Identification of Four Immune Subtypes Characterized by Distinct Composition and Functions of Tumor Microenvironment in Intrahepatic Cholangiocarcinoma.

BACKGROUND AND AIMS: Intrahepatic cholangiocarcinoma (ICC) is a severe malignant tumor in which the standard therapies are mostly ineffective. The biological significance of the desmoplastic tumor microenvironment (TME) of ICC has been stressed but was insufficiently taken into account in the search for classifications of ICC adapted to clinical trial design. We investigated the heterogeneous tumor stroma composition and built a TME-based classification of ICC tumors that detects potentially targetable ICC subtypes. APPROACH AND RESULTS: We established the bulk gene expression profiles of 78 ICCs. Epithelial and stromal compartments of 23 ICCs were laser microdissected. We quantified 14 gene expression signatures of the TME and those of 3 functional indicators (liver activity, inflammation, immune resistance). The cell population abundances were quantified using the microenvironment cell population-counter package and compared with immunohistochemistry. We performed an unsupervised TME-based classification of 198 ICCs (training set) and 368 ICCs (validation set). We determined immune response and signaling features of the different immune subtypes by functional annotations. We showed that a set of 198 ICCs could be classified into 4 TME-based subtypes related to distinct immune escape mechanisms and patient outcomes. The validity of these immune subtypes was confirmed over an independent set of 368 ICCs and by immunohistochemical analysis of 64 ICC tissue samples. About 45% of ICCs displayed an immune desert phenotype. The other subtypes differed in nature (lymphoid, myeloid, mesenchymal) and abundance of tumor-infiltrating cells. The inflamed subtype (11%) presented a massive T lymphocyte infiltration, an activation of inflammatory and immune checkpoint pathways, and was associated with the longest patient survival. CONCLUSION: We showed the existence of an inflamed ICC subtype, which is potentially treatable with checkpoint blockade immunotherapy.

Severe Jaundice Increases Early Severe Morbidity and Decreases Long-Term Survival after Pancreaticoduodenectomy for Pancreatic Adenocarcinoma.

BACKGROUND: The influence of jaundice on outcomes after pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC) is debated. This study aimed to determine, in a large multicentric series, the influence of severe jaundice (serum bilirubin level ≥250 µmol/L and 300 µmol/L) on early severe morbidity and survival after PD. STUDY DESIGN: From 2004 to 2009, twelve hundred patients (median age 66 years, 57% male) with resectable PDAC underwent PD. Patients who received preoperative biliary drainage for neoadjuvant treatment or cholangitis were excluded. Pre- and intraoperative data were collected by a standardized form. Serum bilirubin level and creatinine clearance were analyzed as categorical variables. Predictive factors of severe complications and poor survival (Kaplan-Meier method) were identified by univariate and multivariate analysis. RESULTS: Median follow-up was 21 months (95% CI, 19-23). Operative mortality was 3.9% (n = 47), with no predictive factors in multivariate analysis. Severe complications (Dindo-Clavien grade III to IV) occurred in 22% (n = 268), with male sex (p = 0.025), America Society of Anesthesiologists score 3 to 4 (p = 0.022), serum bilirubin level ≥300 µmol/L (p = 0.034), and creatinine clearance <60 mL/min/1.73 m(2) (p = 0.013) identified as predictive factors in multivariate analysis. Overall 3-year survival rate was 41% (95% CI, 37-45%). In multivariate analysis, serum bilirubin level ≥300 µmol/L (p = 0.048), low-volume center (p < 0.001), venous resection (p = 0.014), N1 status (p < 0.01), R1 status (p < 0.001), and absence of adjuvant treatment (p < 0.001) negatively impacted survival. There was a negative relationship between survival at 12 months or later and higher rates of bilirubin. Presence of a biliary stent did not influence early or long-term results. CONCLUSIONS: In this multicentric study, serum bilirubin level ≥300 µmol/L increased severe morbidity and decreased long-term survival after PD for PDAC. These findings suggest that biliary stenting is appropriately indicated before PD in patients with PDAC and severe jaundice.