Predictors and survival of synchronous peritoneal carcinomatosis of colorectal origin: a population-based study

Cytoreductive surgery plus hyperthermic intraoperative peritoneal chemotherapy for people with peritoneal metastases from colorectal, ovarian or gastric origin: A systematic review of randomized controlled trials

BACKGROUND

There is uncertainty in the relative benefits and harms of hyperthermic intraoperative peritoneal chemotherapy (HIPEC) when added to cytoreductive surgery (CRS) +/- systemic chemotherapy or systemic chemotherapy alone in people with peritoneal metastases from colorectal, gastric, or ovarian cancers.

METHODS

We searched randomized controlled trials (RCTs) in the medical literature until April 14, 2022 and applied methods used for high-quality systematic reviews.

FINDINGS

We included a total of eight RCTs (seven RCTs included in quantitative analysis as one RCT did not provide data in an analyzable format). All comparisons other than ovarian cancer contained only one trial. For gastric cancer, there is high uncertainty about the effect of CRS + HIPEC + systemic chemotherapy. For stage III or greater epithelial ovarian cancer undergoing interval cytoreductive surgery, CRS + HIPEC + systemic chemotherapy probably decreases all-cause mortality compared to CRS + systemic chemotherapy. For colorectal cancer, CRS + HIPEC + systemic chemotherapy probably results in little to no difference in all-cause mortality and may increase the serious adverse events proportions compared to CRS +/- systemic chemotherapy, but probably decreases all-cause mortality compared to fluorouracil-based systemic chemotherapy alone.

INTERPRETATION

The role of CRS + HIPEC in gastric peritoneal metastases is uncertain. CRS + HIPEC should be standard of care in women with stage III or greater epithelial ovarian cancer undergoing interval CRS. CRS + systemic chemotherapy should be standard of care for people with colorectal peritoneal metastases, with HIPEC given only as part of a RCT focusing on subgroups and regimes.

PROSPERO REGISTRATION

CRD42019130504.

Epidemiology of Stage IV Colorectal Cancer: Trends in the Incidence, Prevalence, Age Distribution, and Impact on Life Span

Colorectal cancer is a common malignancy in men and women. Historically, stage IV colorectal cancer has 10 to 15% five-year survival. Developments in the management of colorectal metastatic disease have helped improve the overall survival of stage IV colorectal cancers from 12 to 30 months with some patients achieving disease-free survival.

Genomic Characterization and Clinical Outcomes of Patients with Peritoneal Metastases from the AACR GENIE Biopharma Collaborative Colorectal Cancer Registry

Peritoneal metastases (PM) are common in metastatic colorectal cancer (mCRC). We aimed to characterize patients with mCRC and PM from a clinical and molecular perspective using the American Association of Cancer Research Genomics Evidence Neoplasia Information Exchange (GENIE) Biopharma Collaborative (BPC) registry. Patients' tumor samples underwent targeted next-generation sequencing. Clinical characteristics and treatment outcomes were collected retrospectively. Overall survival (OS) from advanced disease and progression-free survival (PFS) from start of cancer-directed drug regimen were estimated and adjusted for the left truncation bias. A total of 1,281 patients were analyzed, 244 (19%) had PM at time of advanced disease. PM were associated with female sex [OR: 1.67; 95% confidence interval (CI): 1.11-2.54; P = 0.014] and higher histologic grade (OR: 1.72; 95% CI: 1.08-2.71; P = 0.022), while rectal primary tumors were less frequent in patients with PM (OR: 0.51; 95% CI: 0.29-0.88; P < 0.001). APC occurred less frequently in patients with PM (N = 151, 64% vs. N = 788, 79%) while MED12 alterations occurred more frequently in patients with PM (N = 20, 10% vs. N = 32, 4%); differences in MED12 were not significant when restricting to oncogenic and likely oncogenic variants according to OncoKB. Patients with PM had worse OS (HR: 1.45; 95% CI: 1.16-1.81) after adjustment for independently significant clinical and genomic predictors. PFS from initiation of first-line treatment did not differ by presence of PM. In conclusion, PM were more frequent in females and right-sided primary tumors. Differences in frequencies of MED12 and APC alterations were identified between patients with and without PM. PM were associated with shorter OS but not with PFS from first-line treatment.

SIGNIFICANCE

Utilizing the GENIE BPC registry, this study found that PM in patients with colorectal cancer occur more frequently in females and right-sided primary tumors and are associated with worse OS. In addition, we found a lower frequency of APC alterations and a higher frequency in MED12 alterations in patients with PM.

Recommendations for the optimal management of peritoneal metastases in patients with colorectal cancer: a TTD and GECOP-SEOQ expert consensus statement

Peritoneal metastases (PM) occur when cancer cells spread inside the abdominal cavity and entail an advanced stage of colorectal cancer (CRC). Prognosis, which is poor, correlates highly with tumour burden, as measured by the peritoneal cancer index (PCI). Cytoreductive surgery (CRS) in specialized centres should be offered especially to patients with a low to moderate PCI when complete resection is expected. The presence of resectable metastatic disease in other organs is not a contraindication in well-selected patients. Although several retrospective and small prospective studies have suggested a survival benefit of adding hyperthermic intraperitoneal chemotherapy (HIPEC) to CRS, the recently published phase III studies PRODIGE-7 in CRC patients with PM, and COLOPEC and PROPHYLOCHIP in resected CRC with high-risk of PM, failed to show any survival advantage of this strategy using oxaliplatin in a 30-min perfusion. Final results from ongoing randomized phase III trials testing CRS plus HIPEC based on mitomycin C (MMC) are awaited with interest. In this article, a group of experts selected by the Spanish Group for the Treatment of Digestive Tumours (TTD) and the Spanish Group of Peritoneal Oncologic Surgery (GECOP), which is part of the Spanish Society of Surgical Oncology (SEOQ), reviewed the role of HIPEC plus CRS in CRC patients with PM. As a result, a series of recommendations to optimize the management of these patients is proposed.

circMSH3 is a potential biomarker for the diagnosis of colorectal cancer and affects the distant metastasis of colorectal cancer

Objectives

To identify the most significantly differentially expressed circular RNAs (circRNAs) in colorectal cancer (CRC) tissues in terms of their expression levels and circularity, and to analyze the relationship between their expression levels and the clinical characteristics of patients.

Methods

circRNA RNA-seq technology was used to screen differentially expressed circRNAs in CRC. Sanger sequencing was used to identify circRNA back-splice junction sites. The relative expression levels of hsa_circ_0003761 (circMSH3) in CRC tissues and cell lines were detected by quantitative real-time fluorescence PCR technology. An RNA-protein pull-down assay was used to detect protein binding to circRNAs. Dual-luciferase reporter gene vectors were constructed to verify that circRNAs bind to microRNAs.

Results

Four hundred twenty circRNAs were found to be upregulated, and 616 circRNAs were downregulated. circMSH3 was derived from the MutS homolog 3 (MSH3) gene and was formed by a loop of exons 9, 10, 11, and 12. In 110 pairs of CRC and adjacent tissues, circMSH3 expression was 4.487-fold higher in CRC tissues. circMSH3 was also highly expressed in the HT-29 and LOVO CRC cell lines. The expression level of circMSH3 was associated with distant metastasis in CRC patients (P = 0.043); the area under the curve (AUC) of circMSH3 for CRC diagnosis was 0.75, with a sensitivity and specificity of 70.9% and 66.4%, respectively. circMSH3 could bind to a variety of proteins, mainly those involved in RNA transcription, splicing, cell cycle, and cell junctions. Furthermore, circMSH3 could bind to miR-1276, miR-942-5p, and miR-409-3p.

Conclusion

circMSH3 is a potential biomarker for the diagnosis of CRC and affects the distant metastasis of CRC. Multiple RNA-binding protein binds to circMSH3, and circMSH3 binds to miR-1276, miR-942-5p, and miR-409-3p, thereby affecting the expression of circMSH3.

Impact of Molecular Status on Cytoreductive Surgery for Peritoneal Metastases from Colorectal Cancer

Colorectal cancer peritoneal metastases (CRC-PM) are present in 5 to 15% of instances of CRC, and the overall survival (OS) of patients with CRC-PM is much lower than that of patients with other isolated metastatic locations. In recent years, the introduction of cytoreductive surgery (CRS) in conjunction with hyperthermic intraperitoneal chemotherapy has resulted in a significant improvement in CRC-PM patients' OS. Despite this, a significant proportion of CRS patients continue to suffer complications of grades III to V or even die during the perioperative period. Early diagnosis, optimization of patient selection criteria, and refining of individualized combination therapy are necessary for these patients. In this review, we evaluate studies examining the relationship between molecular status and CRS in CRC-PM. Our objective is to gain a comprehensive understanding of how the altered molecular status of CRC-PM impacts CRS, which could increase the likelihood of tailored therapy in the future.

Do Laparoscopic Approaches Ensure Oncological Safety and Prognosis for Serosa-Exposed Colon Cancer? A Comparative Study against the Open Approach

The adoption of laparoscopic surgery in the management of serosa-exposed colorectal cancer has raised concerns. This study aimed to investigate whether laparoscopic surgery is associated with an increased risk of postoperative recurrence in patients undergoing resection for serosa-exposed colon cancer. A retrospective analysis was conducted on a cohort of 315 patients who underwent curative resection for pathologically confirmed T4a colon cancer without distant metastases at the Asan Medical Center between 2006 and 2015. Patients were categorized according to the surgical approach method: laparoscopic surgery (MIS group) versus open surgery (Open group). Multivariate analysis was employed to identify risk factors associated with overall survival (OS) and disease-free survival (DFS). The MIS group included 148 patients and the Open group had 167 patients. Of the total cohort, 106 patients (33.7%) experienced recurrence during the follow-up period. Rates, patterns, and time to recurrence were not different between groups. The MIS group (55.8%) showed more peritoneal metastasis compared to the Open group (44.4%) among recurrence sites, but it was not significant (p = 0.85). There was no significant difference in the five-year OS (73.5% vs. 78.4% p = 0.374) or DFS (62.0% vs. 64.6%; p = 0.61) between the Open and MIS groups. Age and the pathologic N stage were independently associated with OS, and the pathologic N stage was the only associated risk factor for DFS. The laparoscopic approach for serosa-exposed colon cancer did not compromise the DFS and OS. This study provides evidence that laparoscopic surgery does not compromise oncologic outcomes of patients with T4a colon cancer although peritoneal seeding is the most common type of disease failure of serosa-exposed colon cancer.

Updated Incidence, Treatment and Survival of a Nationwide Cohort of Patients with Peritoneal Metastases of Unknown Origin

The aim of this study was to investigate the incidence, treatment and survival of patients with peritoneal metastases (PM) of unknown origin. All Dutch patients diagnosed in 2017 and 2018 with PM of unknown origin (PM-CUP) were evaluated. Data were extracted from the Netherlands Cancer Registry (NCR). Patients with PM-CUP were categorized into the following histological subtypes: 1) adenocarcinoma, 2) mucinous adenocarcinoma, 3) carcinoid, 4) unspecified carcinoma and 5) other. Treatments were compared between the different histological subtypes in patients with PM-CUP. Overall survival (OS) was calculated using the Kaplan-Meier method for all patients with cancer of unknown origin and between histological subtypes in patients with PM-CUP. Significant differences in OS were assessed by using the log-rank test. In total, 3026 patients were diagnosed with cancer of unknown origin, 513 (17%) among them were diagnosed with PM-CUP. Most PM-CUP patients received best supportive care only (76%), whereas 22% received systemic treatment and 4% underwent metastasectomy. Median OS was 1.1 months for all patients with PM-CUP but varied from 0.6 months to 30.5 months depending on the underlying histology. In this study, PM-CUP were diagnosed in 17% of all patients with cancer of unknown primary and the reported survival in this cohort was extremely poor. Since survival differed among histological subtypes and recently more treatment options became available for a selected group of patients with peritoneal malignancies, it is of great importance to identify the histology of the metastases and whenever possible the primary tumor.

Bidirectional Chemotherapy in Advanced Colorectal Cancer Peritoneal Metastases

Colorectal cancer (CRC) patients with extensive peritoneal metastases who are not candidates for CRS-HIPEC have poor prognoses. We evaluated the role of systemic and intra-peritoneal (IP) chemotherapy in these patients. CRC patients with confirmed peritoneal metastasis were enrolled. After implantation of IP chemoport patients received weekly IP paclitaxel in incremental doses of 20 mg/m2 with systemic chemotherapy. The primary end-points were the feasibility, safety, and tolerance (perioperative complications), and the secondary end-point was the clinico-radiological response. Patients included in the study were registered between January 2018 and November 2021. IP chemoport was implanted in 18 patients of which 14 patients underwent successful instillation of IP chemotherapy. Four patients did not receive IP chemotherapy in view of port-site infection for which IP ports were removed. The median age was 39 years (range: 19-61 years). The site of the primary tumor was equal in the colon and rectum. Fifty percent of patients had signet ring-cell adenocarcinoma, and 21% had poorly differentiated adenocarcinoma. The median serum of CEA level was 12.27 ng/mL (1.63-116.16 ng/mL). The median PCI score was 25 (18-35). The median number of IP chemotherapy cycles (weekly) was 3.5 (1-12 cycles). In 14.3% of patients, IP chemoport had to be removed due to block and infection. Three, five, and four patients had clinico-radiologically disease progression, stable disease, and partial response, respectively. One patient underwent subsequent successful CRS-HIPEC. There were no grade 3-5 (CTCAE 3.0) complications. Incremental doses of IP paclitaxel with systemic chemotherapy is safe and feasible in selected colorectal adenocarcinoma patients with peritoneal metastases without any serious adverse events.

Peritoneal Metastases from Extraperitoneal Primary Tumors: Incidence, Treatment, and Survival from a Nationwide Database

The objective of this study was to assess the incidence, treatment, and survival of patients with synchronous peritoneal metastases (PM) from extraperitoneal primary tumors. A cohort was selected from the Netherlands Cancer Registry (NCR), in which all patients diagnosed with PM in 2017 and 2018 were screened for eligibility. The five most common primary extraperitoneal origins of PM were included for further analyses: lung, breast, urinary tract, and kidney cancer and malignant melanoma. Survival was investigated using log-rank test between different primary tumor locations. In total, 480 patients were diagnosed with synchronous PM from extraperitoneal origins. The proportion of patients with PM per extraperitoneal origin ranged between 0.1 and 1.1%, with the highest proportion in lung cancer patients. Of all patients, 234 (49%) received tumor-directed treatment and 246 (51%) received no tumor-directed treatment. Survival in patients with PM from lung, breast, urinary tract, and kidney cancer and malignant melanoma was 1.6 months, 15.7 months, 5.4 months, 3.4 months, and 2.1 months, respectively (p < 0.001). In this study, a small, although significant number of patients with extraperitoneal cancer developed PM. The reported survival in patients with PM ranged between 1.6 and 15.7 months. Only half of the patients with PM received tumor-directed treatment and survival in patients without tumor-directed treatment was only 1.2 months. These findings are stressing the need to explore new diagnostic tools that may enable earlier diagnosis of PM and may potentially lead to a more effective treatment.

Primary tumor resection or systemic treatment as palliative treatment for patients with isolated synchronous colorectal cancer peritoneal metastases in a nationwide cohort study

Limited data are available to guide the decision-making process for clinicians and their patients regarding palliative treatment options for patients with isolated synchronous colorectal cancer peritoneal metastases (CRC-PM). Therefore, the aim of this study is to analyze the outcome of the different palliative treatments for these patients. All patients diagnosed with isolated synchronous CRC-PM between 2009 and 2020 (Netherlands Cancer Registry) who underwent palliative treatment were included. Patients who underwent emergency surgery or curative intent treatment were excluded. Patients were categorized into upfront palliative primary tumor resection (with or without additional systemic treatment) or palliative systemic treatment only. Overall survival (OS) was compared between both groups and multivariable cox regression analysis was performed. Of 1031 included patients, 364 (35%) patients underwent primary tumor resection and 667 (65%) patients received systemic treatment only. Sixty-day mortality was 9% in the primary tumor resection group and 5% in the systemic treatment group (P = 0.007). OS was 13.8 months in the primary tumor resection group and 10.3 months in the systemic treatment group (P < 0.001). Multivariable analysis showed that primary tumor resection was associated with improved OS (HR 0.68; 95%CI 0.57-0.81; P < 0.001). Palliative primary tumor resection appeared to be associated with improved survival compared to palliative systemic treatment alone in patients with isolated synchronous CRC-PM despite a higher 60-day mortality. This finding must be interpreted with care as residual bias probably played a significant role. Nevertheless, this option may be considered in the decision-making process by clinicians and their patients.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) in patients with peritoneal surface malignancies (PSM): a prospective single-center registry study

PURPOSE

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new, palliative approach for patients with peritoneal surface malignancies (PSMs). Its main goals are to control symptoms and ascites. For this experimental procedure, treatment efficacy and patient safety need to be closely monitored.

METHODS

We performed a prospective registry study for patients with PSMs. Cisplatin (C) (7.5 mg/m² body surface) and doxorubicin (D) (1.5 mg/m²) were administered laparoscopically via PIPAC.

RESULTS

Between November 2015 and June 2020, we recorded data from 108 patients and 230 scheduled procedures. Tumor burden, patient fitness, quality of life, operating time and in-hospital stay remained stable over consecutive procedures. We recorded 21 non-access situations and 14 intraoperative complications (11 intestinal injuries, and three aspirations while inducing anesthesia). Three or more previous abdominal surgeries or cytoreductive surgery (CRS) with intraperitoneal hyperthermic chemoperfusion (HIPEC) were risk factors for non-access and intestinal injuries (χ², p ≤ 0.01). Five Grade IV and three Grade V postoperative complications according to the Clavien-Dindo Classification (CDC) occurred. Median overall survival was 264 days (interquartile range 108-586). Therapies were primarily discontinued because of death (34%), progressive (26%), or regressive (16%) disease.

CONCLUSION

PIPAC is effective in stabilizing PSMs and retaining quality of life in selected patients. Earlier abdominal surgeries and CRS with HIPEC should be considered when determining the indication for PIPAC. Randomized controlled studies are needed to evaluate PIPAC's therapeutic benefits compared to systemic chemotherapy (sCHT) alone.

TRIAL REGISTRATION

NCT03100708 (April 2017).

Prognostic Value of Preoperative Serological Biomarkers in Patients Undergoing Curative-Intent Cytoreductive Surgery for Colorectal Cancer Peritoneal Metastases

BACKGROUND

Cytoreductive surgery (CRS) for peritoneal metastases of colorectal cancer (PMCRC) is associated with a high risk of postoperative morbidity, thus making patient selection of upmost importance. Further to data showing an association between preoperative serological biomarkers and patient outcome in various solid tumors, in this study we aim to evaluate their prognostic value in patients with PMCRC treated with curative intent.

PATIENTS AND METHODS

This is a retrospective study including patients with PMCRC treated by complete CRS ± HIPEC at our institution between 2011 and 2020. Preoperative serological biomarkers, along with other standard clinicopathological variables, were studied to determine their prognostic value.

RESULTS

A total of 94 out of 108 patients met the inclusion criteria. Forty-three patients (46%) presented with synchronous PM. The median peritoneal cancer index (PCI) was 6. On univariate analysis, a higher neutrophil-to-lymphocyte ratio (NLR) was associated with poor prognosis in terms of overall survival (OS) [cutoff 3.567, hazard ratio (HR) 2.8 (1.4-5.3), p = 0.002], whereas a higher platelet-to-lymphocyte ratio (PLR) predicted favorable prognosis in terms of disease-free survival (DFS) [cutoff 185.4, HR 1.9 (1.07-3.53), p = 0.030]. On multivariate analysis, NLR > 3.567, positive lymph nodes (LNs), and PCI > 7 were independent predictive factors for worse OS, whereas NLR > 3.567 and positive LNs were significantly associated with worse DFS. PLR > 185.4 was associated with better DFS.

CONCLUSION

High preoperative NLR (> 3.567) and PLR (> 185.4) can predict outcome of patients with PMCRC treated by complete CRS ± HIPEC.

Sex differences in metastatic surgery following diagnosis of synchronous metastatic colorectal cancer

The aim was to investigate gender differences in the likelihood to receive metastatic surgery, and to compare overall survival between men and women, among patients with synchronous metastatic colorectal cancer (mCRC) in a population-based setting. All Swedish adult patients diagnosed with synchronous mCRC in 2007-2016 were identified using the nationwide colorectal cancer database (CRCBaSe). Unadjusted and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using logistic regression, comparing the odds of receiving treatment. The Kaplan-Meier method was used to calculate survival proportions and Cox regression models to estimate hazard ratios (HRs) and 95% CIs of all-cause mortality rates. All multivariable models were adjusted for age, ASA score, Charlson comorbidity index, year of diagnosis, location of primary tumor and single or multiple metastatic locations. A total of 12 201 patients met the study criteria. Women received 23% less metastatic surgery for mCRC (adjusted OR = 0.77, CI:0.69-0.86) and experienced a slightly higher mortality following diagnosis (adjusted HR = 1.09, CI:1.05-1.14). In analyses restricted to patients who received metastatic surgery, no significant differences in mortality were found. In conclusion, this population-based study showed that women less often received metastatic surgery of mCRC and experienced slightly higher all-cause mortality compared with men. The differences persisted despite adjustments of patient and cancer characteristics. Gender differences in receiving treatment are unacceptable if the underlying explanation cannot be motivated. Further studies are needed to understand if the differences are based on sex (i.e., biology) or gender (including clinically unmotivated differences in treatment approach).

Clinical epidemiology of peritoneal metastases in China: The construction of professional peritoneal metastases treatment centers based on the prevalence rate

OBJECTIVE

To understand the tumor burden of peritoneal metastases (PM) in China, and to guide the construction of professional PM treatment centers in China.

METHODS

Based on the cancer statistics by the National Cancer Center of China published in 2016, the prevalence of PM in 2020 was calculated according to the population statistics in China and the survival and mortality rates of various PM.

RESULTS

The prevalence rates of PM in China were as follows: gastric cancer PM 371.0/million, absolute number 523,937; colorectal cancer PM 47.1/million, absolute number 66,482; ovarian cancer PM 97.1/million, absolute number 137,083; pseudomyxoma peritonei 25.1/million, absolute number 35,425; malignant peritoneal mesothelioma 2.6/million, absolute number 3737; the above total was 766,664. According to the annual high-quality treatment volume of 365 cases in each professional PM treatment center, China needs to establish 1194 specialized PM treatment centers. At present, there are 1580 tertiary first-class hospitals in China. Therefore, for every 3 first-class tertiary hospitals in China there should be at least 2 PM treatment centers in full operation.

CONCLUSIONS

Considering the large number of PM patients in China and the relatively small number of professional PM treatment centers, more resources should be devoted to the promotion and construction of PM treatment centers.

Peritoneal metastases in elderly patients with colorectal cancer

BACKGROUND

With the introduction of cytoreductive surgery with intraperitoneal chemotherapy and the development of new systemic anti-cancer agents, the treatment of colorectal cancer (CRC) patients with peritoneal metastases has changed. Real-world data on the treatment of elderly patients and their clinical outcomes is lacking.

METHODS

All CRC patients diagnosed with synchronous peritoneal metastases (SPM) during 2008-2019 (n = 7,748) were identified from the Netherlands Cancer Registry. Trends in treatment and postoperative mortality were described by age category (<70, 70-74, 75-79, ≥80 years) and period of diagnosis (2008-2013, 2014-2019). Kaplan-Meier curves were constructed, and log-rank tests were performed to evaluate differences in overall survival (OS).

RESULTS

With increasing age, less patients received multimodality treatment and systemic treatment. Of the patients aged <70 years, 38% underwent multimodality treatment and 35% palliative systemic therapy, declining to 4% and 12% in patients ≥80 years. A large and increasing proportion of elderly patients did not receive cancer-directed treatment, this increased from 32% in 2008-2013 to 41% in 2014-2019 in 75-79 years old patients and from 52% to 65% in ≥80 years old. Postoperative mortality decreased in all age categories over time, OS remained stable. The median OS of elderly patients ranged from 8 months in 70-74 years old to 3 months in patients aged ≥80 years.

DISCUSSION

Age strongly affects treatment of patients with SPM, with a large and increasing proportion of elderly patients not receiving cancer-directed treatment. Their prognosis remains very poor. There is a need for therapeutic options that are well tolerable for elderly patients.

The measured distance between tumor cells and the peritoneal surface predicts the risk of peritoneal metastases and offers an objective means to differentiate between pT3 and pT4a colon cancer

Substantial variability exists in what pathologists consider as pT4a in colorectal cancer when tumor cells are within 1 mm of the free peritoneal surface. This study aimed to determine if the measured sub-millimeter distance between tumor cells and the free peritoneal surface would offer an objective means of stratifying patients according to the risk of developing peritoneal metastases. Histological slides of patients included in the COLOPEC trial, with resectable primary c/pT4N0-2M0 colon cancer, were centrally reassessed. Specific tumor morphological variables were collected, including distance from tumor to free peritoneal surface, measured in micrometers (µm). The primary outcome, 3-year peritoneal metastasis rate, was compared between four groups of patients stratified for relation of tumor cells to the peritoneum: 1) Full peritoneal penetration with tumor cells on the peritoneal surface, 2) 0-99 µm distance to the peritoneum, 3) 100-999 µm to the peritoneum, and 4) ≥1000 µm to the peritoneum, by using Kaplan-Meier analysis. In total, 189 cases were included in the present analysis. Cases with full peritoneal penetration (n = 89), 0-99 µm distance to the peritoneal surface (n = 34), 100-999 µm distance (n = 33), and ≥1000 µm distance (n = 33), showed significantly different 3-year peritoneal metastases rates of 25% vs 29% vs 6% vs 12%, respectively (Log Rank, p = 0.044). N-category did not influence the risk of peritoneal metastases in patients with a tumor distance beyond 100 µm, while only the N2 category seemed to result in an additive risk in patients with a distance of 0-99 µm. The findings of this study suggest that the measured shortest distance between tumor cells and the free peritoneal surface is useful as an objective means of stratifying patients according to the risk of developing peritoneal metastases. This simple measurement is practical and may help in providing a precise definition of pT4a. Trial registration: NCT02231086 (Clinicaltrials.gov).

Anastomotic leakage after cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal cancer

BACKGROUND

Anastomotic leakage (AL) after colorectal surgery is well-researched, yet the effect of Hyperthermic Intraperitoneal Chemotherapy (HIPEC) after Cytoreductive Surgery (CRS) is unclear. Assessment of risk factors in these patients may assist surgeons during perioperative decision making.

METHODS

This was a single-center, retrospective study of patients who underwent CRS-HIPEC for colorectal peritoneal metastases. Main outcome measures were anastomotic leakage and associated morbidity.

RESULTS

AL was observed in 17 of the 234 (7.3%) anastomoses in 17 of the total of 165 (10.3%) of patients. No association was observed between the number and location of anastomoses and AL, although only one in 87 small bowel anastomoses showed leakage. The only factor associated with AL was administration of bevacizumab within 60 days prior to surgery with an odds ratio (OR) of 6.13 (1.32-28.39), P = 0.03. Deviating stomata were not statistically protective of increased morbidity, although more AL occurred in the patients with colocolic and colorectal anastomoses when no concomitant deviating stoma was created. Deviation stomata were reversed in 52.6%, and no AL was observed after stoma reversal.

CONCLUSION

The overall AL rate of CRS-HIPEC is comparable to colorectal surgery, and there is no cumulative risk of multiple anastomoses - especially in the case of small bowel anastomoses. Deviating stomata should be considered in patients with colocolic or colorectal anastomosis, although there is a significant chance that the stoma will not be reversed in these patients. Due to increased AL-risk surgeons should be aware of previous bevacizumab treatment, and plan the CRS-HIPEC at least 60 days after the treatment-day.

Treatment Response After Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) for Peritoneal Metastases of Colorectal Originf

The objective of this study is to analyze oncological outcomes of patients with peritoneal metastases (PM) of colorectal origin treated with Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC).

Background

PIPAC has been demonstrated to be a feasible and safe novel treatment for patients with PM of various origins. Only small series reports on survival after PIPAC by disease entity.

Methods

International retrospective cohort study of consecutive patients with PM of colorectal origin. Outcome measures were overall survival (OS), radiological response according to Response Evaluation Criteria in Solid Tumors (RECIST), histological response (peritoneal regression grading score [PRGS]: complete response: 1-4: no response), change of peritoneal cancer index (PCI), and symptom control.

Results

Seventeen eligible centers compiled 256 non-selected patients (mean age 61 [50.6-69.2], 43% female) and 606 procedures. Sixty-three percent were treated after 2 lines of chemotherapy, median PCI at PIPAC1 was 18 (interquartile range [IQR] = 10-27). Median OS was 19.00 months (IQR = 12.9-29.8) from diagnosis and 9.4 months (IQR = 4.5-16.8) from PIPAC1. One hundred and four of 256 patients (40.6%) had ≥3 procedures (per protocol [pp]) with the following outcomes at PIPAC3: RECIST: 59.3% partial response/stable, 40.7% progression; mean PRGS: 2.1 ± 0.9. Median PCI was 21 (IQR = 15-29) at baseline and 20 (IQR = 12-27) at PIPAC3 (P = 0.02). Fifty-six (54%) and 48 (46%) patients were symptomatic at baseline and PIPAC3, respectively (P = 0.267). Median OS for the pp cohort was 11.9 months (IQR = 10.7-15.0) from PIPAC1. Independent predictors for survival were radiological response (HR = 3.0; 95% CI = 1.6-5.7) and no symptoms (HR = 4.5, 95% CI = 2.2-9.1) at PIPAC3.

Conclusions

Objective treatment response and encouraging survival were demonstrated after PIPAC for colorectal PM. Prospective registry data and comparative studies are now needed in to confirm these data.

Disparities in access to care among patients with appendiceal or colorectal cancer and peritoneal metastases: A medicare insurance-based study in the United States

BACKGROUND

Prior studies attempting to identify disparities in the care of patients with appendiceal (AC) or colorectal cancer (CRC) with peritoneal metastasis (PM) are limited to single-institution, highly selected patient populations. This observational cohort study sought to identify factors associated with specialty care for Medicare beneficiaries with AC/CRC-PM.

MATERIALS AND METHODS

Patients >65 years old in the United States diagnosed with AC/CRC and isolated PM were identified within the Medicare Standard Analytic File (2013-2017). Mixed-effects analyses assessed patient factors associated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) and outpatient consultation with a peritoneal surface malignancy (PSM) surgeon, and Cox proportional-hazards analysis compared 3-year overall survival (OS) between patients receiving CRS/HIPEC versus systemic therapy alone.

RESULTS

Among 7,653 patients, only 250 (3.3%) underwent CRS/HIPEC. Among those individuals who did not undergo CRS/HIPEC (N=7,403), only 475 (6.4%) had outpatient consultation with a PSM surgeon. Patient factors independently associated with lower odds of CRS/HIPEC and PSM surgery consultation included older age, greater comorbidity burden, higher social vulnerability index, and further distance from a PSM center (p<0.05). CRS/HIPEC was independently associated with better 3-year OS compared with systemic therapy alone (HR=0.29, 95%CI=0.21-0.38).

CONCLUSION

An exceedingly small proportion of Medicare beneficiaries with AC/CRC-PM undergo CRS/HIPEC or even have an outpatient consultation with a PSM surgeon. Significant disparities in treatment and access to care exist for patients with higher levels of social vulnerability and those that live further away from a PSM center. Future research and interventions should focus on improving access to care for these at-risk patient populations.

Hyperthermic intraperitoneal chemotherapy following up-front cytoreductive surgery versus cytoreductive surgery alone for isolated synchronous colorectal peritoneal metastases: A retrospective, observational study

Background

To date, the value of hyperthermic intraperitoneal chemotherapy (HIPEC) following up-front resection for isolated synchronous colorectal peritoneal metastases seems controversial.

Patients and Methods

This retrospective cohort study was conducted from September 1, 2012, to September 1, 2019, at a tertiary medical center in China. Patients with isolated synchronous colorectal peritoneal metastases were included in CRS plus HIPEC group or CRS alone group based on the treatment history. Overall survival and relapse-free survival were estimated using Cox proportional hazards regression analysis and Kaplan–Meier method.

Results

78 patients with isolated synchronous colorectal peritoneal metastases were identified among 396 patients with synchronous colorectal peritoneal metastases. 43 were in the cytoreductive surgery plus HIPEC group and 35 were in the cytoreductive surgery alone group. Among them, 61 patients had relapse-free survival data. The median peritoneal cancer index was 4 in all patients. After a median follow-up of 46.0 months, 5-year overall survival was 66.8% and the median relapse-free survival was 36.0 (95% CI, 6.8-65.1) months in the CRS plus HIPEC group. 5-year overall survival was 31.2% and the median relapse-free survival was 12.0 (95% CI, 9.0-15.0) months in the CRS alone group. Cox regression analyses showed that HIPEC was the independent prognostic factor for overall survival (P = 0.004) and relapse-free survival (P = 0.049).

Conclusion

Findings of the present study suggest that HIPEC following up-front CRS could improve overall survival and relapse-free survival in patients with isolated synchronous colorectal peritoneal metastases.

Clinical outcomes of curative surgical resection of peritoneal metastasis in patients with colorectal cancer: A long-term follow-up study

INTRODUCTION

Colorectal cancer with peritoneal metastasis (PM) has been considered a non-curative disease. PM is associated with reduced overall survival (OS) and worse prognosis compared with metastasis at other sites. We aimed to investigate the treatment outcome and recurrence after curative resection of colorectal PM during a long-term follow-up.

METHODS

Patients who were diagnosed with colorectal PM and underwent surgery between December 2001 and December 2019 were included (n = 309). Curative resection was defined as PM resection without residual disease after surgery (complete macroscopic resection).

RESULTS

Of 309 patients, 208 (67.8%) had PM as an initially metastatic disease. Curative (R0/1) resection was achieved in 155 (50.2%) patients, while non-curative operation (R2 resection or palliative operation including colostomy) was performed in 154 (49.8%) patients. Compared with patients who underwent non-curative operation, those with curative resection more often had a single PM on preoperative imaging (34.2% vs. 20.8%, p = 0.011) and postoperative results (59.4% vs. 22.7%, p < 0.001) and less often had concurrent metastasis (distant lymph node, liver, or lung) at the time of surgery (p < 0.001). During a median follow-up of 90.4 months, 80.6% (125/155) patients had recurrence in the curative resection group; the peritoneum was the most common site (56.0%). The median OS was 47.7 months (95% CI, 39.2-56.2) in the curative resection group and 24.8 months (95% CI, 20.8-28.9) in the non-curative resection group, respectively (p < 0.001). In particular, twenty-six patients without recurrence showed long-term survival after curative resection (median OS, 87.1 months; range, 40.1-127.5).

CONCLUSION

Surgical resection can be considered for selected patients with colorectal PM because a significant number of them could seize the cure changes during their treatment continuum.

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

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

Molecular characterization of colorectal cancer related peritoneal metastatic disease

A significant proportion of colorectal cancer (CRC) patients develop peritoneal metastases (PM) in the course of their disease. PMs are associated with a poor quality of life, significant morbidity and dismal disease outcome. To improve care for this patient group, a better understanding of the molecular characteristics of CRC-PM is required. Here we present a comprehensive molecular characterization of a cohort of 52 patients. This reveals that CRC-PM represent a distinct CRC molecular subtype, CMS4, but can be further divided in three separate categories, each presenting with unique features. We uncover that the CMS4-associated structural protein Moesin plays a key role in peritoneal dissemination. Finally, we define specific evolutionary features of CRC-PM which indicate that polyclonal metastatic seeding underlies these lesions. Together our results suggest that CRC-PM should be perceived as a distinct disease entity.

Colorectal cancer can lead to the development of peritoneal metastases, which are associated with worse disease outcome. Here, the authors characterize peritoneal metastases from 52 patients using RNA-seq and mutational sequencing and show a distinct molecular subtype.

Development and validation of a meta-learning-based multi-modal deep learning algorithm for detection of peritoneal metastasis

PURPOSE

The existing medical imaging tools have a detection accuracy of 97% for peritoneal metastasis(PM) bigger than 0.5 cm, but only 29% for that smaller than 0.5 cm, the early detection of PM is still a difficult problem. This study is aiming at constructing a deep convolution neural network classifier based on meta-learning to predict PM.

METHOD

Peritoneal metastases are delineated on enhanced CT. The model is trained based on meta-learning, and features are extracted using multi-modal deep Convolutional Neural Network(CNN) with enhanced CT to classify PM. Besides, we evaluate the performance on the test dataset, and compare it with other PM prediction algorithm.

RESULTS

The training datasets are consisted of 9574 images from 43 patients with PM and 67 patients without PM. The testing datasets are consisted of 1834 images from 21 testing patients. To increase the accuracy of the prediction, we combine the multi-modal inputs of plain scan phase, portal venous phase and arterial phase to build a meta-learning-based multi-modal PM predictor. The classifier shows an accuracy of 87.5% with Area Under Curve(AUC) of 0.877, sensitivity of 73.4%, specificity of 95.2% on the testing datasets. The performance is superior to routine PM classify based on logistic regression (AUC: 0.795), a deep learning method named ResNet3D (AUC: 0.827), and a domain generalization (DG) method named MADDG (AUC: 0.834).

CONCLUSIONS

we proposed a novel training strategy based on meta-learning to improve the model's robustness to "unseen" samples. The experiments shows that our meta-learning-based multi-modal PM predicting classifier obtain more competitive results in synchronous PM prediction compared to existing algorithms and the model's improvements of generalization ability even with limited data.

Risk Factors for Synchronous Peritoneal Metastases in Colorectal Cancer: A Systematic Review and Meta-Analysis

Background

Early detection of synchronous colorectal peritoneal metastases (CPMs) is difficult due to the absence of typical symptoms and the low accuracy of imaging examinations. Increasing the knowledge of the risk factors for synchronous CPM may be essential for early diagnosis and improving their management. This study aimed to identify the risk factors for synchronous CPM.

Method

The study was registered at PROSPERO (CRD42020198548). The PubMed, Embase and Cochrane Library databases were searched for studies comparing the clinicopathological and molecular features between patients with or without synchronous CPM. The pooled data were assessed by a random-effects model.

Results

Twenty-five studies were included. A synchronous CPM was positively associated with female sex (OR 1.299; 1.118 to 1.509; P = 0.001), PROK1/PROKR2-positivity (OR 2.244; 1.031 to 4.884; P = 0.042), right-sided colon cancer (OR 2.468; 2.050 to 2.970; P < 0.001), poorly differentiated grade (OR 2.560; 1.537 to 4.265; P < 0.001), BRAF mutation (OR 2.586; 1.674 to 3.994; P < 0.001), mucinous adenocarcinoma (OR 3.565; 2.095 to 6.064; P < 0.001), signet-ring cell carcinoma (OR 4.480; 1.836 to 10.933; P = 0.001), N1-2 (OR 5.665; 3.628 to 8.848; P < 0.001), T4 (OR 12.331; 7.734 to 19.660; P < 0.001) and elevated serum CA19-9 (OR 12.868; 5.196 to 31.867; P < 0.001).

Conclusions

These evidence-based risk factors are indicators that could predict the presence of synchronous CPMs and can improve their management.

Systematic Review Registration

www.crd.york.ac.uk/prospero, identifier: CRD42020198548.

Preoperative prognostic factors for obstructive colorectal cancer

AIM

The aim of the study was to determine the preoperative predictive factors of overall survival, relapse-free survival, and peritoneal carcinomatosis in obstructive colorectal cancer.

METHODS

Data from patients undergoing emergency surgery for obstructive colorectal cancer at our center between 2004 and 2016 were extracted retrospectively from our health records. Several preoperative parameters were used to predict survival and peritoneal carcinomatosis using univariate and multivariate analysis, and ROC curves.

RESULTS

A total of 107 patients with obstructive colorectal cancer were included. Five-year relapse-free and overall survival rates were 14% and 28%, respectively, with 15% peritoneal carcinomatosis. Univariate analysis showed that age ≥ 83 years old, preoperative ASA score ≥ 3, initial hemodynamic instability, and CRP > 18.3 mg/L was significantly associated with worse relapse-free and overall survival. In a multivariate analysis, only age > 83 years (HR = 1.75; HR = 2.16, for relapse-free and overall survival status, respectively) and hemodynamic instability (HR = 7.29; HR = 6.55) were confirmed in the multivariate model. Global peritoneal carcinomatosis was significantly associated with synchronous liver metastases in the multivariate model (OR = 4.56), and synchronous peritoneal carcinomatosis only was significantly associated with platelet to lymphocyte ratio (PLR) > 269 and synchronous liver metastases in the multivariate model (OR = 0.003; OR = 7.26).

CONCLUSION

Synchronous liver metastases are prognostic risk factor for global and synchronous peritoneal carcinomatosis whereas PLR > 269 was a significant protective factor for synchronous peritoneal carcinomatosis only for obstructive colorectal cancer. Age > 83 years and initial hemodynamic instability were key preoperative prognostic risk factors for worse relapse-free and overall survival. Prognostic usefulness of blood cell ratios for mortality and peritoneal carcinomatosis warrants further investigation.

Selection Criteria for Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) Treatment in Patients with Peritoneal Metastases

Background: The standard treatment protocol for PIPAC consists of three procedures. Completion of treatment has been shown to be prognostic of improved survival. The aim of this study was to identify predictors for completion of treatment. Methods: Retrospective multicentric cohort study of patients with peritoneal metastases undergoing PIPAC in three PIPAC expert centers. Per protocol (PP) treatment was defined as patients receiving ≥3 PIPACs and was compared to patients receiving <3. Results: Overall, 183 patients had 517 PIPACs. The main reasons for stopping PIPAC were disease progression in 50% patients, bowel obstruction in 15%, patient’s refusal to pursue in 10%, conversion to cytoreductive surgery in 7%, and medical reasons in 8%. Overall, 95 patients (52%) had PP treatment. The PP median OS was 17 vs. 7 months, p = 0.001. PP patients had r ascites (410 ± 100 mL vs. 960 ± 188 mL, p = 0.001), no prior history of bowel obstruction (12% vs. 24%, p = 0.028), and more bimodal treatment (39% vs. 13%, p < 0.001). After multiple regression, bimodal treatment was found as an independent predictive factor for completing PP (OR = 4.202, 95%CI [1.813, 10.630], p < 0.001), along with prior bowel obstruction (OR = 0.389, 95%CI [0.153, 0.920], p = 0.037). Conclusion: The absence of ascites and prior bowel obstruction can help to select patients suitable for PIPAC. Best results seem to be achieved when PIPAC is combined with systemic chemotherapy.

GECOP-MMC: phase IV randomized clinical trial to evaluate the efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) with mytomicin-C after complete surgical cytoreduction in patients with colon cancer peritoneal metastases

BACKGROUND

The French PRODIGE 7 trial, published on January 2021, has raised doubts about the specific survival benefit provided by HIPEC with oxaliplatin 460 mg/m² (30 minutes) for the treatment of peritoneal metastases from colorectal cancer. However, several methodological flaws have been identified in PRODIGE 7, specially the HIPEC protocol or the choice of overall survival as the main endpoint, so its results have not been assumed as definitive, emphasizing the need for further research on HIPEC. It seems that the HIPEC protocol with high-dose mytomicin-C (35 mg/m²) is the preferred regime to evaluate in future clinical studies.

METHODS

GECOP-MMC is a prospective, open-label, randomized, multicenter phase IV clinical trial that aims to evaluate the effectiveness of HIPEC with high-dose mytomicin-C in preventing the development of peritoneal recurrence in patients with limited peritoneal metastasis from colon cancer (not rectal), after complete surgical cytoreduction. This study will be performed in 31 Spanish HIPEC centres, starting in March 2022. Additional international recruiting centres are under consideration. Two hundred sixteen patients with PCI ≤ 20, in which complete cytoreduction (CCS 0) has been obtained, will be randomized intraoperatively to arm 1 (with HIPEC) or arm 2 (without HIPEC). We will stratified randomization by surgical PCI (1-10; 11-15; 16-20). Patients in both arms will be treated with personalized systemic chemotherapy. Primary endpoint is peritoneal recurrence-free survival at 3 years. An ancillary study will evaluate the correlation between surgical and pathological PCI, comparing their respective prognostic values.

DISCUSSION

HIPEC with high-dose mytomicin-C, in patients with limited (PCI ≤ 20) and completely resected (CCS 0) peritoneal metastases, is assumed to reduce the expected risk of peritoneal recurrence from 50 to 30% at 3 years.

TRIAL REGISTRATION

EudraCT number: 2019-004679-37; Clinicaltrials.gov: NCT05250648 (registration date 02/22/2022, ).

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.

Early postoperative outcomes of staging laparoscopy for peritoneal metastases with or without pressurized intra-peritoneal aerosol chemotherapy (PIPAC)

Background

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) has been introduced for palliative treatment of peritoneal surface malignancies (PSM) and is currently tested also in the neoadjuvant and prophylactic setting. The aim was therefore to compare safety and tolerance of staging laparoscopy with or without PIPAC.

Methods

This retrospective analysis compared consecutive patients undergoing staging laparoscopy alone for oesogastric cancer with patients having PIPAC for suspected PSM of various origins from January 2015 until January 2020. Safety was assessed by use of the Clavien classification for complications and CTCAE for capturing of adverse events. Pain and nausea were documented by use of a visual analogue scale (VAS: 0–10: maximal intensity).

Results

Overall, 25 PIPAC procedures were compared to 24 staging laparoscopies. PIPAC procedures took a median of 35 min (IQR: 25–67) longer. Four patients experienced at least one complication in either group (p = 0.741). No differences were noted for postoperative nausea (p = 0.961) and pain levels (p = 0.156). Median hospital stay was 2 (IQR: 1–3) for PIPAC and 1 (IQR: 1–2) for the laparoscopy group (p = 0.104).

Conclusions

The addition of PIPAC did not jeopardize safety and postoperative outcomes of staging laparoscopy alone. Further studies need to clarify its oncological benefits.

What is the Risk for Peritoneal Metastases and Survival Afterwards in T4 Colon Cancers?

BACKGROUND

Patients with T4 colon adenocarcinomas have an increased risk of peritoneal metastases (PM) but the histopathologic risk factors for its development are not well-described.

OBJECTIVE

The purpose of this study was to determine factors associated with PM, time to recurrence, and survival after recurrence among patients with T4 colon cancer.

PATIENTS AND METHODS

Patients with pathologic T4 colon cancer who underwent curative resection from 2005 to 2017 were identified from a prospectively maintained institutional database and classified by recurrence pattern: (a) none - 68.8%; (b) peritoneal only - 7.9%; (c) peritoneal and extraperitoneal - 9.9%; and (d) extraperitoneal only - 13.2%. Associations between PM development and patient, primary tumor, and treatment factors were assessed.

RESULTS

Overall, 151 patients were analyzed, with a median follow-up of 66.2 months; 27 patients (18%) developed PM (Groups B and C) and 20 (13%) patients recurred at non-peritoneal sites only (Group D). Median time to developing metastases was shorter for Groups B and C compared with Group D (B and C: 13.7 months; D: 46.7 months; p = 0.022). Tumor deposits (TDs) and nodal stage were associated with PM (p < 0.05), and TDs (p = 0.048) and LVI (p = 0.015) were associated with additional extraperitoneal recurrence. Eleven (41%) patients with PM underwent salvage surgery, and median survival after recurrence was associated with the ability to undergo cytoreduction (risk ratio 0.20, confidence interval 0.06-0.70).

CONCLUSION

PM risk after resection of T4 colon cancer is independently associated with factors related to lymphatic spread, such as N stage and TDs. Well-selected patients can undergo cytoreduction with long-term survival. These findings support frequent postoperative surveillance and aggressive early intervention, including cytoreduction.

Metastatic Mucinous Adenocarcinoma of Gastrointestinal Origin: A Rare Presentation of Peritoneal Carcinomatosis in a Woman

Peritoneal carcinomatosis is most commonly a rare late-stage manifestation of disseminated ovarian cancer. Women with peritoneal carcinomatosis with no obvious primary tumor are presumptively treated for ovarian cancer. However, less frequently, gastrointestinal cancer disseminates to the peritoneum, which would confer other treatment options. Herein, we present a case of a 68-year-old woman who was managed for peritoneal carcinomatosis of metastatic mucinous adenocarcinoma of lower gastrointestinal origin.

Lobaplatin hyperthermic intraperitoneal chemotherapy plus cytoreduction and rechallenge using cetuximab for wild-type RAS peritoneal metastatic colon cancer: a case report and literature review

Background

Synchronous peritoneal metastasis of colorectal cancer usually predicts a bleak prognosis. Hyperthermic intraperitoneal chemotherapy (HIPEC) and cytoreductive surgery (CRS) have brought a glimmer of hope to the treatment of peritoneal cancer. Few cases treated with lobaplatin have been reported in the literature and the regimen is controversial. In this case, the comprehensive treatment scheme of lobaplatin-based HIPEC plus CRS and rechallenge using cetuximab plus systemic chemotherapy is effective, especially for the patients with left colon cancer (wild-type RAS).

Case presentation

A 49 year-old man with signet ring cell carcinoma of sigmoid colon with extensive abdominal metastasis (wild-type RAS) was hospitalized with prolonged abdominal pain, distention and abdominal mass. After receiving HIPEC with lobaplatin and XELOX regimen combined with cetuximab for eight cycles, the patient had been treated with the FOLFIRI regimen and cetuximab for 24 cycles, which discontinued due to myelosuppression. Because the disease recurred unfortunately 4 months later, the FOLFIRI + cetuximab regimen was initiated again and stopped after two cycles. Intestinal obstruction occurred 1 month later, so open total colectomy, CRS + HIPEC and ileorectal anastomosis were performed. Capecitabine adjuvant chemotherapy was administered, followed by the maintenance therapy with FOLFIRI + cetuximab regimen. After that, the patient has been in relatively stable condition. By August 2021, the overall survival is more than 45 months, which displays significant curative effect.

Conclusion

For peritoneal metastasis from left colon cancer, the management with CRS + lobaplatin HIPEC and rechallenge of systemic chemotherapy plus targeted medicine based on gene detection can dramatically improve prognosis and extend the overall survival.

Intraperitoneal Pretargeted Radioimmunotherapy for Colorectal Peritoneal Carcinomatosis

Peritoneal carcinomatosis (PC) is considered incurable, and more effective therapies are needed. Herein we test the hypothesis that GPA33-directed intracompartmental pretargeted radioimmunotherapy (PRIT) can cure colorectal peritoneal carcinomatosis. Nude mice were implanted intraperitoneally with luciferase-transduced GPA33-expressing SW1222 cells for aggressive peritoneal carcinomatosis (e.g., resected tumor mass 0.369 ± 0.246 g; n = 17 on day 29). For GPA33-PRIT, we administered intraperitoneally a high-affinity anti-GPA33/anti-DOTA bispecific antibody (BsAb), followed by clearing agent (intravenous), and lutetium-177 (Lu-177) or yttrium-86 (Y-86) radiolabeled DOTA-radiohapten (intraperitoneal) for beta/gamma-emitter therapy and PET imaging, respectively. The DOTA-radiohaptens were prepared from S-2-(4-aminobenzyl)-1,4,7, 10-tetraazacyclododecane tetraacetic acid chelate (DOTA-Bn). Efficacy and toxicity of single- versus three-cycle therapy were evaluated in mice 26-27 days post-tumor implantation. Single-cycle treatment ([177Lu]LuDOTA-Bn 111 MBq; tumor dose: 4,992 cGy) significantly prolonged median survival (MS) approximately 2-fold to 84.5 days in comparison with controls (P = 0.007). With three-cycle therapy (once weekly, total 333 MBq; tumor dose: 14,975 cGy), 6/8 (75%) survived long-term (MS > 183 days). Furthermore, for these treated long-term survivors, 1 mouse was completely disease free (microscopic "cure") at necropsy; the others showed stabilized disease, which was detectable during PET-CT using [86Y]DOTA-Bn. Treatment controls had MS ranging from 42-52.5 days (P < 0.001) and 19/20 mice succumbed to progressive intraperitoneal disease by 69 days. Multi-cycle GPA33 DOTA-PRIT significantly prolongs survival with reversible myelosuppression and no chronic marrow (929 cGy to blood) or kidney (982 cGy) radiotoxicity, with therapeutic indices of 12 for blood and 12 for kidneys. MTD was not reached.

Delineating the intra-patient heterogeneity of molecular alterations in treatment-naïve colorectal cancer with peritoneal carcinomatosis

In a non-negligible number of patients with metastatic colorectal cancer (mCRC), the peritoneum is the predominant site of dissemination. Cure can be achieved by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), but this procedure is associated with long-term morbidity and high relapse rates. Thus, there is a pressing need for improved therapeutic strategies and complementary biomarkers. The present study explored the molecular heterogeneity in mCRC with peritoneal carcinomatosis (PC), and the potential clinical implications thereof. Multi-region immunohistochemical profiling and deep targeted DNA-sequencing was performed on chemotherapy-naïve tumours from seven patients with synchronous colorectal PC who underwent CRS and HIPEC. In total, 88 samples (5-19 per patient) were analysed, representing primary tumour, lymph node metastases, tumour deposits, PC and liver metastases. Expression of special AT-rich sequence-binding protein 2 (SATB2), a marker of colorectal lineage, was lacking in the majority of cases, and a conspicuous intra-patient heterogeneity was denoted for expression of the proposed prognostic and predictive biomarker RNA-binding motif protein 3 (RBM3). Loss of mismatch repair proteins MLH1 and PSM2, observed in one case, was concordant with microsatellite instability and the highest tumour mutational burden. When present in a patient, mutations in key CRC driver genes, i.e., KRAS, APC and TP53, were homogenously distributed across all samples, while less common mutations were more heterogenous. On the same note, copy number variations showed intra-patient as well inter-patient heterogeneity. In two out of seven cases, hierarchical clustering revealed that samples from the PC and lymph node metastases were more similar to each other than to the primary tumour. In summary, these findings should encourage additional studies addressing the potential distinctiveness of mCRC with PC, which might pave the way for improved personalized treatment of these patients.

Treatment Strategies and Prognosis of Patients With Synchronous or Metachronous Colorectal Peritoneal Metastases: A Population-Based Study

BACKGROUND

This study aimed to compare treatment strategies and survival of patients with synchronous colorectal peritoneal metastases (CPM) and patients with metachronous CPM in a nationwide cohort.

METHODS

All patients from the Netherlands Cancer Registry with synchronous or metachronous CPM whose primary colorectal cancer (CRC) was diagnosed between 1 January and 30 June 2015 were included in the study. Treatments were categorized as (A) cytoreductive surgery and hyperthermic intraperitoneal chemotherapy [CRS-HIPEC]; (B) palliative treatment; or (C) best supportive care. Overall survival (OS) for all the patients and disease-free survival (DFS) for those who underwent CRS-HIPEC were compared between the two groups.

RESULTS

Of 7233 patients, 743 had a diagnosis of CPM, including 409 patients with synchronous CPM and 334 patients with metachronous CPM. The median OS was 8.1 months for the patients with synchronous CPM versus 12 months for the patients with metachronous CPM (p = 0.003). After multivariable correction, OS no longer differed between the patients with synchronous CPM and those with metachronous CPM (HR 1.03 [0.83-1.27]). The patients with metachronous CPM more often underwent CRS-HIPEC than the patients with synchronous CPM (16 % vs 8 %; p = 0.001). The two groups did not differ statistically in terms of DFS and OS (median DFS, 21.5 vs 14.1 months, respectively; p = 0.094; median OS, 37.8 vs. 35.8 months, respectively; p = 0.553).

CONCLUSION

This population-based study showed that survival for the patients with synchronous CPM and patients with metachronous CPM did not significantly differ. This suggests that a similar prognosis may be expected for patients selected for treatment regardless of the onset of CPM.

Adipocytic Glutamine Synthetase Upregulation via Altered Histone Methylation Promotes 5FU Chemoresistance in Peritoneal Carcinomatosis of Colorectal Cancer

The development of resistance to 5-fluorouracil (5FU) chemotherapy is a major handicap for sustained effective treatment in peritoneal carcinomatosis (PC) of colorectal cancer (CRC). Metabolic reprogramming of adipocytes, a component of the tumor microenvironment and the main composition of peritoneum, plays a significant role in drug resistance of PC, with the mechanisms being not fully understood. By performing metabolomics analysis, we identified glutamine (Gln), an important amino acid, inducing resistance to 5FU-triggered tumor suppression of CRC-PC through activating mTOR pathway. Noteworthily, genetic overexpression of glutamine synthetase (GS) in adipocytes increased chemoresistance to 5FU in vitro and in vivo while this effect was reversed by pharmacological blockage of GS. Next, we showed that methionine metabolism were enhanced in amino acid omitted from CRC-PC of GS transgenic (Tg^GS) mice, increasing intracellular levels of S-carboxymethy-L-cys. Moreover, loss of dimethylation at lysine 4 of histone H3 (H3k4me2) was found in adipocytes in vitro, which may lead to increased expression of GS. Furthermore, biochemical inhibition of lysine specific demethylase 1 (LSD1) restored H3k4me2, thereby reducing GS-induced chemoresistance to 5FU. Our findings indicate that GS upregulation-induced excessive of Gln in adipocytes via altered histone methylation is potential mediator of resistance to 5FU chemotherapy in patients with CRC-PC.

Comparison of model fit and discriminatory ability of M category as defined by the 7th and 8th editions of the tumor-node-metastasis classification of colorectal cancer and the 9th edition of the Japanese classification

Background

In transitioning from the 7th edition of the tumor‐node‐metastasis classification (TNM‐7) to the 8th edition (TNM‐8), colorectal cancer with peritoneal metastasis was newly categorized as M1c. In the 9th edition of the Japanese Classification of colorectal, appendiceal, and anal carcinoma (JPC‐9), M1c is further subdivided into M1c1 (without other organ involvement) and M1c2 (with other organ involvement). This study aimed to compare the model fit and discriminatory ability of the M category of these three classification systems, as no study to date has made this comparison.

Methods

The study population consisted of stage IV colorectal cancer patients who were referred to the National Cancer Center Hospital from 2000 to 2017. The Akaike information criterion (AIC), Harrell's concordance index (C‐index), and time‐dependent receiver operating characteristic (ROC) curves were used to compare the three classification systems. Subgroup analyses, stratified by initial treatment year, were also performed.

Results

According to TNM‐8, 670 (55%) patients had M1a, 273 (22%) had M1b, and 279 (23%) had M1c (87 M1c1 and 192 M1c2 using JPC‐9) tumors. Among the three classification systems, JPC‐9 had the lowest AIC value (JPC‐9: 10546.3; TNM‐7: 10555.9; TNM‐8: 10585.5), highest C‐index (JPC‐9: 0.608; TNM‐7: 0.598; TNM‐8: 0.599), and superior time‐dependent ROC curves throughout the observation period. Subgroup analyses were consistent with these results.

Conclusions

While the revised M category definition did not improve model fit and discriminatory ability from TNM‐7 to TNM‐8, further subdivision of M1c in JPC‐9 improved these parameters. These results support further revisions to M1 subcategories in future editions of the TNM classification system.

Prognostic Value of KRAS Gene Mutation on Survival of Patients with Peritoneal Metastases of Colorectal Adenocarcinoma

Objective

The main objective of the study was to determine the effect of the presence of mutation in the KRAS gene on the survival in patients with colorectal cancer (CRC) and peritoneal metastases (PM).

Materials and Methods

A retrospective cohort study was performed. Patients diagnosed with CRC with synchronous or metachronous PM between January 2006 and December 2019 were included. Data on the histopathological, clinical, and treatment factors were collected. The effect of each variable on survival was evaluated by Cox regression.

Results

A total of 149 patients were included (64 women (43%) and 85 men (57%); mean age, 63 years). The long-term survival rate at 36 months was 24% (median, 21 months). KRAS mutation was detected in 75 patients (50.3%). Kaplan-Meier analysis estimated that likelihood of survival was higher in patients with wild-type KRAS tumours (35%) than in mutated-type KRAS (14%) (median: 28 vs. 15, respectively) (P=0.001). Within the categories into which the peritoneal cancer index (PCI) was classified, survival at 36 months depended on the KRAS status. Survival in wild-type KRAS tumours with PCI 1-10 was 71% and with PCI 11-20 was 26%, while in mutant-type KRAS tumours, survival was 41% and 4%, respectively (P=0.025). In the multiple regression analysis, the KRAS mutation was revealed to have an independent prognostic value (HR: 2.144; 95% CI: 1.342-3.424).

Conclusion

The mutational status of the KRAS gene has demonstrated a strong association with survival and prognostic utility in patients with CRC with PM.

Laparoscopic versus open resection in patients with locally advanced colon cancer

BACKGROUND

Surgical resection of locally advanced colon cancer (LACC) is challenging due to tumor size and the frequent need for multivisceral resection. The role of laparoscopic resection in LACC is controversial. This study aims to compare outcomes for laparoscopic versus open surgery in LACC.

METHODS

A population-based retrospective review was conducted of patients treated at a Provincial Cancer Center for LACC from 2005 to 2015. Patients with non-metastatic T4 colon cancers were included. Descriptive, survival, and recurrence analyses were used.

RESULTS

In all, 1,328 patients were reviewed, 23% of whom had laparoscopic surgery. A greater number of T4b tumors were removed via an open approach (35.9% vs 12.7%, P < .001). Positive resection margins occurred in 7.5% of laparoscopic and 16.5% of open cases (P < .001), and multivisceral resection was required in 11.0% and 27.7% (P < .001), respectively. Median follow-up was 37 months (interquartile range [IQR] 17-64) during which 48.6% patients died and 42.1% developed recurrence: locoregional (15.0%), distant (35.3%), peritoneal (11.4%). Age, right-sided tumors, nodal status, and laparoscopic approach were independent predictors of peritoneal recurrence. Overall survival (OS) (73 vs 61 months, P = .188) and recurrence-free survival (RFS) (39 vs 31 months, P = .288) were similar with both approaches. Age, nodal, and margin status were predictive of OS and RFS.

CONCLUSION

Open surgical approach is used more frequently when tumors invade adjacent organs or require multivisceral resections. When employed, laparoscopic approach had similar rates of survival and recurrence compared with open approach, but was an independent predictor of peritoneal recurrence. Careful patient selection in operative approach is suggested.

Incidence and predictors of peritoneal metastases of gynecological origin: a population-based study in the Netherlands

OBJECTIVE

Peritoneal metastases (PM) are a challenge in gynecological cancers, but its appearance has never been described in a population-based study. Therefore, we describe the incidence of PM and identify predictors that increase the probability of peritoneal spread.

METHODS

All ovarian, endometrial and cervical cancer patients diagnosed in the Netherlands between 1989 and 2015 were identified from the Netherlands Cancer Registry and stratified for PM. Crude and age-adjusted incidence over time was calculated. Independent predictors for PM were identified using uni- and multivariable analyses.

RESULTS

The 94,981 patients were diagnosed with ovarian, endometrial or cervical cancer and respectively 61%, 2% and 1% presented with PM. Predictors for PM in ovarian cancer were: age between 50 and 74 years (odds ratio [OR]=1.19; 95% confidence interval [CI]=1.08-1.32), other distant metastases (OR=1.25; 95% CI=1.10-1.41), poor differentiation grade (OR=2.00; 95% CI=1.73-2.32) and serous histology. Predictors in endometrial cancer were lymph node metastases (OR=2.32; 95% CI=1.65-3.26), other distant metastases (OR=1.38; 95% CI=1.08-1.77), high-grade tumors (OR=1.95; 95% CI=1.38-2.76) and clear cell (OR=1.49; 95% CI=1.04-2.13) or serous histology (OR=2.71; 95% CI=2.15-3.42). In cervical cancer, the risk is higher in adenocarcinoma than in squamous cell carcinoma (OR=4.92; 95% CI=3.11-7.79).

CONCLUSION

PM are frequently seen in patients with ovarian cancer. In endometrial and cervical cancer PM are rare. Histological subtype was the strongest predictive factor for PM in all 3 cancers. Better understanding of predictive factors for PM and thus the biological behavior is of paramount importance.

Prevalence of mesothelin expression in peritoneal disease from colorectal and appendiceal cancers

BACKGROUND

Mesothelin is a cell surface glycoprotein overexpressed in 28%-58% of colorectal cancer (CRC). We hypothesized that CRC mesothelin expression contributes to peritoneal spread and that it is selectively overexpressed in those with peritoneal metastasis versus distant metastasis.

METHODS

This case-controlled study involved mesothelin immunohistochemistry staining of tumor specimens from patients with metastatic CRC/appendiceal cancers between 2017 and 2019. Staining reactivity was graded from trace to 4+ (low ≤1+; high >1+). Staining patterns were characterized on global (focal/patchy/diffuse) and cellular (apical/cytoplasmic) levels. Immunostaining of normal mesothelial cells served as internal control.

RESULTS

Thirty-one patients were identified: 11 peritoneal (study) and 20 distant metastasis (control). The control group did not include appendiceal cancers. The study group had greater proportion of high staining reactivity (55% vs. 5%; odds ratio [OR] = 20.4, 95% confidence interval [CI] 1.96-211.8). The study group had more diffuse (36% vs. 0%; OR = 22.2, 95% CI 1.1-465.3) and cytoplasmic staining patterns (73% vs. 28%; OR = 6.9, 95% CI 1.3-37.2).

CONCLUSION

Mesothelin expression is higher in CRC/appendiceal cancers with peritoneal metastasis than those with distant metastasis. Immunohistochemistry staining patterns suggestive of propensity towards peritoneal metastasis include diffuse and cytoplasmic staining. Mesothelin may be a potential target for novel treatments of CRC/appendiceal carcinoma with peritoneal involvement.

Abundant intratumoral fibrosis prevents lymphocyte infiltration into peritoneal metastases of colorectal cancer

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) have been reported to reflect the anti-tumor immune status. However, recent investigations have demonstrated that intratumoral fibrosis is important as a factor affecting the infiltration of TILs. This study investigated the organ specificities of TIL infiltration and intratumoral fibrosis in primary colorectal cancer and distant metastases, as well as the relationship between the distribution of TILs and intratumoral fibrosis.

METHODS

Patients who underwent resection of primary tumors or distant metastases for colorectal cancer with distant metastases were enrolled. We evaluated the TIL infiltration by immunohistochemical staining with CD3&CD8 and intratumoral fibrosis by immunohistochemical staining with α-SMA positive cancer-associated fibroblasts and Masson's trichrome staining against collagen fibers. The "ImageJ" was used to evaluate fibrosis, and the density of TILs in the dense and sparse areas of fibrosis was calculated. The Immunoscore (IS) was obtained based on the density of CD3+/CD8+TILs in the tumor center and invasive margin of the primary tumor.

RESULTS

The degree of CD3+/CD8+TIL infiltration in peritoneal metastases was significantly lower than that in liver and lung metastases. The area ratio of α-SMA positive cancer-associated fibroblasts and collagen fibers in peritoneal metastases was significantly higher than that of liver and lung metastases. Furthermore, the density of TILs in the high-fibrosis area was significantly lower than that in the low-fibrosis area. In the high-IS group of primary tumors, the degree of TIL infiltration in distant metastases was significantly higher than that in the low-IS group.

CONCLUSION

The infiltration of T lymphocytes into tumors is prevented in peritoneal metastases of colorectal cancer due to the high intratumoral fibrosis, which may lead to treatment resistance and a poor prognosis.

Impact of Primary Tumor Resection on Mortality in Patients with Stage IV Colorectal Cancer with Unresectable Metastases: A Multicenter Retrospective Cohort Study

BACKGROUND

Primary tumor resection (PTR) before commencing systemic chemotherapy in patients with stage IV colorectal cancer and unresectable metastases (mCRC) remains controversial. This study aimed to assess whether PTR before systemic chemotherapy is associated with mortality in mCRC patients, after adjusting for confounding factors, such as the severity of the primary tumor and metastatic lesions.

METHODS

We analyzed hospital-based cancer registries from nine designated cancer hospitals in Fukushima Prefecture, Japan. Patients were divided into two groups (PTR and non-PTR), based on whether PTR was performed as initial therapy for mCRC or not. The primary outcome was all-cause mortality. Kaplan-Meier survival analysis was performed, and survival estimates were compared using the log-rank test. Adjusted hazard ratios were calculated using Cox regression to adjust for confounding factors. All tests were two-sided; P-values < 0.05 were considered statistically significant.

RESULTS

Between 2008 and 2015, 616 mCRC patients were included (PTR: 414 [67.2%]; non-PTR: 202 [32.8%]). The median follow-up time was 18.0 (interquartile range [IQR]: 8.4-29.7) months, and 492 patients (79.9%) died during the study period. Median overall survival in the PTR and non-PTR groups was 23.9 (IQR: 12.2-39.9) and 12.3 (IQR: 6.2-23.8) months, respectively (P < 0.001, log-rank test). PTR was significantly associated with improved overall survival (adjusted hazard ratio: 0.51; 95% confidence interval: 0.42-0.64, P < 0.001).

CONCLUSIONS

PTR before systemic chemotherapy in patients with mCRC was associated with improved survival.

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.

The Characteristics of 206 Long-Term Survivors with Peritoneal Metastases from Colorectal Cancer Treated with Curative Intent Surgery: A Multi-Center Cohort from PSOGI

Simple Summary

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy improves survival in selected patients with peritoneal metastases from colorectal cancer (CRC). However, the characteristics of long-term survivors are not well documented. This study set out to investigate the patient characteristics associated with the long-term survival of peritoneal metastases from CRC. We retrospectively analyzed 206 long-term survivors who underwent CRS for peritoneal metastases from CRC. We found that most long-term survivors showed low peritoneal cancer index (PCI), low PCI of small bowel subsets, and complete cytoreduction (CC-0), while some exhibited characteristics considered associated with poor prognosis.

Abstract

Background: We conducted this study to review the patient characteristics associated with long-term survival in patients with peritoneal metastases from colorectal cancer who underwent cytoreductive surgery (CRS). Methods: We retrospectively investigated patients with peritoneal metastases from CRC treated with curative intent surgery with or without hyperthermic intraperitoneal chemotherapy at 13 institutions worldwide between January 1985 and April 2015 and survived longer than five years after the first CRS for peritoneal metastases. Clinical and oncological features and therapeutic parameters were described and analyzed. Results: Two hundred six long-term survivors were available for study. The median peritoneal cancer index (PCI) of this cohort was 4 (interquartile range (IQR), 2–7), and the median score of the small bowel regions of the PCI (SB-PCI) was 0 (IQR, 0–2). Complete cytoreduction (CC-0) was achieved in 180 (87.4%) patients. Recurrence was observed in 122 (59.2%) patients at a median of 1.8 (IQR, 1.2–2.6) years. Conclusions: While most long-term survivors showed low PCI/SB-PCI and CCR-0, some had characteristics considered associated with poor prognosis. Curative intent treatments may be considered in well-informed and fit patients showing negative factors affecting survival outcome.

Impact of "critical lesions" on outcomes following cytoreductive surgery and hyperthermic intra-peritoneal chemotherapy

BACKGROUND

Peritoneal Cancer Index (PCI) and complete cytoreduction are the best outcome predictors following cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Lesions in critical areas, regardless of PCI, complicate surgery and impact oncological outcomes. We prospectively defined "Critical lesions" (CL) as penetrating the hepatic hilum, diaphragm at hepatic outflow, major blood vessels, pancreas, or urinary tract.

METHODS

Retrospective analysis of a prospective database of 352 CRS + HIPEC patients from 2015 to 2019. Excluded patients with aborted/redo operation (n = 112), or incomplete data (n = 19). Patients categorized by CL status and compared: operative time, estimated blood loss (EBL), PCI, transfusions, hospital stay, post-operative complications and mortality, overall survival (OS) and disease-free survival (DFS).

RESULTS

Included 221 patients (78 CL; 143 no-CL). No difference in patients' characteristics: age, BMI, gender or co-morbidities noted. Operative time longer (5.3 h vs 4.3 h, p < 0.01), EBL higher (769 ml vs 405 ml, p < 0.01), transfusions higher (1.9 vs 0.7 Units, p < 0.001) and PCI higher (15.5 vs 9.5, p < 0.01) in CL. No difference in major complications. Postoperative complications, CL, OR-time and transfusions were predictive of OS in univariate analysis, while only complications remained on multivariate analysis. Median follow up of 21.4 months, 3-year DFS/OS was 22% vs 30% (p < 0.037) and 73% vs 87% (p < 0.014) in CL and non-CL, respectively. Despite CL complete resection, 17/38 patients (44.7%) that recurred had recurrence at previous CL site.

CONCLUSIONS

Critical lesions complicate surgery and may be associated with poor oncological outcomes with high local recurrence rate, despite no significant difference in complications. Utilizing adjuvant or intra-operative radiation may be beneficial.