Clinical benefit of radiation therapy and metallic stenting for unresectable hilar cholangiocarcinoma

Therapeutic Outcome of Multidisciplinary Treatment in Unresectable Biliary Tract Cancer: A Multicenter Retrospective Analysis

Background

There is little established evidence regarding treatment strategies for unresectable biliary tract cancer (BTC). This study aimed to clarify the situation of multidisciplinary treatment for unresectable BTC in the 2000s when there was no international standard first-line therapy.

Methods

We retrospectively reviewed 315 consecutive patients with unresectable BTC who had been treated at seven tertiary institutions in Kanagawa Prefecture, Japan between 1999 and 2008.

Results

The unresectable factors were as follows: locally advanced, 101 cases (32.1%); hematogenous metastases, 80 cases (25.4%); and peritoneal dissemination, 30 cases (9.5%). Chemotherapy or radiation therapy was administered to 218 patients (69.2%). The best supportive care was provided in 97 cases (30.8%). The most common regimen was gemcitabine monotherapy, followed by gemcitabine combination therapy and S-1 monotherapy. The 1- and 2-year survival rates of all patients were 34.6% and 12.2%, respectively. The median survival time (MST) was 8 months in all patients. The 1-year survival rate was 65%, and the MST was 12 months among the locally advanced patients, whereas patients with peritoneal dissemination had the worst outcome; the 1-year survival rate was 7%, and the MST was 5 months. Among treated 90 cases of perihilar cholangiocarcinoma, patients who received chemoradiotherapy (n = 24) had a significantly better outcome than those who received chemotherapy alone (MST: 20 vs. 11 months, P < 0.001).

Conclusions

Unresectable BTC has heterogeneous treatment outcomes depending on the mode of tumor extension and location. Multidisciplinary treatment seems useful for patients with locally advanced BTC, whereas patients with metastatic disease still have a poor prognosis.

Biliary self-expandable metallic stent combined with iodine-125 seeds in the treatment of malignant biliary obstruction (Bismuth type I or II)

BACKGROUND

The purpose of this research was to evaluate the safety and efficacy of a self-expandable metallic stent (SEMS) combined with iodine-125 (125I) seeds in the treatment of Bismuth type I or II malignant biliary obstruction (MBO).

METHODS

The clinical data of 74 cases of MBO treated with percutaneous SEMS combined with 125I seeds (combination group) and 81 cases of MBO treated with SEMS implantation alone (control group) in our hospital from January 2015 to December 2019 were retrospectively analyzed. The short-term and long-term efficacy of the two groups were compared. Multivariate Cox regression analysis was used to analyze the factors affecting the surgical efficacy and survival rate.

RESULTS

The liver blood test results of both groups improved at one week and one month post-stent insertion. No significant difference was established in the short-term efficacy or complications between the two groups (P = NS). Improved stent patency was observed in the combined group, 9.01 ± 4.38 months versus 6.79 ± 3.13 months, respectively (P < 0.001). Improved survival was also noted in the combined group 12.08 ± 5.38 months and 9.10 ± 4.16 months, respectively (P < 0.001). Univariate and multivariate analyses showed that the type of biliary stent and liver metastasis were independent factors affecting survival.

CONCLUSION

The implementation of SEMS combined with 125I seeds resulted in significantly longer stent patency and survival times than that of SEMS implantation alone, which is thus worthy of clinical promotion and application.

American Radium Society (ARS) Appropriate Use Criteria (AUC) for Extrahepatic Cholangiocarcinoma

Although uncommon, extrahepatic cholangiocarcinoma (EHCC) is a deadly malignancy, and the treatment approaches remain controversial. While surgery remains the only cure, few patients are candidates for resection up front, and there are high rates of both local and distant failure following resection. Herein, we systematically review the available evidence regarding treatment approaches for patients with EHCC, including surgery, radiation, and chemotherapy. The evidence regarding treatment outcomes was assessed using the Population, Intervention, Comparator, Outcome, and Study design (PICOS) framework. A summary of recommendations based on the available literature is outlined for specific clinical scenarios encountered by providers in the clinic to guide the management of these patients.

Endobiliary Radiofrequency Ablation for Malignant Biliary Obstruction over 32-Month Follow-Up

Hilar cholangiocellular carcinoma (CCC) is a malignant neoplasm of epithelial origin occurring at the confluence of the right and left hepatic bile ducts. Typically, these tumors are small, poorly differentiated, exhibit aggressive biologic behavior with non-specific symptoms and tend to obstruct the intrahepatic bile ducts. Surgery is the only available curative option. Unfortunately, in less than half of the patients a complete resection is possible with poor survival rate in unresectable cases. In this report, we present the case of a 58-year-old woman with a history of unresectable hilar cholangiocarcinoma. Initially she was treated with intraductal dilatation of malignancy and placement of a plastic stent and chemotherapy (Gemcitabin® and Platinol®). Two years later she underwent a second-line chemotherapy with Gemcitabin® and Oxyplatin® because of tumor progression. Despite a second line chemotherapy and placement of an uncovered self-expandible metal stent (ucSEMS) that was extended later on by stent-in stent technique, there was tumor progression which led to a complex course with relapsing obstructive cholangiosepsis and cholestasis. Because of tumor ingrowth, endobiliary radiofrequency ablation of the malignant stenosis was performed in repeated sessions. This case illustrates that radiofrequency ablation of solitary malignant biliary obstruction is feasible, safe and allows an improvement of quality of life in non-operable patients.

A systematic review of intraluminal high dose rate brachytherapy in the management of malignant biliary tract obstruction and cholangiocarcinoma

PURPOSE

To conduct a systematic review evaluating the impact of high dose rate (HDR) intraluminal brachytherapy (ILBT) in the management of malignant biliary obstruction and cholangiocarcinoma with specific focus on stent patency, clinical outcomes and toxicities.

METHODS AND MATERIALS

A review of published articles was conducted using Medline, Embase and Cochrane databases using the search terms "bile duct carcinoma" or "cholangiocarcinoma" or "bile duct neoplasms" in combination with "brachytherapy" or "high dose rate brachytherapy" or "HDR brachytherapy". Studies published in English and reporting outcomes of ≥10 patients were included in the review. Only the most recent experience was included if same patients were included in sequential publications.

RESULTS

Seventeen studies were identified that met the inclusion criteria. Significant heterogeneity was observed in treatment regimens, which included use of surgery, external beam radiation (EBRT), and/or intra-arterial and intravenous chemotherapy in conjunction with ILBT. Nevertheless, among the included studies, use of ILBT appeared to result in longer duration of stent patency: 10 months with ILBT compared to 4-6 months without ILBT. A trend was observed towards prolonged local control and improved complete and partial response rates in patients treated with ILBT with or without EBRT. Weighted mean overall survival of patients treated with ILBT alone was 11.8 months compared to 10.5 months for those that received EBRT +/- chemotherapy in addition to ILBT. The included studies reported low complication rates and toxicity related to ILBT.

CONCLUSION

Brachytherapy can be an effective and safe tool in the management of malignant biliary tract obstruction in combination with stenting. Both retrospective and prospective studies have suggested improved outcomes when HDR ILBT is combined with percutaneous stenting.

A Comparative Study of Self-Expandable Metallic Stent Combined with Double 125I Seeds Strands or Single 125I Seeds Strand in the Treatment of Advanced Perihilar Cholangiocarcinoma with Malignant Obstructive Jaundice

Purpose

The purpose of this study was to compare the safety and effectiveness of a self-expandable metallic stent (SEMs) with a novel brachytherapy biliary drainage catheter (BBDC, double ¹²⁵I seeds strands) or a single ¹²⁵I seeds strand in the treatment of advanced perihilar cholangiocarcinoma (pCCA) with malignant obstructive jaundice (MOJ).

Methods

From September 2016 to December 2018, we retrospectively enrolled patients with biliary stent implantation after receiving either BBDC loaded with ¹²⁵I seeds (double-strands irradiation group) or an ¹²⁵I seed strand treatment (single-strand irradiation group, control group). The outcomes were analyzed regarding the relief of obstructive jaundice, and interventional-related complications. Moreover, the Kaplan–Meier method was used to analyze stent patency and survival.

Results

The success rate of interventional therapy in both groups was 100%, and all patients with MOJ were alleviated. According to the Common Terminology Criteria for Adverse Events (CTCAE 4.02), the grade 3 or 4 complications in the BBDC group and in the control group were 6/34 (17.65%) and 7/39 (17.95%), respectively (P > 0.05). The median and mean overall stent patency of the BBDC group and the control group were 207 days versus 180 days, 204.212 days versus 186.278 days (P = 0.043). The median and mean overall survivals in the BBDC group were higher than those in the control group (245 days versus 212 days, 244.883 days versus 221.844 days, P = 0.030).

Conclusion

This interim analysis showed that BBDC (double-stranded irradiation) can prolong the stent patency time compared with ¹²⁵I seed strand treatment (single-stranded irradiation) and had the advantage of reducing jaundice, which seemed to extend the survival period of advanced pCCA.

Chemoradiotherapy for patients with locally advanced or unresectable extra-hepatic biliary cancer

Background

Although surgical resection is the preferred curative-intent treatment option for patients with non-metastatic, extra-hepatic biliary cancer (EBC), radiotherapy (RT) or chemoradiotherapy (CRT) may be utilized in select cases when surgical resection is not feasible. The purpose of this study is to report the efficacy and adverse events (AEs) associated with CRT for patients with locally advanced and unresectable EBC.

Methods

This was a retrospective cohort study of patients with EBC, including extra-hepatic cholangiocarcinoma or gallbladder cancer, deemed inoperable who received RT between 1998 and 2018. The median RT dose was 50.4 Gy in 28 fractions and 94% received concurrent 5-fluorouracil. The Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS) from the start of RT. The cumulative incidence of local progression (LP), locoregional progression (LRP), and distant metastasis (DM) were reported with death as a competing risk. Cox proportional hazards regression models were used to assess for correlation between patient and treatment characteristics and outcomes.

Results

Forty-eight patients were included for analysis. The median OS was 12.0 months [95% confidence interval (CI): 2.3-73.2 months]. The 2-, 3-, and 5-year OS were 33% (95% CI: 22-50%), 20% (95% CI: 11-36%), and 7% (95% CI: 2-20%), respectively. The 2-year PFS, LP, LRP, and DM were 21% (95% CI: 12-36%), 27% (95% CI: 17-44%), 31% (95% CI: 20-48%), and 33% (95% CI: 22-50%), respectively. On univariate analysis, biologically effective dose (BED) >59.5 Gy₁₀ was associated with improved OS [hazard ratio (HR): 0.40, 95% CI: 0.18-0.92, P=0.03] and PFS (HR: 0.37, 95% CI: 0.16-0.84, P=0.02) and primary tumor size (per 1 cm increase) was associated with worsened PFS (HR: 1.29, 95% CI: 1.02-1.63, P=0.04). BED >59.5 Gy₁₀ remained associated with PFS on multivariate analysis (HR: 0.34, 95% CI: 0.15-0.78, P=0.01). Treatment-related grade 3+ acute and late gastrointestinal AEs occurred in 13% and 17% of patients, respectively.

Conclusions

RT is associated with 3- and 5-year survival in a subset of patients with unresectable EBC. Further exploration of the role of RT as part of a multi-modality curative treatment strategy is warranted.

New approaches to diagnostics and treatment of cholangiocellular cancer based on photonics methods

Cholangiocellular cancer (CCC) is an oncological disease of the bile ducts characterized by a high mortality rate. To date, the use of standard methods for the diagnosis and treatment of CCC has not been able to reduce mortality from this disease. This work presents the results of fluorescence diagnostics (FD), which consists in using a modified optical fiber and photodynamic therapy (PDT) using a therapeutic laser instead of a low-intensity laser. This technique was tested on 43 patients in a clinical setting. The results obtained indicate a direct correlation between spectroscopic and video FD methods. Furthermore, a direct correlation was found between the photobleaching of a chlorin e6-based photosensitizer, with the commercial names of Photolon Radachlorin and Photoran and stricture regression. Our findings demonstrate the possibility of using a therapeutic laser with a wavelength of 660 nm for both diagnosis and treatment of bile ducts cancer, which results in a significant reduction of the operation time without decreasing its effectiveness.

Palliative radiotherapy for hepatobiliary obstruction caused by colorectal metastases

Hyperbilirubinemia in the setting of stent-intolerant biliary obstruction is a challenging problem and can prevent cancer patients from pursuing additional treatments such as further systemic therapies. We report a case of a 75-year-old female who underwent treatment with palliative radiotherapy (RT) for relieving persistent biliary obstruction secondary to liver metastases from colorectal disease, despite prior appropriate stent placement. Prior to RT, the patient's total bilirubin was 14.6 mg/dL, and she experienced fatigue, diarrhea, nausea, vomiting, and severe jaundice. After treatment with 37.5 Gy in 15 once daily fractions, total bilirubin decreased to 3.9 mg/dL, with resolution of previous symptoms including jaundice and pruritus. The patient did not experience any significant treatment-related toxicities. This case, along with a succinct literature review, demonstrates that palliative RT can be successful in relieving biliary obstruction unrelieved by biliary stent. Further research is required to evaluate the efficacy of RT in palliating biliary obstruction for liver metastases in a general population.

Biliary self-expandable metallic stent combined with Iodine-125 seeds strand in the treatment of hilar malignant biliary obstruction

Objective

To assess the safety and effectiveness of a self-expandable metallic stent (SEMS) combined with Iodine-125 seeds strand to treat hilar malignant biliary obstruction (MBO).

Methods

This retrospective study included patients who had received SEMS with ¹²⁵I seeds strand (seeds group) or SEMS alone (controls) to treat hilar MBO. Demographic, biochemical, stent patency, overall survival and complications data were extracted and analysed.

Results

A total of 76 patients were included (seeds group, n = 40; controls, n = 36), with a total of 608 seeds deployed in the seeds group (mean, 15.2 ± 4.1 [range, 8–25] seeds per patient). Statistically significant between-group differences were shown in median stent patency time (seeds group, 387.0 ± 27.9 days [95% confidence interval {CI} 332.4, 441.6] versus controls, 121.0 ± 9.1 days [95% CI 103.2, 138.8]) and in median overall survival (seeds group, 177.0 ± 17.9 days [95% CI 141.8, 212.2] versus controls, 123.0 ± 20.4 [95% CI 83.0, 163.0]). There were no statistically significant between-group differences in complication rates.

Conclusion

SEMS combined with ¹²⁵I seeds strand is safe, feasible, and tolerable in treating patients with hilar MBO, and may be effective in prolonging stent patency time and overall survival.

Radiation therapy for extrahepatic bile duct cancer: Current evidences and future perspectives

Extrahepatic bile duct cancer (EBDC) is a rare malignancy that involves neoplastic changes extending from both hepatic ducts to the common bile duct. The treatment of choice is surgical resection, but the predominant pattern of initial treatment failure is locoregional recurrence. Accordingly, adjuvant radiotherapy has been administered after surgical resection based on these rationales. At this time, there is minimal evidence supporting adjuvant radiotherapy, because there have been no phase III trials evaluating its benefit. Relatively small retrospective studies have tried to compare outcomes associated with EBDC treated with or without radiotherapy. We aimed to review studies investigating adjuvant radiotherapy for resected EBDC. Because less than one-third of EBDC cases are amenable to curative resection at diagnosis, other locoregional treatment modalities need to be considered, including radiotherapy. The next aim of this review was to summarize reports of definitive radiotherapy for unresectable EBDC. Patients with advanced EBDC often experience biliary obstruction, which can lead to jaundice and progress to death. Biliary stent insertion is an important palliative procedure, but stents are prone to occlusion after subsequent ingrowth of the EBDC. Radiotherapy can be effective for maintaining the patency of inserted stents. We also reviewed the benefit of palliative radiotherapy combined with the biliary stent insertion. Lastly, we discuss the existing gaps in the evidence supporting radiotherapy in the management of EBDC.

Cholangiocarcinoma and Gallbladder Cases: An Expert Panel Case-Based Discussion

Cholangiocarcinoma and gallbladder malignancies are aggressive gastrointestinal malignancies with management dependent on resectability, comorbidities, and location. A multidisciplinary discussion with medical oncologists, radiation oncologists, and surgeons is necessary to determine the optimal treatment approach for each patient. Surgical resection offers the best chance for a long-term cure. Recent studies, such as the phase II SWOG S0809 and the phase III BILCAP study have highlighted the importance of adjuvant treatment with radiation therapy and chemotherapy, respectively, in resected disease. In patients with unresectable disease chemotherapy and chemoradiation therapy to a high dose can improve overall survival and locoregional control. In this expert panel we have brought together radiation oncologists and a medical oncologist to provide case-based feedback on their institutional practices.

Endoscopic Management of Pancreatobiliary Neoplasms

Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) are the mainstays of interventional endoscopic practice. EUS occupies a central role in the diagnosis of pancreatobiliary neoplasms and offers a platform for a wide range of direct tumor therapies. Initial steps have demonstrated the feasibility of such applications in animal models and pilot studies. Larger clinical trials and incorporation of EUS-based therapies into cooperative cancer studies might demonstrate an impact in the clinical prognosis of patients with pancreatic cancer. ERCP plays an important role in elucidating indeterminate biliary strictures and in treating patients with malignant biliary obstruction who are symptomatic or have borderline-resectable or unresectable disease. ERCP-directed ablative therapies enable neoadjuvant and palliative intervention in patients with malignant biliary obstruction, in particular perihilar cholangiocarcinoma. Additional comparative, multicenter studies are needed to better understand the safety and efficacy of endobiliary brachytherapy, photodynamic therapy, and radiofrequency ablation in patients with pancreatobiliary malignancies.

Diagnosis and Management of Intrahepatic and Extrahepatic Cholangiocarcinoma

Cholangiocarcinomas (CC) are rare tumors which usually present late and are often difficult to diagnose and treat. CCs are categorized as intrahepatic, hilar, or extrahepatic. Epidemiologic studies suggest that the incidence of intrahepatic CCs may be increasing worldwide. In this chapter, we review the risk factors, clinical presentation, and management of cholangiocarcinoma.

High dose chemoradiation for unresectable hilar cholangiocarcinomas using intensity modulated external beam radiotherapy: a single tertiary care centre experience

BACKGROUND

We present results of patients diagnosed with unresectable hilar cholangiocarcinomas treated with high dose radiotherapy and concurrent chemotherapy.

METHODS

From Aug 2005 to Dec 2012, 68 consecutive patients were treated. Fifty patients (group 1) presenting to us with obstructive jaundice were planned for endobiliary brachytherapy (EBBT 14 Gy) followed external beam radiotherapy (EBRT 45 Gy). Twenty-two patients (group 2) who had previously undergone biliary drainage underwent EBRT (57 Gy). All patients received injection Gemcitabine 300 mg/m²/weekly along with EBRT.

RESULTS

Twenty-nine patients in group 1 and 22 patients in group 2 completed the treatment. Twenty-six (55%) patients achieved complete radiological response, 16 (64%) belonging to group 1 and 8 (44%) of group 2 (P=0.05). The median overall survival (MOS) was 17.5 and 16 months for group 1 and 2 respectively (P=0.07). The 1- and 2-year survival was 63%, and 18% for group I and 61% and 22% for group II respectively. The MOS was 5 months and 1 year survival was 14% for patients receiving EBBT only. MOS was significantly better after complete response (P=0.001).

CONCLUSIONS

Intensity modulated radiotherapy (IMRT) modulated high dose radiotherapy used either alone or with brachytherapy demonstrates potential to prolonged overall survival in unresectable hilar cholangiocarcinomas.

Percutaneous biliary stenting combined with radiotherapy as a treatment for unresectable hilar cholangiocarcinoma

Hilar cholangiocarcinoma is often unresectable at the time of the initial diagnosis, and the provision of a definite palliative benefit is important in patients with unresectable hilar cholangiocarcinoma. The aim of the present study was to evaluate the safety of percutaneous biliary stenting and to analyze whether percutaneous biliary stenting combined with radiotherapy (RT) prolonged the stent patency and survival time of patients. In total, the cases of 38 patients with unresectable hilar cholangiocarcinoma that underwent percutaneous biliary stenting at the Navy General Hospital were retrospectively reviewed in the present study. Uncovered metallic stenting (UMS) combined with RT was administered to 25 patients, and UMS alone was administered to 13 patients. The records of early complications subsequent to percutaneous biliary stenting were collected, and the stent patency and survival times of patients were analyzed and compared between the two groups. The technical success rate of the procedure was 100% and the successful drainage rate was 86.8%. The overall early complication rate was 15.8% and the procedure-associated mortality rate was 2.6%. The median stent patency was 326 days in the UMS+RT group and 196 days in the UMS group (P=0.022). The UMS+RT group (median, 367 days) demonstrated a longer survival time compared with the UMS group (median, 267 days; P=0.025). Percutaneous biliary stenting offers a safe and effective method for the palliative treatment of patients with unresectable hilar cholangiocarcinoma, and percutaneous biliary stenting combined with RT may prolong stent patency and patient survival time.

Cell-SELEX based selection and optimization of DNA aptamers for specific recognition of human cholangiocarcinoma QBC-939 cells

Cholangiocarcinoma (CCA) is a very aggressive biliary tract malignancy with no efficient early diagnosis and therapeutics available, so there is a call for effective molecular probes. Herein, we performed cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX) to obtain aptamers for the specific recognition of human cholangiocarcinoma QBC-939 cells. By coordinating sequence homology analysis and secondary structure analysis, we successfully obtained two aptamers with dissociation constants (Kd) in the low nanomolar range. A 23 nt truncated sequence was identified after further analysis on the secondary structure. More importantly, because hepatocellular carcinoma SMMC-7721 cells were employed as the control in the counter selection, the obtained aptamers demonstrated excellent specificity to the target cells, and no binding to several other hepatocellular carcinoma cell lines was observed. Moreover, the aptamers were initially found to recognize membrane proteins, giving them great potential in the field of biomarker discovery. These newly generated aptamers may play a key role in the early diagnosis and clinical treatment of CCA.

Advances in endoscopic retrograde cholangiopancreatography for the treatment of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a malignancy of the bile ducts that carries high morbidity and mortality. Patients with CCA typically present with obstructive jaundice, and associated complications of CCA include cholangitis and biliary sepsis. Endoscopic retrograde cholangiopancreatography (ERCP) is a valuable treatment modality for patients with CCA, as it enables internal drainage of blocked bile ducts and hepatic segments by using plastic or metal stents. While there remains debate as to if bilateral (or multi-segmental) hepatic drainage is required and/or superior to unilateral drainage, the underlying tenant of draining any persistently opacified bile ducts is paramount to good ERCP practice and good clinical outcomes. Endoscopic therapy for malignant biliary strictures from CCA has advanced to include ablative therapies via ERCP-directed photodynamic therapy (PDT) or radiofrequency ablation (RFA). While ERCP techniques cannot cure CCA, advancements in the field of ERCP have enabled us to improve upon the quality of life of patients with inoperable and incurable disease. ERCP-directed PDT has been used in lieu of brachytherapy to provide neoadjuvant local tumor control in patients with CCA who are awaiting liver transplantation. Lastly, mounting evidence suggests that palliative ERCP-directed PDT, and probably ERCP-directed RFA as well, offer a survival advantage to patients with this difficult-to-treat malignancy.

Biliary stenting for unresectable cholangiocarcinoma: A population-based study of long-term outcomes and hospital costs in Taiwan

Few studies have compared percutaneous biliary stenting (PBS) and endoscopic biliary stenting (EBS) in terms of long-term effects on cholangiocarcinoma (CC), and few have systematically evaluated outcome associations in Taiwan. This study aimed to compare long-term outcomes between two treatments for unresectable CC: PBS and EBS. After propensity score matching (PSM) to reduce the effect of selection bias, 1002 CC patients were included in this analysis: 501 in the PBS group and 501 in the EBS group. The Kaplan-Meier method was used to construct the survival curve for all CC patients, and the Cox proportional hazards model was used for multivariate assessment of outcome predictors. After PSM, group comparisons revealed a significantly longer length of stay in the PBS group compared to the EBS group (25 days vs. 19 days, respectively; p < 0.001). Hospital costs were also significantly higher in the PBS group than in the EBS group (US$126,575 vs. US$89,326, respectively; p < 0.001). The median survival time was 3.7 months in all CC patients, 3.5 months in the PBS group, and 4.0 months in the EBS group. The 1-year, 3-year, and 5-year survival rates were 17.6%, 6.1%, and 3.2% in all CC patients; 16.6%, 4.8%, and 3.2% in the PBS group; and 18.6%, 7.27%, and 3% in the EBS group, respectively. The most important predictor of survival is extrahepatic CC. Medical professionals and healthcare providers should carefully consider the use of EBS for initial treatment of obstructive jaundice in patients with unresectable CC.

Use of stents in treatment of malignant biliary obstruction

Stents are now recognized as the first choice of palliative therapy for malignant biliary obstruction. Since stents can effectively relieve obstruction, reduce jaundice, and improve the quality of life, their usage in inoperable biliary tract cancer patients has broad prospects. This paper reviews the use of stents in the treatment of malignant biliary obstruction with regards to stent type, selection, placement and the combination of stenting with other means of treatment.

Polymeric photosensitizer-embedded self-expanding metal stent for repeatable endoscopic photodynamic therapy of cholangiocarcinoma

Photodynamic therapy (PDT) is a new therapeutic approach for the palliative treatment of malignant bile duct obstruction. In this study, we designed photosensitizer-embedded self-expanding nonvascular metal stent (PDT-stent) which allows repeatable photodynamic treatment of cholangiocarcinoma without systemic injection of photosensitizer. Polymeric photosensitizer (pullulan acetate-conjugated pheophorbide A; PPA) was incorporated in self-expanding nonvascular metal stent. Residence of PPA in the stent was estimated in buffer solution and subcutaneous implantation on mouse. Photodynamic activity of PDT-stent was evaluated through laserexposure on stent-layered tumor cell lines, HCT-116 tumor-xenograft mouse models and endoscopic intervention of PDT-stent on bile duct of mini pigs. Photo-fluorescence imaging of the PDT-stent demonstrated homogeneous embedding of polymeric Pheo-A (PPA) on stent membrane. PDT-stent sustained its photodynamic activities at least for 2 month. And which implies repeatable endoscopic PDT is possible after stent emplacement. The PDT-stent after light exposure successfully generated cytotoxic singlet oxygen in the surrounding tissues, inducing apoptotic degradation of tumor cells and regression of xenograft tumors on mouse models. Endoscopic biliary in-stent photodynamic treatments on minipigs also suggested the potential efficacy of PDT-stent on cholangiocarcinoma. In vivo and in vitro studies revealed our PDT-stent, allows repeatable endoscopic biliary PDT, has the potential for the combination therapy (stent plus PDT) of cholangiocarcinoma.

Defensive mechanism in cholangiocarcinoma cells against oxidative stress induced by chlorin e6-based photodynamic therapy

In this study, the effect of chlorin e6-based photodynamic therapy (Ce6-PDT) was investigated in human intrahepatic (HuCC-T1) and extrahepatic (SNU1196) cholangiocarcinoma (CCA) cells. The amount of intracellular Ce6 increased with increasing Ce6 concentration administered, or with incubation time, in both cell lines. The ability to take up Ce6 and generate reactive oxygen species after irradiation at 1.0 J/cm² did not significantly differ between the two CCA cell types. However, after irradiation, marked differences were observed for photodamage and apoptotic/necrotic signals. HuCC-T1 cells are more sensitive to Ce6-PDT than SNU1196 cells. Total glutathione (GSH) levels, glutathione peroxidase and glutathione reductase activities in SNU1196 cells were significantly higher than in HuCC-T1 cells. With inhibition of enzyme activity or addition of GSH, the phototoxic effect could be controlled in CCA cells. The intracellular level of GSH is the most important determining factor in the curative action of Ce6-PDT against tumor cells.

Palliation: Hilar cholangiocarcinoma

Hilar cholangiocarcinomas are common tumors of the bile duct that are often unresectable at presentation. Palliation, therefore, remains the goal in the majority of these patients. Palliative treatment is particularly indicated in the presence of cholangitis and pruritus but is often also offered for high-grade jaundice and abdominal pain. Endoscopic drainage by placing stents at endoscopic retrograde cholangio-pancreatography (ERCP) is usually the preferred modality of palliation. However, for advanced disease, percutaneous stenting has been shown to be superior to endoscopic stenting. Endosonography-guided biliary drainage is emerging as an alternative technique, particularly when ERCP is not possible or fails. Metal stents are usually preferred over plastic stents, both for ERCP and for percutaneous biliary drainage. There is no consensus as to whether it is necessary to place multiple stents within advanced hilar blocks or whether unilateral stenting would suffice. However, recent data have suggested that, contrary to previous belief, it is useful to drain more than 50% of the liver volume for favorable long-term results. In the presence of cholangitis, it is beneficial to drain all of the obstructed biliary segments. Surgical bypass plays a limited role in palliation and is offered primarily as a segment III bypass if, during a laparotomy for resection, the tumor is found to be unresectable. Photodynamic therapy and, more recently, radiofrequency ablation have been used as adjuvant therapies to improve the results of biliary stenting. The exact technique to be used for palliation is guided by the extent of the biliary involvement (Bismuth class) and the availability of local expertise.

Association between cellular radiosensitivity and G1/G2 checkpoint proficiencies in human cholangiocarcinoma cell lines

Cholangiocarcinoma is a destructive malignancy with a poor prognosis and lack of effective medical treatment. Radiotherapy is an alternative treatment for patients with unresectable cholangiocarcinoma. However, there are limited data on the radiation responsiveness of individual cholangiocarcinoma cells, which is a key factor that influences radiation treatment outcome. In this study, we found that cholangiocarcinoma cell lines differ remarkably in their radiosensitivity. The variation of radiosensitivity of cholangiocarcinoma cells correlates with their p53 status and existing G1 and/or G2 checkpoint defects. We also demonstrated the potential of checkpoint kinase Chk1/2 inhibition on the enhancement of the radiosensitivity of cholangiocarcinoma cells. Thus, this study provides useful information for predicting radiation response and provides evidence for the enchantment of radiotherapeutic efficiency by targeting checkpoint kinase Chk1/2 in some subpopulations of cholangiocarcinoma patients.

Photodynamic therapy provides local control of cholangiocarcinoma in patients awaiting liver transplantation

Many transplant centers use endoscopically directed brachytherapy to provide locoregional control in patients with otherwise incurable cholangiocarcinoma (CCA) who are awaiting liver transplantation (LT). The use of endoscopic retrograde cholangiopancreatography (ERCP)-directed photodynamic therapy (PDT) as an alternative to brachytherapy for providing locoregional control in this patient population has not been studied. The aim of this study was to report on our initial experience using ERCP-directed PDT to provide local control in patients with unresectable CCA who were awaiting LT. Patients with unresectable CCA who underwent protocol-driven neoadjuvant chemoradiation and ERCP-directed PDT with the intent of undergoing LT were reviewed. Four patients with confirmed or suspected CCA met the inclusion criteria for protocol LT. All four patients (100%) successfully underwent ERCP-directed PDT. All patients had chemoradiation dose delays, and two patients had recurrent cholangitis despite PDT. None of these patients had progressive locoregional disease or distant metastasis following PDT. All four patients (100%) underwent LT. Intention-to-treat disease-free survival was 75% at mean follow-up of 28.1 months. In summary, ERCP-directed PDT is a reasonably well tolerated and safe procedure that may have benefit by maintaining locoregional tumor control in patients with CCA who are awaiting LT.