Cytoreductive surgery and HIPEC offers similar outcomes in patients with rectal peritoneal metastases compared to colon cancer patients: a matched case control study

Colon and rectal peritoneal carcinomatosis: are we mixing apples with oranges? A propensity score-matched analysis

Rectal cancer is universally considered a different disease entity as compared to colon cancer, except when dealing with colorectal peritoneal carcinomatosis (PC), in which the two cancers are deemed as the same one. The present study aims to investigate the influence of primary tumor location (colon vs. rectum) on oncologic outcomes in patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal peritoneal metastases. Data from three referral centers undergoing CRS plus HIPEC for PC of colorectal origin were prospectively collected. The primary outcomes were overall survival (OS) and disease-free survival (DFS) according to primary tumor location (colic vs. rectal). Univariate and multivariate analyses were performed using the Cox proportional hazard model first on the total number of patients. Then, a propensity score matching using the nearest-neighbour method with a 1:1 ratio was performed. The study included 167 patients: 126 colic and 41 rectal PC. After propensity score matching, rectal primary tumor location was independently predictive of a lower DFS (HR 1.91; 95%CI 1.06-3.45; p = 0.031) but not of a lower OS (HR 1.12; 95%CI 0.57-2.21; p = 0.73). Post-matching 3-year DFS rates were 49.2% (95%CI 34,3-70,5%) and 19.4% (95%CI 9,4-40,2%) for colic and rectal PC, respectively. The present study shows a significantly worse DFS for rectal cancer PC undergoing CRS and HIPEC compared to colon cancer PC, suggesting a possible need for dedicated pathways for rectal PC patients and posing a question for rectal PC to be considered as a unique disease entity.

Perioperative management and survival outcomes following cytoreductive surgery in patients with peritoneal metastases from rectal cancer: A scoping review

BACKGROUND

Patients with rectal cancer and peritoneal metastases (PM) may have a worse prognosis and benefit from a different management than patients with colon cancer.

METHODS

A systematic literature search of MEDLINE (PubMed) and EMBASE databases was performed to identify all reported patients with rectal cancer and PM treated with cytoreductive surgery (CRS), with or without hyperthermic intraperitoneal chemotherapy (HIPEC), to investigate the proper selection criteria for this population, the optimal perioperative management, and highlight its specific oncological outcomes.

RESULTS

Twenty studies reporting on 285 patients were identified. Median age varied from 28 to 63 years, and 57.5 % of patients had synchronous disease. The use of neoadjuvant treatment was frequent, but regimens were heterogenous, consisting of radiotherapy alone, chemoradiotherapy or systemic chemotherapy. Thirty-two percent did not receive any neoadjuvant treatment. Most patients (85.6 %) received HIPEC after CRS, with mitomycin C being the most used drug. Complete cytoreduction was performed in 90.1 % of patients. Data on stoma creation and management were poorly reported. Severe complications occurred in 32.2 % of patients. Median disease-free survival ranged from 6 to 22 months, and median overall survival varied from 7 to 53.2 months.

CONCLUSION

This scoping review highlights the paucity of data available regarding the management of patients with rectal cancer and PM. It also emphasizes different issues and dilemmas regarding this specific population, especially on the use of neoadjuvant treatment, the role of HIPEC after CRS and stoma management.

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

This manuscript reports the results of an international consensus on technologies of hyperthermic intraperitoneal perioperative chemotherapy (HIPEC) performed with the following goals: To provide recommendations for the technological parameters to perform HIPEC. To identify the role of heat and its application forms in treating peritoneal metastases. To provide recommendations regarding the correct dosimetry of intraperitoneal chemotherapy drugs and their carrier solutions. To identify for each intraperitoneal chemotherapy regimen the best dosimetry and fractionation. To identify areas of future research pertaining to HIPEC technology and regimens. This consensus was performed by the Delphi technique and comprised two rounds of voting. In total, 96 of 102 eligible panelists replied to both Delphi rounds (94.1%) with a consensus of 39/51 questions on HIPEC technical aspects. Among the recommendations that met with the strongest consensus were those concerning the dose of HIPEC drug established in mg/m2, a target temperature of at least 42°C, and the use of at least three temperature probes to pursue hyperthermia. Ninety minutes as the ideal HIPEC duration seemed to make consensus. These results should be considered when designing new clinical trials in patients with peritoneal surface malignancies.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy with Intra-Operative Radiotherapy for Patients with Locally Advanced or Locally Recurrent Rectal Cancer and Peritoneal Metastases

Purpose: To assess the safety and long-term outcome of a multimodality treatment consisting of radical surgery, intra-operative radiotherapy (IORT), and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for patients with locally advanced rectal cancer (LARC) or locally recurrent rectal carcinoma (LRRC) and peritoneal metastases (PM). Methods: The present study was a single-center cohort study, including all consecutive patients undergoing this treatment in a tertiary referral center for LARC, LRRC, and PM. Postoperative complications, intensive care stay (ICU stay), and re-admission rates were assessed as well as disease-free survival (DFS) and overall survival (OS). Results: A total of 14 LARC and 16 LRRC patients with PM were included in the study. The median ICU stay was 1 day, and 57% of patients developed a severe postoperative complication. No 90-day mortality was observed. Median DFS was 10.0 months (Interquartile Range 7.1-38.7), and median OS was 31.0 months (Interquartile Range 15.9-144.3). Conclusions: As postoperative complications and survival were in line with treatments that are accepted for LARC or LRRC and PM as separate procedures, we conclude that combined treatment with IORT and CRS-HIPEC should be considered as a treatment option for selected patients with LARC or LRRC and peritoneal metastases in tertiary referral centers.

Hyperthermic intraperitoneal chemotherapy and colorectal cancer: From physiology to surgery

The pursuit of this paper is to collect principal reviews and systematic reviews about hyperthermic intraperitoneal chemotherapy (HIPEC) and cytoreductive surgery (CRS) used in colorectal cancer (CRC). We focus on principal biological aspects of CRC, hyperthermia effects, and surgical procedures. We searched PubMed/MEDLINE for the principal reviews and systematic reviews published from 2010 to 2021 regarding the bimodal treatment (CRS + HIPEC) against local and advanced CRC. In the literature, from several studies, it seems that the efficacy of bimodal treatment with an accurate CRS can extend overall survival. Despite these studies, there are not still any straight guidelines more detailed and scheduled about the use of combined treatment in patients with CRC. Even if the concept is still not very clear and shared, after a careful evaluation of the published data, and after some technical and pathophysiological descriptions, we concluded that it is possible to improve the overall survival and quality of life and to reduce the tumor relapse in patients affected by locally advanced (pT4) CRC with peritoneal metastases.

Revised prognostic indicators for treatment of lymph node positive colorectal peritoneal metastases

BACKGROUND

Peritoneal metastases from colon and rectal cancer presents a new target for a regional approach to treatment. Proper patient selection requires an understanding of the natural history of the disease progression.

METHODS

Data from colorectal cancer patients treated for peritoneal metastases by cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy and early postoperative intraperitoneal chemotherapy and the records from the primary colon or rectal cancer surgery were analyzed to assess their impact on survival. Data regarding the anatomic sites of colorectal peritoneal metastases was gathered at the time of a complete CRS.

RESULTS

A cohort of 73 patients with peritoneal metastases and lymph node metastases but no liver metastases provided the information. All patients had a complete cytoreduction. Left-sided primary cancer and a complete or near complete response to neoadjuvant chemotherapy (NAC) indicated improved survival. Tumor progression within the abdominal incision, carcinoembryonic antigen (CEA) >10, peritoneal cancer index >9 and peritoneal metastases present in the abdominopelvic regions 6 and 11 carried an especially guarded prognosis.

CONCLUSIONS

Reduced survival occurred with a right-sided or rectal primary cancer, a CEA >10, tumor cell entrapment, and involvement of abdominopelvic regions 6 and 11. Effective NAC showed a favorable outcome.

Quality Standards for Surgery of Colorectal Peritoneal Metastasis After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

The standardization of surgical outcomes throughout surgical procedures is mandatory. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) should provide proficient oncological and surgical outcomes.

STUDY DESIGN

The aim of this study was to identify clinically relevant quality indicators and their quality standard, and to determine their acceptable quality limit. A systematic review on cytoreductive results from 2000 to 2018 was performed focusing on clinical guidelines, consensus conferences, and publications. After the selection of quality indicators, a systematic review of indexed references was performed in order to calculate the quality standard for each indicator.

STUDY SELECTION

Unicentric/multicentric series, comparative studies, and clinical trials. Studies were to include outcomes after cytoreduction of colorectal origin and series with more than 50 patients. Quality indicators with at least 10 series were mandatory and objective measurements were also mandatory for inclusion.

MAIN OUTCOME MEASUREMENTS

Quality indicators selected were 1- to 5-year survival, overall disease-free survival, 1- to 5-year disease-free survival, complete surgical resection, duration of surgery, length of stay, overall morbimortality, major morbidity, re-intervention, postoperative hemorrhage, intestinal fistula, anastomotic leakage, wound infection, postoperative medical complications, overall recurrence, and failure to rescue.

RESULTS

The most relevant quality indicators and critical quality limits were overall disease-free survival and 5-year overall disease-free survival (14 months and <10 months, and 14% and <4%, respectively), completeness of surgical resection (89% and <80%, respectively), overall mortality (3% and >8%, respectively), overall morbidity (47% and >63%, respectively), failure to rescue (12% and <30%, respectively), reintervention (13 and <22%, respectively), anastomotic leakage (6% and <13%, respectively), and overall recurrence (60% and <74%, respectively).

CONCLUSION

This is the first study to assess quality standards in CRS + HIPEC for colorectal peritoneal metastases. The current data are of particular relevance for future studies to control the variability of this surgery.

Effective Strategies to Predict Survival of Colorectal Peritoneal Metastases Patients Eligible for Cytoreductive Surgery and HIPEC

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), often combined with systemic therapy, can be offered to selected colorectal peritoneal metastases (PM) patients. However, clinical heterogeneity and the lack of high-level evidence challenges determination of the correct treatment strategy. This review aims to provide an overview of current strategies to predict survival of colorectal PM patients treated with CRS and HIPEC, guiding clinicians to select a suitable treatment-strategy and to inform patients about their prognosis. First, the prognostic relevance of several clinicopathological prognostic factors, such as extent of PM, location of primary tumor, histology type, and the presence of lymph node or liver metastases will be discussed. Subsequently, special attention will be given to recent developments in several aspects of tumor biology such as RAF/RAS mutations, circulating tumor DNA, immunoprofiling, and consensus molecular subtypes. Finally, currently available prognostic models to predict survival will be evaluated, concluding these models perform moderate to good, but most of them partly rely on intra-operative data. New insights in tumor biology, as well as the reliable assessment of extent of peritoneal disease by diffusion weighted MRI pose promising opportunities to establish an adequate and clinically meaningful preoperative prognostic model in the near future.

Effect of the ACY-1 gene on HER2 and TRAIL expression in rectal carcinoma

The incidence of rectal carcinoma (RC) is increasing and the age at onset of the disease is reducing. Therefore, elucidating the pathogenesis of RC is beneficial for early diagnosis and improving the prognosis. Aminoacylase-1 (ACY-1) is abnormally expressed in various malignant tumor tissues. Furthermore, the human epidermal growth factor receptor-2 (HER2) gene is involved in tumor metastasis and invasion, while tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces tumor cell apoptosis. The aim of the present study was to investigate the effect of the ACY-1 gene on the expression of HER2 and TRAIL in RC. Cancerous and adjacent tissues from RC patients were collected. ACY-1 expression was analyzed by immunohistochemistry. The rectal cancer cell lines HT29 and SW620, and normal colorectal mucosal epithelial fetal human cells were cultured in vitro. ACY-1 gene and protein expression levels were tested by reverse transcription-quantitative PCR and western blotting. ACY-1 small interfering RNA (siRNA) was transfected into HT29 and SW620 cells. Cell proliferation was detected by thiazolyl blue MTT assay. Caspase-3 activity was assessed using a commercial kit. HER2 and TRAIL expression levels were determined by western blotting. ACY-1 expression was significantly increased in cancer tissue compared with adjacent tissue (P<0.05). ACY-1 expression was elevated in HT29 and SW620 cells compared with normal colorectal mucosal epithelial cells (P<0.05). ACY-1 siRNA transfected into HT29 cells downregulated its expression, inhibited cell proliferation, enhanced caspase-3 activity, reduced HER2 expression and upregulated TRAIL expression (P<0.05). ACY-1 expression was found to be increased in rectal cancer tissue. Therefore, targeting the ACY-1 gene may regulate HER2 and TRAIL expression levels, and may reduce the occurrence and inhibit the development of rectal cancer.

Cytoreductive surgery and HIPEC for malignant ascites from colorectal cancer - a randomized study

INTRODUCTION

The efficacy of different timings of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) in controlling malignant ascites caused by peritoneal carcinomatosis of colorectal cancer (CRC) is not well defined. The study aims to investigate the clinical efficacy and safety of different timings of CRS with HIPEC for malignant ascites caused by peritoneal carcinomatosis from CRC.

MATERIALS AND METHODS

This was a preliminary randomized controlled study performed at the Intracelom Hyperthermic Perfusion Therapy Center of the Cancer Hospital of Guangzhou Medical University (China) from December 2008 to December 2016. The patients were randomized to: CRS, followed by HIPEC (CRS+HIPEC; n = 14), and ultrasound-guided HIPEC, followed by CRS 1 to 2 weeks later (HIPEC+ delayed cytoreductive surgery (dCRS) group, n = 14). The endpoints were complete remission rate of ascites, successful complete CRS rate, and overall survival.

RESULTS

Malignant ascites in all patients showed complete remission; the total effective rate was 100%. Complete CRS was not feasible in any patient. The median follow-up of the 2 groups was 41.9 and 42.3 months in the CRS+HIPEC and HIPEC+dCRS groups, respectively. Overall survival was 14.5 (95%CI: 7-19 months) and 14.3 months (95%CI: 4-21 months) (P > .05). The adverse effects of HIPEC were manageable.

CONCLUSIONS

CRS+HIPEC and HIPEC+dCRS have the same efficacy in controlling malignant ascites caused by CRC and peritoneal carcinomatosis. The timing of CRS and HIPEC does not prolong the survival of patients with peritoneal carcinomatosis from CRC, even when a complete CRS is not feasible.

Meta-analysis of prognostic factors for patients with colorectal peritoneal metastasis undergoing cytoreductive surgery and heated intraperitoneal chemotherapy

Background

Up to 15 per cent of colorectal cancers present with peritoneal metastases (CPM). Cytoreductive surgery and heated intraperitoneal chemotherapy (CRS + HIPEC) aims to achieve macroscopic tumour resection combined with HIPEC to destroy microscopic disease. CRS + HIPEC is a major operation with significant morbidity and effects on quality of life (QoL). Improving patient selection is crucial to maximize patient outcomes while minimizing morbidity and mortality. The aim of this study was to identify prognostic factors for patients with CPM undergoing CRS + HIPEC.

Methods

A systematic search of MEDLINE, Embase and Cochrane Library electronic databases was performed using terms for colorectal cancer, peritoneal metastasis and CRS + HIPEC. Included studies focused on the impact of prognostic factors on overall survival following CRS + HIPEC in patients with CPM.

Results

Twenty-four studies described 3128 patients. Obstruction or perforation of the primary tumour (hazard ratio (HR) 2·91, 95 per cent c.i. 1·5 to 5·65), extent of peritoneal metastasis as described by the Peritoneal Carcinomatosis Index (PCI) (per increase of 1 PCI point: HR 1·07, 1·02 to 1·12) and the completeness of cytoreduction (CC score above zero: HR 1·75, 1·18 to 2·59) were associated with reduced overall survival after CRS + HIPEC.

Conclusion

Primary tumour obstruction or perforation, PCI score and CC score are valuable prognostic factors in the selection of patients with CPM for CRS + HIPEC.

Colic and rectal tumors with peritoneal metastases treated with cytoreductive surgery and HIPEC: One homogeneous condition or two different diseases? A systematic review and meta-analysis

Colorectal cancer (CRC) peritoneal metastasis (PM) is one of the most important cause of cancer-related death in world. CRC PM is considered as a homogeneous disease without differentiating colonic or rectal origin. Aim of this study is to analyze survival of patients treated with cytoreductive surgery and HIPEC, according to the origin of PM. Literature search was performed to identify relevant articles. All meta-analysis were performed using mean difference and log of HR, when appropriate. The I² statistic was used to determine the heterogeneity of included studies. Out of 349 selected records, 9 articles (1308 patients, 1153 colon PM and 155 rectal PM) have been included. OS and DFS is higher in patients affected by colon PM (OS mean difference: 24,49 months [95% CI: 14,70-34,28 months, p < 0,000001]; DFS mean difference: 7,75 months [95% CI: 1,37-14,13 months, p: 0,02]) and pooled Hazard Ratio for disease-related death in rectal PM is 1.62 [95% CI: 1,01-2,59, p: 0,05] compared to colon PM). Heterogeneity among selected studies is high in two subgroups and low in one (OS subgroup A I²: 98%, p < 0,000001; DFS subgroup I²: 91%, p < 0,000001; OS subgroup B I²: 25%, p: 0,26). Our analysis, with all the limitations related to included studies, suggests that peritoneal metastasis of rectal tumors treated with CRS and HIPEC have a worst prognosis of colon tumors PM. Larger studies are required to confirm those results and therefore we invite all Authors in considering also tumor localization when reporting data on CRC peritoneal metastasis treatment.

Pelvic Exenteration with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (CRS + HIPEC) for Rectal Cancer-Case Series with Review of Literature

Incidence of synchronous peritoneal metastases (PM) in colorectal cancer is approximately 5%, with another 5% of the patients develop metachronous PM. Colorectal PM has been hypothesized to be a loco-regional disease rather than a systemic spread, and cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has been considered as a viable treatment option. Pelvic exenteration is an established treatment option for locally advanced rectal cancer, but it is associated with significant morbidity. However, there are no studies evaluating the role of such procedure probably because the majority consider it as an exclusion criterion. Here, we present our experience with three cases of locally advanced rectal cancer with PM, treated successfully with pelvic exenteration and CRS-HIPEC.

Systematic Review of Variations in Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Peritoneal Metastasis from Colorectal Cancer

Background: Cytoreductive surgery (CRS), followed by hyperthermic intraperitoneal chemotherapy (HIPEC), combines radical surgery with abdominal heated chemotherapy, constituting a multimodal treatment approach. Since clear standards for HIPEC conduct in colorectal carcinoma (CRC) are lacking, we aimed to provide a comprehensive structured survey. Data sources and study eligibility criteria: A systematic literature search was performed in PubMed, with keywords “HIPEC” and “colorectal cancer”, according to established guidelines. Articles were systematically screened, selecting 87 publications complemented by 48 publications identified through extended search for subsequent synthesis and evaluation, extracting inter alia details on used drugs, dosage, temperature, exposure times, and carrier solutions. Results: Compiled publications contained 171 reports on HIPEC conduct foremost with mitomycin C and oxaliplatin, but also other drugs and drug combinations, comprising at least 60 different procedures. We hence provide an overview of interconnections between HIPEC protocols, used drugs and carrier solutions as well as their volumes. In addition, HIPEC temperatures and dosing benchmarks, as well as an estimate of in vivo resulting drug concentrations are demonstrated. Conclusions and implications: Owing to recent developments, HIPEC conduct and practices need to be reassessed. Unfortunately, imprecise and lacking reporting is frequent, which is why minimal information requirements should be established for HIPEC and the introduction of final drug concentrations for comparability reasons seems sensible.

Benefit of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy in patients with isolated peritoneal metastases from colorectal cancer

BACKGROUND

Ever since Sugarbaker has established the cytoreductive surgery (CRS) in combination with intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC), there is a chance of cure for selected patients with peritoneal metastases from colorectal cancer. Objective of this study was to investigate the benefit of CRS and HIPEC compared to other therapy options in patients with isolated synchronous and metachronous peritoneal metastases of colorectal origin in terms of long-term overall survival.

METHODS

A retrospective population-based cohort study, including 370 patients diagnosed with isolated synchronous and metachronous peritoneal metastases of colorectal origin, was carried out. Therefore, data were acquired from the cancer registry at the Regensburg Tumor Center in Bavaria, Germany. Patients' overall survival (OAS) according to their therapy received was analyzed by means of Kaplan-Meier method and multivariable Cox regression.

RESULTS

Overall median survival was 41.6 months for patients treated with CRS and HIPEC, compared with surgery and chemotherapy (24.0 months, log-rank p = 0.015), chemotherapy only (14.1 months, p < 0.001), surgery only (11.4 months, p < 0.001), and best supportive care (7.9 months, p < 0.001). This benefit persisted after adjustment for further risk factors in multivariable analysis.

CONCLUSION

The effect of CRS and HIPEC stands out significantly in comparison to all other therapies. The multimodality approach should be a regular option for patients with isolated peritoneal metastases.

Narrow line between benefit and harm: Additivity of hyperthermia to cisplatin cytotoxicity in different gastrointestinal cancer cells

AIM

To investigate the response to hyperthermia and chemotherapy, analyzing apoptosis, cytotoxicity, and cisplatin concentration in different digestive system cancer cells.

METHODS

AGS (gastric cancer cell line), Caco-2 (colon cancer cell line) and T3M4 (pancreatic cancer cell line) were treated by cisplatin and different temperature setting (37 °C to 45 °C) either in isolation, or in combination. Treatment lasted for one hour. 48 h after the treatment viability was evaluated by MTT, cell apoptosis by Annexin V-PE and 7ADD flow cytometry. Intracellular cisplatin concentration was measured immediately after the treatment, using mass spectrometry. Isobologram analysis was performed to evaluate the mathematical combined effect of temperature and cisplatin.

RESULTS

AGS cells were the most sensitive to isolated application of hyperthermia. Hyperthermia, in addition to cisplatin treatment, did not provoke a synergistic effect at intervals from 37 °C to 41 °C in neither cancer cell line. However, a temperature of 43 °C enhanced cisplatin cytotoxicity for Caco-2 cells. Moreover, isobologram analysis revealed mathematical antagonistic effects of cisplatin and temperature combined treatment in AGS cells; variations between synergistic, additive, and antagonistic effects in Caco-2 cells; and additive and antagonistic effects in T3M4 cells. Combined treatment enhanced initiation of cell apoptosis in AGS, Caco-2, and T3M4 cells by 61%, 20%, and 19% respectively. The increase of intracellular cisplatin concentration was observed at 43 °C by 30%, 20%, and 18% in AGS, Caco-2, and T3M4 cells, respectively.

CONCLUSION

In addition to cisplatin, hyperthermia up to 43 °C does not affect the viability of cancer cells in a synergistic manner.

Patient selection for cytoreductive surgery and HIPEC for the treatment of peritoneal metastases from colorectal cancer

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is a viable option for selected patients with peritoneal metastases (PM) from colorectal origin, resulting in long-term survival and even cure in some cases. However, adequate patient selection for this treatment is currently one of the major challenges. The aim of this review is to provide a comprehensive overview of clinically relevant factors associated with overall survival. This may help to guide clinicians through the complex interplay of patient, tumor, and treatment characteristics to adequately select patients who benefit the most from this extensive surgical treatment. First, basic principles of colorectal PM and the CRS and HIPEC treatment will be discussed. According to available literature, especially extent of peritoneal disease, completeness of cytoreduction, and signet ring cell histology have great influence on the outcome after CRS and HIPEC. Other factors that seem to have a negative prognostic value are the presence of liver metastases and the absence of treatment with neo-adjuvant systemic therapy. Prognostic models combining the above-mentioned factors, such as the Colorectal Peritoneal Metastases Prognostic Surgical Score nomogram, may provide clinically relevant tools to use in everyday practice.