Gallbladder cancer mimicking perihilar cholangiocarcinoma-considerable rate of postoperative reclassification with implications for prognosis.

BACKGROUND: For some patients undergoing resection under the suspicion of a perihilar cholangiocarcinoma (pCCA), postoperative diagnosis may differ from the preoperative diagnosis. While a postoperative finding of benign bile duct stricture is known to affect 3-15% of patients, less has been described about the consequences of finding other biliary tract cancers postoperatively. This study compared pre- and postoperative diagnoses, risk characteristics, and outcomes after surgery for suspected pCCA. METHODS: Retrospective single-center study, Karolinska University Hospital, Stockholm, Sweden (January 2009-May 2017). The primary postoperative outcome was overall survival. Secondary outcomes were disease-free survival and postoperative complications. Survival analysis was performed by the Kaplan-Meier method. RESULTS: Seventy-one patients underwent resection for suspected pCCA. pCCA was confirmed in 48 patients (68%). Ten patients had benign lesions (14%), 2 (3%) were diagnosed with other types of cholangiocarcinoma (CCA, distal n = 1, intrahepatic n = 1), while 11 (15%) were diagnosed with gallbladder cancer (GBC). GBC patients were older than patients with pCCA (median age 71 versus 58 years, p = 0.015), with a large proportion of patients with a high tumor extension stage (≥ T3, 91%). Median overall survival was 20 months (95% CI 15-25 months) for patients with pCCA and 17 months (95% CI 11-23 months) for patients with GBC (p = 0.135). Patients with GBC had significantly shorter median disease-free survival (DFS), 10 months (95% CI 3-17 months) compared 17 months (95% CI 15-19 months) for patients with pCCA (p = 0.010). CONCLUSIONS: At a large tertiary referral center, 15% of patients resected for suspected pCCA were postoperatively diagnosed with GBC. Compared to patients with pCCA, GBC patients were older, with advanced tumors and shorter DFS. The considerable rate of re-classification stresses the need for improved preoperative staging, as these prognostic differences could have implications for treatment strategies.

Preoperative immunological plasma markers TRAIL, CSF1 and TIE2 predict survival after resection for biliary tract cancer.

Introduction: Systemic inflammatory markers have been validated as prognostic factors for patients with biliary tract cancer (BTC). The aim of this study was to evaluate specific immunologic prognostic markers and immune responses by analyzing preoperative plasma samples from a large prospectively collected biobank. Methods: Expression of 92 proteins representing adaptive and innate immune responses was investigated in plasma from 102 patients undergoing resection for BTC 2009-2017 (perihilar cholangiocarcinoma n=46, intrahepatic cholangiocarcinoma n=27, gallbladder cancer n=29), by means of a high-throughput multiplexed immunoassay. Association with overall survival was analyzed by Cox regression, with internal validation and calibration. Tumor tissue bulk and single-cell gene expression of identified markers and receptors/ligands was analyzed in external cohorts. Results: Three preoperative plasma markers were independently associated with survival: TRAIL, TIE2 and CSF1, with hazard ratios (95% confidence intervals) 0.30 (0.16-0.56), 2.78 (1.20-6.48) and 4.02 (1.40-11.59) respectively. The discrimination of a preoperative prognostic model with the three plasma markers was assessed with concordance-index 0.70, while the concordance-index of a postoperative model with histopathological staging was 0.66. Accounting for subgroup differences, prognostic factors were assessed for each type of BTC. TRAIL and CSF1 were prognostic factors in intrahepatic cholangiocarcinoma. In independent cohorts, TRAIL-receptor expression was higher in tumor tissue and seen in malignant cells, with TRAIL and CSF1 expressed by intra- and peritumoral immune cells. Intratumoral TRAIL-activity was decreased compared to peritumoral immune cells, while CSF1-activity was increased. The highest CSF1 activity was seen in intratumoral macrophages, while the highest TRAIL-activity was seen in peritumoral T-cells. Discussion: In conclusion, three preoperative immunological plasma markers were prognostic for survival after surgery for BTC, providing good discrimination, even compared to postoperative pathology. TRAIL and CSF1, prognostic factors in intrahepatic cholangiocarcinoma, showed marked differences in expression and activity between intra- and peritumoral immune cells.

Increased Prevalence of Alpha-1-Antitrypsin Deficiency in Patients with Biliary Tract Cancer and Its Associated Clinicopathological Features.

Alpha-1 antitrypsin deficiency (A1ATD) is underdiagnosed and associated with liver diseases. Here, we genotyped 130 patients with biliary tract cancer (BTC) scheduled for liver resection and found A1ATD in 10.8% of the patients. A1ATD was found in all BTC subtypes, and patients had similar clinical features as non-A1ATD BTC, not permitting their identification using clinical routine liver tests. In intrahepatic cholangiocarcinoma (iCCA), the abundance of A1AT protein was increased in the tumor and appeared to be influenced by the genomic alterations. On the one hand, BTC with A1ATD had lower perineural invasion at histopathology and displayed a longer survival, suggesting that a deficiency in this protein is associated with a less aggressive phenotype. On the other hand, iCCA with high A1AT expression had more advanced tumor staging and enriched pathways for complement system and extracellular matrix interactions, indicating that A1AT protein might contribute to a more aggressive phenotype. With increased awareness, screening, and basic studies, A1ATD could represent one more layer of stratification for future targeted therapies in BTC.

Prognostic influence of multiple hepatic lesions in resectable intrahepatic cholangiocarcinoma: A systematic review and meta-analysis.

BACKGROUND: Presence of multiple hepatic lesions in intrahepatic cholangiocarcinoma (iCCA) is included in staging as a negative prognostic factor, but both prognostic value and therapeutic implications remain debated. The aim of this study was to systematically review the prognostic influence of multiple lesions on survival after resection for iCCA, with stratification for distribution and number of lesions. METHODS: Medline and Embase were systematically searched to identify records (2010-2021) reporting survival for patients undergoing primary resection for iCCA. Included were original articles reporting overall survival, with data on multiple lesions including tumour distribution (satellites/other multiple lesions) and/or number. For meta-analysis, the random effects model and inverse variance method were used. PRISMA 2020 guidelines were followed. RESULTS: Thirty-one studies were included for review. For meta-analysis, nine studies reporting data on the prognostic influence of satellite lesions (2737 patients) and six studies reporting data on multiple lesions other than satellites (1589 patients) were included. Satellite lesions (hazard ratio 1.89, 95% confidence interval 1.67-2.13) and multiple lesions other than satellites (hazard ratio 2.41, 95% confidence interval 1.72-3.37) were significant negative prognostic factors. Data stratified for tumour number, while limited, indicated increased risk per additional lesion. CONCLUSION: Satellite lesions, as well as multiple lesions other than satellites, was a negative prognostic factor in resectable iCCA. Considering the prognostic impact, both tumour distribution and number of lesions should be evaluated together with other risk factors to allow risk stratification for iCCA patients with multiple lesions, rather than precluding resection for the entire patient group.

Mucosal-associated invariant T-cell tumor infiltration predicts long-term survival in cholangiocarcinoma.

BACKGROUND AND AIMS: Cholangiocarcinoma (CCA) is a malignancy arising from biliary epithelial cells of intra- and extrahepatic bile ducts with dismal prognosis and few nonsurgical treatments available. Despite recent success in the immunotherapy-based treatment of many tumor types, this has not been successfully translated to CCA. Mucosal-associated invariant T (MAIT) cells are cytotoxic innate-like T cells highly enriched in the human liver, where they are located in close proximity to the biliary epithelium. Here, we aimed to comprehensively characterize MAIT cells in intrahepatic (iCCA) and perihilar CCA (pCCA). APPROACH AND RESULTS: Liver tissue from patients with CCA was used to study immune cells, including MAIT cells, in tumor-affected and surrounding tissue by immunohistochemistry, RNA-sequencing, and multicolor flow cytometry. The iCCA and pCCA tumor microenvironment was characterized by the presence of both cytotoxic T cells and high numbers of regulatory T cells. In contrast, MAIT cells were heterogenously lost from tumors compared to the surrounding liver tissue. This loss possibly occurred in response to increased bacterial burden within tumors. The residual intratumoral MAIT cell population exhibited phenotypic and transcriptomic alterations, but a preserved receptor repertoire for interaction with tumor cells. Finally, the high presence of MAIT cells in livers of iCCA patients predicted long-term survival in two independent cohorts and was associated with a favorable antitumor immune signature. CONCLUSIONS: MAIT cell tumor infiltration associates with favorable immunological fitness and predicts survival in CCA.

Outcome after resection for perihilar cholangiocarcinoma in patients with primary sclerosing cholangitis: an international multicentre study.

BACKGROUND: Resection for perihilar cholangiocarcinoma (pCCA) in primary sclerosing cholangitis (PSC) has been reported to lead to worse outcomes than resection for non-PSC pCCA. The aim of this study was to compare prognostic factors and outcomes after resection in patients with PSC-associated pCCA and non-PSC pCCA. METHODS: The international retrospective cohort comprised patients resected for pCCA from 21 centres (2000-2020). Patients operated with hepatobiliary resection, with pCCA verified by histology and with data on PSC status, were included. The primary outcome was overall survival. Secondary outcomes were disease-free survival and postoperative complications. RESULTS: Of 1128 pCCA patients, 34 (3.0%) had underlying PSC. Median overall survival after resection was 33 months for PSC patients and 29 months for non-PSC patients (p = .630). Complications (Clavien-Dindo grade ≥ 3) were more frequent in PSC pCCA (71% versus 44%, p = .003). The rate of posthepatectomy liver failure (21% versus 17%, p = .530) and 90-day mortality (12% versus 13%, p = 1.000) was similar for PSC and non-PSC patients. CONCLUSION: Median overall survival after resection for pCCA was similar in patients with underlying PSC and non-PSC patients. Complications were more frequent after resection for PSC-associated pCCA, with no difference in postoperative mortality.

Prognostic value of preoperative inflammatory markers in resectable biliary tract cancer - Validation and comparison of the Glasgow Prognostic Score and Modified Glasgow Prognostic Score in a Western cohort.

INTRODUCTION: Established preoperative prognostic factors for risk stratification of patients with biliary tract cancer (BTC) are lacking. A prognostic value of the inflammation-based Glasgow Prognostic Score (GPS) and Modified Glasgow Prognostic Score (mGPS) in BTC has been indicated in several Eastern cohorts. We sought to validate and compare the prognostic value of the GPS and the mGPS for overall survival (OS), in a large Western cohort of patients with BTC. MATERIAL AND METHODS: We performed a retrospective single-center study for the period 2009 until 2017. 216 consecutive patients that underwent surgical exploration with a diagnosis of perihilar cholangiocarcinoma (PHCC), intrahepatic cholangiocarcinoma (IHCC), or gallbladder cancer (GBC) were assessed. GPS and mGPS were calculated where both CRP and albumin were measured pre-operatively (n = 168/216). Survival was analyzed by Kaplan-Meier estimate and uni-/multivariate Cox regression. RESULTS: GPS and mGPS were negatively associated with survival (p < 0.001/p < 0.001), and the association was significant in all three subgroups. GPS, but not the mGPS, identified an intermediate risk group: with GPS = 1 having better OS than GPS = 2 (p = 0.003), but worse OS than GPS = 0 (p = 0.008). In multivariate analyses of resected patients, GPS (p = 0.001) and mGPS (p = 0.03) remained significant predictors of survival, independent of postoperatively available risk factors. CONCLUSIONS: Preoperative GPS and mGPS are independent prognostic factors in BTC. The association to OS was shown in all patients undergoing exploration, in resected patients only, and in both cholangiocarcinoma and gallbladder cancer. Furthermore, GPS - which weights hypoalbuminemia higher - could identify an intermediate risk group.

Imbalance of Genes Encoding Natural Killer Immunoglobulin-Like Receptors and Human Leukocyte Antigen in Patients With Biliary Cancer.

BACKGROUND & AIMS: Bile duct tumors are rare and have poor prognoses. Natural killer (NK) cells are frequent in human liver and infiltrate these tumors but do not control their progression. Responses of NK cells are regulated by NK immunoglobulin-like receptors (KIRs), which interact with HLA class I ligands. We aimed to characterize the features of the KIR gene loci and their ligands in patients with bile duct cancer (BDC). METHODS: We performed combined multidimensional characterization of genes that encode KIRs and their ligands in blood samples from patients with BDC from Sweden, followed for up to 8 years after diagnosis (n = 148), in 2 geographically matched cohorts of healthy individuals from Northern Europe (n = 204 and n = 900), and in healthy individuals from 6 geographically unrelated populations (n = 2917). We used real-time polymerase chain reaction, RNA sequencing, immunohistochemistry, and flow cytometry to evaluate NK-cell presence, as well as KIR and KIR-ligand expression in bile duct tumors and control tissues. RESULTS: Patients with bile duct tumors had multiple alterations at the KIR gene loci. KIR loci are grouped into genotypes that encode more inhibitory (group A) and more activating (group B) receptors, which can be subdivided into centromeric and telomeric fragments. Patients with BDC had a lower prevalence of KIR2DL3, which was linked to disequilibrium in centromeric A/B and B/B genotypes, compared with control individuals. The associations between KIRs and KIR ligands differed between patients with BDC and control individuals; patients had an altered balance between activating and inhibitory KIRs. KIR-positive NK cells infiltrated biliary tumors that expressed matched KIR ligands. CONCLUSIONS: In a multidimensional analysis of DNA from blood samples of patients with BDC in Europe, we found patients to have multiple alterations at the KIR and HLA gene loci compared with control individuals. These alterations might affect NK-cell tumor surveillance. NK cells from bile duct tumors expressed KIRs and were found in tumors that expressed cognate ligands. This should be considered in development of immune-based therapies for BDC.

Evidence for a morphologically distinct and functionally robust cell type in the proximal tubules of human kidney.

Acute tubular necrosis (ATN), elicited by ischemia and/or toxicity, is a potentially life-threatening condition. Histologically, ATN corresponds to necrosis and detachment of renal tubular epithelial cells. However, the tubules possess a considerable regenerative capacity and may be restored. We have previously identified a scattered population of progenitor-like cells within the proximal tubules, sharing marker expression with the parietal epithelial cells of Bowman's capsule as well as with renal tubules regenerating after ATN. In the present analysis, we use transmission electron microscopy, immunoelectron microscopy and immunofluorescence of human kidney cortex to further explore these cells. We demonstrate that the cells are smaller and have drastically fewer mitochondria than the surrounding proximal tubule cells. They also display strong expression of several structural proteins such as vimentin, collagen-7A1 and the tight junction protein claudin-1. To functionally assess these cells, we also developed a novel human kidney explant model of ATN demonstrating that the cells are more resilient to injury than the surrounding proximal tubular cells. Taken together the results suggest a novel robust cell type with a contrasting biological role to that of the bulk of proximal tubular epithelium.