Liquid biopsy-based protein biomarkers for risk prediction, early diagnosis, and prognostication of cholangiocarcinoma.

BACKGROUND & AIMS: Cholangiocarcinoma (CCA), heterogeneous biliary tumours with dismal prognosis, lacks accurate early diagnostic methods especially important for individuals at high-risk (i.e. those with primary sclerosing cholangitis [PSC]). Here, we searched for protein biomarkers in serum extracellular vesicles (EVs). METHODS: EVs from patients with isolated PSC (n = 45), concomitant PSC-CCA (n = 44), PSC who developed CCA during follow-up (PSC to CCA; n = 25), CCAs from non-PSC aetiology (n = 56), and hepatocellular carcinoma (n = 34) and healthy individuals (n = 56) were characterised by mass spectrometry. Diagnostic biomarkers for PSC-CCA, non-PSC CCA, or CCAs regardless of aetiology (Pan-CCAs) were defined and validated by ELISA. Their expression was evaluated in CCA tumours at a single-cell level. Prognostic EV biomarkers for CCA were investigated. RESULTS: High-throughput proteomics of EVs identified diagnostic biomarkers for PSC-CCA, non-PSC CCA, or Pan-CCA, and for the differential diagnosis of intrahepatic CCA and hepatocellular carcinoma, which were cross-validated by ELISA using total serum. Machine learning-based algorithms disclosed CRP/FIBRINOGEN/FRIL for the diagnosis of PSC-CCA (local disease [LD]) vs. isolated PSC (AUC = 0.947; odds ratio [OR] =36.9) and, combined with carbohydrate antigen 19-9, overpowers carbohydrate antigen 19-9 alone. CRP/PIGR/VWF allowed the diagnosis of LD non-PSC CCAs vs. healthy individuals (AUC = 0.992; OR = 387.5). It is noteworthy that CRP/FRIL accurately diagnosed LD Pan-CCA (AUC = 0.941; OR = 89.4). Levels of CRP/FIBRINOGEN/FRIL/PIGR showed predictive capacity for CCA development in PSC before clinical evidence of malignancy. Multi-organ transcriptomic analysis revealed that serum EV biomarkers were mostly expressed in hepatobiliary tissues, and single-cell RNA sequencing and immunofluorescence analysis of CCA tumours showed their presence mainly in malignant cholangiocytes. Multivariable analysis unveiled EV prognostic biomarkers, with COMP/GNAI2/CFAI and ACTN1/MYCT1/PF4V associated negatively and positively with patients' survival, respectively. CONCLUSIONS: Serum EVs contain protein biomarkers for the prediction, early diagnosis, and prognostication of CCA that are detectable using total serum, representing a tumour cell-derived liquid biopsy tool for personalised medicine. IMPACT AND IMPLICATIONS: The accuracy of current imaging tests and circulating tumour biomarkers for cholangiocarcinoma (CCA) diagnosis is far from satisfactory. Most CCAs are considered sporadic, although up to 20% of patients with primary sclerosing cholangitis (PSC) develop CCA during their lifetime, constituting a major cause of PSC-related death. This international study has proposed protein-based and aetiology-related logistic models with predictive, diagnostic, or prognostic capacities by combining two to four circulating protein biomarkers, moving a step forward into personalised medicine. These novel liquid biopsy tools may allow the (i) easy and non-invasive diagnosis of sporadic CCAs, (ii) identification of patients with PSC with higher risk for CCA development, (iii) establishment of cost-effective surveillance programmes for the early detection of CCA in high-risk populations (e.g. PSC), and (iv) prognostic stratification of patients with CCA, which, altogether, may increase the number of cases eligible for potentially curative options or to receive more successful treatments, decreasing CCA-related mortality.

LIFT procedure for posterior fistula-in-ano. Are outcomes good enough? A systematic review and meta-analysisis of observational studies. / Procedimiento LIFT en fístulas anales de localización posterior. ¿Son buenos los resultados? Revisión sistemática y metaanálisis de estudios observacionales.

INTRODUCTION: Efficacy of the ligation of intersphincteric fistula tract (LIFT) procedure for posterior fistula-in-ano remains under debate. However, there is scarcity of quality evidence analysing this issue. Thus, the aim of this study is to evaluate outcomes of LIFT surgery in patients with posterior anal fistula. MATERIAL AND METHODS: Systematic review and meta-analysis to evaluate efficacy of LIFT procedure for posterior anal fistula. MEDLINE (PubMed), EMBASE, Scopus, Web of Science, Cochrane Library and Google Scholar data sources were searched for key-words (MeSH terms): "LIFT" OR "Ligation of the intersphincteric fistula tract" AND "posterior anal fistula" OR "posterior fistula-in-ano". Original, observational and experimental, non-language restriction studies published from January 2000 to March 2020 and reporting outcomes on LIFT procedure for posterior anal fistula were reviewed. Quality and potential biases were assessed using Newcastle-Ottawa scale, following AHRQ recommendations. Additional sensitivity analysis and publication bias evaluation (Beg and Egger's tets) were performed. RESULTS: No significant differences were found in recurrence rate among patients undergoing LIFT procedure for posterior fistula-in-ano in contrast to other locations (OR 1.36 [IC 95% 0.60-3.07]; p=.46). I2 test value was 77%, expressing a fair heterogeneity among included studies. The weighed median for overall recurrence was 37.8% (RI 18.3-47.7%); with a weighed median of 47.1% (RI 30.7 - 63.7%) and 36.3% (RI 15.8-51.3%) (p=.436) respectively for recurrence after LIFT for posterior fistula and fistula in other locations. There was not clear evidence about the sample size ("n") of included studies nor the disparities in quality assessment of those, could justify the observed heterogeneity. No significant publication bias was found. CONCLUSION: This systematic review and meta-analysis suggests that there are no clear data in the literature for not performing the LIFT procedure in posteriorly located fistulas.