Photodynamic Therapy (PDT), Radiofrequency Ablation (RFA) With Biliary Stents in Palliative Treatment of Unresectable Extrahepatic Cholangiocarcinoma: A Systematic Review and Meta-analysis

Surufatinib combined with photodynamic therapy induces ferroptosis to inhibit cholangiocarcinoma in vitro and in tumor models

The curative effect of single therapy for advanced cholangiocarcinoma (CCA) is poor, thus investigating combined treatment strategies holds promise for improving prognosis. Surufatinib (SUR) is a novel multikinase inhibitor that has been confirmed to prolong survival of patients with advanced CCA. Photodynamic therapy (PDT) can also ablate advanced CCA and relieve biliary obstruction. In this study, we explored the anti-CCA effect of SUR combined with PDT, and explored the underlying mechanism. We found that SUR could effectively inhibit the abilities of proliferation, migration and metastasis in CCA cells (HUCCT-1, RBE). The ability of SUR to inhibit CCA was also confirmed by the HUCCT-1 cell xenograft model in Balb/c nude mice and CCA patient-derived organoids. SUR combined with PDT can significantly enhance the inhibitory effect on CCA, and can be alleviated by two ferroptosis inhibitors (Ferrostatin-1, Deferoxamine). By detecting the level of reactive oxygen species, lipid peroxides, malondialdehyde and glutathione, we further confirmed that SUR combined with PDT can inhibit CCA cells by inducing ferroptosis. Glutathione peroxidase 4 (GPX4) belongs to the glutathione peroxidase family and is mainly responsible for the metabolism of intracellular hydrogen peroxide. GPX4 inhibits ferroptosis by reducing cytotoxic lipid peroxides (L-OOH) to the corresponding alcohols (L-OH). Acyl-CoA synthetase long-chain family member 4 (ACSL4) is a member of the long-chain fatty acid coenzyme a synthetase family and is mainly involved in the biosynthesis and catabolism of fatty acids. ACSL4 induces ferroptosis by promoting the accumulation of lipid peroxides. Both SUR and PDT can induce ferroptosis by promoting ACSL4 and inhibiting GPX4. The regulation effect is found to be more significant in combined treatment group. In conclusion, SUR combined with PDT exerted an anti-CCA effect by inducing ferroptosis. Combination therapy provides a new idea for the clinical treatment of CCA.

Advances in research and application of photodynamic therapy in cholangiocarcinoma (Review)

Cholangiocarcinoma (CCA) is a disease characterized by insidious clinical manifestations and challenging to diagnose. Patients are usually diagnosed at an advanced stage and miss the opportunity for radical surgery. Therefore, effective palliative therapy is the main treatment approach for unresectable CCA. Current common palliative treatments include biliary drainage, chemotherapy, radiotherapy, targeted therapy and immunotherapy. However, these treatments only offer limited improvement in quality of life and survival. Photodynamic therapy (PDT) is a novel local treatment method that is considered a safe tumor ablation method for numerous cancers. It has shown good efficacy in various studies of CCA and is expected to become an important treatment for CCA. In the present study, the mechanisms of PDT in the treatment of CCA were systematically explored and the progress in the research of photosensitizers was discussed. The current study focused on the various PDT protocols and their therapeutic effects in CCA, with the objective of providing a new horizon for future research and clinical applications of PDT in the treatment of CCA.

Multimodal treatment with endoscopic ablation and systemic therapy for cholangiocarcinoma

Cholangiocarcinoma (CCA) are primary malignancies of biliary system and usually unresectable at the time of diagnosis. As a consequence, majority of these cases are candidates for palliative care. With the advances in chemotherapeutic agents and multidisciplinary care, the survival rate has improved in cases with inoperable malignant biliary obstruction. As a consequence, there is a need to provide effective and durable palliative care in these patients. The main role of endoscopic palliation in the vast majority of CCA includes biliary stenting for obstructive jaundice. Recent advances in the endoscopic palliation and multimodal approach appear promising in imparting durable relief of symptoms. Use of radiofrequency ablation, photodynamic therapy and intraluminal brachytherapy has been shown to improve the survival rates as well as the patency of biliary stents. Infact, intraductal ablation may act synergistically with chemotherapy by modulating tumour signalling pathways and immune microenvironment.

Current Standards, Multidisciplinary Approaches, and Future Directions in the Management of Extrahepatic Cholangiocarcinoma

OPINION STATEMENT

Biliary tract cancers are molecularly and anatomically diverse cancers which include intrahepatic cholangiocarcinoma, extrahepatic (perihilar and distal) cholangiocarcinoma, and gallbladder cancer. While recognized as distinct entities, the rarer incidence of these cancers combined with diagnostic challenges in classifying anatomic origin has resulted in clinical trials and guideline recommended strategies being generalized patients with all types of biliary tract cancer. In this review, we delve into the unique aspects, subtype-specific clinical trial outcomes, and multidisciplinary management of patients with extrahepatic cholangiocarcinoma. When resectable, definitive surgery followed by adjuvant chemotherapy (sometimes with selective radiation/chemoradiation) is current standard of care. Due to high recurrence rates, there is growing interest in the use of upfront/neoadjuvant therapy to improve surgical outcomes and to downstage patients who may not initially be resectable. Select patients with perihilar cholangiocarcinoma are being successfully treated with novel approaches such as liver transplant. In the advanced disease setting, combination gemcitabine and cisplatin remains the standard base for systemic therapy and was recently improved upon with the addition of immune checkpoint blockade to the chemotherapy doublet in the recently reported TOPAZ-1 and KEYNOTE-966 trials. Second-line all-comer treatments for these patients remain limited in both options and efficacy, so clinical trial participation should be strongly considered. With increased use of molecular testing, detection of actionable mutations and opportunities to receive indicated targeted therapies are on the rise and are the most significant driver of improved survival for patients with advanced stage disease. Though these targeted therapies are currently reserved for the second or later line, future trials are looking at moving these to earlier treatment settings and use in combination with chemotherapy and immunotherapy. In addition to cross-disciplinary management with surgical, medical, and radiation oncology, patient-centered care should also include collaboration with advanced endoscopists, palliative care specialists, and nutritionists to improve global patient outcomes.

Comparison between regular additional endobiliary radiofrequency ablation and photodynamic therapy in patients with advanced extrahepatic cholangiocarcinoma under systemic chemotherapy

Background and aims

Extrahepatic cholangiocarcinoma (eCCA) remains a malignancy with a dismal prognosis. The first-line standard of care includes systemic chemotherapy (SC) and biliary drainage through stenting. Endobiliary ablative techniques, such as photodynamic therapy (ePDT) and radio-frequency ablation (eRFA), have demonstrated feasibility and favorable survival data. This study aimed to compare the oncologic outcome in patients treated with SC and concomitant eRFA or ePDT.

Method

All patients with eCCA were evaluated for study inclusion. Sixty-three patients receiving a combination of SC and at least one endobiliary treatment were retrospectively compared.

Results

Patients were stratified into three groups: SC + ePDT (n = 22), SC + eRFA (n = 28), and SC + ePDT + eRFA (n = 13). The median overall survival (OS) of the whole cohort was 14.2 months with no statistically significant difference between the three therapy groups but a trend to better survival for the group receiving ePDT as well as eRFA, during SC (ePDT + SC, 12.7 months; eRFA + SC, 13.8 months; ePDT + eRFA + SC, 20.2 months; p = 0.112). The multivariate Cox regression and subgroup analysis highlighted the beneficial effect of eRFA on OS. Overall, combined therapy was well tolerated. Only cholangitis occurred more often in the SC + eRFA group.

Conclusion

Additional endobiliary ablative therapies in combination with SC were feasible. Both modalities, eRFA and ePDT, showed a similar benefit in terms of survival. Interestingly, patients receiving both regimes showed the best OS indicating a possible synergism between both ablative therapeutic techniques.

Impact of endobiliary radiofrequency ablation on survival of patients with unresectable cholangiocarcinoma: a narrative review

Cholangiocarcinoma (CCA) is a rare cancer originating from the biliary epithelium and accounts for about 3% of all gastrointestinal malignancies. Unfortunately, the majority of patients are not eligible for surgical resection at the time of diagnosis, because of the locally advanced stage or metastatic disease. The overall survival time of unresectable CCA is generally less than 1 year, despite current chemotherapy regimens. Biliary drainage is often required as a palliative treatment for patients with unresectable CCA. Recurrent jaundice and cholangitis tend to occur because of reobstruction of the biliary stents. This not only jeopardizes the efficacy of chemotherapy, but also causes significant morbidity and mortality. Effective control of tumor growth is crucial for prolonging stent patency and consequently patient survival. Recently, endobiliary radiofrequency ablation (ERFA) has been experimented as a treatment modality to reduce tumor mass, and delay tumor growth, extending stent patency. Ablation is accomplished by means of high-frequency alternating current which is released from the active electrode of an endobiliary probe placed in a biliary stricture. It has been shown that tumor necrosis releases intracellular particles which are highly immunogenic and activate antigen-presenting cells, enhancing local immunity directed against the tumor. This immunogenic response could potentially enhance tumor suppression and be responsible for improved survival of patients with unresectable CCA who undergo ERFA. Several studies have demonstrated that ERFA is associated with an increased median survival of approximately 6 months in patients with unresectable CCA. Furthermore, recent data support the hypothesis that ERFA could ameliorate the efficacy of chemotherapy administered to patients with unresectable CCA, without increasing the risk of complications. This narrative review discusses the results of the studies published in recent years and focuses on the impact that ERFA could have on overall survival of patients with unresectable cholangiocarcinoma.

Efficacy and Safety of Radiofrequency Ablation Plus Stent Versus Stent-alone Treatments for Malignant Biliary Strictures: A Systematic Review and Meta-analysis

BACKGROUND/AIMS

Malignant biliary strictures (MBS) are very aggressive and cannot be diagnosed in the early stages due to their asymptomatic nature. Stenting the stricture area of the biliary tree is palliative treatment but has poor survival time. Radiofrequency ablation plus stent (RFA+S) have been recently used to improve the survival and stent patency time in patients with MBS. In this systematic review and meta-analysis, we tried to evaluate the efficacy and safety of radiofrequency ablation.

MATERIALS AND METHODS

Study search up to December 2021 was performed in different medical databases such as PubMed, Web of Science, and Cochrane library, etc. We selected eligible studies reporting survival time, stent patency time, and adverse events in patients with MBS. We compare the outcomes of RFA+S and stent-alone treatment groups.

RESULTS

A total of 15 studies (6 randomized controlled trials and 9 observational studies) with 1815 patients were included for meta-analysis of which 701 patients were in RFA+S group and 1114 patients in the stent-alone group. Pooled mean difference of survival time was 2.88 months (95% CI: 1.78-3.97) and pooled mean difference of stent patency time was 2.11 months (95% CI: 0.91-3.30) and clinical success risk ratio was 1.05 (95% CI: 1.01-1.09). Risk ratios for adverse events are given; Bleeding 0.84 (95% CI: 0.34-2.11), abdominal pain 1.06 (95% CI: 0.79-1.40), pancreatitis 0.93 (95% CI: 0.43-2.01), cholangitis 1.07 (95% CI: 0.72-1.59), and stent dysfunction 0.87 (95% CI: 0.70-1.07).

CONCLUSIONS

Radiofrequency ablation is involved in increased survival and stent patency time for MBS patients. With the help of better techniques, adverse events can be limited.

Research progress of potential factors influencing photodynamic therapy for gastrointestinal cancer

Gastrointestinal cancer is a malignant tumor of the gastrointestinal tract and its associated digestive organs, including esophageal cancer, gastric cancer, carcinoma of the ampulla, pancreas, bile duct, intestines and rectal cancer. They account for about 30% of global cancer-related incidence and about 40% of mortality. Photodynamic therapy (PDT), as a treatment mode, has been applied to the treatment of gastrointestinal cancer due to potential advantages targeting and potentially lower toxic side effects. However, In the course of clinical treatment, we have found that different patients have various responsiveness to PDT, and even the same patients may have different clinical effects after receiving treatment in different time periods. For influencing factors, traditionally, we only focus on adjusting the dose of photosensitizer and the intensity and time of irradiation,while minimizing other potential factors.Therefore, this paper looks for factors that affect PDT from the patient's own conditions, tumor characteristics and tumor microenvironment(including:tumor acidic microenvironment,tumor hypoxic microenvironment, multi-drug resistance, different tumor characteristics and the immune status of patients) and summarizes how to potentially improve the curative effect of PDT.

Endoscopic palliation of malignant biliary obstruction

Malignant biliary obstruction often presents with challenges requiring the endoscopist to assess the location of the lesion, the staging of the disease, the eventual resectability and patient preferences in term of biliary decompression. This review will focus on the different modalities available in order to offer the most appropriate palliation, such as conventional endoscopic retrograde cholangiopancreatography, endoscopic ultrasound guided biliary drainage as well as ablative therapies including photodynamic therapy or radiofrequency ablation.

Synergetic Thermal Therapy for Cancer: State-of-the-Art and the Future

As a safe and minimal-invasive modality, thermal therapy has become an effective treatment in cancer treatment. Other than killing the tumor cells or destroying the tumor entirely, the thermal modality results in profound molecular, cellular and biological effects on both the targeted tissue, surrounding environments, and even the whole body, which has triggered the combination of the thermal therapy with other traditional therapies as chemotherapy and radiation therapy or new therapies like immunotherapy, gene therapy, etc. The combined treatments have shown encouraging therapeutic effects both in research and clinic. In this review, we have summarized the outcomes of the existing synergistic therapies, the underlying mechanisms that lead to these improvements, and the latest research in the past five years. Limitations and future directions of synergistic thermal therapy are also discussed.

Comparing palliative treatment options for cholangiocarcinoma: photodynamic therapy vs. radiofrequency ablation

Referral to an endoscopist is often done once curative resection is no longer an option for cholangiocarcinoma management. In such cases, palliation has become the main objective of the treatment. Photodynamic therapy and radiofrequency ablation can be performed to achieve palliation, with both procedures associated with improved stent patency and survival. Despite the greatly increased cost and association with photosensitivity, photodynamic therapy allows transmission to the entire biliary tree. In contrast, radiofrequency ablation is cheaper and faster to apply, but requires intraductal contact. This paper reviews both modalities and compares their efficacy and safety for bile duct cancer palliation.

[A Recent Update on Endoscopic Drainage of Advanced Malignant Hilar Obstruction]

Malignant hilar obstruction (MHO) is considered an aggressive perihilar obstruction caused by cholangiocarcinoma, gallbladder cancer, or metastatic malignancies and has a poor prognosis. Although surgical resection is the only curative treatment method, the majority of patients with MHO do not undergo surgery due to an advanced inoperable state at presentation. Currently, effective biliary drainage provides the necessary palliation for symptomatic improvement. Among the drainage methods, percutaneous access may be preferred, especially for advanced MHO because of the technical difficulty involved with other techniques. Recently, primary endoscopic palliation using plastic or metal stents has been shown to have higher technical feasibility and clinical success without increasing adverse events even in patients with high-degree MHO. The development of various accessories, endoscopic ultrasonography, and advances in techniques have facilitated primary endoscopic intervention. However, some aspects continue to be debated such as the palliation methods, appropriate stents, the number of stents, the deployment methods, and additional local ablation therapies. Therefore, this review discusses the current optimal endoscopic treatment methods for advanced MHO based on reported literature.