Endoscopic application of photodynamic therapy for cholangiocarcinoma

Promising Highly Targeted Therapies for Cholangiocarcinoma: A Review and Future Perspectives

To overcome the poor prognosis of cholangiocarcinoma (CCA), highly targeted therapies, such as antibody-drug conjugates (ADCs), photodynamic therapy (PDT) with/without systemic chemotherapy, and experimental photoimmunotherapy (PIT), have been developed. Three preclinical trials have investigated the use of ADCs targeting specific antigens, namely HER2, MUC1, and glypican-1 (GPC1), for CCA. Trastuzumab emtansine demonstrated higher antiproliferative activity in CCA cells expressing higher levels of HER2. Similarly, "staphylococcal enterotoxin A-MUC1 antibody" and "anti-GPC1 antibody-monomethyl auristatin F" conjugates showed anticancer activity. PDT is effective in areas where appropriate photosensitizers and light coexist. Its mechanism involves photosensitizer excitation and subsequent reactive oxygen species production in cancer cells upon irradiation. Hematoporphyrin derivatives, temoporfin, phthalocyanine-4, talaporfin, and chlorine e6 derivatives have mainly been used clinically and preclinically in bile duct cancer. Currently, new forms of photosensitizers with nanotechnology and novel irradiation catheters are being developed. PIT is the most novel anti-cancer therapy developed in 2011 that selectively kills targeted cancer cells using a unique photosensitizer called "IR700" conjugated with an antibody specific for cancer cells. PIT is currently in the early stages of development for identifying appropriate CCA cell targets and irradiation devices. Future human and artificial intelligence collaboration has potential for overcoming challenges related to identifying universal CCA cell targets. This could pave the way for highly targeted therapies for CCA, such as ADC, PDT, and PIT.

Aggregation-induced emission photosensitizer-based photodynamic therapy in cancer: from chemical to clinical

Cancer remains a serious threat to human health owing to the lack of effective treatments. Photodynamic therapy (PDT) has emerged as a promising non-invasive cancer treatment that consists of three main elements: photosensitizers (PSs), light and oxygen. However, some traditional PSs are prone to aggregation-caused quenching (ACQ), leading to reduced reactive oxygen species (ROS) generation capacity. Aggregation-induced emission (AIE)-PSs, due to their distorted structure, suppress the strong molecular interactions, making them more photosensitive in the aggregated state instead. Activated by light, they can efficiently produce ROS and induce cell death. PS is one of the core factors of efficient PDT, so proceeding from the design and preparation of AIE-PSs, including how to manipulate the electron donor (D) and receptor (A) in the PSs configuration, introduce heavy atoms or metal complexes, design of Type I AIE-PSs, polymerization-enhanced photosensitization and nano-engineering approaches. Then, the preclinical experiments of AIE-PSs in treating different types of tumors, such as ovarian cancer, cervical cancer, lung cancer, breast cancer, and its great potential clinical applications are discussed. In addition, some perspectives on the further development of AIE-PSs are presented. This review hopes to stimulate the interest of researchers in different fields such as chemistry, materials science, biology, and medicine, and promote the clinical translation of AIE-PSs.

Benefits and safety of photodynamic therapy in patients with hilar cholangiocarcinoma: A meta-analysis

BACKGROUND

Photodynamic therapy (PDT) is a therapy evaluated for the treatment of cancers resistant to standard oncological treatments. PDT might be beneficial for the palliation of hilar cholangiocarcinoma.

AIM

To evaluate the efficacy and safety of PDT for treating hilar cholangiocarcinoma.

METHODS

PubMed, Embase, the Cochrane Library, and Web of Science were searched for articles published up to May 2021. The patients were grouped as PDT+stent vs. stent alone. The outcomes were survival, quality of life, and adverse events (AEs). Data were summarized using hazard ratios (HRs), odds ratios (ORs), and 95% confidence intervals (CIs).

RESULTS

Six studies were included in this meta-analysis. There were 235 and 211 patients in the PDT+stent and stent groups, respectively. The 1-year survival rate of the PDT+stent group was 0.56, and that of the control group was 0.25. The 2-year survival rate of the PDT+stent group was 0.16, and that of the control group was 0.07. PDT significantly prolonged overall survival compared to the controls (P = 0.002). No differences were detected in the occurrence of cholangitis (P = 0.996) and all other AEs (early complications, stent malfunction, total AEs, acute pancreatitis, liver abscess, and biliary hemorrhage) between the two groups.

CONCLUSION

PDT in patients with hilar cholangiocarcinoma could improve survival without additional AEs. Large-scale randomized controlled trials are needed to confirm the findings.

Recent Advances in Photodynamic Imaging and Therapy in Hepatobiliary Malignancies: Clinical and Experimental Aspects

The therapeutic and diagnostic modalities of light are well known, and derivative photodynamic reactions with photosensitizers (PSs), specific wavelengths of light exposure and the existence of tissue oxygen have been developed since the 20th century. Photodynamic therapy (PDT) is an effective local treatment for cancer-specific laser ablation in malignancies of some organs, including the bile duct. Although curability for extrahepatic cholangiocarcinoma is expected with surgery alone, patients with unresectable or remnant biliary cancer need other effective palliative therapies, including PDT. The effectiveness of PDT for cholangiocarcinoma has been reported experimentally or clinically, but it is not the standard option now due to problems with accompanied photosensitivity, limited access routes of irradiation, tumor hypoxia, etc. Novel derivative treatments such as photoimmunotherapy have not been applied in the field hepatobiliary system. Photodynamic diagnosis (PDD) has been more widely applied in the clinical diagnoses of liver malignancies or liver vascularization. At present, 5-aminolevulinic acid (ALA) and indocyanine green (ICG) dyes are mainly used as PSs in PDD, and ICG has been applied for detecting liver malignancies or vascularization. However, no ideal tools for combining both PDD and PDT for solid tumors, including hepatobiliary malignancies, have been clinically developed. To proceed with experimental and clinical trials, it is necessary to clarify the effective photosensitive drugs that are feasible for photochemical diagnosis and local treatment.

Controlling trapping states on selective theranostic core@shell (NaYF4:Yb,Tm@TiO2-ZrO2) nanocomplexes for enhanced NIR-activated photodynamic therapy against breast cancer cells

Photodynamic and immune therapies are innovative medical strategies against cancer, and their integration with upconversion nanoparticles (UCNPs) can improve the diagnosis and treatment of the disease. The UCNPs convert the deep penetrating near-infrared (NIR) light into higher energy emissions, allowing the imaging and detection of malignant cells and the simultaneous energy transfer for activation of the photosensitizers. In this work, the UCNPs were coated with a photocatalytic TiO₂/ZrO₂ shell and an increase of oxygen defects (V_O) was observed as a result of the partial substitution of Ti⁴⁺ by Zr⁴⁺ ions in the crystalline lattice of TiO₂. Such defects act as trapping states improving charge separation and then reducing the recombination rate of the electron-hole pairs (e^-/h⁺) generated upon resonant energy transfer from the donor (UCNPs) to acceptors (shell). The overall results are the enhancement of both ROS production and the emission band centered at 801 nm which is useful for tracking cells at the deep tissue level. However, an excess of those defects produces deleterious effects on both processes as a result of charge migration. The specificity against HER2 positive breast cancer was provided by bioconjugation with the monoclonal antibody trastuzumab. After administration of the synthesized NaYF₄:Yb,Tm@TiO₂/ZrO₂-trastuzumab theranostic nanocomplex doped with an optimal ZrO₂ molar concentration (25%) and subsequent exposure to 975 nm light (0.71 W cm^-2) during 5 minutes, HER2-positive SKBr3 breast cancer cells were suppressed with 88% drop of the cell viability, 28% higher than UCNPs decorated with a pure TiO₂ shell.

Success of photodynamic therapy in palliating patients with nonresectable cholangiocarcinoma: A systematic review and meta-analysis

AIM

To perform a systematic review and meta-analysis on clinical outcomes of photodynamic therapy (PDT) in non-resectable cholangiocarcinoma.

METHODS

Included studies compared outcomes with photodynamic therapy and biliary stenting (PDT group) vs biliary stenting only (BS group) in palliation of non-resectable cholangiocarcinoma. Articles were searched in MEDLINE, PubMed, and EMBASE. Pooled proportions were calculated using fixed and random effects model. Heterogeneity among studies was assessed using the I2 statistic.

RESULTS

Ten studies (n = 402) that met inclusion criteria were included in this analysis. The P for χ2 heterogeneity for all the pooled accuracy estimates was > 0.10. Pooled odds ratio for successful biliary drainage (decrease in bilirubin level > 50% within 7days after stenting) in PDT vs BS group was 4.39 (95%CI: 2.35-8.19). Survival period in PDT and BS groups were 413.04 d (95%CI: 349.54-476.54) and 183.41 (95%CI: 136.81-230.02) respectively. The change in Karnofsky performance scores after intervention in PDT and BS groups were +6.99 (95%CI: 4.15-9.82) and -3.93 (95%CI: -8.63-0.77) respectively. Odds ratio for post-intervention cholangitis in PDT vs BS group was 0.57 (95%CI: 0.35-0.94). In PDT group, 10.51% (95%CI: 6.94-14.72) had photosensitivity reactions that were self-limiting. Subgroup analysis of prospective studies showed similar results, except the incidence of cholangitis was comparable in both groups.

CONCLUSION

In palliation of unresectable cholangiocarcinoma, PDT seems to be significantly superior to BS alone. PDT should be used as an adjunct to biliary stenting in these patients.

Endoscopic radiofrequency ablation for malignant biliary strictures

Endoscopic radiofrequency ablation (RFA) is a novel palliation therapy for malignant biliary stricture; however, its feasibility and safety has not yet been clearly defined. The aim of the present study was to evaluate the feasibility and safety of endoscopic RFA for the treatment of malignant biliary strictures. A total of 12 patients treated by endoscopic RFA between December 2011 and October 2013 were retrospectively analyzed. Adverse events within 30 days post-intervention, stricture diameters prior to and following RFA, stent patency and survival time were investigated. A total of 12 patients underwent 20 RFA procedures as a treatment for malignant biliary strictures. Two patients required repeated elective RFA (4 and 6 times, respectively). All 20 RFA procedures were successfully performed without technical problems. During a 30 day period following each RFA procedure, two patients experienced fever (38.2 and 38.9°C, respectively) and another patient exhibited post-endoscopic retrograde cholangiopancreatography pancreatitis. The 30- and 90-day mortality rates were 0 and 8.3%, respectively. Mean stricture diameter prior to RFA was 5.3 mm (standard deviation (SD), 0.9 mm; range, 5-8 mm), and the mean diameter following RFA was 12.6 mm (SD, 3.1 mm; range, 8-15 mm). There was a significant increase of 7.3 mm in the bile duct diameter following RFA in comparison with prior to RFA (t=8.6; P≤0.001). Of the 11 patients with stents inserted following RFA, the median stent patency was 125.0 days [95% confidence interval (CI), 94.7-155.3 days]. Extrapolated median survival following the first RFA was 232 days (95% CI, 94.3-369.7 days). In conclusion, RFA appears to be an efficient and safe treatment strategy for the palliation of unresectable malignant biliary strictures.

Efficacy and safety of photodynamic therapy for unresectable cholangiocarcinoma: A meta-analysis

BACKGROUND

Photodynamic therapy with the placement of a biliary stent may improve the prognosis in patients with unresectable cholangiocarcinoma. The aim of this research is to determine the hazard ratio of photodynamic therapy with stent compared to biliary stenting alone or other therapies for the treatment of cholangiocarcinoma.

METHODS

Several databases were searched from inception to December 31 2013 for trials comparing photodynamic therapy+stent vs. stent-only or other treatments for cholangiocarcinoma. The outcomes of interest included patient survival, the changes of serum bilirubin levels, the quality of life (Karnofsky performance status), and adverse events. The hazard ratios (HR) were extracted from the survival curves using Tierney's Method. LnHR and its variance were pooled using an inverse variance-weighted average. Inconsistency was quantified using I(2) statistics.

RESULTS

In all, 8 trials comparing PDT+stent with other therapeutic methods were selected. We made a meta-analysis based on the 7 trials, which compared the result of PDT+stent and the stent-only group. HR summarizes the survival for the two groups. Overall survival was significantly better in patients who received photodynamic therapy than those who did not [HR=0.49, 95% confidence interval (CI), 0.33∼0.73, P=0.0005]. Among the 8 trials (642 subjects), 5 assessed the changes of serum bilirubin levels, and/or Karnofsky performance status, as other indications for improvement. In all, the incidence for phototoxic reaction is 11.11%. The incidence for other events in photodynamic therapy and the stent-only group was 13.64% and 12.79%, respectively.

CONCLUSION

The palliative treatment of cholangiocarcinoma, with photodynamic therapy, is associated with an increased survival benefit, an improved biliary drainage, and a better quality of life. However, the quality of this evidence is low.

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.

Role of photodynamic therapy and intraductal radiofrequency ablation in cholangiocarcinoma

Cholangiocarcinoma comprises 3% of all gastrointestinal malignancies. Prognosis is poor as the disease is locally advanced at the time of its presentation. Biliary endoprosthesis are widely used for biliary decompression, however, they only provides temporary relief. Photodynamic therapy and Radiofrequency ablation are two innovative approaches performed endoscopically to locally destruct the malignant tissue. This chapter focuses on their application and appropriate use along with their benefits and complications.

Current status of photodynamic therapy in digestive tract carcinoma in Japan

Photodynamic therapy (PDT) is an effective local treatment modality as a cancer-specific laser ablation in malignancy of some organs including digestive tracts or bile duct. In Japan, PDT has been applied at the early period after the first clinical induction in 1980’s. Although the useful efficacy was clarified, PDT has not been fully applied because of the phototoxicity of the porfimer sodium. The next generated talaporfin-sodium was used for PDT, in which phototoxicity was reduced and, however, the clinical efficacy for digestive tract malignancy has not yet been clarified. By proceeding the experimental and clinical trials, it is necessary to clarify the evidence of efficacy as a local powerful treatment with the conventional surgery, brachiotherapy and chemotherapy in the future step.

How to access photodynamic therapy for bile duct carcinoma

BACKGROUND

Photodynamic therapy (PDT) is a promising treatment option for local control of remnant cancer after surgical resection or biliary stenosis by the unresectable tumor in patients with bile duct carcinomas (BDC). To achieve effective tumor necrosis, an appropriate approach to laser irradiation is necessary.

METHODS

The efficacy of endoscopy-guided PDT using porfimer (n=12) or talaporfin sodium (n=13) was investigated by evaluating the transhepatic biliary routes and endoscopic retrograde biliary (ERB) routes in 25 patients with BDC.

RESULTS

Diseases included perihilar intrahepatic cholangiocarcinoma (ICC) in four patients, extrahepatic BDCs in 19 and ampular carcinoma (AC) in two patients. Adjuvant PDT after surgical resection was performed in 18 patients, and PDT for tumor biliary stenosis was performed in seven. In patients undergoing surgical resections, the mean period between the operation and PDT was 87±42 days. In patients who underwent prior surgical resections, the transhepatic route was used in five (28%), the jejunal loop was used in 11 (61%), the T-tube route was used in one, and the endoscopic retrograde cholangiography (ERC) route via papilla Vater was used in one. In unresectable BDC, the ERC route was used in four patients (57%), and the transhepatic biliary route was used in three (43%). Endoscopic-guided PDT could not be performed in one patient because of a technical failure. Except for the complication of photosensitivity, endoscopy-related complications were not observed in any patients. Patients undergoing PDT with porfimer sodium had a significantly longer admission period compared to patients undergoing PDT with talaporfin sodium (36 vs. 5 days, respectively) (P<0.01).

CONCLUSIONS

PDT was safely and definitively performed using the endoscopy-guided approach via the transhepatic or ERC route. By considering the disadvantages of both routes, PDT must be adequately achieved for local control of BDC.

Photodynamic therapy in cholangiocarcinoma: an overview

Cholangiocarcinoma is a challenge to manage; mortality rate is nearly as high as the incidence. Unless curative resection is performed, these tumours are rapidly fatal because they respond poorly to current therapies. Symptoms occur late in cholangiocarcinoma and curative resection can be performed in less than half of the patients. In non-resectable disease, endoprostheses insertion can relieve jaundice and improve quality of life, provided that tumour extension does not lead to diffuse intrahepatic stenoses of ductal system. However, tumour growth cannot be influenced and therefore, prognosis remains dismal. Despite the fact, that radiotherapy and chemotherapy could reduce tumour volume and growth, no survival advantage has yet been shown. Photodynamic therapy has been evaluated as an new additional, palliative option. A randomised trial comparing photodynamic therapy plus endoprostheses insertion versus endoprostheses insertion alone, indicates a considerably benefit on survival time, cholestasis and quality of life in large, advanced cholangiocarcinoma. Furthermore, few specific side effects occurred. Since photodynamic therapy is the first approach leading to an improvement of prognosis, it should be offered to patients with non-resectable cholangiocarcinoma.

Endoscopic treatment options for cholangiocarcinoma

Cholangiocarcinomas are often locally advanced or have metastasized, and at the time of diagnosis individuals often have a poor prognosis. Endoscopic treatment options traditionally include biliary decompression via stenting to allow for systemic chemotherapy and radiotherapy, with self-expanding metal biliary stents being preferred. Recent developments in locoregional therapy delivered endoscopically, such as photodynamic therapy and radiofrequency abalation, have shown promising results in improving patient survival.

Utilization of ancillary studies in the cytologic diagnosis of biliary and pancreatic lesions: the Papanicolaou Society of Cytopathology guidelines for pancreatobiliary cytology

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound-guided fine-needle aspiration, terminology and nomenclature of pancreatobiliary disease, ancillary testing, and post-biopsy management. All documents are based on the expertise of the authors, a review of the literature, discussions of the draft document at several national and international meetings, and synthesis of selected online comments of the draft document. This document presents the results of these discussions regarding the use of ancillary testing in the cytologic diagnosis of biliary and pancreatic lesions. Currently, fluorescence in situ hybridization (FISH) appears to be the most clinically relevant ancillary technique for cytology of bile duct strictures. The addition of FISH analysis to routine cytologic evaluation appears to yield the highest sensitivity without loss in specificity. Loss of immunohistochemical staining for the protein product of the SMAD4 gene and positive staining for mesothelin support a diagnosis of ductal adenocarcinoma. Immunohistochemical markers for endocrine and exocrine differentiation are sufficient for a diagnosis of endocrine and acinar tumors. Nuclear staining for beta-catenin supports a diagnosis of solid-pseudopapilary neoplasm. Cyst fluid analysis for amylase and carcinoembryonic antigen aids in the preoperative classification of pancreatic cysts. Many gene mutations (KRAS, GNAS, VHL, RNF43, and CTNNB1) may be of aid in the diagnosis of cystic neoplasms. Other ancillary techniques do not appear to improve diagnostic sensitivity sufficiently to justify their increased costs.

Biliary stenting for cholangiocarcinoma: An update

Cholangiocarcinoma (bile duct cancer) is the most common malignant tumor of the biliary tree. This devastating malignancy presents late, and is notoriously difficult to diagnose, thus resulting a high mortality. The majority of cholangiocarcinoma patients present with an unresectable disease, and survive less than 12 mo following diagnosis. Biliary stent placement is an effective palliative therapy for malignant biliary obstruction, which can significantly improve the quality of life, and extend the survival time of patients. Different biliary stent placement methods would closely affect the prognosis of patients. The purpose of this article is to review the treatment efficacy, insertion paths and types of biliary stents. This paper also covers emerging biliary stents including drug stents, and biliary stent combination local therapy.

Endoscopic treatment options for cholangiocarcinomas

Cholangiocellular carcinoma (CCC) is a very aggressive tumor, which remains highly resistant to current chemoradiation therapies. Death is usually caused by the tumor burden. However, biliary obstruction, which leads to cholangitis and liver failure, is also a cause of death. Therefore, relief of biliary obstruction is one of the key palliative treatment options for patients with hilar or distal CCC. Radiologic or endoscopic insertions of stents (plastic or self-expanding metal) are definite biliary drainage options. Whereas stents alone can help achieve relief of bile duct obstruction, endoscopic ablative interventions with photodynamic therapy or radiofrequency ablation are also useful in destroying intraluminal tumor. Destroying the tumor leads to an increase in the luminal diameter of the obstructed bile duct, allowing for placement of more or larger diameter stents, and thus improving bile flow. Besides decreasing morbidity associated with obstruction, ablative therapies such as photodynamic therapy have also been associated with improved survival in a sub-group of patients with CCC and should therefore be incorporated into the treatment algorithm of any center treating patients with CCC.

Cholangiocarcinoma treatment

Cholangiocarcinoma (CCA) is a tumor of the bile ducts that usually presents with biliary obstruction and has a poor prognosis. The treatment of CCA is challenging as the tumor is usually diagnosed late and the treatments are not very effective except when complete surgical resection is possible. In carefully selected patients, liver transplant can be a curative therapy. In the majority of cases, complete surgical resection is not possible and palliation is the mainstay of treatment. Stenting, using plastic or metallic stents, allows for biliary drainage. Photodynamic therapy plays a role in palliation and might play a role in adjuvant or neoadjuvant therapy. While radiation and chemotherapy can be beneficial, newer ablative techniques and targeted chemotherapies are promising.

Endoscopic management of malignant bile duct strictures

Malignant biliary obstruction can arise from intrahepatic, extrahepatic, and hilar locations from either primary or metastatic disease. Biliary-enteric surgical bypass has been surpassed in the last 20 years by endoscopic balloon dilation and stenting. The goal of stenting for biliary decompression is to palliate obstructive symptoms; it has not been shown that survival is affected by stenting alone. Novel endoscopic therapies, including photodynamic therapy and radiofrequency ablation, have been evaluated and show promise. Both therapies seem to be safe and effective in the treatment of malignant bile duct strictures but are in need of prospective studies of longer duration.

Photodynamic therapy for unresectable cholangiocarcinoma: a comparative effectiveness systematic review and meta-analyses

BACKGROUND

Photodynamic therapy (PDT) with placement of a biliary stent may improve bile duct patency in patients with cholangiocarcinoma (CCA). We aimed to determine the effectiveness of biliary stenting with PDT compared to biliary stenting alone in the palliative treatment of CCA.

MATERIALS AND METHODS

Several databases were searched from inception to December 2011 for prospective studies comparing biliary stenting with PDT vs. biliary stenting only for CCA. Outcomes of interest included patient survival, quality of life (using Karnofsky score), and serum bilirubin levels. The relative risk (RR) for dichotomous outcomes and the weighted mean difference (WMD) for continuous outcomes were estimated using DerSimonian and Laird random-effects model. Inconsistency was quantified using I(2) statistics. The extent of publication bias was ascertained by visual inspection of funnel plots and Egger's test.

RESULTS

There were six studies that met inclusion criteria. A total of 170 participants received PDT and 157 had biliary stenting only. Compared with biliary stenting, PDT was associated with a statistically significant increase in the length of survival (WMD 265 days; 95% CI: 154-376; p = 0.01; I(2) = 65%), improvement in Karnofsky scores (WMD 7.74; 95% CI: 3.73-11.76; p = 0.01; I(2)= 14%), and a trend for decline in serum bilirubin (WMD -2.92 mg/dL; 95% CI: -7.54 to 1.71; p=0.22; I(2) = 94%). The pooled event rate for biliary sepsis was 15% and was similar between PDT and control groups.

CONCLUSION

Palliative treatment of CCA with PDT is associated with increased survival benefit, improved biliary drainage, and quality of life. However, the quality of this evidence is low.

Photodynamic therapy for unresectable cholangiocarcinoma

Cholangiocarcinoma (CC) is a rare primary malignancy of the biliary tract with a dismal prognosis. Curative resection can only be applied to a small proportion of early diagnosed patients. Palliative biliary drainage by either percutaneous or endoscopic insertion of endoprostheses improves quality-of-life by reducing pruritis, cholangitis, and pain, but has been reported to improve survival time only slightly. Photodynamic therapy (PDT) is a relatively new local, minimally invasive palliative strategy for unresectable CC. PDT uses a photosensitive molecule that accumulates in proliferating tissue such as tumors. Activation of the photosensitizer by use of light of a specific wavelength generates reactive oxygen species leading to selective tumor-cell death. After initial feasibility studies and promising prospective phase II studies, results from two prospective randomized controlled trials comparing PDT after endoprostheses insertion with endoprostheses alone for patients with unresectable CC have been published. One study resulted in dramatically prolonged median survival in the PDT group (493 days) compared with the non-PDT group (98 days) (P < 0.0001), and significantly improved performance status (PS) in the PDT group. A second study with high baseline patients' PS confirmed the benefit of PDT for survival (630 days in the PDT group compared with 210 days for endoprostheses alone, P < 0.01). The procedures were generally well tolerated. PDT has also been reported to have a favorable outcome as adjuvant and neoadjuvant therapy for CC. Although accumulated data and local expertise are limited, PDT can be regarded as a standard palliative therapy for unresectable CC.

Feasibility and safety of long-term photodynamic therapy (PDT) in the palliative treatment of patients with hilar cholangiocarcinoma

Background and Aim

PDT is an important palliative option for patients with unresectable extrahepatic cholangiocarcinoma (CC). However, the results published to date reported on studies with no more than 6 (mostly up to 4) PDT procedures. Furthermore, the clinical experience of PDT in combination with chemotherapy is limited. The purpose of this retrospective analysis was to evaluate the feasibility and safety of multiple (4 to 14) settings of PDT, combined with biliary drainage, and (in some cases) with chemotherapy.

Methods

Ten patients with unresectable extrahepatic CC were treated with biliary stenting and at least 4 PDT procedures in our department between 10/2005 and 08/2010.

Results

Ten patients (male/female = 5/5), mean age 68.8 years (range, 54 - 81 years) who received at least 4 PDT procedures were analyzed. All patients underwent endoscopic biliary drainage. Nine patients received metallic stents and one patient a plastic stent. In 4 patients (40%) bilateral metal stenting (JoStent SelfX^®) was performed. The mean number of PDT sessions was 7.9 ± 3.9 (range: 4 - 14). Eight patients had elevated bilirubin levels with a mean bilirubin at admission of 9.9 ± 11.3 mg/dL, which had decreased to an average minimum of 1.2 ± 0.9 mg/dL after 3 months. No severe toxicity was noted. Two patients received concomitant chemotherapy (GEMCIS as 1^st line, GEMOX plus cetuximab as 2^nd line). The median overall survival has not been reached, whereas the estimated survival of all patients was 47.6 months, 95% CI 25.9 - 48.1.

Conclusion

Long-term PDT in patients with extrahepatic CC is feasible and effective and is accompanied - at least in this cohort- by a survival time of more than 2 years.

Advantages of laserphyrin compared with photofrin in photodynamic therapy for bile duct carcinoma

BACKGROUND

The aim of this study was to compare the effects of laserphyrin-PDT (L-PDT) on biliary cancer with those of the conventional photosensitizer, photofrin-PDT (P-PDT).

METHODS

An animal tumor model was established by inoculation of NOZ cells in 4-week-old male BALB/c mice. The laser light wavelength was set at 630 nm for P-PDT and 660 nm for L-PDT, at a frequency of 10 Hz. Each group received a total energy flux of 60 J/cm(2). The proportion of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling)-positive cells, expression of VEGF (vascular endothelial growth factor) and the PCNA (proliferating cell nuclear antigen)-labeling index (LI) were assessed after PDT.

RESULTS

L-PDT had significantly more potent apoptotic effects at 48 and 72 h after light exposure compared with P-PDT (P < 0.001). The mean PCNA-LI was significantly lower in the L-PDT group than the P-PDT group and the index was significantly lower at several time points after PDT (6, 12, 24, 48 and 72 h after laser light exposure) in the L-PDT than P-PDT (P < 0.001 vs. control). The cell proliferative activity was significantly decreased at 12 and 24 h after P-PDT compared with the control (P < 0.001). VEGF expression was significantly higher at 3 h after L-PDT compared with the control (P < 0.05), whereas it was significantly higher at many time points after P-PDT (3, 6, 48 and 72 h; P < 0.05 vs. control).

CONCLUSIONS

L-PDT is a better approach for biliary cancer than the conventional P-PDT, based on its potent apoptotic and cytostatic effects.

Combination of conservative and interventional therapy strategies for intra- and extrahepatic cholangiocellular carcinoma: a retrospective survival analysis

Background. Due to the predominantly advanced stage at the time of diagnosis treatment of cholangiocarcinoma is difficult. Apart from surgical resection, interventional treatment strategies are increasingly used in advanced stage tumours. The aim of the study was a retrospective comparison of the effect of the various forms of treatment on morbidity and mortality. Method. A total of 195 patients, received either chemotherapy or a combination of photodynamic therapy (PDT) or transarterial chemoembolization (TACE) and chemotherapy. Results. The median survival rate for all patients was 15.6 months, 50.8% were still alive 1 year after diagnosis. Patients, who had previously undergone surgery, survived 17.1 months longer than those without surgical treatment (P < .01). Chemotherapy prolonged the survival by 9.2 months (P = .47). Palliative patients under combination of chemotherapy and PDT survived on average 1.8 months longer (P = .28), with chemotherapy and TACE 9.8 months longer (P = .04) compared to chemotherapy alone. Conclusions. It appears that surgical treatment and chemotherapy combined with PDT or TACE may prolong survival.

The role of photodynamic therapy for hilar cholangiocarcinoma

The prognosis for hilar cholangiocarcinoma is limited by tumor spread along the biliary tree leading to refractory obstructive cholestasis, cholangitis, and liver failure. Palliation with biliary endoprostheses results in median survival times of 4-6 months for advanced bile duct cancer. Photodynamic therapy (PDT) is a local photochemical tumor treatment consisting of a photosensitizing agent combined with laser irradiation of a distinct wavelength. Tumor ablation with PDT combined with biliary stenting reduces cholestasis and significantly improves median survival time. However, the treatment is not widely available, and the photosensitizers used for PDT cause prolonged photosensitivity. Optimum control of tumor spread along the bile ducts and control of cholestasis and cholangitis will prolong survival in one to two thirds of patients, and renders them suitable for other antitumor therapies.

Photodynamic therapy: Palliation and endoscopic technique in cholangiocarcinoma

Cholangiocarcinoma is the primary malignancy arising from the biliary epithelium. The disease is marked by jaundice, cholestasis, and cholangitis. Over 50 percent of patients present with advanced stage disease, precluding curative surgical resection as an option of treatment. Prognosis is poor, and survival has been limited even after biliary decompression. Palliative management has become the standard of care for unresectable disease and has evolved to include an endoscopic approach. Photodynamic therapy (PDT) consists of administration of a photosensitizer followed by local irradiation with laser therapy. Several studies conducted in Europe and the United States have shown a marked improvement in the symptoms of cholestasis, survival, and quality of life. This article summarizes the published experience regarding PDT for cholangiocarcinoma and the steps required to administer this therapy safely.

Photodynamic therapy for cholangiocarcinoma

Cholangiocarcinoma is the primary malignancy arising from the biliary epithelium, and it presents as jaundice, cholestasis, and cholangitis. Over 50 percent of patients present with advanced-stage disease, and the prognosis is poor with the survival measured in months even after biliary decompression. Palliative management has become the standard of care for unresectable disease, and this involves an endoscopic approach. Photodynamic therapy (PDT) involves the administration of a photosensitizer followed by local irradiation with laser therapy. The use of PDT for palliation of bile-duct tumors has produced promising results. Several studies conducted in Europe and the United States have shown that PDT produces a marked improvement in the symptoms of cholestasis, survival, and quality of life. This chapter summarizes the principle of PDT, the technique employed, and the published experience regarding PDT for cholangiocarcinoma.

Endoscopic retrograde cholangiopancreatography in the diagnosis and management of cholangiocarcinoma

Cholangiocarcinomas (CCAs) are rare malignancies that arise from the biliary epithelium. Intrahepatic CCAs usually present as mass lesions that are asymptomatic or cause nonspecific systemic symptoms such as fatigue, fever, and weight loss. Hilar and extrahepatic tumors most commonly present with jaundice, though cholangitis also can be seen. Tumor markers such as carbohydrate antigen 19-9 and carcinoembryonic antigen have been used to diagnose CCA, but these are nonspecific and may be elevated in infection, inflammation, or any obstruction. Endoscopic retrograde cholangiopancreatography (ERCP) has been used for the diagnosis and management of CCA for many years. This article summarizes the data regarding the application of ERCP in the diagnosis and management of CCA.

Role of Photodynamic Therapy for the Upper Gut

It may be questioned if PDT is still relevant for practicing gastroenterologists since other types of therapy have currently gained momentum. Important aspects of PDT that continue its development are it's intrinsic applicability to the luminal GI tract where there are often areas of mechanical narrowing, unusual topography, and difficult accessibility where a modality that does not require contact or optical visualization has advantages. Although not used as often in the upper gastrointestinal tract for it's original approved indications such as esophageal cancer or Barrett's esophagus, its value in biliary lesions appears to be well substantiated. In this paper, we will review its current application in the upper gastrointestinal tract.

Biliary drainage, photodynamic therapy and chemotherapy for unresectable cholangiocarcinoma with jaundice

BACKGROUND AND AIM

The combination of photodynamic therapy and biliary stenting seems to be beneficial in the palliative treatment of unresectable cholangiocarcinoma. We aimed to assess the accuracy of photodynamic therapy in a single centre.

METHODS

Fourteen selected patients, with jaundice related to unresectable cholangiocarcinoma, underwent photodynamic therapy and biliary stenting (with or without chemotherapy). Photofrin was injected intravenously (2 mg/kg) 2 days before intraluminal photoactivation. In case of malignant progression, photodynamic therapy was repeated. The outcome parameters were overall survival and quality of life.

RESULTS

There were eight men and six women (median age: 67 [42-81]). Unresectability was related to a low Karnofski index (n = 2), peritoneal carcinomatosis (n = 4), vascular involvement (n = 3), invasion of the hepatoduodenal ligament (n = 2) and an under-sized liver remnant (n = 3). Biliary stenting was efficient (> or = 50% total bilirubin) in 78.5% of cases. Eight patients developed cholangitis. The mean number of photodynamic therapy procedures was two (1-4). Six (43%) patients needed > or = 2 procedures. No severe toxicity was noted. Photodynamic therapy improved the Karnofski index in 64% of cases. Six (42.8%) patients received concomitant chemotherapy (gemcitabine). The median survival time was 13.8 [0.7-29.2] months. The 3-, 6- and 12-month survival rates were 85%, 77% and 77%, respectively.

CONCLUSION

These results confirm the beneficial effect of biliary drainage, photodynamic therapy and chemotherapy for unresectable cholangiocarcinoma in selected patients with jaundice.

Inflammation and carcinogenesis of the biliary tract: update on endoscopic treatment

Both diagnosis and treatment of cholangiocarcinoma are suboptimal. From the former standpoint, fluorescence in situ hybridization, direct cholangioscopy, endocystoscopy, and optical coherence tomography are just a few of the myriad technologies being studied or employed to improve diagnostic yield. From the latter standpoint, most series suggest that fewer than 1 third of patients are resectable for cure, although liver transplantation has increasingly been used in a subset of cholangiocarcinoma patients with extrahepatic disease. Palliation has included chemotherapy which is of dubious value in most series. Instead, a majority of therapies have addressed mechanisms to improve biliary drainage to delay and preclude hepatic failure and minimize the risk of cholangitis. Although the latter has been accomplished with surgery and attempted with external beam irradiation and brachytherapy, percutaneous and/or endoscopic drainage are the most commonly employed methods in widespread use. There are prospective, randomized studies that suggest that bilateral stenting is associated with improved outcomes in bifurcation lesions if plastic stents are placed, that percutaneous transhepatic biliary drainage is more successful than endoscopic stenting in Klatskin tumors, that self-expandable biliary stents have prolonged patency compared with plastic prostheses, and that, if approached with computed tomography and magnetic resonance imaging guidance to preclude contamination of the contralateral undrained system, outcomes are comparable in patients treated with unilateral as opposed to bilateral self-expandable metal stents. There is a single prospective, randomized study suggesting that patients treated with endoscopic or percutaneous stenting in conjunction with photodynamic therapy have prolonged survival compared with stent placement alone.

Photodynamic therapy is associated with an improvement in survival in patients with irresectable hilar cholangiocarcinoma

BACKGROUND

The majority of patients with hilar cholangiocarcinoma have irresectable disease and require palliation with biliary stenting to alleviate symptoms and prevent biliary sepsis. Chemotherapy and radiotherapy have proved ineffective, but recent studies suggest photodynamic therapy (PDT) may improve the outlook for these patients. This prospective clinical cohort study has evaluated the efficacy of radical curative surgery, standard palliative therapy (stent +/- chemotherapy) and a novel palliative therapy (stent +/- Photofrin-PDT) in 50 consecutive patients treated for hilar cholangiocarcinoma over a 5-year period.

METHODS

Between January 2002 and December 2006, 50 patients with hilar cholangiocarcinoma were evaluated for treatment. Ten patients were considered suitable for curative resection (Cohort 1). Forty patients with irresectable disease were stratified into Cohort 2 - Stent +/- chemotherapy (n= 17); and Cohort 3 - Stent +/- PDT (n= 23). Prospective follow-up in all patients and data collected for morbidity, mortality and overall patient survival.

RESULTS

The median age was 68 years [range 44-83]. Positive cytology/histology was obtained in 28/50 (56%). One death in Cohort 1 occurred at 145 days after surgical resection. No treatment related-deaths occurred in Cohort 2 or 3, chemotherapy-induced morbidity in three patients in cohort 2, PDT-induced morbidity in 11 patients in cohort 3. Actual 1-year survival was 80%, 12% and 75% in Cohorts 1, 2 and 3, respectively. Mean survival after resection was 1278 days (median survival not reached). Mean and median survival was 173 and 169 days, respectively, in Cohort 2; and 512 and 425 days in Cohort 3. Patient survival was significantly longer in cohorts 1 and 3 (P < 0.0001; Log rank test).

CONCLUSION

This prospective clinical cohort study has demonstrated that radical surgery and palliative Photofrin-PDT are associated with an increased survival in patients with hilar cholangiocarcinoma.

Photodynamic therapy for cholangiocarcinoma: overview and new developments

PURPOSE OF REVIEW

Photodynamic therapy (PDT) with hematoporphyrins has emerged as promising treatment for nonresectable cholangiocarcinoma in several prospective observational studies and two randomized studies. This review describes the mechanism of action of PDT, gives an overview of clinical experience in cholangiocarcinoma and summarizes the results published in 2007 and 2008.

RECENT FINDINGS

The mechanism of action of PDT has been further elucidated. PDT induces an apoptotic, antiangiogenic as well as an immunomodulatory response. Interleukin-6, a bile duct epithelium growth factor correlating with tumor burden, decreases after PDT. The efficacy of PDT was confirmed in a comparative study in the United States. Patients with no visible mass on imaging studies, high serum albumin levels and treatment immediately after diagnosis seem to benefit most from PDT. Although it is recommended to perform PDT in bile ducts without stents in place, illumination through metal stents is possible if the light dose is adjusted. Meso-tetrahydroxyphenyl chlorine is a new potent photosensitizer for PDT of cholangiocarcinoma.

SUMMARY

In advanced nonresectable cholangiocarcinoma, PDT is the only evidence-based treatment that improves survival when compared with stenting. Therefore, PDT should be offered to those who are unsuitable for surgery.

Hilar cholangiocarcinoma: current management

OBJECTIVE

To review the literature with regard to outcome of surgical management for hilar cholangiocarcinoma (Klatskin tumor).

BACKGROUND

Hilar cholangiocarcinoma is a rare tumor with a poor prognosis. Surgical resection provides the only possibility for cure. Advances in hepatobiliary imaging and surgical strategies to treat this disease have resulted in improved postoperative outcomes.

METHODS

We performed a review of the English literature on hilar cholangiocarcinoma from 1990 to 2007. This review included preoperative evaluation, surgical techniques, issues and controversies in management, prognostic variables, and considerations for future directions.

RESULTS

Complete resection remains the most effective and only potentially curative therapy for hilar cholangiocarcinoma. Negative resection margins are associated with improved outcomes, and major hepatic resections have enhanced the likelihood of R0 resection. Portal vein embolization may be indicated in selected patients before extensive hepatic resection. Staging laparoscopy should be considered to detect occult metastatic disease. Orthotopic liver transplantation might be applicable for a highly selected subgroup.

CONCLUSIONS

Surgical resection including major hepatic resection remains the mainstay of treatment of hilar cholangiocarcinoma. Additional evidence is needed to fully define the role of orthotopic liver transplantation. Improvements in adjuvant therapy are essential for improving long-term outcome.

Photodynamic therapy and Klatskin tumour: An overview

The prognosis of patients with an unresectable bile duct cancer is poor. In 60-70% of patients, cholangiocarcinoma is located in the hepatic duct bifurcation and known as Klatskin tumour. Surgical resection offers the only chance for 5-year survival, but less than 20% are surgical candidates. Patients with unresectable cholangiocarcinoma are treated with biliary drains, but commonly die of liver failure or cholangitis due to biliary obstruction within 6 to 12 months. Chemotherapy and/or radiotherapy have not been evaluated in randomized, controlled trials. Photodynamic therapy (PDT) is a new and promising locoregional treatment, the aim of which is to destroy tumour cells selectively. PDT involves the injection of a photosensitizer followed by percutaneous or endoscopic direct illumination of the tumour with light of a specific wavelength. In recent non-randomized studies of small numbers of patients with unresectable cholangiocarcinoma, PDT induced a decrease in serum bilirubin levels, improved quality of life and a slightly better survival. Other non-randomized trials failed to show clinical benefits. Recently, the first prospective, randomized controlled study with PDT in a selected group of non-resectable cholangiocarcinoma patients was stopped prematurely. The improvement in survival in the PDT-randomized patients was so impressive that it was considered to be unethical to continue randomization. However, further studies are awaited in unselected patients with unresectable cholangiocarcinoma before PDT can be considered as the standard adjuvant therapy.

Systematic review: photodynamic therapy for unresectable cholangiocarcinoma

BACKGROUND

Palliative therapies for unresectable cholangiocarcinoma such as stent, radiotherapy and chemotherapy have generally been disappointing. Therefore, it is necessary to find a new approach to fighting the disease. Several published clinical trials have reported the therapeutic effect of photodynamic therapy (PDT) for unresectable cholangiocarcinoma.

OBJECTIVE

To assess the safety and efficacy of photodynamic therapy for patients with unresectable cholangiocarcinoma.

METHODS

Relevant studies were retrieved from the Medline, Current Contents, Embase, and Cochrane Library databases. Inclusion of papers was determined by using a predetermined protocol; independent assessments and the final consensus decision were performed by two independent reviewers. Acceptable study designs included randomized controlled trials (RCTs), controlled clinical trials (CCTs), case studies, and case reports. Twenty studies met the inclusion criteria, and were tabulated and critically appraised in terms of characteristics, methods, outcomes, and complications.

RESULTS

Twenty studies were included. The quality of the available evidence was low to moderate with the majority of studies being uncontrolled before and after design and thus limited by the retrospective nature of much of the available data. After PDT, it is reported that bilirubin serum levels declined, quality of life improved and survival time increased in most of the patients. At the same time, there were few complications.

CONCLUSIONS

Based on currently available evidence, PDT was safe and effective for patients with inoperable cholangiocarcinoma.

Cholangiocarcinoma: A compact review of the literature

Cholangiocarcinoma (CC) is a devastating cancer arising from biliary epithelia. Unfortunately, the incidence of this disease is increasing in Western countries. These tumors progress insidiously, and liver failure, biliary sepsis, malnutrition and cancer cachexia are general modes of death associated with this disease. To date, no established therapy for advanced disease has been established or validated. However, our knowledge in tumor biology is increasing dramatically and new drugs are under investigation for treatment of this notorious tumor. In clinical practice, there are better diagnostic tools in use to facilitate an earlier diagnosis of CC, at least in those patients with known risk factors. CC is resectable for cure in only a small percentage of patients. Preoperative staging for vascular and biliary extension of CC is very important in this tumor. Laparoscopy and recently endosonography seem to protect against unnecessary laparotomies in these patients. During the last 15 years, aggressive surgical approaches, including combined liver resections and vascular reconstructive surgical expertise, have improved survival in patients with CC. Surgery is contraindicated in CC cases having primary sclerosing cholangitis (PSC). Although CC was previously considered a contraindication to liver transplantation, new cautious protocols, including neo-adjuvant chemoradiation therapies and staging procedures before the transplantation, have made it possible to achieve long-term survival after liver transplantation in this disease. New ablative therapies with photodynamic therapy, intraductal high-intensity ultrasonography and chemotherapy-impregnated plastic biliary endoprosthesis are important steps in the palliative management of extra-hepatic CCs. Radiofrequency and chemo-embolization methods are also applicable for intra-hepatic CCs as palliative modes of treatment. We need more prospective randomized controlled trials to evaluate the role of the new emerging therapies for CC patients.

Photodynamic therapy for non-resectable perihilar cholangiocarcinoma

Photodynamic therapy (PDT) has emerged as a useful tool for palliative treatment of the otherwise difficult to treat perihilar cholangiocarcinoma (CC). PDT is a minimally invasive and effective technique for local tumour ablation with rare and predictable side effects. A modest number of studies and randomised trials using porfimer (Photofrin) could demonstrate an improvement in quality of life and survival time. A novel approach to a priori non-resectable perihilar CC was proven in a pilot study using neoadjuvant porfimer-PDT for down-sizing of the tumour followed by R0 resection. These days, active phase II and phase III trials investigate if the tumouricidal activity can be increased using temoporfin (Foscan) as an alternative photosensitiser with higher penetration capability and whether porfimer-based PDT plus stenting is superior to biliary stenting alone in terms of overall survival, respectively. The local tumour ablation and correction of obstructive cholestasis with PDT will allow for novel multimodal strategies to treat cholangiocarcinoma.