Photodynamic therapy for cholangiocarcinoma: overview and new developments

Long-term efficacy of percutaneous transhepatic cholangioscopy-guided photodynamic therapy for postoperative recurrent extrahepatic cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma recurs frequently following excision surgery and is usually inoperable, while radiotherapy, chemotherapy, and immunotherapy are of limited benefit. As palliative care, percutaneous transhepatic cholangial drainage (PTCD) can relieve biliary obstruction, prevent jaundice, and maintain quality of life (QOL), but does not improve overall survival. In contrast, photodynamic therapy (PDT) has been demonstrated to prolong the survival of inoperable cancer patients.

OBJECTIVE

This study evaluated the clinical efficacy of percutaneous transhepatic cholangioscopy (PTCS)-guided PDT following PTCD versus PTCD alone for recurrent inoperable cholangiocarcinoma.

METHODS

The case files of 39 patients with postoperative recurrence were retrospectively analyzed, including 18 receiving PTCS-guided PDT (PTCS-PDT group) and 21 receiving PTCD only as a control (PTCD group). Survival time was compared by Kaplan-Meier analysis and log-rank test, and QOL by the Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-HEP) questionnaire. Clinicodemographic factors, including serum bilirubin and adverse reaction rates, were compared by Student's t-test or Fisher's exact test. The maximum follow-up period was 71 months.

RESULTS

Median survival time was significantly longer in the PTCS-PDT group than the PTCD group (23 months vs. 10 months, P = 0.00001). At 6 and 12 months post-treatment, total FACT-HEP score was lower in the PTCS-PDT group (P < 0.05), indicating improved QOL. There was no significant difference in total adverse events incidence between groups (19 [51.4%] vs. 15 [71.4%]; P = 0.131).

CONCLUSION

PTCS-guided PDT can prolong survival and improve the QOL of patients with postoperative cholangiocarcinoma recurrence without increasing complications.

SIGNIFICANT AND/OR NEW FINDINGS

Compared to PTCD alone, PTCS-guided PDT significantly prolonged the survival time of patients with postoperative recurrent extrahepatic cholangiocarcinoma. Photodynamic therapy also improved patient quality of life by facilitating timely removal of the PTCD drainage tube. PTCS-guided PDT did not increase surgery-related complications except for skin phototoxicity, which can be easy avoided and treated.

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.

Application of photodynamic therapy for liver malignancies

Liver malignancies include primary and metastatic tumors. Limited progress has been achieved in improving the survival rate of patients with advanced stage liver cancer and who are unsuitable for surgery. Apart from surgery, chemoradiotherapy, trans-arterial chemoembolization and radiofrequency ablation, a novel therapeutic modality is needed for the clinical treatment of liver cancer. Photodynamic therapy (PDT) is a novel strategy for treating patients with advanced cancers; it uses a light-triggered cytotoxic photosensitizer and a laser light. PDT provides patients with a potential treatment approach with minimal invasion and low toxicity, that is, the whole course of treatment is painless, harmless, and repeatable. Therefore, PDT has been considered an effective palliative treatment for advanced liver cancers. To date, PDT has been used to treat hepatocellular carcinoma, cholangiocarcinoma, hepatoblastoma and liver metastases. Clinical outcomes reveal that PDT can be considered a promising treatment modality for all liver cancers to improve the quality and quantity of life of patients. Despite the advances achieved with this approach, several challenges still impede the application of PDT to liver malignancies. In this review, we focus on the recent advancements and discuss the future prospects of PDT in treating liver malignancies.

Two cases of bile duct carcinoma patients who underwent the photodynamic therapy using talaporfin sodium (Laserphyrin®)

The efficacy of adjuvant photodynamic therapy (PDT) using the new photosensitizer, talaporfin sodium (TPS) has been clinically examined in some patients with bile duct carcinoma (BDC). Based on our previous cohorts, a prospective clinical trial was attempted; however, only two cases were ultimately enrolled in 27 months. A 664-nm semiconductor laser (100 J/cm²) was applied through an endoscope to the tumor lesion within 6 h of an intravenous injection of 40 mg/m² TPS according to the protocol for lung cancer. Case 1 was an 82-y.o. female patient with BDC at the left hepatic duct with biliary obstruction, percutaneous transhepatic biliary drainage (PTBD) was achieved, and the patient did not consent to surgery. She was followed up for 15 months to search for non-surgical treatments and eventually received PDT. Although mild photosensitivity occurred, she was discharged without severe adverse events. Biliary stenosis markedly extended and a PTBD tube was scheduled at 1 month. However, cancer immediately metastasized to the liver and she died 155 days after PDT. Case 2 was a 70-y.o. female with perihilar BDC and multiple biliary stenoses. Multiple biliary stenting was considered to be difficult. She received PDT and no adverse events were observed. Biliary stenoses markedly improved and multiple stenting was successfully performed. On day 132, she died of cancer progression. These two cases demonstrated the safety and efficacy of biliary malignant stenosis soon after PDT; however, long-term survival and a sufficient quality of life were not achieved. The combination of the PDT protocol and system chemotherapy or brachytherapy needs to be examined in clinical trials for advanced stage BDC.

WITHDRAWN: A comparative effectiveness meta-analysis of photodynamic therapy and stent drainage for unresectable cholangiocarcinoma

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Indocyanine green-incorporating nanoparticles for cancer theranostics

Indocyanine green (ICG) is a near-infrared dye that has been used in the clinic for retinal angiography, and defining cardiovascular and liver function for over 50 years. Recently, there has been an increasing interest in the incorporation of ICG into nanoparticles (NPs) for cancer theranostic applications. Various types of ICG-incorporated NPs have been developed and strategically functionalised to embrace multiple imaging and therapeutic techniques for cancer diagnosis and treatment. This review systematically summaries the biodistribution of various types of ICG-incorporated NPs for the first time, and discusses the principles, opportunities, limitations, and application of ICG-incorporated NPs for cancer theranostics. We believe that ICG-incorporated NPs would be a promising multifunctional theranostic platform in oncology and facilitate significant advancements in this research-active area.

Combined gemcitabine and S-1 chemotherapy for treating unresectable hilar cholangiocarcinoma: a randomized open-label clinical trial

Although the combination of cisplatin and gemcitabine (GEM) is considered the standard first-line chemotherapy against unresectable hilar cholangiocarcinoma (HC), its efficacy is discouraging. The present randomized open-label clinical trial aimed to evaluate the efficacy and safety of the GEM plus S-1 (GEM-S-1) combination against unresectable HC. Twenty-five patients per group were randomly assigned to receive GEM, S-1 or GEM-S-1. Neutropenia (56%) and leukopenia (40%) were the most common chemotherapy-related toxicities in the GEM-S-1 group. Median overall survival (OS) in the GEM-S-1, GEM and S-1 groups was 11, 10 and 6 months, respectively. GEM plus S-1 significantly improved OS compared to S-1 monotherapy (OR=0.68; 95%CI, 0.50–0.90; P=0.008). Median progression-free survival (PFS) times in the GEM-S-1, GEM and S-1 groups were 4.90, 3.70 and 1.60 months, respectively. GEM plus S-1 significantly improved PFS compared to S-1 monotherapy (OR=0.50; 95%CI, 0.27–0.91; P=0.024). Response rates were 36%, 24% and 8% in the GEM-S-1, GEM and S-1 groups, respectively. A statistically significant difference was found in response rates between the gemcitabine-S-1 and S-1 groups (36% vs 8%, P=0.017). Patients with CA19-9<466 U/ml were more responsive to chemotherapeutic agents than those with CA19-9≥571 U/ml (88.9% vs 0%, P<0.001). We conclude that the combination of GEM plus S-1 provides a better OS, PFS and response rate than S-1 monotherapy, but it did not significantly differ from GEM monotherapy. (ChiCTR-TRC-14004733).

A novel photodynamic therapy-based drug delivery system layered on a stent for treating cholangiocarcinoma

This study aimed to investigate the drug delivery efficacy and bio-effectiveness of a novel photodynamic therapy (PDT)-matrix drug delivery system for cholangiocarcinoma (CCA). Metallic stents were coated with polyurethane (PU) as the first layer. A 2-hydroxyethyl methacrylate (2-HEMA)/ethylene glycol dimethacrylate (EGDMA)/benzoyl peroxide (BPO) layer and a poly(ethylene-co-vinyl acetate) (PEVA)/poly(n-butyl methacrylate) (PBMA)/polyvinylpyrrolidone K30 (K30) layer containing various concentrations of Photofrin were then incorporated onto the stent as the second and third layers. After incubating the layered membranes with cultured CCA cell line, the release of Photofrin, cell viability, the intracellular uptake of Photofrin, reactive oxygen species (ROS) generation, and apoptosis were determined. Using a single-layer diffusion model, the maximum release of Photofrin from the 5 to 10% K30 formulas was 80 and 100%, respectively, after 24 h. When using the multiple-layer diffusion model, the released Photofrin showed an initial burst of the loading dose from the PEVA/PBMA/K30 layer. In the immobilized model, less than 5% of the Photofrin from the 2-HEMA/EGDMA/BPO layer was released over the 24-h period. Cell viability decreased linearly with increasing Photofrin concentrations, and ROS generation and apoptosis were shown to increase significantly with increasing Photofrin concentrations, until the concentration of Photofrin reached a saturation point of 1.5 μg/ml. This new, multiple-layered, PDT-based stent with dual-release mechanisms is a promising treatment for CCA and cancer-related ductal stenosis.

The safety and efficacy of percutaneous intraductal radiofrequency ablation in unresectable malignant biliary obstruction: A single-institution experience

Background

Patients with unresectable malignant biliary obstruction have limited life expectancy because of limited stent patency and tumor progression. The aim of our study was to retrospectively evaluate the safety and efficacy of combining intraductal RFA with biliary metal stent placement for patients with malignant biliary obstruction.

Methods

Patients who received percutaneous intraductal RFA and biliary stent placement for malignant biliary obstruction between 2013 and 2015 were identified. Outcomes were stent patency, technique and clinical success rate, overall survival (OS) and complication rates. Kaplan-Meier and Cox regression analyses were used to examine the association of various factors with stent patency and OS. Complications and laboratory abnormalities were recorded.

Results

Fifty patients were treated with percutaneous RFA and stent placement. The rates of technical success and clinical success were 98% and 92%, respectively. The median stent patency was 7.0 (95% confidence interval [CI]: 5.3, 8.7) months and OS was 5.0 (95% CI: 4.0, 6.0) months. On univariable analysis, previously cholangitis was an independent poor prognosis factor for recurrent biliary obstruction. OS was improved in patients who received more than one intervention compared to those who received only one intervention (log-rank P = 0.007), and in those treated without versus those treated with sequential chemotherapy (log-rank P = 0.017). On multivariable analysis, the occurrence of more than one intervention (P = 0.019) had independent prognostic significance for OS.

Conclusion

Percutaneous RFA and stent placement is a technically safe and feasible therapeutic option for the palliative treatment of malignant biliary obstruction. The long-term efficacy and safety of the procedure is promising, but further study is required via randomized and prospective trials.

Percutaneous intraductal radiofrequency ablation for treatment of biliary stent occlusion: A preliminary result

AIM

To assess the feasibility and effectiveness of a novel application of percutaneous intraductal radiofrequency (RF) for the treatment of biliary stent obstruction.

METHODS

We specifically report a retrospective study presenting the results of percutaneous intraductal RF in patients with biliary stent occlusion. A total of 43 cases involving biliary stent obstruction were treated by placing an EndoHPB catheter and percutaneous intraductal RF was performed to clean stents. The stent patency was evaluated by cholangiography and follow-up by contrast enhanced computed tomography or ultrasound after the removal of the drainage catheter.

RESULTS

Following the procedures, of the 43 patients, 40 survived and 3 died with a median survival of 80.5 (range: 30-243) d. One patient was lost to follow-up. One patient had the stent patent at the time of last follow-up. Two patients with stent blockage at 35 d and 44 d after procedure underwent percutaneous transhepatic drain insertion only. The levels of bilirubin before and after the procedure were 128 ± 65 μmol/L and 63 ± 29 μmol/L, respectively. There were no related complications (haemorrhage, bile duct perforation, bile leak or pancreatitis) and all patients’ stent patency was confirmed by cholangiography after the procedure, with a median patency time of 107 (range: 12-180) d.

CONCLUSION

This preliminary clinical study demonstrated that percutaneous intraductal RF is safe and effective for the treatment of biliary stent obstruction, increasing the duration of stent patency, although randomized controlled trials are needed to confirm the effectiveness of this approach.

Raman microspectroscopy of Hematoporphyrins. Imaging of the noncancerous and the cancerous human breast tissues with photosensitizers

Raman microspectroscopy combined with fluorescence were used to study the distribution of Hematoporphyrin (Hp) in noncancerous and cancerous breast tissues. The results demonstrate the ability of Raman spectroscopy to distinguish between noncancerous and cancerous human breast tissue and to identify differences in the distribution and photodegradation of Hematoporphyrin, which is a photosensitizer in photodynamic therapy (PDT), photodynamic diagnosis (PDD) and photoimmunotherapy (PIT) of cancer. Presented results show that Hematoporphyrin level in the noncancerous breast tissue is lower compared to the cancerous one. We have proved also that the Raman intensity of lipids and proteins doesn't change dramatically after laser light irradiation, which indicates that the PDT treatment destroys preferably cancer cells, in which the photosensitizer is accumulated. The specific subcellular localization of photosensitizer for breast tissues samples soaked with Hematoporphyrin was not observed.

Treatment of unresectable extrahepatic cholangiocarcinoma using hematoporphyrin photodynamic therapy: A prospective study

BACKGROUND

The available evidence of Photodynamic therapy (PDT) combined with stent placement treatment for unresectable extrahepatic cholangiocarcinoma (EHCC) is still insufficient. It also remains unclear whether PDT influences systemic inflammatory response.

AIM

To explore the clinical efficacy and safety of the combination treatment and the systemic inflammatory response in patients with EHCC.

METHODS

Patients with unresectable EHCC underwent either the combined treatment using Hematoporphyrin PDT and stent placement (PDT+stent group, n=12) or stent-only (stent group, n=27). The primary end-point was overall survival. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels were measured. Quality of life was assessed using the Karnofsky performance scale (KPS) every 3 months.

RESULTS

Average survival time (13.8 vs. 9.6 months), and 6-month (91.7% vs. 74.1%), and 1-year (58.3% vs. 3.7%) survival rates of PDT+stent group were significantly increased compared with the stent group. KPS scores in the PDT+stent group were significantly improved. TNF-α and IL-6 levels were significantly increased in the PDT+stent group.

CONCLUSION

Hematoporphyrin-PDT combined with stent placement is an effective and safe treatment for EHCC. The treatment might promote systemic inflammatory response.

The Clinical Usefulness of Simultaneous Placement of Double Endoscopic Nasobiliary Biliary Drainage

BACKGROUND/AIMS

To evaluate the technical feasibility and clinical efficacy of double endoscopic nasobiliary drainage (ENBD) as a new method of draining multiple bile duct obstructions.

METHODS

A total of 38 patients who underwent double ENBD between January 2004 and February 2010 at the Asan Medical Center were retrospectively analyzed. We evaluated indications, laboratory results, and the clinical course.

RESULTS

Of the 38 patients who underwent double ENBD, 20 (52.6%) had Klatskin tumors, 12 (31.6%) had hepatocellular carcinoma, 3 (7.9%) had strictures at the anastomotic site following liver transplantation, and 3 (7.9%) had acute cholecystitis combined with cholangitis. Double ENBD was performed to relieve multiple biliary obstruction in 21 patients (55.1%), drain contrast agent filled during endoscopic retrograde cholangiopancreatography in 4 (10.5%), obtain cholangiography in 4 (10.5%), drain hemobilia in 3 (7.9%), relieve Mirizzi syndrome with cholangitis in 3 (7.9%), and relieve jaundice in 3 (7.9%).

CONCLUSIONS

Double ENBD may be useful in patients with multiple biliary obstructions.

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.

The Role of Endoscopy in the Diagnosis and Management of Cholangiocarcinoma

Cholangiocarcinomas (CCAs) are associated with poor overall survival, and majority of the tumors are unresectable at the time of diagnosis. Early diagnosis at a resectable stage is essential for improved outcomes. Noninvasive imaging plays an important role in evaluating patients with biliary obstruction, but is limited due to the lack of tissue sampling and in many cases due to the absence of a mass, especially for extrahepatic CCAs. Endoscopic diagnosis is needed in majority of patients with CCA and the diagnostic yield depends on the tumor location as well as the expertise and experience of the endoscopist. Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound remain the most common endoscopic diagnostic tools although newer technologies including fluorescence in situ hybridization, single-operator cholangioscopy, confocal laser endomicroscopy, and intraductal ultrasound are being increasing used. Traditionally, the role of endoscopy has been mainly palliative and limited to biliary drainage in patients with obstructive jaundice, however, newer treatment options like photodynamic therapy and radiofrequency ablation have shown promise toward improved patient survival. Multidisciplinary approach that involves medical oncology, gastroenterology, radiology, and surgical oncology teams is imperative for improved outcomes. In this review, we will first review the diagnostic approach to CCAs including imaging and endoscopic methods followed by a discussion of different endoscopic techniques in management of patients after a diagnosis of CCA.

Photodynamic Therapy using Talaporfin Sodium for the Recurrence of Cholangiocarcinoma after Surgical Resection

We herein report the case of a 72-year-old man who underwent photodynamic therapy (PDT) with talaporfin sodium for recurrent cholangiocarcinoma after surgical resection. Endoscopic retrograde cholangiography (ERC) showed severe stenosis with an irregular surface measuring approximately 1 cm in length from the anastomotic site, and a recurrent nodular lesion was observed at the anastomotic site of the right anterior intrahepatic bile duct on gastrointestinal endoscopy. ERC after PDT revealed a dramatic improvement in the bile duct stenosis, and the nodular lesion had disappeared. No adverse events from the PDT were detected. PDT using talaporfin sodium may be a safe alternative treatment for cholangiocarcinoma.

Photodynamic therapy using nanoparticle loaded with indocyanine green for experimental peritoneal dissemination of gastric cancer

Although there have been multiple advances in the development of novel anticancer agents and operative procedures, prognosis of patients with advanced gastric cancer remains poor, especially in patients with peritoneal metastasis. In this study, we established nanoparticles loaded with indocyanine green (ICG) derivatives: ICG loaded lactosomes (ICGm) and investigated the diagnostic and therapeutic value of photodynamic therapy (PDT) using ICGm for experimental peritoneal dissemination of gastric cancer. Experimental peritoneal disseminated xenografts of human gastric cancer were established in nude mice. Three weeks after intraperitoneal injection of the cancer cells, either ICGm (ICGm-treated mice) or ICG solution (ICG-treated mice) was injected through the tail vein. Forty-eight hours after injection of the photosensitizer, in vivo and ex vivo imaging was carried out. For PDT, 48 h after injection of the photosensitizer, other mice were irradiated through the abdominal wall, and the body weight and survival rate were monitored. In vivo imaging revealed that peritoneal tumors were visualized through the abdominal wall in ICGm-treated mice, whereas only non-specific fluorescence was observed in ICG-treated mice. The PDT reduced the total weight of the disseminated nodules and significantly improved weight loss and survival rate in ICGm-treated mice. In conclusion, ICGm can be used as a novel diagnostic and therapeutic nanodevice in peritoneal dissemination of gastric cancer.

Effect of external beam radiotherapy on patency of uncovered metallic stents in patients with inoperable bile duct cancer

BACKGROUND

Although biliary decompression with metallic stenting is the preferred treatment for inoperable bile duct cancer (BDC), maintenance of patency is still unsatisfactory. We tried to assess the effectiveness and safety of external beam radiotherapy (EBRT) for prolonging stent patency in patients having uncovered metallic stents.

METHOD

We retrospectively reviewed 50 patients who received endoscopic stenting, of whom 18 received EBRT (RT group) and 32 did not (non-RT group).

RESULTS

No difference was found in baseline characteristics between the two groups. Although stent patency was longer in the RT group than that in the non-RT group (140.7+/-51.3 vs 136.4+/-34.9 days, P=0.94), the difference was not statistically significant. There were a lower rate of stent occlusion (27.8% vs 50.0% of patients, P=0.12) and a longer overall survival (420.1+/-73.2 vs 269.1+/-41.7 days, P=0.11) in the RT group than in the non-RT group, and the difference again was not statistically significant. The development of adverse reactions did not differ (55.6% vs 53.1% of patients, P=0.91). There was no serious adverse reaction in both groups (P=0.99).

CONCLUSIONS

EBRT did not significantly improve stent patency in patients with inoperable BDC having uncovered metallic stents. However, EBRT was safe. Future trials with refined protocols for better efficacy are expected.

Antioxidant-photosensitizer dual-loaded polymeric micelles with controllable production of reactive oxygen species

Poly(ethylene glycol)-b-poly(caprolactone) (PEG-b-PCL) micelles dually loaded with both pheophorbide a (PhA) as a photosensitizer and β-carotene (CAR) as a singlet oxygen ((1)O2) scavenger were designed to control photodynamic therapy (PDT) activity in cancer treatment. The CAR in the PhA/CAR micelles significantly diminished PhA-generated (1)O2 through direct (1)O2 scavenging, whereas the CAR molecules lost their (1)O2 scavenging activity when the PhA and CAR were spatially isolated by the disintegration of the PEG-b-PCL micelles. In cell-culture systems, light irradiation at a post-treatment time that corresponded to the presence of the micelles in the blood environment induced negligible phototoxicity, whereas light irradiation at a post-treatment time that corresponded to the presence of the micelles in the intracellular environment induced remarkable phototoxicity. In addition, a longer post-treatment time induced greater internalization of PhA/CAR micelles, which resulted in higher phototoxicity, suggesting an increase in photo killing activity against the tumor cells of interest. Thus, the co-loading of a (1)O2 generator and a (1)O2 scavenger into a single micelle is a potential strategy that may be useful in facilitating more accurate and reliable PDT with site-specific controllable production of singlet oxygen species for cancer treatment.

Randomised phase II trial of photodynamic therapy plus oral fluoropyrimidine, S-1, versus photodynamic therapy alone for unresectable hilar cholangiocarcinoma

BACKGROUND

Hilar cholangiocarcinoma is an uncommon cancer and its overall incidence is increasing. Photodynamic therapy (PDT) has been proposed as palliative management for unresectable hilar cholangiocarcinoma (UHC). To date, little is known about the role of the addition of systemic chemotherapy to PDT for UHC. We performed a prospective, randomised, phase II trial to compare PDT plus S-1 and PDT alone for UHC.

METHODS

Patients with UHC were randomly assigned (in a 1:1 ratio) to PDT plus S-1 or PDT alone. The primary end-point was overall survival. The secondary end-points were progression-free survival, complications, re-intervention rate and quality of life. This trial is registered with clinicalTrials.gov, number NCT00869635.

FINDINGS

Between February 2009 and May 2012, we randomly assigned 21 patients to receive PDT plus S-1 and 22 to receive PDT alone. The UHC patients treated with PDT plus S-1 showed higher 1-year survival rate compared with the patients treated with PDT alone (76.2% versus 32%, P=0.003) and prolonged overall survival (median 17 months, 95% confidence interval [CI]: 12.6-21.4, versus 8 months, 95% CI: 6-10, P=0.005, hazard ratio [HR], 0.36; 95% CI: 0.17-0.75). Regarding the secondary end-points, PDT plus S-1 was associated with prolonged progression-free survival compared with PDT alone (median 10 months [95% CI: 4.1-16] versus 2 months [95% CI: 0.4-3.5], P=0.009 (HR for progression 0.39, 95% CI: 0.19-0.83). There were no differences in the number of PDT sessions, the frequency of cholangitis, overall adverse events or the quality of life in either group.

INTERPRETATIONS

PDT plus S-1 was well tolerated and was associated with a significant improvement of overall survival and progression-free survival compared with PDT alone in patients with UHC. These findings warrant further clinical investigation of PDT plus S-1 in patients with UHC.

Potential genotype-specific single nucleotide polymorphism interaction of common variation in p53 and its negative regulator mdm2 in cholangiocarcinoma susceptibility

Aberrant cell cycle control and apoptosis deregulation are involved in biliary carcinogenesis. The tumor suppressor gene p53 and its key negative regulator murine double minute 2 (mdm2) cooperate in modulating these basic cell functions and germline p53 alteration promotes cholangiocarcinoma (CCA) formation in animal models. The potential association between common functional genetic variation in p53 (SNP72 G/C) and mdm2 (SNP309 T/G) and susceptibility to bile duct cancer, however, has not been studied. p53/SNP72 G/C (rs1042522) and mdm2/SNP309 T/G (rs2279744) were genotyped in 182 Caucasian CCA patients and 350 controls using TaqMan assays. Allelic and genotypic differences, including exploratory data analyses (according to gender, tumor localization, early onset and genotypic interactions) were compared in contingency tables using the χ(2) and Fisher's exact tests. The overall comparison of allele and genotype frequencies yielded no significant association between either SNP and CCA susceptibility. Similarly, gender- and localization-specific analyses did not reveal deviations in allelic or genotypic distributions. In carriers of the low-apoptotic p53 genotype CC, the mdm2 SNP309 T allele conferred borderline significant CCA risk [P=0.049; odds ratio (OR), 4.36; 95% CI, 0.92-20.77]. Power analysis confirmed adequate statistical power to exclude major SNP effects (each >97% for OR 1.7). Collectively, the results we obtained from the largest European CCA cohort do not support the hypothesis of a prominent role of common p53 and mdm2 variation in the genetic susceptibility to bile duct cancer. However, epistatic effects may modulate genetic CCA risk in individual subsets.

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.

Comprehensive review of the diagnosis and treatment of biliary tract cancer 2012. Part II: multidisciplinary management

Biliary tract cancers (gallbladder cancer, intra- and extra-hepatic cholangiocarcinoma and selected periampullary cancers) accounted for 12,760 new cases of cancer in the USA in 2010. These tumors have a dismal prognosis with most patients presenting with advanced disease. Early, accurate diagnosis is essential, both for potential cure where possible and for optimal palliative therapy in all others. This review examines the currently available and emerging technologies for diagnosis and treatment of this group of diseases.

ROS-mediated killing efficiency with visible light of bacteria carrying different red fluorochrome proteins

Red fluorescent proteins can generate reactive oxygen species (ROS) if their fluorochrome is stimulated e.g. by visible light illumination. ROS compounds have very reactive, highly toxic properties leading to cell damage which results in cell killing. In this context, the toxicity of the various red fluorochromes KillerRed, DsRed2, mCherry, and mRFP expressed in Escherichia coli bacteria was tested after illumination with white light. The toxic effect was determined by measurement of the colony forming ability 24h after transfection and illumination. KillerRed was found to be the most harmful, followed by mRFP and DsRed2 while bacteria expressing mCherry and controls without fluorescent proteins survived after application of identical illumination doses. Their application and a possible bactericide role is discussed.

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.

Photodynamic antimicrobial chemotherapy in aquaculture: photoinactivation studies of Vibrio fischeri

Background

Photodynamic antimicrobial chemotherapy (PACT) combines light, a light-absorbing molecule that initiates a photochemical or photophysical reaction, and oxygen. The combined action of these three components originates reactive oxygen species that lead to microorganisms' destruction. The aim was to evaluate the efficiency of PACT on Vibrio fischeri: 1) with buffer solution, varying temperature, pH, salinity and oxygen concentration values; 2) with aquaculture water, to reproduce photoinactivation (PI) conditions in situ.

Methodology/Principal Findings

To monitor the PI kinetics, the bioluminescence of V. fischeri was measured during the experiments. A tricationic meso-substituted porphyrin (Tri-Py⁺-Me-PF) was used as photosensitizer (5 µM in the studies with buffer solution and 10–50 µM in the studies with aquaculture water); artificial white light (4 mW cm⁻²) and solar irradiation (40 mW cm⁻²) were used as light sources; and the bacterial concentration used for all experiments was ≈10⁷ CFU mL⁻¹ (corresponding to a bioluminescence level of 10⁵ relative light units - RLU). The variations in pH (6.5–8.5), temperature (10–25°C), salinity (20–40 g L⁻¹) and oxygen concentration did not significantly affect the PI of V. fischeri, once in all tested conditions the bioluminescent signal decreased to the detection limit of the method (≈7 log reduction). The assays using aquaculture water showed that the efficiency of the process is affected by the suspended matter. Total PI of V. fischeri in aquaculture water was achieved under solar light in the presence of 20 µM of Tri-Py⁺-Me-PF.

Conclusions/Significance

If PACT is to be used in environmental applications, the matrix containing target microbial communities should be previously characterized in order to establish an efficient protocol having into account the photosensitizer concentration, the light source and the total light dose delivered. The possibility of using solar light in PACT to treat aquaculture water makes this technology cost-effective and attractive.

Cholangiocarcinoma--controversies and challenges

Cholangiocarcinomas are a diverse group of tumors that are presumed to originate from the biliary tract epithelium either within the liver or the biliary tract. These cancers are often difficult to diagnose, their pathogenesis is poorly understood, and their dismal prognosis has resulted in a nihilistic approach to their management. The two major clinical phenotypes are intrahepatic, mass-forming tumors and large ductal tumors. Among the ductal cancers, lesions at the liver hilum are most prevalent. The risk factors, clinical presentation, natural history and management of these two types of cholangiocarcinoma are distinct. Efforts to improve outcomes for patients with these diseases are affected by several challenges to effective management. For example, designations based on anatomical characteristics have been inconsistently applied, which has confounded analysis of epidemiological trends and assessment of risk factors. The evaluation of therapeutic options, particularly systemic therapies, has been limited by a lack of appreciation of the different phenotypes. Controversies exist regarding the appropriate workup and choice of management approach. However, new and emerging tools for improved diagnosis, expanded indications for surgical approaches, an emerging role for locoregional and intrabiliary therapies and improved systemic therapies provide optimism and hope for improved outcomes in the future.

Advances in photodynamic therapy for the treatment of hilar biliary tract cancer

The prognosis of patients with nonresectable hilar biliary tract cancer (hBTC) is poor. Responsiveness to chemotherapy or radiochemotherapy is moderate at best, and patients are at a high risk of dying early from complications of local tumor infiltration (e.g., cholestasis, septic cholangitis, empyema or liver failure) rather than systemic disease. Therefore, palliative local therapy for the prevention of tumor complications plays a central role and still yields the longest survival times. Photodynamic therapy (PDT) is a local-ablative, tumor tissue-specific treatment currently representing the standard of care for nonresectable hBTC. Throughout the literature, PDT plus biliary drainage achieves median survival times in the range of 9-21 months (average 14-16 months), compared with approximately 6 months for drainage only. This article summarizes the recent advances in preclinical and clinical experience of PDT for hBTC, including experimental in vitro and in vivo studies, clinical studies and an overview of the ongoing clinical trials.

An update on cholangiocarcinoma associated with primary sclerosing cholangitis

PURPOSE OF REVIEW

Primary sclerosing cholangitis (PSC) is being diagnosed with increasing frequency. The most feared complication is the presence or development of cholangiocarcinoma (CCA). The present review summarizes recent data with regards to diagnosis, pathobiology and treatment.

RECENT FINDINGS

Several investigations have focused on aspects of the molecular biology of CCA in general; such data should be explored now in the context of PSC-related CCA to yield new diagnostic markers and approaches for therapy.

SUMMARY

CCA has to be suspected in any new PSC patient presenting with jaundice. Exploration should include carbohydrate antigen19-9 and two imaging techniques. Endoscopic cholangioscopy might become very rewarding. Important progress has been achieved in liver transplantation by the use of preoperative radio-chemotherapy. Molecular biology points to inflammation-induced cytokines with mutagenic action and to the relevance of extracellular matrix proteins for invasion but also for proliferation. Micro-RNAs prove to be very important in the control of cell proliferation, differentiation and apoptosis. Mutated p53, cyclins, wnt/beta-catenin signaling, proliferation indices, mucins, carbohydrate antigen19-9, CRP and aneuploidy appear to hold significant potential as predictors of outcome in CCA. It is expected that the further unraveling of these molecular processes will ultimately lead to development of tests allowing early diagnosis and to development of medical approaches to retard tumor formation or recurrence following surgical interventions.

Uptake and phototoxicity of meso-tetrahydroxyphenyl chlorine are highly variable in human biliary tract cancer cell lines and correlate with markers of differentiation and proliferation

Photodynamic therapy (PDT) using Photofrin and, recently, Foscan has gained broad acceptance for palliative treatment of non-resectable cholangiocarcinoma (CC). No information, however, is available whether the phenotype of CC tumour cells has an effect on the efficiency of the treatment. Using a well-characterised set of n = 9 biliary tract cancer cell lines this study investigated the uptake, phototoxicity, and release of meso-tetrahydroxyphenyl chlorine (mTHPC, Foscan) after incubation with 200 or 400 ng ml(-1) mTHPC. For uptake of mTHPC we found great variations between the individual cell lines (up to a factor 2), resulting in even more pronounced differences in phototoxicity. Based on statistical classification by hierarchical cluster analysis, two groups of cell lines can be distinguished which are characterised by either high or low susceptibility towards mTHPC-based photodynamic treatment. Correlation analysis with previously established immunochemical parameters showed that cells with a low cytokeratin-19 (ductal differentiation), high vimentin (mesenchymal marker), and high proliferative phenotype preferentially show higher uptake of mTHPC and subsequent phototoxicity. These results demonstrate high variability of biliary tract cancer cells when subjected to mTHPC-based photodynamic treatment and identify possible markers that could be used in the clinical setting in order to predict the efficiency of PDT and adjust the dose for complete tumour elimination.