to achieve best outcomes are underlined, while inclusion of patients considered for CRS HIPEC and PIPAC in a clinical registry is strongly advised. The present recommendations are in line with current international guidelines and provide the first comprehensive treatment proposal for patients with PC including intraperitoneal chemotherapy. The SPCG comprehensive treatment algorithms provide evidence-based guidance for the multimodal care of patients with PC of gastrointestinal origin that were endorsed by all Swiss clinicians routinely involved in the multimodal care of these challenging patients.

Beware of lethal Wernicke's encephalopathy after cytoreductive surgery with HIPEC for peritoneal pseudomyxoma: Case report of morbidity and mortality review

Background

Pseudomyxoma peritonei (PMP) arising from the appendix is a rare entity. Complete cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is the only established curative treatment, and is reputedly linked to high morbidity and mortality.

We report, to our knowledge, the first case of delayed lethal Wernicke encephalopathy (WE) complicating CRS with HIPEC for an appendicular PMP. WE, caused by a thiamine deficiency, is characterized by ataxia, nystagmus and changes in consciousness.

Methods

A patient underwent complete CRS with HIPEC for a low grade mucinous appendicular tumor at the stage of PMP with a peritoneal index of 31, and was readmitted at POD 36 for persistent vomiting and vague neurological symptoms of mental confusion. The classic triad of WE appeared tardily. Although thiamine substitution was promptly applied, the patient died at POD53.

Conclusion

WE is an uncommon and severe neurological disorder with a mortality rate up to 20 % and only 16 % of treated patients can fully recover. This diagnosis should always be anticipated in patients undergoing major surgery such as CRS- HIPEC. Efficient treatment should be quickly introduced in order to avoid a lethal outcome.

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Pseudomyxoma peritonei is a rare entity, treatment consists of complete cytoreductive surgery and hyperthermic intra peritoneal chemotherapy with positive effects established in the literature.

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However, this combined treatment is a complex procedure and is associated with high morbidity and mortality.

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Wernicke’s encephalopathy is a rare complication of this procedure and has been reported once in the literature.

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Wernicke’s encephalopathy is a diagnosis to keep in mind and anticipate in patients undergoing cytoreductive surgery and hyperthermic intra peritoneal chemotherapy

Validation of a Nomogram to Predict Recurrence in Patients with Mucinous Neoplasms of the Appendix with Peritoneal Dissemination After Cytoreductive Surgery and HIPEC

BACKGROUND

Survival of patients affected by mucinous appendiceal neoplasms with peritoneal dissemination (PD) is mainly related to histopathological features. However, prognostic stratification is still a concern, as the clinical course of the disease is often unpredictable. The aim of this study is to construct and externally validate a nomogram predicting disease-free survival (DFS) in mucinous appendiceal neoplasms with PD treated by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC).

PATIENTS AND METHODS

Patients treated in two referral centers were included: Hospital General Universitario Gregorio Marañón, Madrid, Spain (derivation cohort) and Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy (validation cohort). Cox regression analysis identified factors associated with shorter DFS in the derivation cohort. The nomogram performance was externally evaluated in the validation cohort using concordance index and calibration plots. Histology was classified according to the Peritoneal Surface Oncology Group International (PSOGI).

RESULTS

The derivation cohort included 95 patients, and the validation cohort 348. Five-year DFS rates were 51.5 and 62%, respectively. Cox regression analysis (derivation cohort) identified PSOGI histology of the peritoneal components, number of preoperative elevated tumor marker, and peritoneal disease extent, as assessed by peritoneal carcinomatosis index, to be predictors of DFS. The model's predictive capacity was higher than that of PSOGI classification alone, with respective concordance indexes of 0.702 ± 0.023 and 0.610 ± 0.018 (validation cohort). The nomogram approximated the perfect model in the calibration plots at 3- and 5-year DFS.

CONCLUSIONS

An easy-to-use model that provides better prognostic stratification than histopathological features has been constructed. This nomogram may help clinicians in individualized survival predictions and informed clinical decision-making.

A proposal for changing nomenclature from pseudomyxoma peritonei (PMP) to abdomino-peritoneal mucinous carcinoma (APM) based on its long journey and experience from tertiary oncology center in India

Introduction

Pseudomyxoma peritonei (PMP) is a generalized term, usually known as “jelly belly” since 1884. Incidence is very low, 1–3 per million people per year. Because of its indolent nature, it is usually diagnosed at an advanced stage, thereby impacting the quality of life. The 5-year survival rate varies from 23 to 86% in world literature. Even 10 years and 20 years of survival have been described. With our experience, we like to propose rename of PMP as abdomino-peritoneal mucinous carcinoma (APM) as we strongly feel the time has come to specify the term and standardize the management strategy.

Methodology

In the premier institute of India and as a tertiary referral center, we experienced the maximum number of advanced cases of APM. From 2012 to 2021, we analyzed all the APM patients based on a prospectively maintained computerized database in the department of surgical oncology and found the reasons for renaming from this traditional one.

Results

We included a total of 87 patients who underwent surgical intervention. Thirty-five patients underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), and 52 patients underwent debulking. In CRS-HIPEC patients, CC-0 was achieved in 28 patients (80%), CC-1 in 4 patients (11.4%), and CC-2 in 3 patients (8.6%). Palliative intent HIPEC was done in 3 patients (8.6%). Clavien-Dindo grade III and IV morbidity was observed in 18.8% of patients with 90 days mortality of 5.7%.

Conclusion

With our long-term experience and advancement of scientific evidence, we like to propose a new name for PMP as APM. We strongly believe this paper will give a clear picture of this rare disease and standard management outlines.

Current Trends in Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Peritoneal Disease from Appendiceal and Colorectal Malignancies

Peritoneal carcinomatosis (PC) is a poor prognostic factor for all malignancies. This extent of metastatic disease progression remains difficult to treat with systemic therapies due to poor peritoneal vascularization resulting in limited drug delivery and penetration into tissues. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are surgical interventions that directly target peritoneal tumors and have improved outcomes for PC resulting from appendiceal and colorectal cancer (CRC). Despite these radical therapies, long-term survival remains infrequent, and recurrence is common. The reasons for these outcomes are multifactorial and signal the need for the continued development of novel therapeutics, techniques, and approaches to improve outcomes for these patients. Here, we review landmark historical studies that serve as the foundation for current recommendations, recent discoveries, clinical trials, active research, and areas of future interest in CRS/HIPEC to treat PC originating from appendiceal and colorectal malignancies.

Is CRS-HIPEC Still Indicated in Patients With Extraperitoneal Disease?

INTRODUCTION

The role of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with extraperitoneal disease (EPD) is controversial.

METHODS

Among patients with peritoneal metastases from appendiceal cancer (AC) and colorectal cancer (CRC) who underwent CRS-HIPEC, those with EPD (liver, lung, or retroperitoneal lymph nodes [RP LN]) were retrospectively compared to those without EPD. Overall (OS) and recurrence-free survival (RFS) analyses were performed before/after propensity score matching (PSM).

RESULTS

Among 1341 patients with AC (64%) or CRC (36%) who underwent CRS ± HIPEC, 134 (10%) had EPD whereas 1207 (90%) did not. EPD was located in the lungs (47%), RP LN (28%), liver (18%), or multiple (6%). Patients with EPD experienced worse median OS (34 versus 63 mo; P = 0.002) and RFS (12 versus 19 mo; P < 0.001). On a multivariable analysis, EPD was associated with worse RFS (P = 0.003), but not OS (P = 0.071). After PSM, the association of EPD with OS (P = 0.204) and RFS (P = 0.056) was no longer significant. In the multivariable analysis of the PSM cohort, EPD was not associated with OS (P = 0.157) or RFS (P = 0.110).

CONCLUSIONS

The findings of this large retrospective multi-institutional study suggest that EPD alone, while a negative prognostic indicator, should not be considered an absolute contraindication to CRS ± HIPEC for otherwise well-selected patients with peritoneal surface malignancies. Further research is needed to delineate whether location of EPD influences OS and RFS following CRS-HIPEC.

Rare occurrence of pseudomyxoma peritonei (PMP) syndrome arising from a malignant transformed ovarian primary mature cystic teratoma treated by cytoreductive surgery and HIPEC: a case report

Background

Pseudomyxoma peritonei (PMP) syndrome is a disease process that typically occurs from ruptured appendiceal mucocele neoplasms. PMP syndrome arising from malignant transformation of an ovarian primary mature cystic teratoma (MCT) is a pathogenesis rarely encountered.

Case Presentation

Herein, we report a 28-year-old patient evaluated and treated for a right ovarian mass and large volume symptomatic abdominopelvic mucinous ascites. Molecular profiling and genetic analysis revealed mutations in ATM, GNAS, and KRAS proteins while IHC demonstrated gastrointestinal-specific staining for CK20, CDX2, CK7, and SATB2. Peritoneal cytology showed paucicellular mucin. Diffuse peritoneal adenomucinosis (DPAM) variant of PMP arising from a ruptured ovarian primary MCT after malignant transformation to a low-grade appendiceal-like mucinous neoplasm was ultimately confirmed. Treatment included staged therapeutic tumor debulking and right salpingo-oophorectomy followed by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC).

Conclusions

Our report builds upon the existing literature supporting this aggressive treatment option reserved for advanced abdominal malignancies utilized in this patient with a rare clinical entity.

Prognostic Significance of Preoperative Tumor Markers in Pseudomyxoma Peritonei from Low-Grade Appendiceal Mucinous Neoplasm: a Study from the US HIPEC Collaborative

BACKGROUND

Tumor markers are commonly utilized in the diagnostic evaluation, treatment decision making, and surveillance of appendiceal tumors. In this study, we aimed to determine the prognostic significance of elevated preoperative tumor markers in patients with pseudomyxoma peritonei secondary to low-grade appendiceal mucinous neoplasm who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

METHODS

Using a multi-institutional database, eligible patients with measured preoperative tumor markers [carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), or cancer antigen 125 (CA-125)] were identified. Univariate and multivariate Cox-proportional hazards regression analysis assessed relationships between normal and elevated serum tumor markers with progression-free and overall survival in the context of multiple clinicopathologic variables.

RESULTS

zTwo hundred and sixty-four patients met criteria. CEA was the most commonly measured tumor marker (97%). Patients who had any elevated tumor marker had a higher peritoneal carcinomatosis index (PCI) as compared to those with normal range markers. Elevated CEA and CA 19-9 levels were individually associated with longer inpatient length of stay, requirement for intraoperative transfusion, and incomplete cytoreduction. Utilization of neoadjuvant chemotherapy, increased PCI score, elevated CA 19-9 (p = 0.007), and CA-125 levels (p = 0.01) were predictive of decreased progression-free survival on univariate analysis. However, in a multivariate model, only elevated PCI was a statistically significant predictor of progression-free survival.

CONCLUSION

Elevated preoperative tumor markers indicate a higher burden of disease but are not independently associated with survival in this retrospective multi-institutional cohort. Further prospective studies are needed to clarify the utility of these markers in this patient population.

Exploring the prognostic and therapeutic utility of expanded mutation profiling in appendix peritoneal metastasis managed with CRS/HIPEC

INTRODUCTION

Interrogation of cancers with next-generation sequencing (NGS) mutation panels has become widely utilized, identifying prognostic and actionable mutations. This study explored the value of expanded mutation analysis in appendix peritoneal metastases (APM).

METHODS

Forty-eight APM patients treated 2013-2018 were retrospectively collected from a registry. Fifty-gene NGS analysis was performed in CLIA approved lab to obtain mutation profiles. All patients underwent cytoreductive surgery (CRS)/hyperthermic intraperitoneal chemotherapy (HIPEC) with mitomycin C. Peritoneal cancer index (PCI), optimal CRS, survival (overall survival [OS] and progression-free survival [PFS]) data were collected. Survival analyses were performed on all APM, high-grade (HG), and low grade (LG) subsets, evaluating the impact of specific mutations on the outcome.

RESULTS

Eighty-three percent of APM had a mutation identified. KRAS was most frequent, 65% (88% LG 42% HG) with GNAS identified in 92% of LG-APM. SMAD4 and/or TP53 mutations occurred in 25% of APM with observed decreased OS (46 vs. 81 months p = .0029); worse in HG-APM (26 vs. 49 months p = .0451). SMAD4 was associated with the most significant reduction in PFS in APM (p = .0085). Actionable mutations were identified in 73% of APM patients.

CONCLUSIONS

Most frequent mutations were KRAS, TP53, and SMAD4, and actionable mutation detection was common. SMAD4 and TP53 were associated with decreased OS. NGS mutation profiling has potential utility in APM.

Current Management of Appendiceal Neoplasms

Appendiceal neoplasms include a heterogeneous group of epithelial and nonepithelial tumors that exhibit varying malignant potential. This review article summarizes current diagnostic criteria, classification systems, and optimal therapeutic strategies for the five main histopathologic subtypes of appendiceal neoplasms. In particular, the management of epithelial appendiceal neoplasms has evolved. Although their treatment has historically been extrapolated from colon cancer, improved understanding of their unique histopathologic and molecular characteristics and a growing body of published clinical data support a more nuanced approach to their management.

Consensuses and controversies on pseudomyxoma peritonei: a review of the published consensus statements and guidelines

Background

Pseudomyxoma peritonei (PMP) is a clinical malignant syndrome mainly originating from the appendix, with an incidence of 2–4 per million people. As a rare disease, an early and accurate diagnosis of PMP is difficult. It was not until the 1980s that the systematic study of this disease was started.

Main body

As a result of clinical and basic research progress over the last 4 decades, a comprehensive strategy based on cytoreductive surgery (CRS) + hyperthermic intraperitoneal chemotherapy (HIPEC) has been established and proved to be an effective treatment for PMP. Currently, CRS + HIPEC was recommended as the standard treatment for PMP worldwide. There are several consensuses on PMP management, playing an important role in the standardization of CRS + HIPEC. However, controversies exist among consensuses published worldwide. A systematic evaluation of PMP consensuses helps not only to standardize PMP treatment but also to identify existing controversies and point to possible solutions in the future. The controversy underlying the consensus and vice versa promotes the continuous refinement and updating of consensuses and continue to improve PMP management through a gradual and continuous process. In this traditional narrative review, we systemically evaluated the consensuses published by major national and international academic organizations, aiming to get a timely update on the treatment strategies of CRS + HIPEC on PMP.

Conclusion

Currently, consensuses have been reached on the following aspects: pathological classification, terminology, preoperative evaluation, eligibility for surgical treatment, maximal tumor debulking, CRS technical details, and severe adverse event classification system. However, controversies still exist regarding the HIPEC regimen, systemic chemotherapy, and early postoperative intraperitoneal chemotherapy.

Clinicopathological analysis of appendiceal goblet cell adenocarcinoma with peritoneal metastasis: World Health Organization grade predicts survival following cytoreductive surgery with intraperitoneal chemotherapy

AIMS

Peritoneal spread is the most common route of metastasis in appendiceal goblet cell adenocarcinoma. The aim of this study was to assess the prognostic significance of the World Health Organization (WHO) 5th edition grading criteria in peritoneal metastases of goblet cell adenocarcinoma.

METHODS AND RESULTS

We evaluated the clinicopathological features and survival of 63 patients with peritoneal metastasis of goblet cell adenocarcinoma who underwent cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC), stratified according to the WHO 5th edition and the Tang et al. grading schemes. The patients were also compared with 120 patients with peritoneal metastasis of appendiceal mucinous neoplasia. Most (73%) peritoneal metastases of goblet cell adenocarcinoma were WHO Grade 3 (G3), there being fewer cases of Grade 2 (G2) (16%) and Grade 1 (G1) (11%) disease. No significant differences in overall survival were observed between WHO G1 and G2 tumours or between the three Tang grades. In the multivariable model of survival, WHO G3 [hazard ratio (HR) 2.81, 95% confidence interval (CI) 1.02-7.70] and the presence of >50% extracellular mucin (HR 2.30, 95% CI 1.09-4.88) were associated with reduced overall survival for patients with goblet cell adenocarcinoma. As compared with patients with peritoneal metastasis of mucinous neoplasia, patients with goblet cell adenocarcinoma had significantly reduced survival (median overall survival of 37 months versus 102 months, P < 0.001), which was attributed to the reduced survival of patients with G1/G2 goblet cell adenocarcinoma as compared with patients with G1 mucinous neoplasia (median survival of 98 months versus 204 months, P < 0.001).

CONCLUSIONS

Grade of peritoneal goblet cell adenocarcinoma determined according to the WHO 5th edition criteria is a clinically relevant measure that independently predicts survival in patients treated with CRS-HIPEC.

Surgical management of appendiceal mucinous neoplasm: Is appendectomy sufficient?

BACKGROUND AND OBJECTIVES

Due to the rarity of appendiceal mucinous neoplasms (AMNs), there are few established treatment guidelines. The clinical course varies from incidental detection to progressive spread with pseudomyxoma peritonei (PMP). This study investigated the extent of resection on the prognosis and outcomes of AMNs.

METHODS

This multicenter retrospective study evaluated patients with AMN who underwent surgery between 4/2006 to 9/2017. Primary endpoints included overall survival (OS) and disease-specific survival (DSS). Secondary endpoints included PMP incidence and treatment with cytoreductive surgery (CRS).

RESULTS

Of the 138 patients with AMN, 70 patients (54%) underwent appendectomy, 26 (19%) cecectomy, and 37 (27%) right hemicolectomy. The median age was 59.7 years and 57 patients (41%) were male. Males were less likely to undergo cecectomy (P = .03). Rupture rates, tumor characteristics, and incidence of PMP were similar across surgery groups. Median follow-up was 61.3 months. Five-year OS and DSS for the total cohort were 94.9% and 98.6%, respectively, and remained similar across all surgery groups. CRS patients were more likely to undergo right hemicolectomy with no difference in survival by surgery type (P = .03).

CONCLUSIONS

Patients with AMN have a good overall prognosis and there may be minimal benefit to performing extended surgical resection in these patients.