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

Locally Administered Photodynamic Therapy for Cancer Using Nano-Adhesive Photosensitizer

Photodynamic therapy (PDT) is a great potential anti-tumor therapy owing to its non-invasiveness and high spatiotemporal selectivity. However, systemically administered photosensitizers diffuse in the skin and the eyes for a long duration, which cause phototoxicity to bright light and sunlight. Therefore, following PDT, patients must avoid exposure of to light and sunlight to avoid this phototoxicity. In this study, we have developed a locally administered PDT using nano-adhesive porphyrin with polycations consisting of quaternary ammonium salt groups (aHP) as a photosensitizer. The aHP, approximately 3.0 nm in diameter, adhered the negatively charged cell membrane via electrostatic interaction. The aHP localized to the endosome via cell adhesion and induced apoptosis upon 635 nm light irradiation. On being administered subcutaneously on the tumor, 30% of the injected aHP remained in the administered sites. However, low-molecular-weight hematoporphyrin dihydrochloride (HP) disappeared due to rapid diffusion. PDT with locally administered aHP showed a higher anti-tumor effect after light irradiation at 635 nm for three days compared to low-molecular-weight HP. Intraperitoneal administration of HP caused severe phototoxicity upon irradiation with ultraviolet A at 10 J cm-2, whereas aHP did not cause phototoxicity because its diffusion into the skin could be suppressed, probably due to the high-molecular weight of aHP. Therefore, locally administered PDT with aHP is a potential PDT having high therapeutic efficacy without phototoxicity.

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.

Photomedicine based on heme-derived compounds

Photoimaging and phototherapy have become major platforms for the diagnosis and treatment of various health complications. These applications require a photosensitizer (PS) that is capable of absorbing light from a source and converting it into other energy forms for detection and therapy. While synthetic inorganic materials such as quantum dots and gold nanorods have been widely explored for their medical diagnosis and photodynamic (PDT) and photothermal (PTT) therapy capabilities, translation of these technologies has lagged, primarily owing to potential cytotoxicity and immunogenicity issues. Of the various photoreactive molecules, the naturally occurring endogenous compound heme, a constituent of red blood cells, and its derivatives, porphyrin, biliverdin and bilirubin, have shown immense potential as noteworthy candidates for clinically translatable photoreactive agents, as evidenced by previous reports. While porphyrin-based photomedicines have attracted significant attention and are well documented, research on photomedicines based on two other heme-derived compounds, biliverdin and bilirubin, has been relatively lacking. In this review, we summarize the unique photoproperties of heme-derived compounds and outline recent efforts to use them in biomedical imaging and phototherapy applications.

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.

Personalized Endoscopy in Complex Malignant Hilar Biliary Strictures

Malignant hilar biliary obstruction (HBO) represents a complex clinical condition in terms of diagnosis, surgical and medical treatment, endoscopic approach, and palliation. The main etiology of malignant HBO is hilar cholangiocarcinoma that is considered an aggressive biliary tract's cancer and has still today a poor prognosis. Endoscopy plays a crucial role in malignant HBO from the diagnosis to the palliation. This technique allows the collection of cytological or histological samples, direct visualization of the suspect malignant tissue, and an echoendoscopic evaluation of the primary tumor and its locoregional staging. Because obstructive jaundice is the most common clinical presentation of malignant HBO, endoscopic biliary drainage, when indicated, is the preferred treatment over the percutaneous approach. Several endoscopic techniques are today available for both the diagnosis and the treatment of biliary obstruction. The choice among them can differ for each clinical scenario. In fact, a personalized endoscopic approach is mandatory in order to perform the proper procedure in the singular patient.

Long-term results of ERCP- or PTCS-directed photodynamic therapy for unresectable hilar cholangiocarcinoma

BACKGROUND

Photodynamic therapy (PDT) can be performed as palliative therapy for cholangiocarcinoma, while there is currently insufficient evidence for the efficacy. The aim of this study was to explore the clinical efficacy and safety of endoscopic retrograde cholangiopancreatography (ERCP)- or percutaneous transhepatic cholangioscopy (PTCS)-directed PDT combined with stent placement for unresectable hilar cholangiocarcinoma.

METHODS

A retrospective analysis was conducted on 62 patients with unresectable hilar cholangiocarcinoma. Thirty patients received PDT using hematoporphyrin combined with biliary stent placement (PDT+stent group), including 22 receiving ERCP-directed PDT and 8 receiving PTCS-directed PDT. Survival time, quality of life, and postoperative adverse events were compared to 32 patients receiving biliary stent placement alone (Stent-only group).

RESULTS

After 42 months of follow-up, median survival time was significantly longer in the PDT+stent group than the Stent-only group (14.2 vs. 9.8 months, P = 0.003). In the PDT+stent group, the median survival time was longer in the 6 patients with recurrence after surgical resection than the 24 patients without prior surgical resection (20.0 vs. 13.0 months, P = 0.017). The QOL total scores was significantly higher in the PDT+stent group than the Stent-only group at postoperative 6, 9, and 12 months (P<0.05). There was no significant difference in the incidence of postoperative adverse events between the two groups (24 [38.7%] vs. 20 [29.0%], P = 0.239).

CONCLUSION

ERCP- or PTCS-directed PDT + stent placement can prolong the survival of patients with unresectable hilar cholangiocarcinoma, especially those with recurrence and improve quality of life without increasing adverse events.

Nonsurgical Approaches to Treat Biliary Tract and Liver Tumors

Endoscopic and percutaneous therapies have been shown to prolong life and reduce morbidity for patients with unresectable advanced stages of primary hepatobiliary malignancies. This article reviews pertinent studies published within the last 5 years that involve locoregional techniques to manage hepatocellular carcinoma, perihilar and distal cholangiocarcinoma. A major emphasis is placed on photodynamic therapy, radiofrequency ablation, irreversible electroporation, and microwave ablation. Technical advances, combinational therapies, and postintervention outcomes are discussed. Despite widespread application, high-quality evidence does not show superiority of any particular locoregional technique for treating advanced hepatobiliary cancers.

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.

A Basic Study of Photodynamic Therapy with Glucose-Conjugated Chlorin e6 Using Mammary Carcinoma Xenografts

By using the Warburg effect—a phenomenon where tumors consume higher glucose levels than normal cells—on cancer cells to enhance the effect of photodynamic therapy (PDT), we developed a new photosensitizer, glucose-conjugated chlorin e6 (G-Ce6). We analyzed the efficacy of PDT with G-Ce6 against canine mammary carcinoma (CMC) in vitro and in vivo. The pharmacokinetics of G-Ce6 at 2, 5, and 20 mg/kg was examined in normal dogs, whereas its intracellular localization, concentration, and photodynamic effects were investigated in vitro using CMC cells (SNP cells). G-Ce6 (10 mg/kg) was administered in vivo at 5 min or 3 h before laser irradiation to SNP tumor-bearing murine models. The in vitro study revealed that G-Ce6 was mainly localized to the lysosomes. Cell viability decreased in a G-Ce6 concentration- and light intensity-dependent manner in the PDT group. Cell death induced by PDT with G-Ce6 was not inhibited by an apoptosis inhibitor. In the in vivo study, 5-min-interval PDT exhibited greater effects than 3-h-interval PDT. The mean maximum blood concentration and half-life of G-Ce6 (2 mg/kg) were 15.19 ± 4.44 μg/mL and 3.02 ± 0.58 h, respectively. Thus, 5-min-interval PDT with G-Ce6 was considered effective against CMC.