Towards Equal Access to Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy and Survival in Patients with Isolated Colorectal Peritoneal Metastases: A Nationwide Population-Based Study.

BACKGROUND: Before 2016, patients with isolated synchronous colorectal peritoneal metastases (PMCRC) diagnosed in expert centers had a higher odds of undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) and better overall survival (OS) than those diagnosed in referring centers. Nationwide efforts were initiated to increase awareness and improve referral networks. METHODS: This nationwide study aimed to evaluate whether the between-center differences in odds of undergoing CRS-HIPEC and OS have reduced since these national efforts were initiated. All patients with isolated synchronous PMCRC diagnosed between 2009 and 2021 were identified from the Netherlands Cancer Registry. Associations between hospital of diagnosis and the odds of undergoing CRS-HIPEC, as well as OS, were assessed using multilevel multivariable regression analyses for two periods (2009-2015 and 2016-2021). RESULTS: In total, 3948 patients were included. The percentage of patients undergoing CRS-HIPEC increased from 17.2% in 2009-2015 (25.4% in expert centers, 16.5% in referring centers), to 23.4% in 2016-2021 (30.2% in expert centers, 22.6% in referring centers). In 2009-2015, compared with diagnosis in a referring center, diagnosis in a HIPEC center showed a higher odds of undergoing CRS-HIPEC (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.02-2.67) and better survival (hazard ratio [HR] 0.80, 95% CI 0.66-0.96). In 2016-2021, there were no differences in the odds of undergoing CRS-HIPEC between patients diagnosed in HIPEC centers versus referring centers (OR 1.27, 95% CI 0.76-2.13) and survival (HR 1.00, 95% CI 0.76-1.32). CONCLUSION: Previously observed differences in odds of undergoing CRS-HIPEC were no longer present. Increased awareness and the harmonization of treatment for PMCRC may have contributed to equal access to care and a similar chance of survival at a national level.

Comparing patient reported abdominal pain between patients treated with oxaliplatin-based pressurized intraperitoneal aerosol chemotherapy (PIPAC-OX) and primary colorectal cancer surgery.

Oxaliplatin-based pressurized intraperitoneal aerosol chemotherapy (PIPAC-OX) is an emerging palliative treatment for patients with unresectable colorectal peritoneal metastases. Previously, our study group reported that patients experienced abdominal pain for several weeks after PIPAC-OX. However, it is unknown how this compares to abdominal pain after regular colorectal cancer surgery. To provide some perspective, this study compared the presence of abdominal pain after PIPAC-OX to the presence of abdominal pain after primary tumor surgery. Patient reported abdominal pain scores (EORTC QLQ-CR-29), from two prospective, Dutch cohorts were used in this study. Scores ranged from 0 to 100, a higher score represents more abdominal pain. Abdominal pain at baseline and at four weeks after treatment were compared between the two groups. Twenty patients who underwent PIPAC-OX and 322 patients who underwent primary tumor surgery were included in the analysis. At baseline, there were no differences in abdominal pain between both groups (mean 20 vs. 18, respectively; p = 0.688). Four weeks after treatment, abdominal pain was significantly worse in the PIPAC group (39 vs 15, respectively; p < 0.001; Cohen's d = 0.99). The differential effect over time for abdominal pain differed significantly between both groups (mean difference: 19 vs - 3, respectively; p = 0.004; Cohen's d = 0.88). PIPAC-OX resulted in significantly worse postoperative abdominal pain than primary tumor surgery. These results can be used for patient counseling and stress the need for adequate analgesia during and after PIPAC-OX. Further research is required to prevent or reduce abdominal pain after PIPAC-OX.Trial registration CRC-PIPAC: Clinicaltrails.gov NCT03246321 (01-10-2017).

Twenty-four hours stay after colorectal surgery: a systematic review

Introduction: The introduction of Enhanced Recovery After Surgery led to increasing twenty-four hours discharge pathways, for example in laparoscopic cholecystectomy and bariatric surgery. However, implementation in colorectal surgery still must set off. This systematic review assesses safety and feasibility of twenty-four hours discharge in colorectal surgery in terms of readmission and complications in current literature. Secondary outcome was identification of factors associated with success of twenty-four hours discharge. Methods: Pubmed and EMBASE databases were searched to identify studies investigating twenty-four hours discharge in colorectal surgery, without restriction of study type. Search strategy included keywords relating to ambulatory management and colorectal surgery. Studies were scored according to MINORS score. Results: Thirteen studies were included in this systematic review, consisting of six prospective and seven retrospective studies. Number of participants of the included prospective studies ranged from 5 to 157. Median success of discharge was 96% in the twenty-four hours discharge group. All prospective studies showed similar readmission and complication rates between twenty-four hours discharge and conventional postoperative management. Factors associated with success of twenty-four hours discharge were low ASA classification, younger age, minimally invasive approach, and relatively shorter operation time. Conclusions: Twenty-four hours discharge in colorectal surgery seems feasible and safe, based on retro- and prospective studies. Careful selection of patients and establishment of a clear and adequate protocol are key items to assure safety and feasibility. Results should be interpreted with caution, due to heterogeneity. To confirm results, an adequately powered prospective randomized study is needed. (AU)

Risk factors of postoperative intensive care unit admission during the COVID-19 pandemic: A multicentre retrospective cohort study.

Background: During the Coronavirus disease 2019 (COVID-19) pandemic, intensive care unit (ICU) capacity was scarce. Since surgical patients also require ICU admission, determining which factors lead to an increased risk of postoperative ICU admission is essential. This study aims to determine which factors led to an increased risk of unplanned postoperative ICU admission during the COVID-19 pandemic. Methods: This multicentre retrospective cohort study investigated all patients who underwent surgery between 9 March 2020 and 30 June 2020. The primary endpoint was the number of surgical patients requiring postoperative ICU admission. The secondary endpoint was to determine factors leading to an increased risk of unplanned postoperative ICU admission, calculated by multivariate analysis with odds ratios (OR's) and 95% confidence (CI) intervals. Results: One hundred eighty-five (4.6%) of the 4051 included patients required unplanned postoperative ICU admission. COVID-19 positive patients were at an increased risk of being admitted to the ICU compared to COVID-19 negative (OR 3.14; 95% CI 1.06-9.33; p = 0.040) and untested patients (OR 0.48; 95% CI 0.32-0.70; p = 0.001). Other predictors were male gender (OR 1.36; 95% CI 1.02-1.82; p = 0.046), body mass index (BMI) (OR 1.05; 95% CI 1.02-1.08; p = 0.001), surgical urgency and surgical discipline. Conclusion: A confirmed COVID-19 infection, male gender, elevated BMI, surgical urgency, and surgical discipline were independent factors for an increased risk of unplanned postoperative ICU admission. In the event of similar pandemics, postponing surgery in patients with an increased risk of postoperative ICU admission may be considered.

Use of ileostomy versus colostomy as a bridge to surgery in left-sided obstructive colon cancer: retrospective cohort study.

BACKGROUND: Colorectal cancer causes the majority of large bowel obstructions and surgical resection remains the gold standard for curative treatment. There is evidence that a deviating stoma as a bridge to surgery can reduce postoperative mortality rate; however, the optimal stoma type is unclear. The aim of this study was to compare outcomes between ileostomy and colostomy as a bridge to surgery in left-sided obstructive colon cancer. METHODS: This was a national, retrospective population-based cohort study with 75 contributing hospitals. Patients with radiological left-sided obstructive colon cancer between 2009 and 2016, where a deviating stoma was used as a bridge to surgery, were included. Exclusion criteria were palliative treatment intent, perforation at presentation, emergency resection, and multivisceral resection. RESULTS: A total of 321 patients underwent a deviating stoma; 41 (12.7 per cent) ileostomies and 280 (87.2 per cent) colostomies. The ileostomy group had longer length of stay (median 13 (interquartile range (i.q.r.) 10-16) versus 9 (i.q.r. 6-14) days, P = 0.003) and more nutritional support during the bridging interval. Both groups showed similar complication rates in the bridging interval and after primary resection, including anastomotic leakage. Stoma reversal during resection was more common in the colostomy group (9 (22.0 per cent) versus 129 (46.1 per cent) for ileostomy and colostomy respectively, P = 0.006). CONCLUSION: This study demonstrated that patients having a colostomy as a bridge to surgery in left-sided obstructive colon cancer had a shorter length of stay and lower need for nutritional support. No difference in postoperative complications were found.

Omentectomy as Part of Radical Surgery for Gastric Cancer: 5-Year Follow-Up Results of a Multicenter Prospective Cohort Study.

INTRODUCTION: Curative therapy for gastric cancer usually consists of perioperative chemotherapy combined with a radical (R0) gastrectomy. In addition to a modified D2 lymphadenectomy, a complete omentectomy is recommended. However, there is little evidence for a survival benefit of omentectomy. This study presents the follow-up data of the OMEGA study. METHODS: This multicenter prospective cohort study included 100 consecutive patients with gastric cancer undergoing (sub)total gastrectomy with complete en bloc omentectomy and modified D2 lymphadenectomy. Primary outcome of the current study was 5-year overall survival. Patients with or without omental metastases were compared. Pathological factors associated with locoregional recurrence and/or metastases were tested with multivariable regression analysis. RESULTS: Of 100 included patients, five had metastases in the greater omentum. Five-year overall survival was 0.0% in patients with omental metastases and 44.2% in patients without omental metastases (p = 0.001). Median overall survival time for patients with or without omental metastases was 7 months and 53 months. A (y)pT3-4 stage tumor and vasoinvasive growth were associated with locoregional recurrence and/or metastases in patients without omental metastases. CONCLUSION: The presence of omental metastases in gastric cancer patients who underwent potentially curative surgery was associated with impaired overall survival. Omentectomy as part of radical gastrectomy for gastric cancer might not contribute to a survival benefit in case of undetected omental metastases.

Unusual site of pseudomyxoma peritonei recurrence after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: a case report of intraluminal disease manifestation in the small bowel.

BACKGROUND: Pseudomyxoma peritonei (PMP) is an uncommon clinical condition characterized by the presence of mucinous ascites, mainly induced by perforated appendiceal mucinous neoplasms (AMN). The peritoneal surface of the small bowel is usually spared from disease manifestation due to peristaltic movements. Mucinous tumours can disseminate as PMP on the entire peritoneum, but are rarely intraluminal. For the first time in literature, we report a case of intraluminal PMP involving the ileum. CASE PRESENTATION: A 75-year-old male was treated for perforated AMN and disseminated PMP with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. During follow-up, the patient developed intraperitoneal recurrence together with intraluminal depositions in the ileum, both disease manifestations with identical KRAS and SMAD4 mutations. Hereafter, the patient was treated with palliative care. CONCLUSION: This case illustrates the variation in the biological and clinical behaviour of this rare disease. Clinicians should be aware of unusual tumour distribution patterns of PMP, including the presence of mucinous tumour within the small bowel.

Fibroblast activation protein identifies Consensus Molecular Subtype 4 in colorectal cancer and allows its detection by 68Ga-FAPI-PET imaging.

BACKGROUND: In colorectal cancer (CRC), the consensus molecular subtype 4 (CMS4) is associated with therapy resistance and poor prognosis. Clinical diagnosis of CMS4 is hampered by locoregional and temporal variables influencing CMS classification. Diagnostic tools that comprehensively detect CMS4 are therefore urgently needed. METHODS: To identify targets for molecular CMS4 imaging, RNA sequencing data of 3232 primary CRC patients were explored. Heterogeneity of marker expression in relation to CMS4 status was assessed by analysing 3-5 tumour regions and 91.103 single-tumour cells (7 and 29 tumours, respectively). Candidate marker expression was validated in CMS4 peritoneal metastases (PM; n = 59). Molecular imaging was performed using the 68Ga-DOTA-FAPI-46 PET tracer. RESULTS: Fibroblast activation protein (FAP) mRNA identified CMS4 with very high sensitivity and specificity (AUROC > 0.91), and was associated with significantly shorter relapse-free survival (P = 0.0038). Heterogeneous expression of FAP among and within tumour lesions correlated with CMS4 heterogeneity (AUROC = 1.00). FAP expression was homogeneously high in PM, a near-homogeneous CMS4 entity. FAPI-PET identified focal and diffuse PM that were missed using conventional imaging. Extra-peritoneal metastases displayed extensive heterogeneity of tracer uptake. CONCLUSION: FAP expression identifies CMS4 CRC. FAPI-PET may have value in the comprehensive detection of CMS4 tumours in CRC. This is especially relevant in patients with PM, for whom effective imaging tools are currently lacking.

Peritoneal metastases from colorectal cancer belong to Consensus Molecular Subtype 4 and are sensitised to oxaliplatin by inhibiting reducing capacity.

BACKGROUND: Peritoneal metastases (PM) in colorectal cancer (CRC) are associated with therapy resistance and poor survival. Oxaliplatin monotherapy is widely applied in the intraperitoneal treatment of PM, but fails to yield clinical benefit. We aimed to identify the mechanism(s) underlying PM resistance to oxaliplatin and to develop strategies overcoming such resistance. EXPERIMENTAL DESIGN: We generated a biobank consisting of 35 primary tumour regions and 59 paired PM from 12 patients. All samples were analysed by RNA sequencing. We also generated a series of PM-derived organoid (PMDO) cultures and used these to design and test strategies to overcome resistance to oxaliplatin. RESULTS: PM displayed various hallmarks of aggressive CRC biology. The vast majority of PM and paired primary tumours belonged to the Consensus Molecular Subtype 4 (CMS4). PMDO cultures were resistant to oxaliplatin and expressed high levels of glutamate-cysteine ligase (GCLC) causing detoxification of oxaliplatin through glutathione synthesis. Genetic or pharmacological targeting of GCLC sensitised PMDOs to a 1-h exposure to oxaliplatin, through increased platinum-DNA adduct formation. CONCLUSIONS: These results link oxaliplatin resistance of colorectal PM to their CMS4 status and high reducing capacity. Inhibiting the reducing capacity of PM may be an effective strategy to overcome PM resistance to oxaliplatin.

Antibiotic prophylaxis for acute cholecystectomy: PEANUTS II multicentre randomized non-inferiority clinical trial.

BACKGROUND: Guidelines recommending antibiotic prophylaxis at emergency cholecystectomy for cholecystitis were based on low-quality evidence. The aim of this trial was to demonstrate that omitting antibiotics is not inferior to their prophylactic use. METHODS: This multicentre, randomized, open-label, non-inferiority clinical trial randomly assigned adults with mild-to-moderate acute calculous cholecystitis (immediate cholecystectomy indicated) to 2 g cefazolin administered before incision or no antibiotic prophylaxis. The primary endpoint was a composite of all postoperative infectious complications in the first 30 days after surgery. Secondary endpoints included all individual components of the primary endpoint, other morbidity, and duration of hospital stay. RESULTS: Sixteen of 226 patients (7.1 per cent) in the single-dose prophylaxis group and 29 of 231 (12.6 per cent) in the no-prophylaxis group developed postoperative infectious complications (absolute difference 5.5 (95 per cent c.i. -0.4 to 11.3) per cent). With a non-inferiority margin of 10 per cent, non-inferiority of no prophylaxis was not proven. The number of surgical-site infections was significantly higher in the no-prophylaxis group (5.3 versus 12.1 per cent; P = 0.010). No differences were observed in the number of other complications, or duration of hospital stay. CONCLUSION: Omitting antibiotic prophylaxis is not recommended.

Functional Dyspepsia and Irritable Bowel Syndrome are Highly Prevalent in Patients With Gallstones and Are Negatively Associated With Outcomes After Cholecystectomy: A Prospective, Multicenter, Observational Study (PERFECT - Trial).

OBJECTIVE: To determine the prevalence of FD and IBS in patients eligible for cholecystectomy and to investigate the association between presence of FD/ IBS and resolution of biliary colic and a pain-free state. SUMMARY BACKGROUND DATA: More than 30% of patients with symptomatic cholecystolithiasis reports persisting pain postcholecystectomy. Coexistence of FD/IBS may contribute to this unsatisfactory outcome. METHODS: We conducted a multicenter, prospective, observational study (PERFECT-trial). Patients ≥18 years with abdominal pain and gallstones were included at 5 surgical outpatient clinics between 01/2018 and 04/2019. Follow-up was 6 months. Primary outcomes were prevalence of FD/IBS, and the difference between resolution of biliary colic and pain-free state in patients with and without FD/IBS. FD/IBS was defined by the Rome IV criteria, biliary colic by the Rome III criteria, and pain-free by an Izbicki Pain Score ≤10 and visual analogue scale ≤4. RESULTS: We included 401 patients with abdominal pain and gallstones (assumed eligible for cholecystectomy), mean age 52 years, 76% females. Of these, 34.9% fulfilled criteria for FD/IBS. 64.1% fulfilled criteria for biliary colic and 74.9% underwent cholecystectomy, with similar operation rates in patients with and without FD/IBS. Postcholecystectomy, 6.1% of patients fulfilled criteria for biliary colic, with no significant difference between those with and without FD/IBS at baseline (4.9% vs 8.6%, P = 0.22). Of all patients, 56.8% was pain-free after cholecystectomy, 40.7% of FD/IBS-group vs 64.4% of no FD/IBS-group, P < 0.001. CONCLUSIONS: One third of patients eligible for cholecystectomy fulfil criteria for FD/IBS. Biliary colic is reported by only a few patients postcholecys-tectomy, whereas nonbiliary abdominal pain persists in >40%, particularly in those with FD/IBS precholecystectomy. Clinicians should take these symptom-dependent outcomes into account in their shared decision-making process. TRIAL REGISTRATION: The Netherlands Trial Register NTR-7307. Registered on 18 June 2018.

Outcomes of Combined Peritoneal and Local Treatment for Patients with Peritoneal and Limited Liver Metastases of Colorectal Origin: A Systematic Review and Meta-Analysis.

BACKGROUND: Almost half of all colorectal cancer (CRC) patients will experience metastases at some point, and in the majority of cases, multiple organs will be involved. If the peritoneum is involved in addition to the liver, the current guideline-driven treatment options are limited. The reported overall survival ranges from 6 to 13 months for the current standard of care (systemic treatment). This study aimed to evaluate morbidity and clinical long-term outcomes from a combined local treatment of hepatic metastases with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) used to treat peritoneal metastases. METHODS: A systematic search was performed in PubMed, Embase.com, Web of Science, and Cochrane. Studies evaluating the clinicopathologic data of patients who had both peritoneal and hepatic metastases treated with CRS-HIPEC were included provided sufficient data on the primary outcomes (overall and disease-free survival) were presented. The quality of included studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS). RESULTS: Patients treated for peritoneal and liver metastases (PMLM group) had a pooled mean survival of 26.4 months (95% confidence interval [CI] 22.4-30.4 months), with a 3-year survival rate of 34% (95% CI 26.7-42.0%) and a 5-year survival rate of 25% (95% CI 17.3-33.8%). Surgical complications occurred more frequently for these patients than for those with peritoneal metastasis only (40% vs 22%; p = 0.0014), but the mortality and reoperation rates did not differ significantly. CONCLUSION: This systematic review showed that CRS and HIPEC combined with local treatment of limited liver metastasis for selected patients is feasible, although with increased morbidity and an association with a long-term survival rate of 25%, which is unlikely to be achievable with systemic treatment only.

Patient-reported outcomes during repetitive oxaliplatin-based pressurized intraperitoneal aerosol chemotherapy for isolated unresectable colorectal peritoneal metastases in a multicenter, single-arm, phase 2 trial (CRC-PIPAC).

BACKGROUND: CRC-PIPAC prospectively assessed repetitive oxaliplatin-based pressurized intraperitoneal aerosol chemotherapy (PIPAC-OX) as a palliative monotherapy (i.e., without concomitant systemic therapy in between subsequent procedures) for unresectable colorectal peritoneal metastases (CPM). The present study explored patient-reported outcomes (PROs) during trial treatment. METHODS: In this single-arm phase 2 trial in two tertiary centers, patients with isolated unresectable CPM received 6-weekly PIPAC-OX (92 mg/m2). PROs (calculated from EQ-5D-5L, and EORTC QLQ-C30 and QLQ-CR29) were compared between baseline and 1 and 4 weeks after the first three procedures using linear mixed modeling with determination of clinical relevance (Cohen's D ≥ 0.50) of statistically significant differences. RESULTS: Twenty patients underwent 59 procedures (median 3 [range 1-6]). Several PROs solely worsened 1 week after the first procedure (index value - 0.10, p < 0.001; physical functioning - 20, p < 0.001; role functioning - 27, p < 0.001; social functioning - 18, p < 0.001; C30 summary score - 16, p < 0.001; appetite loss + 15, p = 0.007; diarrhea + 15, p = 0.002; urinary frequency + 13, p = 0.004; flatulence + 13, p = 0.001). These PROs returned to baseline at subsequent time points. Other PROs worsened 1 week after the first procedure (fatigue + 23, p < 0.001; pain + 29, p < 0.001; abdominal pain + 32, p < 0.001), second procedure (fatigue + 20, p < 0.001; pain + 21, p < 0.001; abdominal pain + 20, p = 0.002), and third procedure (pain + 22, p < 0.001; abdominal pain + 22, p = 0.002). Except for appetite loss, all changes were clinically relevant. All analyzed PROs returned to baseline 4 weeks after the third procedure. CONCLUSIONS: Patients receiving repetitive PIPAC-OX monotherapy for unresectable CPM had clinically relevant but reversible worsening of several PROs, mainly 1 week after the first procedure. TRIAL REGISTRATION: Clinicaltrials.gov: NCT03246321; Netherlands trial register: NL6426.

Factors affecting 30-day postoperative complications after emergency surgery during the COVID-19 outbreak: A multicentre cohort study.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) has influenced (surgical) care worldwide. Measures were taken to prioritize surgical care in order to maintain capacity for COVID-19 healthcare. However, the influence of these measures on emergency surgery is limited. Therefore, the aim of this study is to describe the trends in emergency surgery and determine the factors influencing the risk of postoperative complications during the first wave of the COVID-19 pandemic. METHODS: This multicentre retrospective cohort study investigated all emergency patients operated on from March 9th to June 30th, 2020. The primary endpoint was identifying the number of emergency surgical procedures performed. Secondary endpoints were determining the number of postoperative complications and factors determining the risk of postoperative complications, which were calculated by multivariate analysis with odds ratio (OR) and 95% confidence (CI) intervals. RESULTS: In total, 1399 patients who underwent an emergency surgical procedure were included. An increase in the number of emergency vascular and trauma surgical procedures occurred during the study period. In contrast, the number of emergency general and oncological surgical procedures performed remained stable. An increased age (OR 1.01, 95% CI 1.00-1.02; p = 0.024), American Society of Anaesthesiologists (ASA) (OR 1.34, 95% CI 1.09-1.64; p = 0.005), and surgical discipline were independent predictors for an increased risk of postoperative complications. CONCLUSION: The performance of emergency vascular and trauma surgical procedures increased. The performance of emergency general and oncological surgical procedures remained stable. In addition, increased age, ASA, and surgical discipline were independent predictors for an increased risk of postoperative complications.

Perioperative Systemic Therapy vs Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Alone for Resectable Colorectal Peritoneal Metastases: A Phase 2 Randomized Clinical Trial.

Importance: To date, no randomized clinical trials have investigated perioperative systemic therapy relative to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) alone for resectable colorectal peritoneal metastases (CPM). Objective: To assess the feasibility and safety of perioperative systemic therapy in patients with resectable CPM and the response of CPM to neoadjuvant treatment. Design, Setting, and Participants: An open-label, parallel-group phase 2 randomized clinical trial in all 9 Dutch tertiary centers for the surgical treatment of CPM enrolled participants between June 15, 2017, and January 9, 2019. Participants were patients with pathologically proven isolated resectable CPM who did not receive systemic therapy within 6 months before enrollment. Interventions: Randomization to perioperative systemic therapy or CRS-HIPEC alone. Perioperative systemic therapy comprised either four 3-week neoadjuvant and adjuvant cycles of CAPOX (capecitabine and oxaliplatin), six 2-week neoadjuvant and adjuvant cycles of FOLFOX (fluorouracil, leucovorin, and oxaliplatin), or six 2-week neoadjuvant cycles of FOLFIRI (fluorouracil, leucovorin, and irinotecan) and either four 3-week adjuvant cycles of capecitabine or six 2-week adjuvant cycles of fluorouracil with leucovorin. Bevacizumab was added to the first 3 (CAPOX) or 4 (FOLFOX/FOLFIRI) neoadjuvant cycles. Main Outcomes and Measures: Proportions of macroscopic complete CRS-HIPEC and Clavien-Dindo grade 3 or higher postoperative morbidity. Key secondary outcomes were centrally assessed rates of objective radiologic and major pathologic response of CPM to neoadjuvant treatment. Analyses were done modified intention-to-treat in patients starting neoadjuvant treatment (experimental arm) or undergoing upfront surgery (control arm). Results: In 79 patients included in the analysis (43 [54%] men; mean [SD] age, 62 [10] years), experimental (n = 37) and control (n = 42) arms did not differ significantly regarding the proportions of macroscopic complete CRS-HIPEC (33 of 37 [89%] vs 36 of 42 [86%] patients; risk ratio, 1.04; 95% CI, 0.88-1.23; P = .74) and Clavien-Dindo grade 3 or higher postoperative morbidity (8 of 37 [22%] vs 14 of 42 [33%] patients; risk ratio, 0.65; 95% CI, 0.31-1.37; P = .25). No treatment-related deaths occurred. Objective radiologic and major pathologic response rates of CPM to neoadjuvant treatment were 28% (9 of 32 evaluable patients) and 38% (13 of 34 evaluable patients), respectively. Conclusions and Relevance: In this randomized phase 2 trial in patients diagnosed with resectable CPM, perioperative systemic therapy seemed feasible, safe, and able to induce response of CPM, justifying a phase 3 trial. Trial Registration: ClinicalTrials.gov Identifier: NCT02758951.

First-line palliative systemic therapy alternated with electrostatic pressurised intraperitoneal aerosol chemotherapy (oxaliplatin) for isolated unresectable colorectal peritoneal metastases: protocol of a multicentre, single-arm, phase II study (CRC-PIPAC-II).

INTRODUCTION: Despite its increasing use, first-line palliative systemic therapy alternated with electrostatic pressurised intraperitoneal aerosol chemotherapy with oxaliplatin (ePIPAC-OX), hereinafter referred to as first-line bidirectional therapy, has never been prospectively investigated in patients with colorectal peritoneal metastases (CPM). As a first step to address this evidence gap, the present study aims to assess the safety, feasibility, antitumour activity, patient-reported outcomes, costs and systemic pharmacokinetics of first-line bidirectional therapy in patients with isolated unresectable CPM. METHODS AND ANALYSIS: In this single-arm, phase II study in two Dutch tertiary referral centres, 20 patients are enrolled. Key eligibility criteria are a good performance status, pathologically proven isolated unresectable CPM, no previous palliative systemic therapy for colorectal cancer, no (neo)adjuvant systemic therapy ≤6 months prior to enrolment and no previous pressurised intraperitoneal aerosol chemotherapy (PIPAC). Patients receive three cycles of bidirectional therapy. Each cycle consists of 6 weeks first-line palliative systemic therapy at the medical oncologists' decision (CAPOX-bevacizumab, FOLFOX-bevacizumab, FOLFIRI-bevacizumab or FOLFOXIRI-bevacizumab) followed by ePIPAC-OX (92 mg/m2) with an intraoperative bolus of intravenous leucovorin (20 mg/m2) and 5-fluorouracil (400 mg/m2). Study treatment ends after the third ePIPAC-OX. The primary outcome is the number of patients with-and procedures leading to-grade ≥3 adverse events (Common Terminology Criteria for Adverse Events V.5.0) up to 4 weeks after the last procedure. Key secondary outcomes include the number of bidirectional cycles in each patient, treatment-related characteristics, grade ≤2 adverse events, tumour response (histopathological, cytological, radiological, biochemical, macroscopic and ascites), patient-reported outcomes, systemic pharmacokinetics of oxaliplatin, costs, progression-free survival and overall survival. ETHICS AND DISSEMINATION: This study is approved by the Dutch competent authority, a medical ethics committee and the institutional review boards of both study centres. Results will be submitted for publication in peer-reviewed medical journals and presented to patients and healthcare professionals. TRIAL REGISTRATION NUMBER: NL8303.

Detection of tumor-derived cell-free DNA from colorectal cancer peritoneal metastases in plasma and peritoneal fluid.

Tumor-derived cell-free DNA (cfDNA) is an emerging biomarker for guiding the personalized treatment of patients with metastatic colorectal cancer (CRC). While patients with CRC liver metastases (CRC-LM) have relatively high levels of plasma cfDNA, little is known about patients with CRC peritoneal metastases (CRC-PM). This study evaluated the presence of tumor-derived cfDNA in plasma and peritoneal fluid (i.e. ascites or peritoneal washing) in 20 patients with isolated CRC-PM and in the plasma of 100 patients with isolated CRC-LM. Among tumor tissue KRAS/BRAF mutation carriers, tumor-derived cfDNA was detected by droplet digital polymerase chain reaction (ddPCR) in plasma of 93% of CRC-LM and 20% of CRC-PM patients and in peritoneal fluid in all CRC-PM patients. Mutant allele fraction (MAF) and mutant copies per ml (MTc/ml) were lower in CRC-PM plasma than in CRC-LM plasma (median MAF = 0.28 versus 18.9%, p < 0.0001; median MTc/ml = 21 versus 1,758, p < 0.0001). Within patients with CRC-PM, higher cfDNA levels were observed in peritoneal fluid than in plasma (median MAF = 16.4 versus 0.28%, p = 0.0019; median MTc/ml = 305 versus 21, p = 0.0034). These data imply that tumor-derived cfDNA in plasma is a poor biomarker to monitor CRC-PM. Instead, cfDNA detection in peritoneal fluid may offer an alternative to guide CRC-PM treatment decisions.