Radical surgery: vascular and pancreatic resection for cholangiocarcinoma

Transgelin-2, a novel cancer stem cell-related biomarker, is a diagnostic and therapeutic target for biliary tract cancer

BACKGROUND

Biliary tract cancer (BTC) is a relatively rare but aggressive gastrointestinal cancer with a high mortality rate. Cancer stem cell (CSC) populations play crucial roles in tumor biology and are responsible for the low response to anti-cancer treatment and the high recurrence rate. This study investigated the role of Transgelin-2 (TAGLN2), overexpressed in CSC in BTC cells, and analyzed its expression in patient tissues and serum to identify potential new targets for BTC.

METHODS

TAGLN2 expression was suppressed by small-interfering or short hairpin RNAs, and its effects on tumor biology were assessed in several BTC cell lines. Furthermore, the effects of TAGLN2 silencing on gemcitabine-resistant BTC cells, differentially expressed genes, proteins, and sensitivity to therapeutics or radiation were assessed. TAGLN2 expression was also assessed using western blotting and immunohistochemistry in samples obtained from patients with BTC to validate its clinical application.

RESULTS

Suppression of TAGLN2 in BTC cell lines decreased cell proliferation, migration, invasion, and tumor size, in addition to a reduction in CSC features, including clonogenicity, radioresistance, and chemoresistance. TAGLN2 was highly expressed in BTC tissues, especially in cancer-associated fibroblasts in the stroma. Patients with a low stromal immunohistochemical index had prolonged disease-free survival compared to those with a high stromal immunohistochemical index (11.5 vs. 7.4 months, P = 0.013). TAGLN2 expression was higher in the plasma of patients with BTC than that in those with benign diseases. TAGLN2 had a higher area under the curve (0.901) than CA19-9, a validated tumor biomarker (0.799; P < 0.001).

CONCLUSION

TAGLN2 plays a critical role in promoting BTC cell growth and motility and is involved in regulating BTC stemness. Silencing TAGLN2 expression enhanced cell sensitivity to radiation and chemotherapeutic drugs. The expression of TAGLN2 in patient tissue and plasma suggests its potential to serve as a secretory biomarker for BTC. Overall, targeting TAGLN2 could be an appropriate therapeutic strategy against advanced cancer following chemotherapy failure.

New method for the assessment of perineural invasion from perihilar cholangiocarcinoma

PURPOSE

Perineural invasion (PN) is often found in perihilar cholangiocarcinoma. New procedure was developed to assess PN around the right hepatic artery (RHA) using dual-energy computed tomography (DECT).

METHODS

Thirty patients with perihilar cholangiocarcinoma who underwent DECT before biliary drainage were retrospectively reviewed. Mask images, i.e., the periarterial layer (PAL) around the RHA and superior mesenteric artery (SMA), were made from late arterial phase DECT. The mean CT number of the PAL was measured.

RESULTS

Twenty patients with PN around the RHA were classified into the PN (+) group. The remaining 10 patients without PN and other 26 patients with other diseases that are never accompanied with PN were classified into the PN (-) group. The PAL ratio (the CT number of the PAL around the RHA relative to that around the SMA) was calculated. Both the mean CT number of the PAL around the RHA and the PAL ratio were significantly higher in the PN (+) group than in the PN (-) group. According to an ROC analysis, the predictive ability of the PAL ratio was superior. Using the cutoff value of the PAL ratio 1.009, a diagnosis of PN around the RHA was made with approximately 75% accuracy.

CONCLUSIONS

Assessment with CT number of the PAL reconstructed from DECT images is an easy and objective method to diagnose PN.

Outcome and complications of combined liver and pancreas resections: a retrospective analysis

BACKGROUND

Combined resections of the liver and pancreas are related to high complication and mortality rates. The present study assessed the outcome of these procedures and identified specific risk factors for morbidity and mortality.

METHODS

Between January 2001 and April 2012, 28 combined liver/pancreas resections were performed at our institution. All patients were retrospectively analysed using a database with regards to baseline characteristics, surgical procedures, complications and survival.

RESULTS

Among the pancreatic resections, there were 12 (42.9%) Kausch-Whipple (KW), 9 (32.1%) pylorus-preserving pancreaticoduodenectomy (PPPD), 6 (21.4%) distal pancreatectomies (DP) and 1 (3.6%) total pancreaticoduodenectomy (TPD). In 12 (48.9%) cases, major complications (grade IIIb-V) were observed. Overall survival was 35 months (SD = 40.5) and the 3-year survival rate was 35.7% (1-year survival rate: 50%).

DISCUSSION

Combined resections of the liver and pancreas are associated with high complication rates, especially if major liver resections are performed. Therefore, it is mandatory to do a thorough evaluation of potential patients.

Vascular Reconstruction in Hepatic Malignancy

With surgery for hepatic malignancy, there are poor options for chemotherapy; many patients are deemed unresectable because of vascular involvement or location of tumors. Over the past few decades, advances in surgical technique have allowed resection of these tumors with vascular reconstruction to achieve negative margins and improve chances for survival. This article reviews those reconstruction techniques and outcomes in detail, including in situ perfusion and ex vivo liver surgery, and provides a discussion of implications and operative planning for patients with hepatic malignancy in order to provide surgeons with better understanding of these complicated operations.

Extra-Hepatic Bile Duct Resection: an Insight in the Management of Gallbladder Cancer

BACKGROUND

Involvement of extrahepatic bile duct in gallbladder cancer (GBC) is considered a sign of advanced disease; resection of extrahepatic bile duct in GBC has been a contentious issue considering the poor prognosis of the disease.

METHODS

This retrospective study was done in two tertiary teaching hospitals of North India. The case records of all the GBC patients who underwent radical cholecystectomy with extra-hepatic bile duct resection were reviewed. Details concerning the clinical presentation, preoperative therapy, operative procedure, indication of bile duct resection, postoperative complications and outcome were retrieved from the case records. Kaplan-Meier analysis was done to estimate median disease-free survival and overall survival.

RESULTS

There were 17 GBC patients who underwent radical cholecystectomy with resection of extrahepatic bile duct. Median age of the patients was 51 years (range 35-62); male to female ratio was 5:12. Six patients were diagnosed after histopathological examination of resected gallbladder specimen following cholecystectomy (incidental gallbladder cancer). All the patients had R'0' resection. The indication for extra-hepatic bile duct resection was direct infiltration of hepatoduodenal ligament in nine, positive cystic duct margin in two, densely adherent pericholedochal lymphnodes in one and associated ampullary growth in one patient. Kaplan-Meier analysis predicted median disease-free survival of 20 months and median overall survival of 26 months.

CONCLUSION

Extrahepatic bile duct resection to achieve R'0' resection in the management of advanced gallbladder cancer is safe with acceptable postoperative morbidity and has potential to improve survival.

Evolving role of vascular resection and reconstruction in hepatic surgery for malignancy

Primary and secondary hepatic malignancies, including hepatocellular cancer, cholangiocarcinoma and metastatic disease from colorectal cancer continue to increase in incidence worldwide, and remain diseases with a high mortality. Liver resection, with negative margins, is associated with improved survival and better quality of life over nonoperative treatment. As liver resection continues to evolve, aggressive centers are increasingly using vascular resection and reconstruction to achieve negative margins and improve outcomes. As these resections become more common, the morbidity and mortality associated with these complex surgical procedures is decreasing. Currently, resections of the portal vein are becoming routine in major liver and pancreatic resections, and experience with hepatic artery, hepatic vein and inferior vena cava resections is increasing. This review paper looks at the current indications, techniques and outcomes for major vascular resection in hepatic malignancy.

Decorin-mediated inhibition of cholangiocarcinoma cell growth and migration and promotion of apoptosis are associated with E-cadherin in vitro

Emerging evidences have shown that decorin expression is significantly reduced in many cancer tissues and cancer cells. However, its biological role and clinical significance in cholangiocarcinoma development and progression are unknown. In this study, immunohistochemistry was conducted to investigate the expression of decorin in cholangiocarcinomas. The results showed that decorin levels markedly decreased in 44 cholangiocarcinoma tissues compared to 40 adjacent normal tissues. The analysis between decorin expression and clinicopathological characteristics in cholangiocarcinoma patients showed that patients with low levels of decorin expression had a relatively poor prognosis. Moreover, recombinant human decorin treatment and overexpression of decorin in cholangiocarcinoma cells could inhibit cell proliferation, migration, and invasion and promote apoptosis. Furthermore, the E-cadherin expression significantly increased after decorin overexpression or use of recombinant human decorin in cholangiocarcinoma cells. Our findings indicated that downregulation of decorin may be identified as a poor prognostic biomarker in cholangiocarcinomas. Also, decorin-mediated inhibition of cholangiocarcinoma cell growth, migration, and invasion and promotion of cell apoptosis might be through regulation of the expression of E-cadherin in vitro.

Recent advances in cancer stem cell research for cholangiocarcinoma

Cancer stem cells have been identified as cells with the capacity to self-renew and differentiate into multiple lineages of human malignancies. Cholangiocarcinoma is one of the most difficult intra-abdominal malignancies that can be treated using a surgical approach. Chemotherapy in addition to surgery is necessary to improve patient survival. However, its clinical benefit is limited, and, to date, no other effective anticancer drug is available for this disease. Several reports have shown the existence of cholangiocarcinoma stem cells. Cell surface antigens such as CD133, CD24, EpCAM, CD44, and others have been used to isolate cholangiocarcinoma stem cells. In general, enhanced expression of these markers in resected specimens of cholangiocarcinoma was associated with malignant potential. Distinct and specific pathways are expected to be present in cancer stem cells compared to other cancer cells that have no stem cell properties. To date, reports showing possible signaling pathways in cholangiocarcinoma stem cells are limited. More research is anticipated. Targeting therapies for surface molecular markers or specific signaling pathways of cholangiocarcinoma stem cells may be important in order to change the clinical outcome of patients with this disease. However, no clinical trial has been performed so far. This review will focus on the markers and signaling pathways used to define cholangiocarcinoma stem cells. A novel therapeutic approach of targeting cholangiocarcinoma stem cells will also be discussed.