Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Moderately and Poorly Differentiated Appendiceal Adenocarcinoma: Survival Outcomes and Patient Selection

Paired primary-metastasis patient-derived organoids and mouse models identify phenotypic evolution and druggable dependencies of peritoneal metastasis from appendiceal cancer

Peritoneal carcinomatosis is a common yet deadly manifestation of gastrointestinal cancers, with few effective treatments. To identify targetable determinants of peritoneal metastasis, we focused on appendiceal adenocarcinoma (AC), a gastrointestinal cancer that metastasizes almost exclusively to the peritoneum. Current treatments are extrapolated from colorectal cancer (CRC), yet AC has distinct genomic alterations, mucinous morphology and peritoneum restricted metastatic pattern. Further, no stable preclinical models of AC exist, limiting drug discovery and representing an unmet clinical need. We establish a first-in-class stable biobank of 16 long-term cultured AC patient-derived organoids (PDOs), including 3 matched, simultaneously resected primary AC-peritoneal carcinomatosis (AC-PC) pairs. By enriching for cancer cells, AC PDOs enable accurate genomic characterization relative to paucicellular AC tissue. We establish an organoid orthotopic intraperitoneal xenograft model that recapitulates diffuse peritoneal carcinomatosis and show that PC-organoids retain increased metastatic capacity, decreased growth factor dependency and sensitivity to standard of care chemotherapy relative to matched primary AC organoids. Single cell profiling of AC-PC pairs reveals dedifferentiation from mucinous differentiated states in primary AC into intestinal stem cell and fetal progenitor states in AC-PC, with upregulation of oncogenic signaling pathways. Through hypothesis-driven drug testing, we identify KRASMULTI-ON inhibitor RMC-7977 and Wnt-targeting tyrosine kinase inhibitor WNTinib as novel, clinically actionable strategies to target AC-PC more effectively.

Negative Impact of Systemic Therapy on Survival in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Low-Grade Metastatic Appendiceal Adenocarcinoma

BACKGROUND

Despite studies demonstrating that patients with peritoneal metastases from low-grade appendiceal adenocarcinoma (AA) do not respond well to systemic chemotherapy (SC), patients frequently undergo combination of SC with cytoreductive surgery/hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) regardless of grade.

METHODS

A nationwide retrospective analysis using the National Cancer Database evaluated patients with AA with peritoneal metastasis from 2016 to 2021. Cox proportional hazards model was used to evaluate the impact of SC in addition to CRS/HIPEC on overall survival (OS) stratified by tumor grade.

RESULTS

A total of 1,449 patients were included: 481 low-grade, 428 intermediate-grade, and 540 high-grade tumors. Clinical variables, such as age, sex, and comorbidity index, were similar across tumor grades. Cytoreductive surgery/hyperthermic intraperitoneal chemotherapy without SC was utilized in 65.73% of low-grade cases compared with 41.01% in intermediate-grade and 11.11% in high-grade cases. Systemic chemotherapy was utilized alone in 17.74% and with CRS/HIPEC in 16.53% of low-grade cases. In adjusted survival analysis, addition of SC to CRS/HIPEC was associated with worse OS for patients with low-grade AA (hazard ratio [HR] 2.77, 95% confidence interval [CI] 1.18-6.50) but not for intermediate (HR 1.65, 95% CI 0.82-3.35) and high-grade tumors (HR 1.18, 95% CI 0.67-2.45). The addition of time to definitive surgery variable nullified the negative impact of adding SC to CRS/HIPEC in low-grade AA (HR 1.76, 95% CI 0.68-4.53).

CONCLUSIONS

Negative OS impact of SC may be mediated by delays in effective surgical/intraoperative therapy. If CRS/HIPEC is planned for patients with metastatic low-grade AA, avoiding SC may facilitate earlier surgical intervention and improve survival.

Effect of RAS and BRAF mutations on peritoneal metastasis risk and cytoreductive surgery/hyperthermic intraperitoneal chemotherapy efficacy in colorectal cancer: A systematic review and meta-analysis

BACKGROUND

Colorectal cancer (CRC) patients with peritoneal metastasis (CRC-PM) have a worse prognosis than those with liver and lung metastases. Cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is an effective locoregional treatment for CRC-PM. To date, the prognostic analysis of CRS/HIPEC mostly focuses on clinical and pathological characteristics; however, genetic characteristics, such as RAS/BRAF mutation status, are not sufficient. This study aimed to systematically assess the correlation between RAS/BRAF status and PM risk, as well as the prognostic efficacy of CRS/HIPEC for CRC.

METHOD

This study was written in accordance with the 2020 guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols. We searched PubMed, EMBASE, and the Cochrane library with the following keywords: "Peritoneal Neoplasms," "raf Kinases" and "ras Proteins". The fixed-effects model and inverse variance method were used for analysis. Odds ratios (OR) and 95 % confidence intervals (CI) were used to reflect the risk of PM associated with RAS/BRAF mutations. Hazard ratios (HR) and 95 % CI were used to evaluate the effects of RAS/BRAF mutations on the prognosis of CRS/HIPEC.

RESULT

Eighteen articles included 5567 patients. In the risk analysis of PM, patients with BRAF mutation were more likely to have PM than those with wild-type BRAF (OR = 2.28, 95 % CI = 1.73-3.01, P < 0.001, I2 = 0 %). In contrast, there was no significant difference in the effect of RAS mutation and wild-type on PM of CRC (OR = 1.28, 95 % CI = 0.99-1.66, P = .06, I2 = 0 %). In a prognostic analysis of CRS/HIPEC, RAS mutation predicted poor overall survival (HR = 1.68, 95 % CI = 1.39-2.02, P < 0.001, I2 = 1 %) and disease-free survival (HR = 1.61, 95 % CI = 1.34-1.94, P < 0.001, I2 = 42 %). The results for BRAF mutation was consistent with the prognostic impact of RAS mutation's overall survival (HR = 2.57, 95 % CI = 1.93-3.44, P < 0.001, I2 = 0 %) and disease-free survival (HR = 1.90, 95 % CI = 1.40-2.56, P < 0.001, I2 = 82 %).

CONCLUSION

BRAF mutation, rather than RAS mutation, was a high-risk factor for CRC-PM. And both BRAF and RAS mutations negatively affected the prognosis of CRS/HIPEC in CRC-PM patients. Our results could provide suggestions for the selection of comprehensive treatment for CRC-PM with RAS/BRAF mutations.

Mutational Features and Tumor Microenvironment Alterations in High-Grade Appendiceal Cancers Treated With Iterative Hyperthermic Intraperitoneal Chemotherapy

PURPOSE

High-grade appendiceal adenocarcinomas (HGAA) with peritoneal metastases (PMs) are associated with poor survival. Hyperthermic intraperitoneal chemotherapy (HIPEC) is a novel treatment approach for unresectable HGAA-PM. However, its influence on immunogenomic profiles has not yet been fully explored.

MATERIALS AND METHODS

We obtained 79 samples of metastatic peritoneal tumor deposits from patients diagnosed with HGAA and performed whole-exome sequencing, RNA sequencing, and immunoprofiling before and after HIPEC. Tumor biopsies were subjected to immunogenomic profiling to detect mutational signatures and immune populations associated with oncologic outcomes.

RESULTS

Fifteen patients with HGAA-PMs were included in the study. The median progression-free survival (PFS) was 6.7 months (2.7-25.3) and the median overall survival was 11.4 months (4.7-42). Mucin-associated genes (MUC16, MUC3A, and MUC5AC) and titin (TTN) had the highest mutation frequencies. Mutational signatures such as single-base substitution 29 and doublet-base substitution 11 were present in >50% of single-base and double-base mutations. Higher PD-L1 coexpression on CD8+ T cells demonstrated a higher PFS both intratumorally (P = .019) and at the margin (P = .025).

CONCLUSION

HIPEC-associated mutational signatures were identified in HGAA-PMs. Elevated PD-L1+ cytotoxic T-cell populations after HIPEC had better PFS, offering valuable insights for prognostication in the context of HIPEC treatment.

Top Peritoneal Surface Malignancy Articles from 2022 to Inform your Cancer Practice

Over the last few decades, the role of cytoreductive surgery (CRS) with or without regional-based peritoneal therapies such as hyperthermic intraperitoneal chemotherapy (HIPEC) has evolved in the management of patients with peritoneal surface malignances (PSMs). Despite the benefit of CRS in improving oncologic outcomes, significant challenges remain in the treatment of patients with advanced PSMs, and the role of HIPEC continues to be questioned. Additionally, while there has been improvement in perioperative outcomes, long-term survival remains poor. As a result, there is much need to improve our understanding of the processes that drive tumor biology, thereby improving patient selection for various treatment approaches. Additionally, newer therapies are needed for patients who remain poor surgical candidates and who progress on systemic therapy. This article highlights recently published studies that we consider impactful in the care of patients with PSMs.

Role of Tumor-informed Personalized Circulating Tumor DNA Assay in Informing Recurrence in Patients With Peritoneal Metastases From Colorectal and High-grade Appendix Cancer Undergoing Curative-intent Surgery

OBJECTIVE

To investigate the role of a personalized, tumor-informed circulating tumor DNA (ctDNA) assay in informing recurrence in patients with peritoneal metastases (PM) from colorectal (CRC) and high-grade appendix (HGA) cancer after curative cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC).

BACKGROUND

Over 50% of patients with CRC/HGA-PM recur after optimal CRS-HIPEC. The limited sensitivity of axial imaging and diagnostic biomarkers is a significant cause of delay in the detection of recurrence and initiation of further therapies. Plasma ctDNA has a promising role in monitoring response to treatment and/or recurrence after primary cancer resection.

METHODS

Patients with CRC/HGA-PM who underwent curative CRS-HIPEC and serial postresection ctDNA assessments were included. Patients with rising postoperative ctDNA levels were compared with those with stable, undetectable ctDNA levels. Primary outcomes were the percentage of patients with recurrence and disease-free survival (DFS). Secondary outcomes were overall survival, ctDNA sensitivity, lead time, and performance of ctDNA compared with carcinoembryonic antigen.

RESULTS

One hundred thirty serial postresection ctDNA assessments [median 4, interquartile range (IQR), 3 to 5] were performed in 33 patients (n = 13 CRC, n = 20 HGA) who underwent completeness of cytoreduction-0/1 CRS with a median follow-up of 13 months. Of the 19 patients with rising ctDNA levels, 90% recurred versus 21% in the stable ctDNA group (n = 14, < 0.001). Median DFS in the rising ctDNA cohort was 11 months (IQR, 6 to 12) and not reached in the stable ( P = 0.01). A rising ctDNA level was the most significant factor associated with DFS (hazard ratio: 3.67, 95% CI: 1.06-12.66, P = 0.03). The sensitivity and specificity of rising ctDNA levels in predicting recurrence were 85% and 84.6%, respectively. The median ctDNA lead time was 3 months (IQR, 1 to 4). Carcinoembryonic antigen was less sensitive (50%) than ctDNA.

CONCLUSIONS

This study supports the clinical validity of serial ctDNA assessment as a strong prognostic biomarker in informing recurrence in patients with CRC/HGA-PM undergoing curative resection. It also holds promises for informing future clinical trial designs and further research.

Validation of the AJCC 8th Edition Staging System for Disseminated Appendiceal Cancer Patients Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: A Multi-institutional Analysis

BACKGROUND

The AJCC 8th edition stratifies stage IV disseminated appendiceal cancer (dAC) patients based on grade and pathology. This study was designed to externally validate the staging system and to identify predictors of long-term survival.

METHODS

A 12-institution cohort of dAC patients treated with CRS ± HIPEC was retrospectively analyzed. Overall survival (OS) and recurrence-free survival (RFS) were analyzed by using Kaplan-Meier and log-rank tests. Univariate and multivariate cox-regression was performed to assess factors associated with OS and RFS.

RESULTS

Among 1009 patients, 708 had stage IVA and 301 had stage IVB disease. Median OS (120.4 mo vs. 47.2 mo) and RFS (79.3 mo vs. 19.8 mo) was significantly higher in stage IVA compared with IVB patients (p < 0.0001). RFS was greater among IVA-M1a (acellular mucin only) than IV M1b/G1 (well-differentiated cellular dissemination) patients (NR vs. 64 mo, p = 0.0004). Survival significantly differed between mucinous and nonmucinous tumors (OS 106.1 mo vs. 41.0 mo; RFS 46.7 mo vs. 21.2 mo, p < 0.05), and OS differed between well, moderate, and poorly differentiated (120.4 mo vs. 56.3 mo vs. 32.9 mo, p < 0.05). Both stage and grade were independent predictors of OS and RFS on multivariate analysis. Acellular mucin and mucinous histology were associated with better OS and RFS on univariate analysis only.

CONCLUSIONS

AJCC 8th edition performed well in predicting outcomes in this large cohort of dAC patients treated with CRS ± HIPEC. Separation of stage IVA patients based on the presence of acellular mucin improved prognostication, which may inform treatment and long-term, follow-up strategies.

The Vermiform Appendix and Its Pathologies

The vermiform appendix is a muscular cylindrical structure originating near the junction of the cecum and ileum, averaging 9 cm (5-35 cm) in size. As the most mobile viscera, it can adopt several positions, the most common being the retrocecal position. Perceived as an atavistic organ lacking physiological relevance, the vermiform appendix appears to be involved in immune function, serving in the maturation of B lymphocytes and the production of immunoglobulin A, in endocrine function, excreting amines and hormones in the 2-3 mL of mucus secreted daily, and in digestive function, by storing beneficial bacteria from where they can recolonize the colon. With a lumen of about 6 mm, the vermiform appendix has a reduced storage capacity, so any blockage of the appendix with fecoliths (fecaliths), seeds derailed from the colon, or enlarged lymph nodes prevents drainage and intraluminal accumulation of secreted mucus. Unable to relax, the appendix wall severely limits its intraluminal volume, so mucus accumulation leads to inflammation of the appendix, known generically as appendicitis. In addition, the vermiform appendix may be the site of the development of neoplastic processes, which may or may not involve mucus production, some of which can significantly affect the standard of living and ultimately lead to death. In general, mucinous tumors may have a better prognosis than non-mucinous tumors. This review takes a comprehensive path, starting by describing the anatomy and embryology of the vermiform appendix and further detailing its inflammatory pathologies, pathologies related to congenital anomalies, and appendix tumors, thus creating an up-to-date framework for better understanding, diagnosis, and treatment of these health problems.

Prolonged Survival in Peritoneal Metastatic Appendiceal Carcinoma Patients Treated With Combined Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

INTRODUCTION

Primary treatment for peritoneal dissemination of appendiceal cancer is the combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. The endpoints were overall survival and evaluation of prognostic factors.

METHODS

Clinicopathological and treatment-related factors were obtained from a prospective database. A total of 84 patients, 55 (65%) primary and 29 (35%) recurrent malignant appendiceal carcinomas with synchronous and metachronous peritoneal metastases, underwent multimodal treatment between 2011 and 2021. The endpoints of the study were overall survival and evaluation of prognostic factors.

RESULTS

The median follow-up was 4.8 y; the mean age was 54.5 y (range 25-77), with a sex distribution of 69% female and 31% male. The mean peritoneal cancer index was 11.3. The proportion of mucinous, intestinal-type, signet ring cell, and goblet cell carcinoma was 56%, 23%, 11%, and 10%, respectively. The 5-y survival rate of the whole cohort was 56.7%. In primary and recurrent diseases, the overall median survival was 8.4 and 4.9 y. Significantly improved survival was detected after complete cytoreduction resection (hazard ratio [HR] for CCR-2 versus CCR-0: 9.388, 95% confidence interval [CI] 3.026-29.124, P = 0.001) and initial local operation with undelayed admission to the center (HR 0.262, 95% CI 0.089-0.773; P = 0.015). The five independent factors in Kaplan-Meier analysis and univariable Cox regression analysis associated with significant adverse survival were cancer antigen (CA) 19-9 over 37 IU/mL, signet ring cell and intestinal-type histology, positive nodal status, grading, and peritoneal cancer index >20. Neoadjuvant chemotherapy administration did not impact survival (HR 1.220, 95% CI 0.612-2.432, P = 0.571).

CONCLUSIONS

With multimodal treatment, prolonged survival is attainable in stage IV primary and recurrent appendiceal carcinoma with peritoneal dissemination. Direct referral to specialized centers after confirmation of peritoneal metastasis is recommended because prompt definitive treatment may significantly improve survival.

The contemporary management of peritoneal metastasis: A journey from the cold past of treatment futility to a warm present and a bright future

Peritoneal metastasis (PM) is often regarded as a less frequent pattern of spread; however, collectively across all spectra of primary tumors, the consequences of PM impact a large population of patients annually. Unlike other modes of metastasis, symptoms at presentation or during the treatment course are common, representing an additional challenge in the management of PM. Early efforts with chemotherapy and incomplete surgical interventions transiently improved symptoms, but durable symptom control and survival extension were rare, which established a perspective of treatment futility for PM through most of the 20th century. Notably, the continued development of better systemic therapy combinations, optimization of cytoreductive surgery (CRS), and rigorous investigation of combining regional therapy-specifically hyperthermic intraperitoneal chemotherapy-with CRS, have resulted in more effective multimodal treatment options for patients with PM. In this article, the authors provide a comprehensive review of the data establishing the contemporary approach for tumors with a high frequency of PM, including appendix, colorectal, mesothelioma, and gastric cancers. The authors also explore the emerging role of adding hyperthermic intraperitoneal chemotherapy to the well established paradigm of CRS and systemic therapy for advanced ovarian cancer, as well as the recent clinical trials identifying the efficacy of poly(adenosine diphosphate ribose) polymerase maintenance therapy. Finally, recent data are included that explore the role of precision medicine technology in PM management that, in the future, may help further improve patient selection, identify the best systemic therapy regimens, detect actionable mutations, and identify new targets for drug development.

[Current treatment recommendations for pseudomyxoma peritonei]

BACKGROUND

The term pseudomyxoma peritonei (PMP) describes a clinical syndrome characterized by the presence of gelatinous intraperitoneal accumulation of mucus. It mostly originates from a mucocele of the vermiform appendix. Affected patients are often asymptomatic for a long time. Because of its indolent nature it is usually diagnosed at an advanced stage. Clinical presentation is determined by the dissemination of the tumor.

METHOD

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

RESULTS

Based on the morphological characteristics PMP subtypes with various malignant potential can be differentiated. The prognosis depends on the histopathological differentiation and the clinical stage. The treatment spectrum varies from laparoscopic appendectomy to complete cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC).

CONCLUSION

Due to the rarity of PMP there are no prospective randomized studies. Therefore, there is still controversy regarding the best stage-dependent treatment strategy. This review article attempts to clarify the optimal management of mucinous neoplasms of the appendix and PMP taking the clinical presentation and the histological differentiation into consideration.

Role and usefulness of mr imaging in the assessment of peritoneal carcinomatosis

BACKGROUND

For many years, peritoneal carcinomatosis (PC) entitled poor prognosis until the development of the cytoreductive surgery technique associated with hyperthermic intraperitoneal chemotherapy. Imaging of peritoneal carcinomatosis plays an essential role in the diagnosis and management of the patients being considered for cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC).

MAIN BODY

The key role of imaging in patients with peritoneal malignancy is to aid surgical decision making. A standardized peritoneal magnetic resonance (MR) imaging protocol, including T2-weighted fat suppressed, diffusion-weighted and gadolinium-enhanced sequences, allows to detect small peritoneal tumours that are often missed on other imaging. A systematic approach to MR imaging and a close collaboration between the radiologist and the oncologic surgeon are key elements for an accurate evaluation of candidate patients for CRS and HIPEC.

CONCLUSION

MR imaging provides a powerful tool for accurate preoperative imaging in patients considered for curative surgery and assists the surgeon in evaluating patients for CRS and HIPEC.

Imaging of pre- and post-cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pediatric intraperitoneal malignancy

Although rare, pediatric peritoneal carcinomatosis does occur in primary abdominopelvic tumors. Additionally, peritoneal carcinomatosis has been described to occur as metastatic disease where the primary tumor is outside the abdominopelvic cavity. Where amenable, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) can be beneficial in disease management. However, favorable outcomes are predicated on specific tumor histology as well as proper patient selection, which significantly relies on preoperative imaging. This review gives a comprehensive, up-to-date summary on pediatric peritoneal carcinomatosis pre-surgical evaluation; where imaging is beneficial and limited; pediatric radiologists' role in helping to quantify disease; and how we, as pediatric radiologists, can help the surgeons and oncologists in the selection of patients for cytoreductive surgery and HIPEC.

Outcomes and prognostic factors of cytoreductive surgery and perioperative intraperitoneal chemotherapy in high-volume peritoneal carcinomatosis

BACKGROUND AND OBJECTIVES

The management of patients with extensive appendiceal mucinous neoplasms and mesothelioma is controversial. Our aims were to analyze overall survival (OS), disease-free survival (DFS) and independent prognostic factors associated with high peritoneal cancer index (PCI) status in patients who underwent cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy (PIC).

METHODS

A prospectively-maintained database for patients with appendiceal neoplasms and mesothelioma undergoing CRS/PIC from year 1996 to 2018 was retrospectively analyzed. Patients who achieved complete cytoreduction were stratified into limited (PCI < 30) and extensive (PCI ≥ 30) disease groups.

RESULTS

260 female and 235 male patients were identified. The 5-year survival for low-grade appendiceal mucinous neoplasms (LAMN) was significantly higher in the low PCI group (96.2% vs. 63.5%, p < 0.001). There was no difference in the OS across both groups in high-grade appendiceal mucinous neoplasms (HAMN) (63 vs. 69 months; p = 0.942) and mesothelioma (72 vs. 42 months; p = 0.058). Overall mortality was 2%. Grade III/IV complications were significantly higher in extensive disease (68% vs. 36.6%, p < 0.001). On multivariate analysis, use of EPIC and blood transfusion (>8 units) were independent positive and negative prognostic factors, respectively, associated with OS. Meanwhile, use of EPIC conferred benefit in DFS while increased blood transfusion (>8 units) and elevated preoperative CA125 were predictive of a poor DFS.

CONCLUSION

Long-term survivals following CRS/PIC are achievable with acceptable mortality and higher morbidity rates in extensive appendiceal mucinous neoplasms and mesothelioma. High PCI status does not preclude treatment with CRS/PIC.

The role of chemotherapy in the treatment of advanced appendiceal cancers: summary of the literature and future directions

Appendiceal cancer is rare and encompasses a diverse group of tumours ranging from low-grade appendiceal mucinous neoplasms to high-grade adenocarcinomas. Appendiceal cancers often spread to the peritoneal cavity causing extensive mucinous dissemination and peritoneal metastases. Prognosis varies with histological subtype. Cytoreductive surgery and heated intraperitoneal chemotherapy is well-established as the most effective treatment achieving long-term survival in some patients. Chemotherapy regimens used to treat appendiceal cancer are extrapolated from the colorectal cancer setting, but disease biology differs and outcomes are inferior. The role of chemotherapy in the treatment of appendiceal cancer remains poorly defined. There is an urgent need to develop novel tailored treatment strategies in the perioperative and unresectable setting. This review aims to evaluate the literature for patients who received intraperitoneal and systemic chemotherapy for appendiceal cancers.

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.

The Landmark Series: Appendiceal Primary Peritoneal Surface Malignancy

Appendiceal primary peritoneal surface malignancies are rare and include a broad spectrum of pathologies ranging from indolent disease to aggressive disease. As such, the data that drive the management of appendiceal peritoneal surface malignancies is generally not based on prospective clinical trial data, but rather consists of level 1 data based on retrospective studies and high-volume institutional experiences. Complete surgical debulking typically offers the best chance for long-term survival. This review highlights the landmark articles on which management of primary appendiceal peritoneal surface malignancies are based.

Risk of Intraoperative Hyperthermia and Outcomes in Adults Undergoing Cytoreductive Surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is commonly used to treat peritoneal surface malignancies. We aimed to identify risk factors of intraoperative patient hyperthermia and the postoperative outcome of adults undergoing HIPEC PATIENTS AND METHODS: A retrospective, IRB approved, single center cohort study was conducted. Adults treated with cytoreductive surgery and HIPEC between 2006 and 2021 were included. The primary outcome was bladder hyperthermia during perfusion, stratified by severity and duration. Secondary outcomes were postoperative complications and recurrence-free (RFS) and overall (OS) survival. Multivariable logistic regression models were fit to estimate the effects of important covariates.

RESULTS

Out of 214 patients, 114 had mild hyperthermia (≥ 38 °C) at any time, and in 73 of these it lasted for ≥ 30 min. Independent prognostic factors of mild hyperthermia ≥ 30 min were age (OR = 0.958, 95% CI 0.933-0.984), body mas index (BMI; OR = 0.959 95% CI 0.917-1.002), gender (OR = 0.199, 95% CI 0.092-0.431), and type of chemotherapy [cisplatin versus mitomycin (OR = 0.186, 95% CI 0.070-0.491; oxaliplatin versus mitomycin (OR = 0.430, 95% CI 0.163-1.139)]. Prognostic factors of moderate-to-severe hyperthermia (≥ 39 °C) at any time were perfusion duration (OR = 1.094, 95% CI 1.018-1.177) and blood transfusion (OR = 5.689, 95% CI 1.784-18.137). Intraoperative hyperthermia was not associated with increased postoperative complications but was associated with better RFS and OS.

CONCLUSIONS

Our study demonstrates age, gender, BMI, and chemotherapy type to be associated with hyperthermia ≥ 38 °C for ≥ 30 min, whereas longer perfusion time and blood transfusion were associated with hyperthermia ≥ 39 °C. Mild hyperthermia at the end of perfusion is associated with better RFS and OS.

Appendiceal pseudomyxoma peritonei: predictors of recurrence and iterative surgery

AIM

Appendiceal pseudomyxoma peritonei (PMP) is a rare entity, with recurrence rates up to 26% despite optimal cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Evidence specific to PMP originating from non-infiltrative appendiceal mucinous neoplasms (low grade - LAMN and high grade - HAMN) is lacking. The aim of this study was to identify patterns of recurrence and predictive factors for patients appropriate for iterative surgery.

METHOD

A bi-institutional retrospective analysis was performed on patients undergoing complete cytoreduction and HIPEC for PMP derived from perforated LAMN or HAMN. Multivariate logistic regression was performed to identify independent predictors for re-do CRS. Five-year overall survival (OS) was stratified according to surgical intervention, and 5-year disease-free survival (DFS) was stratified according to histological PMP grade. Cox regression analysis was performed to identify independent predictors for OS and DFS.

RESULTS

Sixty of 239 (25.1%) patients developed peritoneal recurrence between 2007 and 2020. The median time to recurrence was 20.7 months. The risk of disease recurrence was highest with high-grade PMP (P <0.001) and increasing PCI (P <0.001). Patients with high-grade histology from their index procedure and aged over 60 years were less likely to be offered iterative surgery on multivariate analysis. Patients who underwent iterative CRS and HIPEC had a 5-year survival of 100%.

CONCLUSION

Iterative CRS and HIPEC is feasible in selected patients with recurrent PMP, displaying good oncological outcomes. Age, index histology and level of abdominal quadrant involvement are predictive of proceeding to re-do surgery.

Women survive longer than men undergoing cytoreductive surgery and HIPEC for appendiceal cancer

BACKGROUND

We hypothesize that women undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal carcinomatosis from appendiceal cancer will have a survival advantage compared to men.

METHODS

The National Cancer Database (NCDB) public user file (2004-2014) was used to select patients with PC undergoing CRS and HIPEC from appendiceal cancer. Univariate and multivariable analyses were performed.

RESULTS

1,190 patients with PC from appendiceal cancer underwent HIPEC and CRS. OS was significantly longer for women than for men, with mean and median OS being 73.8 months and 98.2 months for women vs 58.7 months and 82.5 months for men, respectively (p = 0.0032). On multivariable analysis, male sex (HR: 1.444, 95% CI: 1.141-1.827, p = 0.0022) and increasing age (HR: 1.017, 95% CI: 1.006-1.027, p = 0.0017) were both found to be independent risk factors for worse OS.

CONCLUSION

Women undergoing CRS and HIPEC for PC from appendiceal origin live longer than men undergoing the same treatment. Increasing age was also found to be independent risk factors for worse survival.

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.

The Role of Hyperthermic Intraperitoneal Chemotherapy for Non-colorectal Peritoneal Surface Malignancies

BACKGROUND

Peritoneal carcinomatosis, from a variety of gastrointestinal and gynecological malignancies, has been historically challenging to treat and there remains a wide range of biologic aggressiveness in these patients. Malignancies commonly associated with PC include those of colorectal, appendiceal, gastric, ovarian, sarcoma, small intestinal, and primary peritoneal origin among others. Advances in our understanding of this unique disease process have led to significant interest in cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) as an emerging treatment option. The goal of CRS-HIPEC is to remove all visible macroscopic disease while preserving organ function, and then treat microscopic disease through perfusion of the peritoneal cavity with heated chemotherapy.

PURPOSE

Although recent reviews have focused on the management of peritoneal carcinomatosis secondary to colorectal cancer given the publication of several recent randomized controlled trials, the purpose of the current review is to summarize the evidence on CRS-HIPEC for non-colorectal peritoneal surface malignancies, including appendiceal neoplasms, malignant peritoneal mesothelioma, gastric cancer, and ovarian cancer.

RESULTS

While retrospective studies have clarified the importance of prognostic factors such as the peritoneal carcinomatosis index, completeness of cytoreduction, histopathological characteristics, and lymph node positivity, the lack of convincing level 1 evidence for the use of CRS-HIPEC has led to it remaining a highly controversial topic.

CONCLUSION

The decision to utilize CRS-HIPEC should involve a multidisciplinary team approach and evaluation of prognostic factors to balance the short-term morbidity of the operation with maximum long-term benefits. Large, multi-institutional groups and ongoing trials hold promise for clarifying the role of CRS-HIPEC in peritoneal surface malignancies.

Impact of signet ring cells on overall survival in peritoneal disseminated appendix cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

INTRODUCTION

To determine the effect of signet ring cell (SRC) histopathology in appendix cancer with peritoneal dissemination on overall survival (OS) in patients undergoing cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC).

MATERIALS AND METHODS

Retrospective cohort study from a prospectively maintained database of patients that underwent CRS/HIPEC for appendix cancer from April 1999 to December 2019.

RESULTS

255 patients were identified. 174 had high-grade disease with no SRC component, 35 with a low count of SRC and 46 with a high count of SRC. Median OS without SRC was 93.8 months vs 58.2 months for low count SRC and 23.7 months for high count SRC (P < 0.001). 5-year OS was 60% for patients with no SRC, 35.5% and 10% in those with low count and high count SRC respectively. On multivariate analysis, presence of SRC and complete cytoreduction score were identified as independent factors that affect OS.

CONCLUSION

The presence of SRC in appendix cancer with peritoneal dissemination is associated with worse OS when compared to an absence of SRC in patients undergoing CRS/HIPEC.

Factors Prognostic for Peritoneal Metastases from Colorectal Cancer Treated with Surgery

Purpose

To analysis factors prognostic for peritoneal metastases (PM) from colorectal cancer (CRC) treated with surgery using data from two sources and investigate the origin and effective treatment of ovarian metastases (OM).

Patients and Methods

Data from CRC patients with PM who had undergone surgery were collected from the Surveillance, Epidemiology, and End Results (SEER) database (n = 639) and a single Chinese institution (n = 60). Cumulative survival was evaluated by Kaplan–Meier analysis. Factors associated with overall survival (OS) and progression-free survival (PFS) prognosis were assessed using Cox’s proportional hazard regression models.

Results

Median OS values for patients who underwent surgery were 19 and 32 months in the SEER database and Chinese center, respectively. Age was an independent predictor of OS in both datasets. Signet-ring cell cancer and perineural invasion were independent predictors of inferior OS only in the SEER dataset, while completeness of cytoreduction (CC) and peritoneal carcinomatosis index were independent predictors for OS and PFS only in the Chinese center. Median OS was 24 months in CRC patients with PM alone and 36 months in those with both PM and OM (p = 0.181). Further, median PSF in patients with PM alone was 10 months, while that in individuals with both PM and OM was 20 months (p = 0.181).

Conclusion

Surgical treatment of the primary and metastatic sites is effective and safe for CRC patients with PM. CC-0 is recommended for improved prognosis. Moreover, OM should be recognized as a feature of PM, and cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is beneficial for CRC patients with OM.

Investigating the utility of extended mutation analysis in gastrointestinal peritoneal metastasis

BACKGROUND AND OBJECTIVES

Outcomes for gastrointestinal peritoneal metastases (GI-PM) are worse compared to systemic metastases, with a paucity of data exploring extended mutation profiling. An exploratory mutation analysis in GI-PMs was performed as a "proof of concept" of potential predictive values of profiling in GI-PM and rates of actionable mutations.

METHODS

The study included 40 GI-PM patients: 14 low-grade mucinous carcinoma peritonei and 26 HG-PM (12 colons, 10 appendix, 4 small bowels). Demographics, histologies, peritoneal cancer indexes, cytoreduction scores, and survival data were collected. NGS 50-gene mutation profiling was performed on 38 specimens. The association of mutations with survival was evaluated in high-grade PM.

RESULTS

KRAS, TP53, and SMAD4 mutations were observed in 61%, 29%, and 8% of cases across all tumor histologies. In 66% cases >1 mutations occurred, associated with decreased survival in HG-PM: 32 vs 73 months, P = .03. TP53 or SMAD4 mutations were associated with decreased survival in HG-PM: 22 vs 48 months, P = .02. Actionable mutations were detected in 70%.

CONCLUSION

Actionable mutations were detected at high rates. GI-PMs have similar mutational profiles and TP53, SMAD4, and/or >1 mutation were associate with decreased survival in HG-PM. This data supports the concept of the extended mutation profiling utility in GI-PM warranting further investigation.

Novel prognostic score for outcomes after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal cancer with metachronous peritoneal carcinomatosis

BACKGROUND

This study aimed to determine pre- and peri-operative parameters with significant predictive value for post-operative outcomes in patients with recurrent colorectal cancer presenting as peritoneal carcinomatosis undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), and to develop a novel prognostic scoring system for prediction of survival outcomes.

METHODS

A single-institution review of prospectively collected data from all patients who underwent CRS-HIPEC between October 2005 and October 2017 was conducted. Univariate and multivariate analyses were used to identify significant parameters for prediction of post-CRS-HIPEC disease-free survival and overall survival (OS).

RESULTS

A total of 278 patients underwent CRS-HIPEC, of whom 72 were for peritoneal carcinomatosis from recurrent colorectal cancer. Disease-free interval (DFI; P = 0.006), peritoneal cancer index (PCI; P = 0.001) and left upper quadrant disease (P = 0.023) were significant independent predictors of 3-year OS. DFI (0.007), PCI (P < 0.001) and intraoperative blood loss (BL; P = 0.001) were significant independent predictors of 5-year OS. PCI and BL were significant independent predictors of both 3-year (P = 0.026, PCI; P = 0.009, BL) and 5-year (P = 0.002, PCI; P = 0.011, BL) disease-free survival. Predictive models were developed for risk stratification of OS.

CONCLUSION

PCI, DFI, left upper quadrant disease and BL have significant predictive value for post-CRS-HIPEC outcomes. Risk stratification models allow for more prudent patient selection and ultimately more accurate prognostication of post-operative outcomes.

Should We Be Doing Cytoreductive Surgery with HIPEC for Signet Ring Cell Appendiceal Adenocarcinoma? A Study from the US HIPEC Collaborative

BACKGROUND

Appendiceal adenocarcinoma with signet ring cells (SCA) is associated with worse overall survival (OS), and it is unclear whether cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) should be pursued in this patient population. We assessed the prognostic implications of signet ring cells in patients with appendiceal adenocarcinoma and peritoneal carcinomatosis undergoing CRS-HIPEC.

METHODS

The US HIPEC Collaborative, a 12-center, multi-institutional database of patients undergoing CRS-HIPEC, was reviewed for patients with SCA. Univariate and multivariate analyses were performed.

RESULTS

Of 514 patients undergoing CRS-HIPEC for appendiceal adenocarcinoma, 125 (24%) had SCA. The SCA and non-SCA groups had similar baseline characteristics. SCA had worse OS compared with non-SCA (32.0 vs 91.4 months, p < 0.001). In univariate analysis for only SCA cases, there was worse OS in patients with poorly differentiated tumors, positive lymph nodes, LVI, PCI > 20, or incomplete cytoreduction (CC-2/3). However, multivariate analysis showed only positive lymph nodes (HR 1.14 [95% CI 1.00-1.31], p = 0.04), poor differentiation (5.60 [1.29-24.39], p = 0.02), and incomplete cytoreduction (4.90 [1.11-12.70], p = 0.03) were independently associated with decreased OS for SCA.

CONCLUSION

While signet cells are a negative prognostic feature, they should not be a contraindication to CRS-HIPEC in patients with well-moderately differentiated tumors with negative lymph nodes, where complete cytoreduction can be achieved.

Mucinous appendiceal neoplasms: classification, imaging, and HIPEC

Recent advances, specifically cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), offer advantages compared to the traditional therapeutic approach of systemic chemotherapy in the treatment of peritoneal carcinomatosis from mucinous appendiceal neoplasms (MAN). This review provides an up-to-date, comprehensive summary of the histologic classification of MAN, reviews common imaging findings of mucoceles and pseudomyxoma peritonei, and describes the radiologist's role in the multidisciplinary care team in quantifying disease and in helping select patients for definitive surgery.

Sites of Recurrence After Complete Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Patients with Peritoneal Carcinomatosis from Colorectal and Appendiceal Adenocarcinoma: A Tertiary Center Experience

BACKGROUND

This report describes patterns of disease recurrence after optimal cytoreduction (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal carcinomatosis (PC) of colorectal (CRC) and appendiceal adenocarcinoma (AC) origin.

METHODS

Patients undergoing optimal CRS/HIPEC (2007-2016) at the authors' institution were retrospectively reviewed from a prospectively maintained database. Data regarding disease recurrence were analyzed.

RESULTS

Of 74 patients who underwent CRS/HIPEC for PC from CRC (n = 46) or AC (n = 28), 49 (66%) had recurrence during a median follow-up period of 39.5 months. The sites of recurrence were peritoneal-only (n = 34, 69%), hematogenous-only (n = 6, 12%), and combined peritoneal and hematogenous (n = 9, 19%) sites. No patients with AC had hematogenous-only recurrence. The median disease-free survival (DFS) time for all the patients was 15 months (95% confidence interval [CI] 12.5-17.5 months). The recurrence rate after CRS/HIPEC was 41% at 1 year, 73% at 3 years, and 76% at 5 years. All the patients with hematogenous-only metastases experienced recurrence within 12 months after CRS/HIPEC. Mucinous or signet ring features predicted peritoneal recurrence (p = 0.041), whereas a complete cytoreduction of 1 was a predictor of early recurrence (p = 0.040). Patients who underwent repeat cytoreduction survived longer than those who received systemic chemotherapy alone. The median survival time after peritoneal-only recurrence was 33 months (95% CI 27.8-38.9 months).

CONCLUSION

Recurrence for patients with PC is common, even after optimal CRS/HIPEC. Hematogenous-only recurrence occurs early after CRS/HIPEC, suggesting occult disease at the time of treatment and highlighting the need for methods to identify micro-metastases and improve patient selection. Patients experiencing peritoneal-only recurrence had long survival period after CRS/HIPEC, suggesting its effectiveness at controlling peritoneal disease for a time.

Patient Selection for Cytoreductive Surgery

The peritoneal malignancies span the biologic spectrum of aggressiveness from the indolent growth pattern and superficial nature of well-differentiated mucinous appendiceal adenocarcinoma to the rapidly growing and invasive nature of poorly differentiated signet ring cell adenocarcinomas of the appendix, colon, and stomach. An understanding of the biology, distribution, and volume of disease is critical to appropriately selecting patients for cytoreduction and HIPEC with the goal of long-term survival. Herein the authors discuss appropriate the evaluation and selection of patients for with peritoneal surface malignancies for cytoreduction and HIPEC.