Immunological tolerance in the evolution of male pregnancy.

The unique male pregnancy in pipefishes and seahorses ranges from basic attachment (pouch-less species: Nerophinae) of maternal eggs to specialized internal gestation in pouched species (e.g. Syngnathus and Hippocampus) with many transitions in between. Due to this diversity, male pregnancy offers a unique platform for assessing physiological and molecular adaptations in pregnancy evolution. These insights will contribute to answering long-standing questions of why and how pregnancy evolved convergently in so many vertebrate systems. To understand the molecular congruencies and disparities in male pregnancy evolution, we compared transcriptome-wide differentially expressed genes in four syngnathid species, at four pregnancy stages (nonpregnant, early, late and parturition). Across all species and pregnancy forms, metabolic processes and immune dynamics defined pregnancy stages, especially pouched species shared expression features akin to female pregnancy. The observed downregulation of adaptive immune genes in early-stage pregnancy and its reversed upregulation during late/parturition in pouched species, most notably in Hippocampus, combined with directionless expression in the pouch-less species, suggests immune modulation to be restricted to pouched species that evolved placenta-like systems. We propose that increased foeto-paternal intimacy in pouched syngnathids commands immune suppression processes in early gestation, and that the elevated immune response during parturition coincides with pouch opening and reduced progeny reliance. Immune response regulation in pouched species supports the recently described functional MHC II pathway loss as critical in male pregnancy evolution. The independent co-option of similar genes and pathways both in male and female pregnancy highlights immune modulation as crucial for the evolutionary establishment of pregnancy.

Vibrio syngnathi sp. nov., a fish pathogen, isolated from the Kiel Fjord.

A new Vibrio strain, K08M4T, was isolated from the broad-nosed pipefish Syngnathus typhle in the Kiel Fjord. Infection experiments revealed that K08M4T was highly virulent for juvenile pipefish. Cells of strain K08M4T were Gram-stain-negative, curved rod-shaped and motile by means of a single polar flagellum. The strain grew aerobically at 9-40° C, at pH 4-10.5 and it tolerated up to 12 % (w/v) NaCl. The most prevalent (>10 %) cellular fatty acids of K08M4T were C16 : 1 ω7c and C16 : 0. Whole-genome comparisons revealed that K08M4T represents a separate evolutionary lineage that is distinct from other Vibrio species and falls within the Splendidus clade. The genome is 4,886,292 bp in size, consists of two circular chromosomes (3,298,328 and 1, 587,964 bp) and comprises 4,178 protein-coding genes and 175 RNA genes. In this study, we describe the phenotypic features of the new isolate and present the annotation and analysis of its complete genome sequence. Based on these data, the new isolate represents a new species for which we propose the name Vibrio syngnathi sp. nov. The type strain is K08M4T (=DSM 109818T=CECT 30086T).

Liver surgery in the 2020s: ante-situm and in-situ resection are still indicated - A single-center study.

BACKGROUND: Tumor infiltration of the hepatic outflow comprising all three hepatic veins and the inferior vena cava remains a surgical challenge. Liver resection under total vascular exclusion with or without extracorporeal bypass has been described as a therapeutic option for these tumors. Here, we present our experience with these complex surgical methods. METHODS: We searched our database for patients treated with an in-situ or ante-situm liver resection (ISR and ASR, respectively) with extracorporeal bypass. We collected demographic and perioperative data. RESULTS: From January 2010 to December 2021, we performed 2122 liver resections. Nine patients were treated with ASR and five were treated with ISR. Out of these 14 patients, six had colorectal liver metastases, six had cholangiocarcinoma, and two had non-colorectal liver metastases. The median operative time and bypass time in all patients were 536.5 and 150 min, respectively. Compared with ISR, ASR required a longer operative time (ASR 586 min and ISR 495 min) and a longer bypass time (ASR 155 min and ISR 122 min). Morbidity (Clavien-Dindo grade > 3A adverse events) occurred in 78.5% of patients. 90-day postoperative mortality was 7%. Median overall survival was 33 months. Seven patients experienced recurrence. In these patients, median disease-free survival was 9 months. CONCLUSION: Resection of tumors infiltrating the hepatic outflow poses a high risk for patients. However, with rigorous selection and an experienced perioperative team, these patients can be treated surgically with reasonable oncological outcomes.

Signaling Mechanisms and Pharmacological Modulators Governing Diverse Aquaporin Functions in Human Health and Disease.

The aquaporins (AQPs) are a family of small integral membrane proteins that facilitate the bidirectional transport of water across biological membranes in response to osmotic pressure gradients as well as enable the transmembrane diffusion of small neutral solutes (such as urea, glycerol, and hydrogen peroxide) and ions. AQPs are expressed throughout the human body. Here, we review their key roles in fluid homeostasis, glandular secretions, signal transduction and sensation, barrier function, immunity and inflammation, cell migration, and angiogenesis. Evidence from a wide variety of studies now supports a view of the functions of AQPs being much more complex than simply mediating the passive flow of water across biological membranes. The discovery and development of small-molecule AQP inhibitors for research use and therapeutic development will lead to new insights into the basic biology of and novel treatments for the wide range of AQP-associated disorders.

The rate of cholangiocarcinoma in Caroli Disease A German multicenter study.

BACKGROUND: Caroli Disease (CD) and Caroli Syndrome (CS) are rare disorders presenting with dilation of the intrahepatic bile ducts. CD/CS are associated with cholangiocarcinoma (CCA). However, the true incidence of CCA is still unclear, although it may serve as an indication for surgery. In this paper, we analyzed (I) the incidence of CCA in German centers, (II) reviewed our single center population together with its clinical presentation and (III) performed a thorough literature review. METHODS: 17 large HPB-centers across Germany were contacted and their patients after surgical treatment due to CD/CS with histopathology were included. Medline search for all studies published in English or German literature was performed. Patients who underwent surgery at our department between 2012 and 2020 due to CD or CS were analyzed. RESULTS: In the multicenter study, 79 patients suffered from CD and 119 patients from CS, with a total number of 198 patients. In 14 patients, CCA was found (Overall: 7,1%; CD: 6,3%, CS 7,6%). Between 2012 and 2020, 1661 liver resections were performed at our department. 14 patients underwent surgery due to CD or CS. Histological examination showed synchronous cholangiocarcinoma in one patient. The literature review revealed a CCA-rate of 7,3% in large series, whereas in case reports a rate of 6,8% was found. CONCLUSION: There is risk of malignant transformation and patients with CD might also benefit from resection due to improvement of symptoms. Therefore, resection is strongly advised. As certain patients with CS require transplantation, treatment should not be guided by the relatively low rate of CCA but by the concomitant diseases that come along with hepatic failure.

Perihilar Cholangiocarcinoma - Novel Benchmark Values for Surgical and Oncological Outcomes From 24 Expert Centers.

OBJECTIVE: The aim of this study was to define robust benchmark values for the surgical treatment of perihilar cholangiocarcinomas (PHC) to enable unbiased comparisons. BACKGROUND: Despite ongoing efforts, postoperative mortality and morbidity remains high after complex liver surgery for PHC. Benchmark data of best achievable results in surgical PHC treatment are however still lacking. METHODS: This study analyzed consecutive patients undergoing major liver surgery for PHC in 24 high-volume centers in 3 continents over the recent 5-year period (2014-2018) with a minimum follow-up of 1 year in each patient. Benchmark patients were those operated at high-volume centers (≥50 cases during the study period) without the need for vascular reconstruction due to tumor invasion, or the presence of significant co-morbidities such as severe obesity (body mass index ≥35), diabetes, or cardiovascular diseases. Benchmark cutoff values were derived from the 75th or 25th percentile of the median values of all benchmark centers. RESULTS: Seven hundred eight (39%) of a total of 1829 consecutive patients qualified as benchmark cases. Benchmark cut-offs included: R0 resection ≥57%, postoperative liver failure (International Study Group of Liver Surgery): ≤35%; in-hospital and 3-month mortality rates ≤8% and ≤13%, respectively; 3-month grade 3 complications and the CCI: ≤70% and ≤30.5, respectively; bile leak-rate: ≤47% and 5-year overall survival of ≥39.7%. Centers operating mostly on complex cases disclosed better outcome including lower post-operative liver failure rates (4% vs 13%; P = 0.002). Centers from Asia disclosed better outcomes. CONCLUSION: Surgery for PHC remains associated with high morbidity and mortality with now the availability of benchmark values covering 21 outcome parameters, which may serve as key references for comparison in any future analyses of individuals, group of patients or centers.

Association of subcellular localization of TEAD transcription factors with outcome and progression in pancreatic ductal adenocarcinoma.

BACKGROUND: Transcriptional enhanced associated domain (TEAD) transcription factors are nuclear effectors of several oncogenic signalling pathways including Hippo, WNT, TGF-ß and EGFR pathways that interact with various cancer genes. The subcellular localization of TEAD regulates the functional output of these pathways affecting tumour progression and patient outcome. However, the impact of the TEAD family on pancreatic ductal adenocarcinoma (PDAC) and its clinical progression remain elusive. METHODS: A cohort of 81 PDAC patients who had undergone surgery was established. Cytoplasmic and nuclear localization of TEAD1, TEAD2, TEAD3 and TEAD4 was evaluated with the immunoreactive score (IRS) by immunohistochemistry (IHC) using paraffin-embedded tissue. Results were correlated with clinicopathological data, disease-free and overall survival. RESULTS: Nuclear staining of all four TEADs was increased in pancreatic cancer tissue. Patients suffering from metastatic disease at time of surgery showed a strong nuclear staining of TEAD2 and TEAD3 (p < 0.05). Furthermore, a nuclear > cytoplasmic ratio of TEAD2 and TEAD3 was associated with a shorter overall survival and TEAD2 emerged as an independent prognostic factor for disease-free survival. CONCLUSION: Our study underlines the importance of TEAD transcription factors in PDAC as a nuclear localization was found to be associated with metastatic disease and an unfavourable prognosis after surgical resection.

Impact of acute kidney injury after extended liver resections.

BACKGROUND: Complex liver resection is a risk factor for the development of AKI, which is associated with increased morbidity and mortality. Aim of this study was to assess risk factors for acute kidney injury (AKI) and its impact on outcome for patients undergoing complex liver surgery. METHODS: AKI was defined according to the KDIGO criteria. Primary endpoint was the occurrence of AKI after liver resection. Secondary endpoints were complications and mortality. RESULTS: Overall, 146 patients undergoing extended liver resection were included in the study. The incidence of AKI was 21%. The incidence of chronic kidney disease (CKD) and hepatocellular carcinoma were significantly higher in patients with AKI. In the AKI group, the proportion of extended right hepatectomies was the highest (53%), followed by ALPPS (43%). Increased intraoperative blood loss, increased postoperative complications and perioperative mortality was associated with AKI. Besides age and CKD, ALPPS was an independent risk factor for postoperative AKI. A small future liver remnant seemed to increase the risk of AKI in patients undergoing ALPPS. CONCLUSION: Following extended liver resection, AKI is associated with an increased morbidity and mortality. ALPPS is a major independent risk factor for the development of AKI and a sufficient future liver remnant could avoid postoperative AKI.

Liver Resection with In Situ Hypothermic Perfusion: An Old but Effective Method.

BACKGROUND: More than 40 years ago, patients with tumors infiltrating the confluence of the hepatic veins were deemed unresectable; however, in situ hypothermic perfusion, first described by Fortner et al. (Ann Surg 180(4):644-652, 1974), allowed resection of these tumors. In order to prevent liver ischemia after total vascular exclusion, the liver was flushed with a cooled organ preservation solution. The surgeon was able to resect the tumor and reconstruct the hepatic veins with occlusion of the hepatic inflow and outflow. METHODS: A 55-year-old female suffering from a leiomyosarcoma of the inferior vena cava (IVC) presented to our clinic. Three years ago, the IVC was replaced with a synthetic graft. During the patient's follow-up, a computed tomography (CT) scan revealed three hepatic metastases of the sarcoma. A central metastasis in Segment 8 infiltrated the right hepatic vein (RHV), and two additional metastases were located in the left lateral segments. We used Fortner's technique to resect these tumors. RESULTS: The postoperative course of the patient was prolonged due to a hematoma that partially compressed the new RHV graft. A re-laparotomy was performed and drains were placed. On the 15th postoperative day, the patient was discharged in good health. CONCLUSIONS: Although nowadays patients with these unfortunate tumor locations can, to some extent, be managed non-operatively, surgery remains an option with a chance of cure. Azoulay et al. (Ann Surg 262(1):93-104, 2015) were able to show satisfactory 5-year-survival in 77 patients (30.4%), however 90-day mortality was high (19.5%). Therefore, patients need to be selected carefully. In the era of minimally invasive liver surgery, these old techniques should not vanish from the armamentarium of liver surgeons.

Long-term effects of AAV1/SERCA2a gene transfer in patients with severe heart failure: analysis of recurrent cardiovascular events and mortality.

RATIONALE: The Calcium Up-Regulation by Percutaneous Administration of Gene Therapy In Cardiac Disease (CUPID 1) study was a phase 1/phase 2 first-in-human clinical gene therapy trial using an adeno-associated virus serotype 1 (AAV1) vector carrying the sarcoplasmic reticulum calcium ATPase gene (AAV1/SERCA2a) in patients with advanced heart failure. The study explored potential benefits of the therapy at 12 months, and results were previously reported. OBJECTIVE: To report long-term (3-year) clinical effects and transgene expression in the patients in CUPID 1. METHODS AND RESULTS: A total of 39 patients with advanced heart failure who were on stable, optimal heart failure therapy were randomized to receive intracoronary infusion of AAV1/SERCA2a in 1 of 3 doses (low-dose, 6×10(11) DNase-resistant particles; mid-dose, 3×10(12) DNase-resistant particles; and high-dose, 1×10(13) DNase-resistant particles) versus placebo. The following recurrent cardiovascular and terminal events were tracked for 3 years in all groups: myocardial infarction, worsening heart failure, heart failure-related hospitalization, ventricular assist device placement, cardiac transplantation, and death. The number of cardiovascular events, including death, was highest in the placebo group, high but delayed in the low- and mid-dose groups, and lowest in the high-dose group. Evidence of long-term transgene presence was also observed in high-dose patients. The risk of prespecified recurrent cardiovascular events was reduced by 82% in the high-dose versus placebo group (P=0.048). No safety concerns were noted during the 3-year follow-up. CONCLUSIONS: After a single intracoronary infusion of AAV1/SERCA2a in patients with advanced heart failure, positive signals of cardiovascular events persist for years.

Parenchyma-Preserving Hepatectomy in Perihilar Cholangiocarcinoma: A Chance for Critical Patients?

Introduction: Surgery for perihilar cholangiocarcinoma (pCCA) is associated with high rates of postoperative morbidity and mortality. Extended liver resection (EXT) increases R0 resection rate and survival; however, patients with high perioperative risk are not suitable for extended resection. This study aimed to compare overall survival and surgical morbidity in patients with extended liver resection and parenchyma-preserving hepatectomy (PPH). Methods: Between January 2010 and November 2020, 113 consecutive patients with pCCA underwent surgery at our institution. Eighty-two patients were resected in curative intent. Sixty-four patients received extended liver resection, and 18 patients PPH. Outcomes of resections were evaluated. Results: There was no significant difference in overall survival in patients with PPH compared to extended liver resection (log-rank p = 0.286). Patients with PPH experienced lower rates of postoperative morbidity and mortality. There was no case of in-house mortality in PPH-resected patients compared to 10 cases (16%) in patients that received EXT (p = 0.073). Conclusion: PPH shows similar overall survival with lower rates of postoperative morbidity and mortality. Our findings support the role of a PPH, in selected patients with pCCA, that are not suitable for extended resection due to increased perioperative risk.

Complex Liver Resections for Intrahepatic Cholangiocarcinoma.

The only curative treatment option for intrahepatic cholangiocarcinoma (iCCA) is liver resection. Due to central tumor localization and vascular invasion, complex liver resections play an important role in curative treatment. However, the long-term outcomes after complex liver resection are not known. Methods: A retrospective cohort study was conducted for all patients undergoing liver surgery for iCCA. Complex liver resections included ante situm resections, associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) and major liver resection with vascular reconstructions. Results: Forty-nine patients (34%) received complex liver resection, 66 patients (46%) received conventional liver resection and 28 patients (20%) were not resectable during exploration. Preoperative characteristics were not different between the groups, except for Union for International Cancer Control (UICC) stages. The postoperative course for complex liver resections was associated with more complications and perioperative mortality. However, long-term survival was not different between complex and conventional resections. Independent risk factors for survival were R0 resections and UICC stage. Four patients underwent ante situm resection without any mortality. Conclusions: Complex liver resections are justified in selected patients and survival is comparable with conventional liver resections. Survival in iCCA is affected by UICC stage or resections margins and not by the complexity of the case.

The clinical relevance of the Hippo pathway in pancreatic ductal adenocarcinoma.

PURPOSE: The Hippo pathway has broadened in cancer research in the past decade and revealed itself to be an important driver for tumorigenesis and metastatic spread. In this study, we investigated the clinical relevance of the Hippo pathway with regard to metastatic invasion, patients' outcome and histopathological features. METHODS: Protein expression of components of the Hippo pathway were analyzed by immunohistochemistry (IHC) using paraffin-embedded tissue from 103 patients who had been diagnosed with pancreatic ductal adenocarcinoma and had undergone surgery. Results were correlated with clinicopathological data, disease-free and overall survival. RESULTS: Immunohistochemistry studies in pancreatic tumour tissues revealed a significant upregulation of MST1, MST2, pLATS, pYAP and 14-3-3, representing the active Hippo pathway, in non-metastasized patients (p < 0.01). In turn, the pathway is more inactive in metastasized patients and relating liver metastases as LATS1, LATS2, YAP, transcriptional factors TEAD2 and TEAD3 were upregulated in these patients (p < 0.01). A higher pYAP expression was associated with a favorable OS and DFS. CONCLUSION: The Hippo pathway is inactive in metastasized patients releasing the pro-metastatic and proliferative potential of the pathway. Furthermore, our study underlines the prognostic relevance of the Hippo pathway as a shift in the balance towards the inactive pathway predicts an unfavorable OS and DFS.

Intraoperative (Contrast-Enhanced) Ultrasound Has the Highest Diagnostic Accuracy of Any Imaging Modality in Resection of Colorectal Liver Metastases.

AIM: Defining sensitivity, specificity, diagnostic accuracy for detection of colorectal liver metastases in imaging compared to intraoperative assessment. Defining a cutoff, where accuracy of detection is impaired. METHODS: Prospective single-institution clinical trial (clinicaltrials.gov: NCT01522209). Patients underwent CEUS, MDCT, and 3 Tesla EOB-MRI within 2 weeks preoperatively. Intraoperative palpation, IOUS, and CEIOUS were performed. A patient and lesion-based database was analyzed for accuracy of detection of CEUS, CT, MRI, and Palp/IOUS/CEIOUS combined read. Histology was standard of reference. RESULTS: Forty-seven high tumor load (mean 5, 4 lesions) patients were analyzed. Histopathology confirmed 264 lesions (245 malignant: 19 benign). Accuracy for detection of all lesions: CEUS 63%, CT 71%, MRI 92%, and PALP/IOUS/CEIOUS 98%. ROC analysis for lesion size showed severe impairment of accuracy in lesion detection smaller than 5mm. Intraoperative imaging was not impaired by lesion size. Patient-based analysis revealed a change of resection plan after IOUS/CEIOUS in 35% of patients. CONCLUSION: At 5-mm lesion size, preoperative imaging shows a drop in accuracy of detection. In patients with multiple lesions, addition of MRI to MDCT seems useful. Accuracy of intraoperative ultrasound is not impacted by lesion size and should be mandatory. CEIOUS can improve intraoperative decision-making. TRIAL REGISTRATION: Study registered with clinicaltrials.gov : NCT01522209.

Benign Liver Tumors.

BACKGROUND: Due to the frequent use of medical imaging including ultrasonography, the incidence of benign liver tumors has increased. There is a large variety of different solid benign liver tumors, of which hemangioma, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA) are the most frequent. Advanced imaging techniques allow precise diagnosis in most of the patients, which reduces the need for biopsies only to limited cases. Patients with benign liver tumors are mostly asymptomatic and do not need any kind of treatment. Symptoms can be abdominal pain and pressure effects on adjacent structures. The 2 most serious complications are bleeding and malignant transformation. SUMMARY: This review focuses on hepatic hemangioma (HH), FNH, and HCA, and provides an overview on clinical presentations, surgical and interventional treatment, as well as conservative management. Treatment options for HHs, if indicated, include liver resection, radiofrequency ablation, and transarterial catheter embolization, and should be carefully weighed against possible complications. FNH is the most frequent benign liver tumor without any risk of malignant transformation, and treatment should only be restricted to symptomatic patients. HCA is associated with the use of oral contraceptives or other steroid medications. Unlike other benign liver tumors, HCA may be complicated by malignant transformation. HCAs have been divided into 6 subtypes based on molecular and pathological features with different risk of complication. KEY MESSAGE: The vast majority of benign liver tumors remain asymptomatic, do not increase in size, and rarely need treatment. Biopsies are usually not needed as accurate diagnosis can be obtained using modern imaging techniques.

Significance of unphosphorylated and phosphorylated heat shock protein 27 as a prognostic biomarker in pancreatic ductal adenocarcinoma.

PURPOSE: Few studies reported about the potential of unphosphorylated heat shock protein 27 (HSP27) and phosphorylated heat shock protein 27 (pHSP27) as a predictor for survival and gemcitabine resistance in pancreatic ductal adenocarcinoma (PDAC). In this study, we analysed the expression patterns of pHSP27 and HSP27 in a patient population after surgery and correlated the immunohistochemical results with clinicopathological data and long-term outcome of the patients. METHODS: HSP27 and pHSP27 (Ser-15, Ser-78 and Ser-82) protein expression were analysed by immunohistochemistry using the immunoreactive score (IRS) from paraffin-embedded tissue of 106 patients with PDAC who underwent surgery. Immunohistochemical results were correlated with clinicopathological data, disease-free (DFS) and overall survival (OS). RESULTS: HSP27 expression was significantly lower in patients with a shorter OS (p = 0.006) and DFS (p < 0.0001). A higher HSP27 expression was associated with a better response to gemcitabine in the resected, non-metastasised patients group (p = 0.001). Furthermore, HSP27 was downregulated in patients suffering from metastases at time of surgery (p < 0.001) and in undifferentiated tumours (p = 0.007). In contrast, pHSP27-Ser15, -Ser78 and -Ser82 were not associated with any survival data of the study population. CONCLUSION: HSP27 seems to be a strong indicator for the prediction of OS and DFS. Moreover, HSP27 could play a role in the formation and migration of liver metastases of PDAC.

Extended liver resection including hypertrophy concept with portal venous embolisation for giant haemangioma. Too much surgery?

Haemangiomas of the liver are benign tumours, which are often diagnosed randomly. With an increase in size haemangiomas could become symptomatic. In this case therapeutic options, surgical or interventional, have to be weighted to a conservative approach. We present a case of a 36-year old woman with a symptomatic giant haemangioma of the right liver lobe. Because of the size of the tumor and the small future liver remnant we decided to perform a major liver resection after hypertrophy induction with a preoperative portal vein embolization; an option mainly used for major hepatectomies in malignant tumors of the liver. But however, this case shows, that using a hypertrophy concept also for benign liver tumours is the safer approach, if an extended resection is necessary and the future liver remnant is critical.

Adenosquamous Carcinoma of the Pancreas Comprise a Heterogeneous Group of Tumors With the Worst Outcome: A Clinicopathological Analysis of 25 Cases Identified in 562 Pancreatic Carcinomas Resected With Curative Intent.

OBJECTIVES: Information of the clinicopathological characteristics and outcome data of patients with adenosquamous carcinoma of the pancreas (ASCAP) remains limited. This study's aim is to describe the clinical, pathological, and molecular characteristics of 25 resected ASCAPs. METHODS: Of all 25 cases, patient characteristics, follow-up data, and pathological/immunohistological features were reviewed and analyzed. RESULTS: In this 3-institutional retrospective analysis of 562 pancreatic cancer patients, we identified 25 cases with histologically confirmed ASCAP (4.4%). Follow-up was available in 21 ASCAP and 50 pancreatic ductal adenocarcinoma control patients with a median overall survival of 8.2 and 21 months, respectively. Age, tumor size, localization in the tail, lymph node status, and resection margin seem to be the most significant factors of survival in our ASCAP cohort. In contrast to pancreatic ductal adenocarcinoma, positive expression of p63, keratins K5/14, and the epidermal growth factor receptor are a robust marker profile of these tumors. CONCLUSIONS: Adenosquamous carcinoma of the pancreas comprises a group of neoplasms in which stage and adverse morphological features contribute to its bad prognosis. Further work must be pursued to improve detection and treatment options to reduce mortality. Specifically, differences in biology might become a target for the development of possible therapies.