Oncological recurrence following pathological complete response after neoadjuvant treatment in patients with esophageal cancer - a retrospective cohort study.

BACKGROUND: To evaluate recurrence in patients with post-neoadjuvant pathological complete response (pCR) and in patients with complete response of primary tumor but persisting lymphatic spread of disease (non-pCR, ypT0ypN +) of esophageal cancer. METHODS: Seventy-five patients (63 pCR, 12 non-pCR) were analyzed retrospectively. Pattern and incidence of local and distant recurrence as well as the impact on overall (OS) and disease-free survival (DFS) were evaluated. The efficacy of neoadjuvant chemotherapy according to FLOT protocol was compared to neoadjuvant chemoradiation according to CROSS protocol. RESULTS: In the pCR group, isolated local recurrence was diagnosed in 3%, while no isolated local recurrence was observed in the non-pCR group due to the high incidence of distant recurrence. Distant recurrence was most common in both cohorts (isolated distant recurrence: pCR group 10% to non-pCR group 55%; simultaneous distant and local recurrence: pCR group 3% to non-pCR group 18%). Median time to distant recurrence was 5.5 months, and median time to local recurrence was 8.0 months. Cumulative incidence of distant recurrence (with and without simultaneous local recurrence) was 16% (± 6%) in pCR patients and 79% (± 13%) in non-pCR patients (hazard ratio (HR) 0.123) estimated by Kaplan-Meier method. OS (HR 0.231) and DFS (HR 0.226) were significantly improved in patients with pCR compared to patients with non-pCR. Advantages for FLOT protocol compared to CROSS protocol, especially with regard to distant control of disease (HR 0.278), were observed (OS (HR 0.361), DFS (HR 0.226)). CONCLUSION: Distant recurrence is the predominant site of treatment failure in patients with pCR and non-pCR grade 1a regression, whereby recurrence rates are much higher in patients with non-pCR.

Pathological complete response in multimodal treatment of esophageal cancer: a retrospective cohort study.

To evaluate pathological complete response (pCR, ypT0ypN0) after neoadjuvant treatment compared with non-complete response (non-CR) in patients with esophageal cancer (EC), and 393 patients were retrospectively analyzed. Survival probability was analyzed in patients with: (i) pCR vs non-CR; (ii) complete response of the primary tumor but persisting lymphatic metastases (non-CR-T0N+) and (iii) pCR and tumor-free lymphnodes exhibiting signs of postneoadjuvant regression vs. no signs of regression. (i) Median overall survival (mOS) was favorable in patients with pCR (pCR: mOS not reached vs. non-CR: 41 months, P < 0.001). Multivariate analysis revealed that grade of regression was not an independent predictor for prolonged survival. Instead, the achieved postneoadjuvant TNM-stage (T-stage: Hazard ratio [HR] ypT3-T4 vs. ypT0-T2: 1.837; N-stage: HR ypN1-N3 vs. ypN0: 2.046; Postneoadjuvant M-stage: HR ypM1 vs. ycM0: 2.709), the residual tumor (R)-classification (HR R1 vs. R0: 4.195) and the histologic subtype of EC (HR ESCC vs. EAC: 1.688) were prognostic factors. Patients with non-CR-T0N+ have a devastating prognosis, similar to those with local non-CR and lymphatic metastases (non-CR-T + N+) (non-CR-T0N+: 22.0 months, non-CR-T + N-: mOS not reached, non-CR-T + N+: 23.0 months; P-values: non-CR-T0N+ vs. non-CR-T + N-: 0.016; non-CR-T0N+ vs. non-CR-T + N+: 0.956; non-CR-T + N- vs. non-CR-T + N+: <0.001). Regressive changes in lymphnodes after neoadjuvant treatment did not influence survival-probability in patients with pCR (mOS not reached in each group; EAC-patients: P = 0.0919; ESCC-patients: P = 0.828). Particularly, the achieved postneoadjuvant ypTNM-stage influences the survival probability of patients with EC. Patients with non-CR-T0N+ have a dismal prognosis, and only true pathological complete response with ypT0ypN0 offers superior survival probabilities.

Coffee break has no impact on laparoscopic skills: a randomized double-blinded placebo-controlled parallel-group trial.

BACKGROUND: Coffee is a widely consumed beverage. Surgeons often drink coffee before performing surgery. Caffeine intake leads to tremor which might have a negative effect on surgeons' fine motor skills. METHODS: A double-blinded parallel-group trial was conducted in order to investigate if caffeinated coffee intake has a negative effect on laparoscopic skills and increases tremor, regardless of previous coffee consumption. 118 participants were selected during a congress of the German Society of Surgery. Exclusion criteria were immaturity and no given consent. Participants and investigators were blinded. Participants were randomized with a 1:1 allocation into interventional group receiving caffeinated coffee or placebo group receiving decaffeinated coffee. The motor skills were tested with two validated laparoscopic exercises at a laparoscopy simulator (LapSim®) before and 30 min after coffee intake. Data on influencing factors were recorded in a standardized questionnaire and tested for equal distribution in both groups. In both exercises four parameters were recorded: left and right hand path length and angular path. Their differences and the resulting effect scores were calculated for both groups as primary outcome to test which group showed greater improvement on the second round of exercises. Registration number DRKS00023608, registered retrospectively. RESULTS: Fifty nine subjects were assigned to each the interventional (54 analyzed) and placebo group (53 analyzed) with 11 drop outs. There was no significant difference between the placebo and interventional group in the two exercises in effect score 30 min after coffee intake [mean (SD); 38.58 (10.66) vs. 41.73 (7.40) and 113.09 (28.94) vs. 116.59 (25.63)]. A significant improvement from first to second measurement in the first exercise could be observed for both groups, demonstrating the training effect. CONCLUSION: In our study, we verified that additional caffeinated coffee intake, e.g., during a coffee break, does not lead to deterioration of laparoscopic fine motor skills.

Longitudinal analysis of cell-free mutated KRAS and CA 19-9 predicts survival following curative resection of pancreatic cancer.

BACKGROUND: Novel biomarkers and molecular monitoring tools hold potential to improve outcome for patients following resection of pancreatic ductal adenocarcinoma (PDAC). We hypothesized that the combined longitudinal analysis of mutated cell-free plasma KRAS (cfKRASmut) and CA 19-9 during adjuvant treatment and follow-up might more accurately predict disease course than hitherto available parameters. METHODS: Between 07/2015 and 10/2018, we collected 134 plasma samples from 25 patients after R0/R1-resection of PDAC during adjuvant chemotherapy and post-treatment surveillance at our institution. Highly sensitive discriminatory multi-target ddPCR assays were employed to screen plasma samples for cfKRASmut. cfKRASmut and CA 19-9 dynamics were correlated with recurrence-free survival (RFS) and overall survival (OS). Patients were followed-up until 01/2020. RESULTS: Out of 25 enrolled patients, 76% had undergone R0 resection and 48% of resected PDACs were pN0. 17/25 (68%) of patients underwent adjuvant chemotherapy. Median follow-up was 22.0 months, with 19 out of 25 (76%) patients relapsing during study period. Median RFS was 10.0 months, median OS was 22.0 months. Out of clinicopathologic variables, only postoperative CA 19-9 levels and administration of adjuvant chemotherapy correlated with survival endpoints. cfKRASmut. was detected in 12/25 (48%) of patients, and detection of high levels inversely correlated with survival endpoint. Integration of cfKRASmut and CA 19-9 levels outperformed either individual marker. cfKRASmut outperformed CA 19-9 as dynamic marker since increase during adjuvant chemotherapy and follow-up was highly predictive of early relapse and poor OS. CONCLUSIONS: Integrated analysis of cfKRASmut and CA 19-9 levels is a promising approach for molecular monitoring of patients following resection of PDAC. Larger prospective studies are needed to further develop this approach and dissect each marker's specific potential.

Immunological effects of hybrid minimally invasive versus conventional open pancreatoduodenectomy - A single center cohort study.

BACKGROUND: Minimally invasive surgery is a field of rapid development. Evidence from randomized controlled trials in visceral surgery however still falls short of attesting unequivocal superiority to laparoscopic procedures over conventional open approaches with regard to postoperative outcome. The aim of this study was to explore the perioperative immune status of patients undergoing hybrid minimally invasive or conventional open pancreatoduodenectomy in a prospective cohort study. MATERIAL AND METHODS: Subtyping, quantification and functional analysis of circulating immune cells and determination of cytokine-levels in blood samples from patients receiving either hybrid minimally invasive (laPD) or conventional open pancreatoduodenectomy (oPD) was performed. Samples were taken from 29 patients (laPD: n = 14, oPD: n = 15) prior, during and up to six weeks after surgery. Cells were analyzed by flow cytometry, cytokines/chemokines were measured by proximity extension and enzyme-linked immunoassays. RESULTS: Open surgery induced higher levels of circulating inflammatory CD14++CD16+ intermediate monocytes. In contrast, hybrid minimally invasive resection was accompanied by increased numbers of circulating regulatory CD4+CD25+CD127low T-cells and by a reduced response of peripheral blood CD3+CD4+ T-cell populations to superantigen stimulation. Yet, rates of postoperative morbidity and infectious complications were similar. CONCLUSIONS: In summary, the results of this exploratory study may suggest a more balanced postoperative inflammatory response and a better-preserved immune regulation after hybrid minimally invasive pancreatoduodenectomy when compared to open surgery. Whether these results may translate to or be harnessed for improved patient outcome needs to be determined by future studies including larger cohorts and fully laparoscopic or robotic procedures.

Management and outcome of esophageal stenting for spontaneous esophageal perforations.

Treatment of spontaneous esophageal perforation (SEP) consists of different conservative, surgical and endoscopic treatment modalities. In this study, we evaluated the clinical efficacy and the outcome of covered self-expanding stent (CSES) treatment of SEP. All patients with SEP treated by CSES at our institution between 2005 and 2014 were included in this prospective single-center study. The data were collected from a prospective database based on clinical, endoscopic and operative reports. Follow-up data were procured by contacting the patients or their family doctors. The patient data were analyzed concerning course of treatment, leakage sealing rate, complications, and mortality. Patients with iatrogenic or malignant perforations were excluded. In total, 16 patients underwent endoscopic CSES placement for SEP between 2005 and 2014. Sealing of the leakage was immediately successful in 50% (8 patients). A second stent was placed in 5 patients, but did not achieve sealing of the perforation in any case, requiring a switch in treatment to a surgical procedure (n=4) or drainage of the persisting leakage (n=4). In-hospital mortality was 13%. Only delayed treatment was identified as a risk factor for inferior outcome. Patients with successful CSES treatment had a shorter ICU- and hospital stay and had a reduced risk of developing esophageal stenosis (RR: 0.4) or persisting dysphagia despite treatment (RR: 0.33). Endoscopic treatment of SEP is beneficial to the patient if immediately successful, but in our experience, failure rates are higher than described in the literature. Secondary placement of CSES was not successful when initial stent treatment failed, while both surgical intervention and drainage of the perforation showed good results in sealing the leakage.

Proximal gastrectomy and double-tract reconstruction vs total gastrectomy in gastric and gastro-esophageal junction cancer patients - a systematic review and meta-analysis protocol (PROSPERO registration number: CRD42021291500).

BACKGROUND: In Germany and Western Europe, gastroesophageal junction cancer (AEG) and proximal gastric cancer are currently treated with (transhiatal-extended) total gastrectomy (TG) according to the latest treatment guidelines. TG leads to a severe and long-lasting impairment of postoperative health-related quality of life (HRQoL) of the treated patients. Recent studies have suggested that HRQoL of these patients could be improved by proximal gastrectomy with double-tract reconstruction (PG-DTR) without compromising oncologic safety. Our aim is therefore to conduct a randomized controlled non-inferiority trial comparing PG-DTR with TG in AEG II/III and gastric cancer patients with overall survival as primary endpoint and HRQoL as key secondary endpoint. METHODS: This protocol is written with reference to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P 2015) statement. We will conduct searches in the electronic databases MEDLINE, Web of Science Core Collection, ScienceDirect, and Cochrane Library. We will also check references of relevant studies and perform a cited reference research. Titles and abstracts of the records identified by the searches will be screened, and full texts of all potentially relevant articles will be obtained. We will consider randomized trials and non-randomized studies. The selection of studies, data extraction, and assessment of risk of bias of the included studies will be conducted independently by two reviewers. Meta-analysis will be performed using RevMan 5.4 (Review Manager (RevMan) Version 5.4, The Cochrane Collaboration). DISCUSSION: This systematic review will identify the current study pool concerning the comparison of TG and PG-DTR and help to finally refine the research questions and to allow an evidence-based trial design of the planned multicenter randomized-controlled trial. ETHICS AND DISSEMINATION: Ethical approval is not required for this systematic review. Study findings will be shared by publication in a peer-reviewed journal. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021291500.

Postoperative Hiatal Hernia after Ivor Lewis Esophagectomy-A Growing Problem in the Age of Minimally Invasive Surgery.

BACKGROUND: Even though minimally invasive esophagectomy is a safe and oncologically effective procedure, several authors have reported an increased risk of postoperative hiatal hernia (PHH). This study evaluates the incidence and risk factors of PHH after hybrid minimally invasive (HMIE) versus open esophagectomy (OE). METHODS: A retrospective single-center analysis was performed on patients who underwent Ivor Lewis esophagectomy between January 2009 and April 2018. Computed tomography scans and patient files were reviewed to identify the PHH. RESULTS: 306 patients were included (152 HMIE; 154 OE). Of these, 23 patients (8%) developed PHH. Most patients (13/23, 57%) were asymptomatic at the time of diagnosis and only 4 patients (17%) presented in an emergency setting with incarceration. The rate of PHH was significantly higher after HMIE compared to OE (13.8% vs. 1.3%, p < 0.001). No other risk factors for the development of PHH were identified in uni- or multi-variate analysis. Surgical repair of PHH was performed in 19/23 patients (83%). The recurrence rate of PHH after surgical repair was 32% (6/19 patients). CONCLUSIONS: The development of PHH is a relevant complication after hybrid minimally invasive esophagectomy. Although most patients are asymptomatic, surgical repair is recommended to avoid incarceration with potentially fatal outcomes. Innovative techniques for the prevention and repair of PHH are urgently needed.

Systematic review and meta-analysis comparing proximal gastrectomy with double-tract-reconstruction and total gastrectomy in gastric and gastroesophageal junction cancer patients: Still no sufficient evidence for clinical decision-making.

BACKGROUND: To compare proximal gastrectomy with double-tract reconstruction and total gastrectomy in patients with gastroesophageal junction (AEG II-III) and gastric cancer. METHODS: We conducted systematic searches in Medline, Web of Science, and Cochrane Library until December 20, 2021 (PROSPERO registration number: CRD42021291500). Risk of bias was assessed using the revised Cochrane risk of bias tool and the ROBINS-I tool, as applicable. Evidence was rated by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. RESULTS: One randomized controlled trial (RCT) and 13 non-RCTs with 1,317 patients (715 patients with total gastrectomy and 602 patients with proximal gastrectomy with double-tract reconstruction) were included. Patients treated by total gastrectomy had a significantly higher proportion of advanced cancer stages International Union Against Cancer IB-III (odds ratio: 0.68, 95% confidence interval: 0.51-0.91, P = .01). This heterogeneity biases the observed improved overall survival of patients after proximal gastrectomy with double-tract reconstruction (odds ratio: 0.67, 95% confidence interval: 0.44-1.01, P = .05). Both procedures were comparably efficient regarding perioperative parameters. Postoperative/preoperative bodyweight ratio (mean difference: 3.56, 95% confidence interval: 1.32-5.79, P = .002), postoperative/preoperative serum-hemoglobin ratio (mean difference 3.73, 95% confidence interval: 1.59-5.88, P < .001), and postoperative serum vitamin B12 levels (mean difference 42.46, 95% confidence interval: 6.37-78.55, P = .02) were superior after proximal gastrectomy with double-tract reconstruction, while postoperative/preoperative serum-albumin ratio (mean difference 1.24, 95% confidence interval: -4.76 to 7.24, P = .69) and postoperative/preoperative serum total protein ratio (mean difference 1.12, 95% confidence interval: -2.77 to 5.00, P = .57) were not different. Health-related quality of life data were reported in only 2 studies, which found no significant advantages for proximal gastrectomy with double-tract reconstruction. CONCLUSION: Proximal gastrectomy with double-tract reconstruction offers advantages in postoperative nutritional parameters compared to total gastrectomy (GRADE: moderate quality of evidence). Oncological effectiveness of proximal gastrectomy with double-tract reconstruction cannot be assessed (GRADE: very low quality of evidence). Further thoroughly planned randomized controlled trials in Western patient cohorts are necessary to improve treatment for gastric cancer patients.

Surgical complications requiring late surgical revisions after pancreatoduodenectomy increase postoperative morbidity and mortality.

BACKGROUND: Pancreatoduodenectomies are complex surgical procedures with considerable postoperative morbidity and mortality. Here, we describe complications and outcomes in patients requiring surgical revisions following pancreatoduodenectomy. METHODS: A total of 1048 patients undergoing a pancreatoduodenectomy at our institution between 2002 and 2019 were analyzed retrospectively. All patients with surgical revisions were included. Revisions were divided into early and late using a cut-off of 5 days after the first surgery. Statistical significance was examined by using chi-square tests and Fisher's exact tests. Survival analysis was performed using Kaplan-Meier curves and log-rank tests. RESULTS: A total of 150 patients with at least 1 surgical revision after pancreatoduodenectomy were included. Notably, 64 patients had a revision during the first 5 days and were classified as early revision. Compared with the 86 patients with late revisions, we found no differences concerning wound infections, delayed gastric emptying, or acute kidney failure. After late revisions, we found significantly more cases of sepsis (31.4% late versus 15.6% early, p = 0.020) and reintubation due to respiratory failure (33.7% versus 18.8%, p = 0.031). Postoperative mortality was significantly higher within the late revision group (23.2% versus 9.4%, p = 0.030). CONCLUSION: Arising complications after pancreatoduodenectomy should be addressed as early as possible as patients requiring late surgical revisions frequently developed septic complications and multiorgan failure.

[Complete response after neoadjuvant therapy for esophageal cancer : Implications for surgery]. / Komplettresponse nach neoadjuvanter Therapie beim Ösophaguskarzinom : Implikationen für die Chirurgie.

A relevant number of patients with locally advanced esophageal squamous cell carcinoma and adenocarcinoma show a locoregional complete response of the tumor in the resected material after neoadjuvant therapy with modern chemotherapy and chemoradiation protocols. Due to a high rate of perioperative morbidity and decreased long-term quality of life following esophagectomy, the current treatment algorithm with neoadjuvant therapy and post-neoadjuvant esophagectomy on principle is critically questioned. An individualized treatment algorithm with extended clinical evaluation of post-neoadjuvant remission status and esophagectomy as needed is discussed. Patients with complete remission after neoadjuvant therapy are identified in an extended restaging protocol. Cases of clinical complete remission are treated with an active surveillance concept with esophagectomy as needed, i.e. surgery only when a local tumor recurrence is detected. Retrospective cohort studies have suggested that the active surveillance concept with esophagectomy as needed does not lead to a deterioration of overall survival rates in the patient collective. European prospective randomized, controlled, noninferiority studies with an oncological endpoint are currently evaluating the possibilities of organ-preserving concepts for clinical complete remission of esophageal cancer.

Postneoadjuvant surveillance and surgery as needed compared with postneoadjuvant surgery on principle in multimodal treatment for oesophageal cancer: a scoping review protocol.

INTRODUCTION: In current medical practice of curative treatment for non-metastatic oesophageal cancer, surgery on principle is carried out by oesophagectomy after neoadjuvant treatment. However, oesophagectomy is often associated with postoperative morbidity and mortality. Taking into account that modern neoadjuvant therapy is effective and many of patients show no vital tumour cells in the operative specimens, we aim to perform a scoping review as part of the development phase for a prospectively planned multicentre randomised controlled trial investigating 'surgery as needed vs surgery on principle in patients with postneoadjuvant complete response of oesophageal cancer' (Prospective trial registration number DRKS00022801). This scoping approach will allow us to finally define and/or adapt the research question including the design and methodology of the randomised controlled trial taking into account the findings for example, research gaps and/or pitfalls in the currently available study pool addressing this or very similar questions. METHODS AND ANALYSIS: To identify relevant research, we will conduct searches in the electronic databases Medline, Web of Science Core Collection, Cochrane Library and Science Direct. We will also check references of relevant studies and perform a cited reference research (forward citation tracking). Titles and abstracts of the records identified by the searches will be screened and full texts of all potentially relevant articles will be obtained. We will consider randomised trials and non-randomised controlled studies. Data extraction tables will be set up, including study and patients' characteristics, aim of study and reported outcomes. We will summarise the data using tables and figures (eg, bubble plots) to present the research landscape and to describe potential clusters and/or gaps to support the planning of a randomised trial in this patient population. ETHICS AND DISSEMINATION: Ethical approval is not required for this scoping review. Study findings will be shared by publication in a peer-reviewed journal and by presentation to key stakeholders on scientific meetings.

Post-Neoadjuvant Surveillance and Surgery as Needed Compared with Post-Neoadjuvant Surgery on Principle in Multimodal Treatment for Esophageal Cancer: A Scoping Review.

BACKGROUND: A substantial fraction of patients with esophageal cancer show post-neoadjuvant pathological complete response (pCR). Principal esophagectomy after neoadjuvant treatment is the standard of care for all patients, although surveillance and surgery as needed in case of local recurrence may be a treatment alternative for patients with complete response (CR). METHODS: We performed a scoping review to describe key characteristics of relevant clinical studies including adults with non-metastatic esophageal cancer receiving multimodal treatment. Until September 2020, relevant studies were identified through systematic searches in the bibliographic databases Medline, Web of Science, Cochrane Library, Science Direct, ClinicalTrials, the German study register, and the WHO registry platform. RESULTS: In total, three completed randomized controlled trials (RCTs, with 468 participants), three planned/ongoing RCTs (with a planned sample size of 752 participants), one non-randomized controlled study (NRS, with 53 participants), ten retrospective cohort studies (with 2228 participants), and one survey on patients' preferences (with 100 participants) were identified. All studies applied neoadjuvant chemoradiation protocols. None of the studies examined neoadjuvant chemotherapeutic protocols. Studies investigated patient populations with esophageal squamous cell carcinoma, adenocarcinoma, and mixed cohorts. Important outcomes reported were overall, disease-free and local recurrence-free survival. Limitations of the currently available study pool include heterogeneous chemoradiation protocols, a lack of modern neoadjuvant treatment protocols in RCTs, short follow-up times, the use of heterogeneous diagnostic methods, and different definitions of clinical CR. CONCLUSION: Although post-neoadjuvant surveillance and surgery as needed compared with post-neoadjuvant surgery on principle has been investigated within different study designs, the currently available results are based on a wide variation of diagnostic tools to identify patients with pCR, short follow-up times, small sample sizes, and variations in therapeutic procedures. A thoroughly planned RCT considering the limitations in the currently available literature will be of great importance to provide patients with CR with the best and less harmful treatment.

Study Protocol of a Prospective Multicenter Study on Patient Participation for the Clinical Trial: Surgery as Needed Versus Surgery on Principle in Post-Neoadjuvant Complete Tumor Response of Esophageal Cancer (ESORES).

Ideally, patient-centered trial information material encourages the discussion with the treating physician, and helps patients making trade-offs regarding treatment decisions In a situation of possible equivalent treatment options in terms of overall survival (OS), it can make it easier to weigh up advantages and disadvantages. Preferences for choice of treatment in esophageal cancer (EC) are complex, and no standardized assessment tools are available. We will explore patient's factors for treatment choice and develop a comprehensive patient information leaflet for the inclusion into randomized controlled trials (RCT) on EC. We conduct a cross-sectional, observational study based on a mixed-methods design with patients suffering from non-metastatic EC with post-neoadjuvant complete response after neoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiation (nCRT), to develop patient-centered trial information material. This pilot study is performed in a concept development phase and a subsequent pilot phase. We start with patient interviews (n = 10-15) in the concept development phase to evaluate patients' needs, and develop a Preference and Decision Aid Questionnaire (PDAQ). We pre-test the PDAQ with another n = 10 patients with EC after nCT or nCRT, former patients from a self-help organization, and n = 10 medical experts for their comments on the questionnaire. In the pilot phase, a multicenter trial using the PDAQ and additional measures is carried out (n = 120). Based on evidence of a possible equivalence in terms of OS of the treatment options "surgery as needed" and "surgery on principle" in patients with post-neoadjuvant complete response of EC, this pilot study on patient participation is conducted to assess patient's needs and preferences, and optimize patients' inclusion in a planned RCT. The aim is to develop patient-centered trial information material for the RCT to increase patients' consent and compliance with the randomized treatment. The trial is registered at the German Clinical Trials Register (DRKS00022050, October 15, 2020).

Curative-intent pancreas resection for pancreatic metastases: surgical and oncological results.

BACKGROUND: Pancreatic metastasis is a rare cause for pancreas surgery and often a sign of advanced disease no chance of curative-intent treatment. However, surgery for metastasis might be a promising approach to improve patients' survival. The aim of this study was to analyze the surgical and oncological outcome after pancreatic resection of pancreatic metastasis. METHODS: This is a retrospective cohort analysis of a prospectively-managed database of patients undergoing pancreatic resection at the University of Freiburg Pancreatic Center from 2005 to 2017. RESULTS: In total, 29 of 1297 (2%) patients underwent pancreatic resection due to pancreatic metastasis. 20 (69%) patients showed metastasis of renal cell carcinoma (mRCC), followed by metastasis of melanoma (n = 5, 17%), colon cancer (n = 2, 7%), ovarian cancer (n = 1, 3%) and neuroendocrine tumor of small intestine (n = 1, 3%). Two (7%) patients died perioperatively. Median follow-up was 76.4 (range 21-132) months. 5-year and overall survival rates were 82% (mRCC 89% vs. non-mRCC 67%) and 70% (mRCC 78% vs. non-mRCC 57%), respectively. Patients with mRCC had shorter disease-free survival (14 vs. 22 months) than patients with other primary tumor entities. CONCLUSION: Despite malignant disease, overall survival of patients after metastasectomy for pancreatic metastasis is acceptable. Better survival appears to be associated with the primary tumor entity. Further research should focus on molecular markers to elucidate the mechanisms of pancreatic metastasis to choose the suitable therapeutic approach for the individual patient.

Development and Clinical Validation of Discriminatory Multitarget Digital Droplet PCR Assays for the Detection of Hot Spot KRAS and NRAS Mutations in Cell-Free DNA.

Detection and quantification of tumor-derived KRAS and NRAS mutations in plasma cell-free DNA (cfDNA) holds great potential for cancer diagnostics and treatment response monitoring. Because of high sensitivity, specificity, robustness, and affordability, digital droplet PCR (ddPCR) is ideally suited for this application but requires discriminatory multiplexing when used as screening assay. We therefore designed, optimized, and clinically validated mutation-specific locked nucleic acid-based ddPCR assays for 14 commonly occurring KRAS and NRAS mutations and assembled these assays into seven discriminatory multitarget screening assays covering two to six single-nucleotide variants each. Limit of detection, limit of blank, and interassay accuracy were determined. Assay performance and suitability for screening in cfDNA were validated with plasma samples from a clinically fully characterized cohort of pancreatic cancer patients and healthy controls. Limits of detection for single-target assays were between 0.0015% and 0.069% variant allele fraction, and between 0.022% and 0.16% for multitarget assays. Dilution linearity and interassay accuracy were excellent throughout (r2 > 0.99). Multitarget assay screening of cfDNA extracted from pancreatic cancer patients with unknown KRAS mutational status correctly identified single-nucleotide variants in 45 of 45 (100%) of tumor-derived cell-free DNA-positive samples. In summary, we herein present and clinically validate generic single-target and discriminatory multitarget ddPCR assays for KRAS and NRAS hot spot mutations with broad applicability for clinical and translational research.