BACKGROUND:Various studies have reported on the prognostic impact of ductal margin and radial margin status in resected perihilar cholangiocarcinoma (PCCA). No study has considered differences in the prognostic impact of individual resection margins. This study investigated the prognostic impact of individual planes on survival. METHODS:All patients undergoing surgery for PCCA at Amsterdam UMC and Karolinska University Hospital between January 2010 and May 2023 were included. Clinicopathological data were retrospectively retrieved. The primary outcomes were the prognostic significance of residual disease (< 1 mm to the nearest tumour growth) in individual dissection planes and resection margins for overall survival (OS) and disease-free survival (DFS), expressed as adjusted hazard ratios (aHRs). RESULTS:Of 199 patients, 81 (41%) underwent radical resection and 118 (59%) were reported to have microscopic residual disease. Only a positive proximal bile duct resection margin was significantly associated with shorter OS (adjusted median OS 24 versus 36 months; aHR 1.64; 95% confidence interval (c.i.) 1.05 to 2.56; P = 0.031) and DFS (aHR 2.01; 95% c.i. 1.30 to 3.10; P = 0.002). Other positive resection margins and dissection planes did not carry any prognostic information for OS (Pinteraction = 0.95) or DFS (Pinteraction = 0.56). Similar results were obtained in a 90-day landmark sensitivity analysis. CONCLUSION:This study found that only tumour infiltration of the proximal bile duct resection margin was associated with worse prognosis, most likely reflecting the malignant behaviour of the disease rather than surgical failure. Larger prospective studies are needed to clarify the true prognostic impact of residual disease in individual resection planes to allocate patients to specific chemotherapeutic (neo)adjuvant treatments.

Intraductal papillary neoplasms (IPN) are a well-defined group of precursor lesions of biliary tract carcinoma (BTC) whose significance in the multistep model of biliary carcinogenesis is still vastly unexplored. Programmed death-ligand 1 (PD-L1) is a primary immune inhibitory molecule expressed on both tumour and immune cells and plays an important role in promoting immune evasion. This study aimed at studying the evolution of PD L1 expression during IPN-related biliary carcinogenesis. METHODS: Intraindividually corresponding high-grade IPN (n=65), including 54 IPNB, 11 ITPN and their associated invasive BTC (n=46) were selected for TMA construction. Immunohistochemistry and chromogen-in-situ-hybridization were employed to assess the expression of various targetable biomarkers, including p16, p53, c-myc, c-met, EGFR, HER2, BRAF and PD-L1. These results were correlated with our previously studied spatiotemporal evolution of the immune microenvironment during IPN-associated carcinogenesis focusing on infiltrating immune cell populations. RESULTS: In 6.2% BTC patients including only distal cholangiocarcinoma, IPN cells expressed PD-L1 at a Tumor Proportion Score (TPS) cut-off of 1%. Higher PD-L1 levels above 1% and 10% Combined Positive Score (CPS) also considering PD-L1 expressing immune cells were reached in 7.7% and 50.8% of BTC cases, respectively. At a 1% cut-off, TPS was associated with distinct histomorphological IPN-subtypes and UICC-Stages. PD-L1 expression in IPN was associated with increased total, stromal and intraepithelial CD3+-, CD4+- and CD8+-immune cell densities. In contrast, only a significant correlation between PD L1 expression and CD8+-cell density was found in the corresponding BTC tissue. We here showed that PD-L1 expression undergoes dynamic changes throughout IPN-driven carcinogenesis.

Background and aims: The DRAINAGE trial was a randomized controlled trial comparing preoperative endoscopic (EBD) and percutaneous biliary drainage (PTBD) in patients with potentially resectable, perihilar cholangiocarcinoma (pCCA). The aim of this study was to compare the long-term outcomes.Methods: Patients were randomized in four tertiary referral centers. Follow-up data were available for all included patients. Primary outcome was overall survival (OS). Secondary outcomes were readmissions, and re-interventions not including in-trial interventions.Results: A total of 54 patients were randomized; 27 in both groups. Median follow-up for both groups was 62 months (95% CI 54-70). The median OS was 13 months (95% CI 7.9-18.1) in the EBD and 7 months (95% CI 0.0-17.2) in the PTBD group (P = 0.28). Twenty (37%, n = 8 EBD vs n = 12 PTBD, P = 0.43) of 54 patients were readmitted at least once, mostly due to drainage-related complications (n = 13, 24%). Of note, 14 out of the 54 patients died within the trial. A total of 76 drainage procedures (32 EBD and 44 PTBD) were performed in 28 patients. The median number of stent or drain placements was 2 (2-4) for the EBD group and 2 (1-3) for the PTBD group (P = 0.77).Discussion: Although this follow-up study represented a small cohort, no long-term differences in survival, readmissions, and drainage procedures for EBD and PTBD were found, even when comparing the resected and unresected group. However, this study demonstrates the complexity of biliary drainage for patients with potentially resectable pCCA, even in tertiary referral centers.

Introduction: Effective (neo) adjuvant chemotherapy for cholangiocarcinoma is lacking due to chemoresistance and the absence of predictive biomarkers. Human equilibrative nucleoside transporter 1 (hENT1) has been described as a potential prognostic and predictive biomarker. In this study, the potential of rabbit-derived (SP120) and murine-derived (10D7G2) antibodies to detect hENT1 expression was compared in tissue samples of patients with extrahepatic cholangiocarcinoma (ECC), and the predictive value of hENT1 was investigated in three ECC cell lines.Methods: Tissues of 71 chemonaïve patients with histological confirmation of ECC were selected and stained with SP120 or 10D7G2 to assess the inter-observer variability for both antibodies and the correlation with overall survival. Concomitantly, gemcitabine sensitivity after hENT1 knockdown was assessed in the ECC cell lines EGI-1, TFK-1, and SK-ChA-1 using sulforhodamine B assays.Results: Scoring immunohistochemistry for hENT1 expression with the use of SP120 antibody resulted in the highest interobserver agreement but did not show a prognostic role of hENT1. However, 10D7G2 showed a prognostic role for hENT1, and a potential predictive role for gemcitabine sensitivity in hENT1 in SK-ChA-1 and TFK-1 cells was found.Discussion: These findings prompt further studies for both preclinical validation of the role of hENT1 and histochemical standardization in cholangiocarcinoma patients treated with gemcitabine-based chemotherapy.

Background Intraductal papillary neoplasms (IPN) and biliary epithelial neoplasia (BilIN) are well‐defined precursor lesions of biliary tract carcinoma (BTC). The aim of this study was to provide a comprehensive characterisation of the inflammatory microenvironment in BTC precursor lesions. Methods Immunohistochemistry was employed to assess tumour-infiltrating immune cells in tissue samples from patients, for whom precursor lesions were identified alongside invasive BTC. The spatiotemporal evolution of the immune microenvironment during IPN-associated carcinogenesis was comprehensively analysed using triplet sample sets of non-neoplastic epithelium, precursor lesion and invasive BTC. Immune-cell dynamics during IPN- and BilIN-associated carcinogenesis were subsequently compared. Results Stromal CD3 + ( P = 0.002), CD4 + ( P = 0.007) and CD8 + ( P < 0.001) T cells, CD20 + B cells ( P = 0.008), MUM1 + plasma cells ( P = 0.012) and CD163 + M2-like macrophages ( P = 0.008) significantly decreased in IPN compared to non-tumorous biliary epithelium. Upon transition from IPN to invasive BTC, stromal CD68 + ( P = 0.001) and CD163 + ( P < 0.001) macrophages significantly increased. In contrast, BilIN-driven carcinogenesis was characterised by significant reduction of intraepithelial CD8 + T-lymphocytic infiltration from non-tumorous epithelium via BilIN ( P = 0.008) to BTC ( P = 0.004). Conclusion IPN and BilIN are immunologically distinct entities that undergo different immune-cell variations during biliary carcinogenesis. Intraepithelial CD8 + T-lymphocytic infiltration of biliary tissue decreased already at the IPN-precursor stage, whereas BilIN-associated carcinogenesis showed a slowly progressing reduction towards invasive carcinoma.

Purpose and context. Angiotensin-converting enzyme 2 is the entry receptor for SARS-CoV and SARS-CoV-2. Variations in ACE2 expression might explain age-related symptomatology of COVID-19, that is, more gastro-intestinal symptoms and less pulmonary complaints. This study qualitatively investigated ACE2 protein expression in various organs from the fetal to the young adolescent stage. Method. Autopsy samples from lung, heart, liver, stomach, small intestine, pancreas, kidney, adrenals, and brain (when available) were obtained from twenty subjects aged 24 weeks gestational age through 28 years. Formalin-fixed paraffin-embedded 4-um-thick tissue sections were stained against ACE2. Key results. We showed that the extent of ACE2 expression is age-related. With age, expression increases in lungs and decreases in intestines. In the other examined organs, ACE2 protein expression did not change with age. In brain tissue, ACE2 was expressed in astrocytes and endothelial cells. Conclusions. Age-related ACE2 expression differences could be one substrate of the selective clinical vulnerability of the respiratory and gastro-intestinal system to SARS-CoV-2 infection during infancy.

Purpose: To investigate the safety and efficacy of percutaneous or open irreversible electroporation (IRE) in a prospective cohort of patients with locally advanced, unresectable perihilar cholangiocarcinoma (PHC). Materials and Methods: In a multicenter Phase I/II study, patients with unresectable PHC due to extensive vascular involvement or N2 lymph node metastases or local recurrence after resection for PHC were included and treated by open or percutaneous IRE combined with palliative chemotherapy (current standard of care). The primary outcome was the number of major adverse events occurring within 90 d after IRE (grade >= 3), and the upper limit was predefined at 60%. Secondary outcomes included technical success rate, hospital stay, and overall survival (OS). Results: Twelve patients (mean age, 63 y +/- 12) were treated with IRE. The major adverse event rate was 50% (6 of 12 patients), and no 90-d mortality was observed. All procedures were technically successful, with no intraprocedural adverse events requiring additional interventions. The median OS from diagnosis was 21 mos (95% confidence interval, 15-27 mos), with a 1-y survival rate of 75% after IRE. Conclusions: Percutaneous IRE in selected patients with locally advanced PHC seems feasible, with a major adverse event rate of 50%, which was below the predefined upper safety limit in this prospective study. Future comparative research exploring the efficacy of IRE is warranted.

Cancer patients benefit from early tumor detection since treatment outcomes are more favorable for less advanced cancers. Platelets are involved in cancer progression and are considered a promising biosource for cancer detection, as they alter their RNA content upon local and systemic cues. We show that tumor-educated platelet (TEP) RNA-based blood tests enable the detection of 18 cancer types. With 99% specificity in asymptomatic controls, thromboSeq correctly detected the presence of cancer in two-thirds of 1,096 blood samples from stage I-IV cancer patients and in half of 352 stage I-III tumors. Symptomatic controls, including inflammatory and cardiovascular diseases, and benign tumors had increased false-positive test results with an average specificity of 78%. Moreover, thromboSeq determined the tumor site of origin in five different tumor types correctly in over 80% of the cancer patients. These results highlight the potential properties of TEP-derived RNA panels to supplement current approaches for blood-based cancer screening.

BackgroundThe patients with unresectable perihilar cholangiocarcinoma require biliary drainage to relieve symptoms and allow for palliative systemic chemotherapy. The aim of this study was to establish the success, complication, and mortality rates of the initial biliary drainage in patients with unresectable perihilar cholangiocarcinoma at presentation.MethodsIn this retrospective multicenter study, patients with unresectable perihilar cholangiocarcinoma who underwent initial endoscopic or percutaneous transhepatic biliary drainage between 2002 and 2014 were included. The success of drainage was defined as a successful biliary stent or drain placement, no unscheduled reintervention within 14 days, and serum bilirubin levels <50 μmol/L (ie, 2.9 mg/dL) or a >50% decrease in serum bilirubin after 14 days. Severe complications, and 90-day mortality were recorded.ResultsIncluded were 186 patients: 161 (87%) underwent initial endoscopic biliary drainage and 25 (13%) underwent initial percutaneous transhepatic biliary drainage. The success of initial drainage was observed in 73 patients (45%) after endoscopic biliary drainage and 6 (24%) after percutaneous transhepatic biliary drainage. The reasons for an unsuccessful initial drainage were: the failure to place a drain or stent in 39 patients (21%), an unplanned reintervention within 14 days in 52 patients (28%), and the bilirubin level >50 μmol/L (or not halved) after 14 days of initial drainage in 16 patients (9%). Severe drainage-related complications occurred in 19 patients (12%) after endoscopic biliary drainage and in 3 (12%) after percutaneous transhepatic biliary drainage. Overall, 66 patients (36%) died within 90 days after initial biliary drainage.ConclusionInitial biliary drainage in patients with unresectable perihilar cholangiocarcinoma had a success rate of 45% and a 90-day mortality rate of 36%. Future studies for patients with perihilar cholangiocarcinoma should focus on improving biliary drainage.

Visualization of the subcellular localization of SARS-CoV-2 proteins in lung patient material of COVID-19 patients is important for the understanding of this new virus. We detected viral proteins in the context of the ultrastructure of infected cells and tissues and discovered that some viral proteins accumulate in novel, lipid-filled compartments.

COVID-19 is a pandemic with high morbidity and mortality. In an autopsy cohort of COVID-19 patients, we found extensive accumulation of the tryptophan degradation products 3-hydroxy-anthranilic acid and quinolinic acid in the lungs, heart, and brain. This was not related to the expression of the tryptophan-catabolizing indoleamine 2,3-dioxygenase (IDO)-1, but rather to that of its isoform IDO-2, which otherwise is expressed rarely. Bioavailability of tryptophan is an absolute requirement for proper cell functioning and synthesis of hormones, whereas its degradation products can cause cell death. Markers of apoptosis and severe cellular stress were associated with IDO-2 expression in large areas of lung and heart tissue, whereas affected areas in brain were more restricted. Analyses of tissue, cerebrospinal fluid, and sequential plasma samples indicate early initiation of the kynurenine/aryl-hydrocarbon receptor/IDO-2 axis as a positive feedback loop, potentially leading to severe COVID-19 pathology. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd on behalf of The Pathological Society of Great Britain and Ireland.

SARS-CoV-2 causes acute respiratory disease, but many patients also experience neurological complications. Neuropathological changes with pronounced neuroinflammation have been described in individuals after lethal COVID-19, as well as in the CSF of hospitalized patients with neurological complications. To assess whether neuropathological changes can occur after a SARS-CoV-2 infection, leading to mild-to-moderate disease, we investigated the brains of four rhesus and four cynomolgus macaques after pulmonary disease and without overt clinical symptoms. Postmortem analysis demonstrated the infiltration of T-cells and activated microglia in the parenchyma of all infected animals, even in the absence of viral antigen or RNA. Moreover, intracellular α-synuclein aggregates were found in the brains of both macaque species. The heterogeneity of these manifestations in the brains indicates the virus' neuropathological potential and should be considered a warning for long-term health risks, following SARS-CoV-2 infection.

Background: Compelling evidence has shown cardiac involvement in COVID-19 patients. However, the overall majority of these studies use data obtained during the first wave of the pandemic, while recently differences have been reported in disease course and mortality between first- and second wave COVID-19 patients. The aim of this study was to analyze and compare cardiac pathology between first- and second wave COVID-19 patients. Methods: Autopsied hearts from first- (n = 15) and second wave (n = 10) COVID-19 patients and from 18 nonCOVID-19 control patients were (immuno)histochemically analyzed. CD45+ leukocyte, CD68+ macrophage and CD3+ T lymphocyte infiltration, cardiomyocyte necrosis and microvascular thrombosis were quantified. In addition, the procoagulant factors Tissue Factor (TF), Factor VII (FVII), Factor XII (FXII), the anticoagulant protein Dipeptidyl Peptidase 4 (DPP4) and the advanced glycation end-product N(epsilon)-Carboxymethyllysine (CML), as markers of microvascular thrombogenicity and dysfunction, were quantified. Results: Cardiac inflammation was significantly decreased in second wave compared to first wave COVID-19 patients, predominantly related to a decrease in infiltrated lymphocytes and the occurrence of lymphocytic myocarditis. This was accompanied by significant decreases in cardiomyocyte injury and microvascular thrombosis. Moreover, microvascular deposits of FVII and CML were significantly lower in second wave compared to first wave COVID-19 patients. Conclusions: These results show that in our cohort of fatal COVID-19 cases cardiac inflammation, cardiomyocyte injury and microvascular thrombogenicity were markedly decreased in second wave compared to first wave patients. This may reflect advances in COVID-19 treatment related to an increased use of steroids in the second COVID-19 wave.

A correction to this paper has been published: https://doi.org/10.1245/s10434-021-10171-2

Patients with coronavirus disease 2019 (COVID‐19) pneumonia present with typical findings on chest computed tomography (CT), but the underlying histopathological patterns are unknown. Through direct regional correlation of imaging findings to histopathological patterns, this study aimed to explain typical COVID‐19 CT patterns at tissue level.

SARS-CoV-2 may cause acute respiratory disease, but the infection can also initiate neurological symptoms. Here we show that SARS-CoV-2 infection causes brain inflammation in the macaque model. An increased metabolic activity in the pituitary gland of two macaques was observed by longitudinal positron emission tomography-computed tomography (PET-CT). Post-mortem analysis demonstrated infiltration of T-cells and activated microglia in the brain, and viral RNA was detected in brain tissues from one animal. We observed Lewy bodies in brains of all rhesus macaques. These data emphasize the virus’ capability to induce neuropathology in this nonhuman primate model for SARS-CoV-2 infection. As in humans, Lewy body formation is an indication for the development of Parkinson’s disease, this data represents a warning for potential long-term neurological effects after SARS-CoV-2 infection. Teaser SARS-CoV-2 causes brain inflammation and Lewy bodies, a hallmark for Parkinson, after an asymptomatic infection in macaques. ### Competing Interest Statement The authors have declared no competing interest.

Background: In patients undergoing resection for perihilar cholangiocarcinoma(PHC), intraoperative frozen sections are performed to assess completeness of the proximal and distal bile duct resection planes. In case of a positive proximal margin, re-resection of the bile duct stump is usually undertaken to achieve R0-resection. In case of a positive distal margin, additional PPPD (hepato-pancreatoduodenectomy, HPD) is considered. However, the Results of re-resection on R0-status and oncological outcomes in patients with PHC remain inconclusive. Therefore, we aimed to assess survival after re-resection of the bile duct after intra-operative positive frozen section in patients with PHC. Material and Methods: All consecutive patients undergoing resection for PHC at a single tertiary center between 2000-2018 were evaluated. Primary outcome was overall survival(OS), determined in patients with initial R0 resection, R1 resection and R0 resection after re-resection. Secondary outcome was severe morbidity(Clavien-Dindo=3). Results: A total of 162 PHC patients were evaluated(2000-2018), in which 30 positive intra-operative frozen sections were found in 27 patients. Additional resection was performed in 25 patients, representing 27 re-resections(Figure 1). In three cases re-resection was deemed technically not feasible. Re-resection at the distal resection margin(CBD) was performed in 8/27 patients, including 3 HPDs. Although Results of 18/27 re-resections(in 16 patients) were negative, 9 of the 16 patients (56%) still had R1 resection due to other positive, usually circumferential resection margins. Only four patients achieved true R0-resection after re-resection. Median OS for patients with initial R0, R1 and R0 after re-resection were 77, 35 and 33 months, respectively(p=0.334). Severe morbidity was not significantly different (72% after re-resection and 54% without re-resection, p=0.102). Conclusion: In the majority of patients (84%) undergoing re-resection of positive biliary margins in this series, R0-resection was not achieved, often due to additional positive resection margins.

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) targets multiple organs and causes severe coagulopathy. Histopathological organ changes might not only be attributable to a direct virus-induced effect, but also the immune response. The aims of this study were to assess the duration of viral presence, identify the extent of inflammatory response, and investigate the underlying cause of coagulopathy.MethodsThis prospective autopsy cohort study was done at Amsterdam University Medical Centers (UMC), the Netherlands. With informed consent from relatives, full body autopsy was done on 21 patients with COVID-19 for whom autopsy was requested between March 9 and May 18, 2020. In addition to histopathological evaluation of organ damage, the presence of SARS-CoV-2 nucleocapsid protein and the composition of the immune infiltrate and thrombi were assessed, and all were linked to disease course.FindingsOur cohort (n=21) included 16 (76%) men, and median age was 68 years (range 41–78). Median disease course (time from onset of symptoms to death) was 22 days (range 5–44 days). In 11 patients tested for SARS-CoV-2 tropism, SARS-CoV-2 infected cells were present in multiple organs, most abundantly in the lungs, but presence in the lungs became sporadic with increased disease course. Other SARS-CoV-2-positive organs included the upper respiratory tract, heart, kidneys, and gastrointestinal tract. In histological analyses of organs (sampled from nine to 21 patients per organ), an extensive inflammatory response was present in the lungs, heart, liver, kidneys, and brain. In the brain, extensive inflammation was seen in the olfactory bulbs and medulla oblongata. Thrombi and neutrophilic plugs were present in the lungs, heart, kidneys, liver, spleen, and brain and were most frequently observed late in the disease course (15 patients with thrombi, median disease course 22 days [5–44]; ten patients with neutrophilic plugs, 21 days [5–44]). Neutrophilic plugs were observed in two forms: solely composed of neutrophils with neutrophil extracellular traps (NETs), or as aggregates of NETs and platelets..InterpretationIn patients with lethal COVID-19, an extensive systemic inflammatory response was present, with a continued presence of neutrophils and NETs. However, SARS-CoV-2-infected cells were only sporadically present at late stages of COVID-19. This suggests a maladaptive immune response and substantiates the evidence for immunomodulation as a target in the treatment of severe COVID-19.FundingAmsterdam UMC Corona Research Fund.

The recently published INTERCPT-study was after the DRAINAGE-study, the second randomized controlled trial that compared endoscopic biliary drainage versus percutaneous biliary drainage in patients with perihilar cholangiocarcinoma (PHC).1Elmunzer B.J. et al.Clin Gastroenterol Hepatol. 2020 May 23; (S1542-3565(20)30696-0)Google Scholar,2Coelen R.J.S. et al.Lancet Gastroenterol Hepatol. 2018; 3: 681-690Abstract Full Text Full Text PDF PubMed Scopus (103) Google Scholar Unfortunately, both studies have been prematurely stopped, raising several concerns. The INTERCPT-study was started in October 2017 and stopped in March 2019 by the Data Safety Monitoring Board because of slow accrual. In 18 months, only 13 patients were included out of 51 screened individuals among 16 centers in the United States, while the calculated sample size was 184. The authors described several factors that may have caused slow enrollment; many patients had been referred after initial drainage had already been undertaken, precluding enrollment in the trial. This was also encountered in the Dutch multicenter DRAINAGE-trial, which also randomized patients with PHC to endoscopic biliary drainage or percutaneous biliary drainage.2Coelen R.J.S. et al.Lancet Gastroenterol Hepatol. 2018; 3: 681-690Abstract Full Text Full Text PDF PubMed Scopus (103) Google Scholar This trial was stopped because of higher overall mortality in the percutaneous biliary drainage group. Within a 2.5-year period, 54 out of 261 screened patients could be included. A national, multidisciplinary clinical pathway, succeeded in more patients being referred to our center without previous biliary drainage. We believe that awareness among gastroenterologists and surgeons in referring centers of assessment of imaging before inserting biliary drains, is key to staging and to devising a treatment strategy. Although both randomized trials had the same objective (ie, to identify the optimal, initial biliary drainage technique in PHC), primary endpoints differed. In the INTERCPT-study, the primary endpoint was successful biliary drainage, defined as 50% reduction in bilirubin level within 3 weeks without additional drainage procedures. In the DRAINAGE-trial, the primary outcome was the number of severe complications of biliary drainage occurring between randomization and surgery. Therapeutic success was a secondary endpoint and was defined as normal-caliber bile ducts on ultrasound and a 20% decrease in bilirubin level within 1 week. Although difficult to compare because of different definitions, therapeutic success of biliary drainage was achieved in 6 out of 13 patients (46%) in the INTERCPT-study versus 38 out of 54 patients (70%) in the DRAINAGE-trial. Remarkably, the high mortality rate in the DRAINAGE-trial led to early study termination, whereas high mortality and complication rates were also observed in the INTERCPT-study: 10 of 13 patients (77%) experienced adverse events requiring hospital admission (vs 65% in the DRAINAGE-trial) and 8 of 13 patients (62%) died within 3 months follow-up (vs 26% in the DRAINAGE-trial). The unexpectedly high mortality rates in both trials require special attention. In the DRAINAGE-trial, with an all-cause mortality design, mortality seemed unrelated to drainage in 5 of 14 patients (2 myocardial infarction and 3 disease progression). Six patients died because of postoperative complications. The causes of death in the INTERCPT-trial have not been specified. An important difference between both trials was that the DRAINAGE-trial included patients with tumors deemed resectable, whereas the INTERCPT-study also included patients requiring biliary drainage in the palliative setting. This may have resulted in an even more heterogenous and complex trial population, hampering conduct and progress of this study. The authors of the INTERCPT-study encountered logistic issues in enrolling patients on-site and that institutional/clinician bias in favor of 1 of the 2 drainage techniques prevailed. The DRAINAGE-trial was conducted in 4 Dutch tertiary centers, whereas the INTERCPT-trial included 16 centers scattered among the United States. Effective collaboration among surgery, gastroenterology, and interventional radiology departments is more likely in a limited number of dedicated, participating centers. Remarkably, 2 randomized studies including patients with PHC both showed outcomes that contradict only retrospective data available in literature. Especially in this complex disease, retrospective cohort studies are biased by patient selection and inadequate registration of complications emphasizing the need for more prospective cohort studies. Whether a new randomized trial with the same objective will be attempted in the near future is questionable, in the wake of the 2 recently failed trials. Nevertheless, in any new trial examining the mode of biliary drainage in PHC, we strongly advise to focus on drainage-specific complications as primary outcome.

Background: Curative treatment for patients with perihilar cholangiocarcinoma (PHC) generally consists of extrahepatic bile duct resection with (extended) hemihepatectomy, an operation that is known for its high morbidity and mortality. Diagnostic tests are often lacking in establishing the diagnosis of PHC preoperatively; as a result, 5-15% of patients resected for presumed PHC have benign disease. Molecular imaging combined with cancer biomarker-specific imaging agents could serve as a novel diagnostic tool. Integrin ανβ6 is a cell surface receptor that is highly upregulated in pancreaticobiliary malignancies. We have developed imaging agents selectively binding integrin ανβ6 for both (preoperative)PET and (intraoperative)fluorescent imaging. We aimed to evaluate the expression of integrin ανβ6 in PHC and in benign disease mimicking PHC using immunohistochemistry in a pilot study.