A systematic review of minimally invasive cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with peritoneal malignancy.

BACKGROUND: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is traditionally a maximally invasive operation with a large abdominal incision and multi-visceral resections. However, to minimize abdominal wall morbidity and improve functional recovery, some centres have adopted a minimally invasive (MI) approach in select cases. The primary aim of this systematic review and meta-analysis was to assess the evidence for safety and patient selection for minimally invasive approaches to CRS and HIPEC with curative intent. METHODS: A PRISMA-compliant systematic review was performed using three electronic databases: Ovid MEDLINE, EMBASE and Web of Science. Data regarding postoperative morbidity was meta-analysed. RESULTS: Thirteen studies met the inclusion criteria (N = 462 MI patients), all of which were retrospective in design. Six studies included an open comparison group. Pseudomyxoma peritonei, mesothelioma and ovarian carcinoma made up the majority of cases (>90%), with a PCI < 10 listed as a prerequisite to selection across all studies. On pooled analysis there was no difference in major morbidity between MI and open groups (OR 0.52 95% CI 0.18-1.46, P = 0.33). There was one perioperative death reported in the MI group. Length of stay appeared shorter in the MI group (median range MI: 4-11 v Open: 7-13 days). Short-term recurrence and overall survival between both groups also appeared no different. CONCLUSION: Minimally invasive CRS and HIPEC appears feasible and safe in appropriately selected patients. Clear histological stratification and longer term follow up is required to determine oncological safety, particularly in more aggressive tumours such as colorectal peritoneal metastases.

Impact of neoadjuvant systemic chemotherapy followed by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for appendiceal adenocarcinoma.

AIM: Peritoneal dissemination of infiltrative appendiceal tumors is a rare and poorly understood phenomenon. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is a well-recognized treatment option for selected patients. Neoadjuvant systemic chemotherapy (NAC) has been shown to be associated with improved overall survival (OS) in colorectal peritoneal metastases but little is known of the impact of this from an appendiceal adenocarcinoma perspective. METHOD: A prospective database of 294 patients with advanced appendiceal primary tumors undergoing CRS ± HIPEC between June 2009 and December 2020 was reviewed. Baseline characteristics and long-term outcomes were compared between patients with adenocarcinoma who received neoadjuvant chemotherapy or upfront surgery. RESULTS: Eighty-six (29%) patients were histologically diagnosed with an appendiceal cancer. These included intestinal-type adenocarcinoma (11.6%), mucinous adenocarcinoma (43%), and goblet cell adenocarcinoma (GCA) or signet ring cell adenocarcinoma (SRCA) (45.4%). Twenty-five (29%) of these underwent NAC, of which eight (32%) exhibited some degree of radiological response. There was no statistical difference in OS at 3 years between the NAC and upfront surgery groups (47.3% vs. 75.8%, p = 0.372). Appendiceal histology subtypes, particularly GCA and SRCA (p = 0.039) and peritoneal carcinomatosis index >10 (p = 0.009), were factors independently associated with worse OS. CONCLUSION: Administration of NAC did not appear to prolong OS in the operative management of disseminated appendiceal adenocarcinomas. GCA and SRCA subtypes display a more aggressive biological phenotype.

Redo Pelvic Surgery and Combined Metastectomy for Locally Recurrent Rectal Cancer with Known Oligometastatic Disease: A Multicentre Review.

INTRODUCTION: Historically, surgical resection for patients with locally recurrent rectal cancer (LRRC) had been reserved for those without metastatic disease. 'Selective' patients with limited oligometastatic disease (OMD) (involving the liver and/or lung) are now increasingly being considered for resection, with favourable five-year survival rates. METHODS: A retrospective analysis of consecutive patients undergoing multi-visceral pelvic resection of LRRC with their oligometastatic disease between 1 January 2015 and 31 August 2021 across four centres worldwide was performed. The data collected included disease characteristics, neoadjuvant therapy details, perioperative and oncological outcomes. RESULTS: Fourteen participants with a mean age of 59 years were included. There was a female preponderance (n = 9). Nine patients had liver metastases, four had lung metastases and one had both lung and liver disease. The mean number of metastatic tumours was 1.5 +/- 0.85. R0 margins were obtained in 71.4% (n = 10) and 100% (n = 14) of pelvic exenteration and oligometastatic disease surgeries, respectively. Mean lymph node yield was 11.6 +/- 6.9 nodes, with positive nodes being found in 28.6% (n = 4) of cases. A single major morbidity was reported, with no perioperative deaths. At follow-up, the median disease-free survival and overall survival were 12.3 months (IQR 4.5-17.5 months) and 25.9 months (IQR 6.2-39.7 months), respectively. CONCLUSIONS: Performing radical multi-visceral surgery for LRRC and distant oligometastatic disease appears to be feasible in appropriately selected patients that underwent good perioperative counselling.

Technological advances define shifting pathway signaling from normal to primary and metastatic colorectal cancer.

Adoption of organoid/tumoroid propagation of normal and malignant intestinal epithelia has provided unparalleled opportunities to compare cell growth factor and signaling dependencies. These 3D structures recapitulate tumours in terms of gene expression regarding the tumor cells but also allow deeper insights into the contribution of the tumour microenvironment (TME). Elements of the TME can be manipulated or added back in the form of infiltrating cytotoxic lymphocytes and/or cancer associated fibroblasts. The effectiveness of chemo-, radio- and immunotherapies can be explored within weeks of deriving these patient-derived tumour avatars informing treatment of these exact patients in a timely manner. Entrenched paths to colorectal cancer (CRC) from the earliest steps of conventional adenoma or serrated lesion formation, and the recognition of further sub-categorisations embodied by consensus-molecular-subtypes (CMS), provide genetic maps allowing a molecular form of pathologic taxonomy. Recent advances in organoid propagation and scRNAseq are reshaping our understanding of CMS and CRC.

Perioperative outcomes of cytoreductive surgery for tumours of colorectal or appendiceal origin with ovarian involvement.

BACKGROUND AND OBJECTIVES: Ovarian metastases (OM) are a common site for metastases in gastrointestinal tumours with peritoneal disease. This study aimed to evaluate perioperative complications between patients with and without OM following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for appendiceal/colorectal cancer. METHODS: Female patients undergoing CRS ± HIPEC for appendiceal/colorectal tumours at a single centre from 2009 to 2020 were analysed. Patients were grouped according to presence or absence of OM at the time of CRS. RESULTS: The study included 318 patients, 72 (22.6%) had OM. Operation duration was longer for patients with OM (332 vs. 276 min, p < 0.0001). Patients with OM achieved higher rates of complete cytoreduction (93% vs. 79%, p = 0.006) despite a higher peritoneal carcinomatosis index (13 vs. 7, p < 0.001) and were more likely to require a blood transfusion (32% vs. 19%, p = 0.024) and a stoma (24% vs.10%, p = 0.005). Increasing age and presence of abdominal symptoms were independent predictors of major and all-cause morbidity, respectively. The presence of abdominal symptoms was independently associated with all-cause morbidity in the OM group. CONCLUSION: These results may assist with preoperative counselling. Prospective multicentre datasets are needed to evaluate morbidity in one- versus two-stage approaches for those with abdominal symptoms and OM.

The impact of molecular and mismatch repair status on the survival outcomes of surgically treated patients with colorectal peritoneal metastases.

BACKGROUND: Stratification of patients with colorectal peritoneal metastases (CRPM) using RAS/BRAF mutational status may refine patient selection for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). This study aimed to analyse the association of RAS/BRAF status and their variants, with clinicopathological variables and survival outcomes in patients who have undergone CRS ± HIPEC. METHODS: A single centre, peritonectomy database was interrogated for patients with CRPM who underwent peritonectomy procedures between 2010 and 2020. RESULTS: During the study period, 174 patients were included. Molecular status was obtained on 169 patients, with 68 (40.5%) KRAS, 25 (14.8%) BRAF and 6 (3.6%) NRAS mutations detected. Patients with BRAF mutations were more likely to be mismatch repair deficient (dMMR) (BRAF 20%, KRAS 4.4%, wild type 8.6%, p = 0.015). Most common BRAF and KRAS variants were, V600E (80%) and G12D (39.7%), respectively. BRAF V600E was independently associated with worse overall (median: 28 months, multivariate: HR 2.29, p = 0.026) and disease-free survival (median: 8 months, multivariate: HR 1.8, p = 0.047). KRAS G12V was a strong prognostic factor associated with disease-free survival (median: 9 months, HR 2.63, p = 0.016). dMMR patients (14/161, 8.7%) exhibited worse median overall survival compared to those with proficient MMR (dMMR 27 months, pMMR 29 months p = 0.025). CONCLUSION: This study highlights the importance of molecular analysis in CRPM stratification. BRAF V600E mutations predict poor outcomes post CRS and HIPEC and may help refine patient selection for this procedure. Molecular analysis should be performed preoperatively to characterise prognosis and guide perioperative therapeutic options.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases in an elderly population: outcomes from a single centre.

BACKGROUND: The prevalence of elderly patients with resectable colorectal peritoneal metastases (CRPM) is increasing. This study aimed to compare short and long-term outcomes of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for CRPM in patients above and below 70 years of age. METHODS: This was a retrospective, 10-year analysis of 90-day major morbidity and mortality, and long-term survival. RESULTS: Thirty-two (21.3%) of 150 consecutive patients who underwent CRS and HIPEC during the study period were aged 70 and older. PCI (P = 0.04), perioperative chemotherapy use (P < 0.01) and organ resections (rectum P = 0.04, diaphragm P = 0.03) were less in the over 70 group. There was no significant differences in major morbidity (P = 0.19) and mortality (P = 0.32). There was also no difference in 5-year overall survival (OS) (≥70: 26% vs. <70: 39%; P = 0.68) and disease-free survival (DFS) (≥70: 25% vs. <70: 14%; P = 0.22). Age above 70 was not independently associated with worse OS (HR 1.55, P = 0.20) and DFS (HR 1.07, P = 0.81). CONCLUSION: The surgical management of CRPM appears safe and feasible in this elderly population. Appropriate selection of elderly patients for such radical intervention is reinforced by the comparable survival with those under 70.

The Impact of Neoadjuvant Chemotherapy on the Surgical Management of Colorectal Peritoneal Metastases: A Systematic Review and Meta-Analysis.

BACKGROUND: Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is a well-recognised treatment option for the management of colorectal peritoneal metastases (CRPM). However, incorporating the routine use of neoadjuvant chemotherapy (NAC) into this management plan is controversial. METHODS: A systematic review and meta-analysis were conducted to evaluate the impact of neoadjuvant chemotherapy on perioperative morbidity and mortality, and long-term survival of patients with CRPM undergoing CRS and HIPEC. RESULTS: Twelve studies met the inclusion criteria (n = 2,463 patients). Ten were retrospective cohort, one was prospective cohort, and one was a prospective randomised by design. Patients who received NAC followed by CRS and HIPEC experienced no difference in major perioperative morbidity and mortality compared with patients who underwent surgery first (SF). There was no difference in overall survival at 3 years, but at 5 years NAC patients had superior survival (relative risk [RR] 1.31; 95% confidence interval [CI] 1.11-1.54, P < 0.001). There were no differences in 1- and 3-year, disease-free survival (DFS) between groups. Study heterogeneity was generally high across all outcome measures. CONCLUSIONS: Patients who received neoadjuvant chemotherapy did not experience any increase in perioperative morbidity or mortality. The potential improvement in 5-year overall survival in patients receiving NAC is based on limited confidence due to several limitations in the data, but not sufficiently enough to curtail its use. The practice of NAC in this setting will remain heterogeneous and guided by retrospective evidence until prospective, randomised data are reported.

Diagnostic performance of positron emission tomography in the staging of pseudomyxoma peritonei.

BACKGROUND: Pseudomyxoma peritonei (PMP) is a rare clinical entity, commonly derived from a mucin-producing tumour of the appendix. International consensus is unclear on the role of positron emission tomography (PET) in preoperative staging. This study aimed to assess the ability of preoperative PET in predicting the histological grade of PMP. METHODS: All patients scheduled for cytoreductive surgery (CRS) +/- hyperthermic intraperitoneal chemotherapy (HIPEC) for PMP who underwent preoperative PET at a single centre between June 2007 and June 2020 were included. A nuclear medicine physician, blinded to patient outcomes, retrospectively reviewed imaging studies to assess for maximum tumour standardised uptake value (SUV) to mean liver SUV ratio (SUVTLR) and maximum porta hepatis SUV to mean liver SUV ratio (SUVPLR). RESULTS: Between April 2007 and December 2020, a total of 204 patients underwent surgical intervention for PMP. Of these, 124 (60.8%) met the inclusion criteria. Median peritoneal carcinomatosis index for the entire cohort was 9 and complete cytoreduction (CC0/1) was achieved in 109 (88%) patients. Patients with high-grade PMP were more likely to have diffuse peritoneal disease (p < 0.001) and higher SUVTLR (p<0.001). The area under the ROC curve (AUC) of SUVTLR in predicting high-grade pathology was 71% (p = 0.003). Patients with a SUVTLR ≤ 0.78 had improved disease-free survival (p = 0.042). CONCLUSION: Preoperative PET showed positive correlation with high-grade PMP and acceptable sensitivity and specificity as a diagnostic tool. PET should be considered a useful adjunct to standard imaging for predicting histological grade in the staging of patients with PMP.

Pelvic exenteration, cytoreductive surgery, and hyperthermic intraperitoneal chemotherapy for peritoneal surface malignancy: experience and outcomes from an exenterative and peritonectomy unit.

PURPOSE: Pelvic exenteration (PE) for locally advanced pelvic malignancy is well established, though high rates of morbidity and mortality exist. Such a complication profile has often deterred the surgical community from offering exenteration in combination with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). We aimed to evaluate the perioperative outcomes following pelvic exenteration when combined with CRS and HIPEC for peritoneal surface malignancy (PSM) in a tertiary referral centre. METHODS: A review of a prospectively maintained PSM database from June 2015 to December 2020 at a tertiary referral institution was performed. Patients who underwent CRS, PE, and HIPEC were matched with patients who underwent PE alone. Primary endpoints were perioperative morbidity and mortality. RESULTS: From June 2015 to December 2020, 20 patients required PE as part of their CRS and HIPEC for PSM. The majority of patients were female (n = 16, 80%) with a median age of 52 (range 21-70). Colorectal cancer was the predominant pathology (n = 12, 60%). Median PCI was 11.5 (range 3-39). CC0 and R0 resections were achieved in all patients. CRS, PE, and HIPEC and PE-alone groups were well matched for clinicopathological variables. There was no difference in perioperative major morbidity (HIPEC: 30% vs PE: 15% p = 0.256) and mortality (HIPEC: 0 vs PE: 5% p = 0.311) between groups. Median follow-up was 17.5 months (range 7-68). Eight patients (40%) died from disease-related issues during the study period. CONCLUSION: An aggressive surgical strategy with complete resection is feasible and safe in select patients with complex PSM involving the pelvis.

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.

Outcomes following synchronous liver resection, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal liver and peritoneal metastases: A bi-institutional study.

PURPOSE: Synchronous liver resection, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal liver (CRLM) and peritoneal metastases (CRPM) has traditionally been contraindicated. However, latest practice promotes specialist, multidisciplinary-led consideration for select patients. This study aimed to evaluate the perioperative and oncological outcomes of synchronous resection in the management of CRLM and CRPM from two tertiary referral centres. METHOD: This bi-institutional, retrospective, cohort study included patients undergoing simultaneous liver resection, CRS and HIPEC for metastatic colorectal cancer from 2013 to 2020. Patients treated with ablative liver techniques, staged operative approaches and extra abdominal disease were excluded. Overall survival (OS) and disease-free survival (DFS) rates were assessed. Univariate and multivariate analyses identified variables associated with survival and major morbidity (Clavien-Dindo grade III/IV). RESULTS: Twenty-three patients were included. The median peritoneal carcinomatosis index (PCI) was 9 (range 0-22). There were two major liver resections and 21 minor resections. CC-0 resections were achieved in all patients. Major morbidity occurred in 7 patients. There were no deaths at 90 days. PCI was independently associated with morbidity (p = 0.04). PCI >10 (p = 0.069), major morbidity (p = 0.083) and presence of KRAS mutation (p = 0.052) approached significance for poor OS. Median follow up was 21 months (4-54 months). Median OS was 37 months, 3-year survival 54%, and median DFS 18 months. CONCLUSION: Synchronous liver resection, cytoreductive surgery and HIPEC is feasible in selected patients with low-volume CRPM and CRLM. Increasing PCI is associated with postoperative major morbidity, and should be considered during operative planning.

Synchronous Liver Resection, Cytoreductive Surgery, and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Liver and Peritoneal Metastases: A Systematic Review and Meta-analysis.

BACKGROUND: Synchronous liver resection, cytoreductive surgery, and hyperthermic intraperitoneal chemotherapy for colorectal liver and peritoneal metastases have traditionally been contraindicated. More recent clinical practice has begun to promote this aggressive treatment in select patients. OBJECTIVE: This study aimed to investigate the perioperative and oncological outcomes of patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, with and without liver resection, in the management of metastatic colorectal cancer. DATA SOURCES: Medline, Embase, and Cochrane Library databases were searched up to July 2020. STUDY SELECTION: Cohort studies comparing outcomes following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy with and without liver resection for metastatic colorectal cancer were reviewed. No randomized controlled trials were available. INTERVENTION: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy with or without synchronous liver resection were compared. MAIN OUTCOME MEASURES: The primary outcome measures were perioperative mortality and major morbidity. Secondary outcomes included 3- and 5-year overall survival and 1- and 3-year disease-free survival. RESULTS: Fourteen studies fitted the inclusion criteria, with 8 studies included in the meta-analysis. On pooled analysis, there was no significant difference in perioperative morbidity and mortality between the two groups. Patients that underwent concomitant liver resection had worse 1- and 3-year disease-free survival and 3- and 5-year overall survival. LIMITATIONS: Only a limited number of studies were available, with a moderate degree of heterogeneity. CONCLUSIONS: The addition of synchronous liver resection to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for the treatment of resectable metastatic colorectal cancer was not associated with increased perioperative major morbidity and mortality in comparison with cytoreduction and hyperthermic intraperitoneal chemotherapy alone. However, the presence of liver metastases was associated with inferior disease-free and overall survival. These data support the continued practice of liver resection, cytoreductive surgery, and hyperthermic intraperitoneal chemotherapy in the management of select patients with such stage IV disease.

Medium-throughput Drug Screening of Patient-derived Organoids from Colorectal Peritoneal Metastases to Direct Personalized Therapy.

PURPOSE: Patients with colorectal cancer with peritoneal metastases (CRPMs) have limited treatment options and the lowest colorectal cancer survival rates. We aimed to determine whether organoid testing could help guide precision treatment for patients with CRPMs, as the clinical utility of prospective, functional drug screening including nonstandard agents is unknown. EXPERIMENTAL DESIGN: CRPM organoids (peritonoids) isolated from patients underwent parallel next-generation sequencing and medium-throughput drug panel testing ex vivo to identify specific drug sensitivities for each patient. We measured the utility of such a service including: success of peritonoid generation, time to cultivate peritonoids, reproducibility of the medium-throughput drug testing, and documented changes to clinical therapy as a result of the testing. RESULTS: Peritonoids were successfully generated and validated from 68% (19/28) of patients undergoing standard care. Genomic and drug profiling was completed within 8 weeks and a formal report ranking drug sensitivities was provided to the medical oncology team upon failure of standard care treatment. This resulted in a treatment change for two patients, one of whom had a partial response despite previously progressing on multiple rounds of standard care chemotherapy. The barrier to implementing this technology in Australia is the need for drug access and funding for off-label indications. CONCLUSIONS: Our approach is feasible, reproducible, and can guide novel therapeutic choices in this poor prognosis cohort, where new treatment options are urgently needed. This platform is relevant to many solid organ malignancies.