Photodynamic Therapy Using Talaporfin Sodium for Local Failure after Chemoradiotherapy or Radiotherapy for Esophageal Cancer: A Single Center Experience

Predictive model for acute radiation esophagitis in esophageal carcinoma based on prognostic nutritional index and systemic inflammatory index and its application

Acute radiation esophagitis (ARE) is a common complication in patients with esophageal cancer undergoing radiotherapy. Therefore, it is important to construct an effective ARE risk-prediction model for clinical treatment. The present study performed a retrospective analysis of 225 patients with esophageal cancer who received radiotherapy at the First Affiliated Hospital of Anhui Medical University (Hefei, China) from January 2018 to December 2022. Univariate and logistic regression analyses were performed to screen patients with esophageal cancer after radiotherapy. The results revealed that 147 patients developed radiation esophagitis. Logistic regression analysis results demonstrated that the prognostic nutritional index [odds ratio (OR), 0.864; 95% confidence interval (CI), 0.809-0.924], neutrophil to lymphocyte ratio (OR, 1.795; 95% CI, 1.209-2.667) and platelet to lymphocyte ratio (OR, 1.011; 95% CI, 1.000-1.022) were independent predictors of ARE in patients receiving intensity-modulated conformal radiotherapy for esophagus cancer (P<0.05). A nomogram model for predicting the occurrence of ARE was established based on the three risk factors. The decision curve suggested a high net benefit value when the threshold probability was within 0.25-1.0. External verification confirmed the reproducibility and generalizability of the nomogram model. In general, the calibration curve of this model was close to the ideal curve and had excellent prediction accuracy. Therefore, it may be used as a new tool for early prediction of the ARE risk.

Clinical Impact of the Charlson Comorbidity Index on the Efficacy of Salvage Photodynamic Therapy Using Talaporfin Sodium for Esophageal Cancer

Introduction Photodynamic therapy (PDT) is a salvage treatment for local failure after chemoradiotherapy for esophageal cancer. Salvage PDT is the treatment available for vulnerable patients with various comorbidities at risk of salvage esophagectomy. This study assessed the impact of the Charlson comorbidity index (CCI) on the outcomes of salvage PDT using talaporfin sodium (TS) for esophageal cancer. Metohds Consecutive patients with esophageal cancer who underwent salvage TS-PDT from 2016 to 2022 were included in this retrospective study. We investigated the local complete response (L-CR), progression-free survival (PFS) and overall survival (OS) and evaluated the relationship between the CCI and therapeutic efficacy. Results In total, 25 patients were enrolled in this study. Overall, 12 patients (48%) achieved an L-CR, and the 2-year PFS and OS rates were 24.9% and 59.4%, respectively. In a multivariate analysis, a CCI ≥1 (p=0.041) and deeper invasion (p=0.048) were found to be significant independent risk factors for not achieving an L-CR. To evaluate the efficacy associated with comorbidities, we divided the patients into the CCI=0 group (n=11) and the CCI ≥1 group (n=14). The rate of an L-CR (p=0.035) and the 2-year PFS (p=0.029) and OS (p=0.018) rates in the CCI ≥1 group were significantly lower than those in the CCI=0 group. Conclusion This study found that the CCI was negatively associated with the efficacy of salvage TS-PDT for esophageal cancer.

Aluminium phthalocyanine-mediated photodynamic therapy induces ATM-related DNA damage response and apoptosis in human oesophageal cancer cells

Introduction

Photodynamic therapy (PDT) is a light-based technique used in the treatment of malignant and non-malignant tissue. Aluminium-phthalocyanine chloride tetra sulfonate (AlPcS4Cl)-mediated PDT has been well investigated on several cancer types, including oesophageal cancer. However, the effects of (AlPcS4Cl)-mediated PDT on DNA damage response and the mechanism of cell death in oesophageal cancer needs further investigation.

Methods

Here, we examined the in vitro effects of AlPcS4Cl-mediated PDT on cell cycle, DNA damage response, oxidative stress, and intrinsic apoptotic cell death pathway in HKESC-1 oesophageal cancer cells. The HKESC-1 cells were exposed to PDT using a semiconductor laser diode (673.2 nm, 5 J/cm2 fluency). Cell viability and cytotoxicity were determined by the ATP cell viability assay and the lactate dehydrogenase (LDH) release assay, respectively. Cell cycle and DNA damage response (DDR) analyses were conducted using the Muse™ cell cycle kit and the Muse® multi-color DNA damage kit, respectively. The mode of cell death was identified using the Annexin V-FITC/PI detection assay and Muse® Autophagy LC3 antibody-based kit. The intrinsic apoptotic pathway was investigated by measuring the cellular reactive oxygen species (ROS) levels, mitochondrial membrane potential (ΔΨm) function, cytochrome c levels and the activity of caspase 3/7 enzymes.

Results

The results show that AlPcS4Cl-based PDT reduced cell viability, induced cytotoxicity, cell cycle arrest at the G0/G1 phase, and DNA double-strand break (DSB) through the upregulation of the ataxia telangiectasia mutated (ATM), a DNA damage sensor. In addition, the findings showed that AlPcS4Cl-based PDT induced cell death via apoptosis, which is observed through increased ROS production, reduced ΔΨm, increased cytochrome c release, and activation of caspase 3/7 enzyme. Finally, no autophagy was observed in the AlPcS4Cl-mediated PDT-treated cells.

Conclusion

Our findings showed that apoptotic cell death is the main cell death mechanism triggered by AlPcS4Cl-mediated PDT in oesophageal cancer cells.

Novel Photodynamic Therapy for Esophageal Squamous Cell Carcinoma following Radiotherapy

Radiotherapy (RT) or chemoradiotherapy (CRT) are frequently selected as treatments for esophageal squamous cell carcinoma (ESCC). However, salvage treatment remains challenging when endoscopic resection is not indicated for residual or recurrent ESCC following RT or CRT. Recently, owing to the emergence of second-generation photodynamic therapy (PDT) using talaporfin sodium, PDT can be performed with less phototoxicity and therefore has regained popularity in the treatment of ESCC. In this study, the effectiveness and safety of second-generation PDT in patients with residual or recurrent ESCC following RT or CRT were examined. Local complete response (L-CR) rates, procedure-related adverse events, and prognosis were evaluated. In 12 patients with 20 ESCC lesions, the L-CR rates were 95.0%. Perforation, postoperative bleeding, and photosensitivity were not observed. Esophageal stricture following PDT developed in one patient, but this could be addressed using balloon dilation. During a median follow-up period of 12 (range, 3-42) months, the 3-year cause-specific survival rate was 85.7%. Even in patients with a Charlson comorbidity index score ≥ 3, the 2-year overall survival rates were 100%. In conclusion, PDT was an efficacious and a safe salvage treatment in patients with local residual or recurrent ESCC following RT or CRT.

Assessment of photodynamic therapy as a salvage treatment for local failure after chemoradiotherapy or radiotherapy for esophageal cancer in patients aged 80 years or older

Objectives

Chemoradiotherapy (CRT) or radiotherapy (RT) alone is often the treatment of choice for elderly patients with esophageal cancer with the expectation of organ preservation. However, salvage treatment remains a problem when endoscopic resection is not indicated for local failure after CRT/RT. Photodynamic therapy (PDT) is indicated for local failure after CRT/RT, but there are few reports on its efficacy and safety in elderly patients. This study aimed to assess the outcome of PDT for local failure after CRT/RT for esophageal cancer in elderly patients.

Methods

This retrospective single-center study included 42 patients who first underwent PDT between April 2013 and June 2021. Patients aged ≥80 and <80 years were classified into the elderly and nonelderly groups, respectively. Local complete response rate, overall survival, progression-free survival, and incidence of adverse events related to PDT were compared retrospectively between the groups.

Results

The local complete response rate was 93.3% in the elderly group and 85.7 in the non-elderly group. The 2-year overall survival rate was 68.6% and 72.5%, and the 2-year progression-free survival rate was 49.5% and 70.0% in the elderly and nonelderly groups, respectively. There was no significant difference in any of these outcomes between the groups. In terms of adverse events, pneumonia and delirium tended to occur more frequently in the elderly group, but there were no serious adverse events in either group.

Conclusion

The outcome of salvage PDT in the local control was comparable between the elderly and nonelderly patients for local failure after CRT/RT for esophageal cancer.

Synthesis and evaluation of radiolabeled porphyrin derivatives for cancer diagnoses and their nonradioactive counterparts for photodynamic therapy

Radioiodinated porphyrin derivatives and the corresponding nonradioactive iodine introduced compounds, [125I]I-TPPOH ([125I]3), [125I]I-l-tyrosine-TPP ([125I]9), I-TPPOH (3), and I-l-tyrosine-TPP (9) were designed, synthesized, and evaluated by in vitro and in vivo experiments. In cytotoxicity assays, 3 and 9 exhibited significant cytotoxicity under light conditions but did not show significant cytotoxicity without light irradiation. Biodistribution experiments with [125I]3 and [125I]9 showed similar distribution patterns with high retention in tumors. In photodynamic therapeutic (PDT) experiments, 3 and 9 at a dose of 13.6 μmol kg-1 weight with 50 W single light irradiation onto the tumor area significantly inhibited tumor growth. These results indicate that the iodinated porphyrin derivatives [123/natI]3 and [123/natI]9 are promising cancer theranostic agents.

Advancements in photodynamic therapy of esophageal cancer

The poor prognosis of patients with esophageal cancer leads to the constant search for new ways of treatment of this disease. One of the methods used in high-grade dysplasia, superficial invasive carcinoma, and sometimes palliative care is photodynamic therapy (PDT). This method has come a long way from the first experimental studies to registration in the treatment of esophageal cancer and is constantly being improved and refined. This review describes esophageal cancer, current treatment methods, the introduction to PDT, the photosensitizers (PSs) used in esophageal carcinoma PDT, PDT in squamous cell carcinoma (SCC) of the esophagus, and PDT in invasive adenocarcinoma of the esophagus. For this review, research and review articles from PubMed and Web of Science databases were used. The keywords used were "photodynamic therapy in esophageal cancer" in the years 2000-2020. The total number of papers returned was 1,000. After the review was divided into topic blocks and the searched publications were analyzed, 117 articles were selected.

Targeted Photodynamic Diagnosis and Therapy for Esophageal Cancer: Potential Role of Functionalized Nanomedicine

Esophageal cancer is often diagnosed at the late stage when cancer has already spread and is characterized by a poor prognosis. Therefore, early diagnosis is vital for a better and efficient treatment outcome. Upper endoscopy with biopsy is the standard diagnostic tool for esophageal cancer but is challenging to diagnose at its premalignant stage, while conventional treatments such as surgery, chemotherapy, and irradiation therapy, are challenging to eliminate the tumor. Photodynamic diagnosis (PDD) and therapy (PDT) modalities that employ photosensitizers (PSs) are emerging diagnostic and therapeutic strategies for esophageal cancer. However, some flaws associated with the classic PSs have limited their clinical applications. Functionalized nanomedicine has emerged as a potential drug delivery system to enhance PS drug biodistribution and cellular internalization. The conjugation of PSs with functionalized nanomedicine enables increased localization within esophageal cancer cells due to improved solubility and stability in blood circulation. This review highlights PS drugs used for PDD and PDT for esophageal cancer. In addition, it focuses on the various functionalized nanomedicine explored for esophageal cancer and their role in targeted PDD and PDT for diagnosis and treatment.

Current Advances in Photoactive Agents for Cancer Imaging and Therapy

Photoactive agents are promising complements for both early diagnosis and targeted treatment of cancer. The dual combination of diagnostics and therapeutics is known as theranostics. Photoactive theranostic agents are activated by a specific wavelength of light and emit another wavelength, which can be detected for imaging tumors, used to generate reactive oxygen species for ablating tumors, or both. Photodynamic therapy (PDT) combines photosensitizer (PS) accumulation and site-directed light irradiation for simultaneous imaging diagnostics and spatially targeted therapy. Although utilized since the early 1900s, advances in the fields of cancer biology, materials science, and nanomedicine have expanded photoactive agents to modern medical treatments. In this review we summarize the origins of PDT and the subsequent generations of PSs and analyze seminal research contributions that have provided insight into rational PS design, such as photophysics, modes of cell death, tumor-targeting mechanisms, and light dosing regimens. We highlight optimizable parameters that, with further exploration, can expand clinical applications of photoactive agents to revolutionize cancer diagnostics and treatment.

Salvage treatment after definitive chemoradiotherapy for esophageal squamous cell carcinoma

Definitive chemoradiotherapy (dCRT) for the esophageal squamous cell carcinoma (ESCC) is performed for patients with cT4 disease without distant metastasis and also for those with cStage I-III who are unable to tolerate or who refuse surgery. The rates of clinical complete response (cCR) after dCRT differ depending on the cStage, and patients who once achieved cCR frequently experience tumor recurrence. For those with residual tumor or with recurrence, salvage treatment is performed to achieve a cure. Several procedures have been reported as salvage treatments. Salvage esophagectomy is associated with high rates of morbidity and mortality, but can offer long-term survival. With R0 resection, with cCR to dCRT, pulmonary complications appear to be important prognostic factors affecting overall survival (OS). Lymphadenectomy is performed for the patients with lymph node metastasis without recurrence of primary lesions or distant metastasis, but the contribution to long-term OS is unclear. Metastasectomy is performed when distant metastasis is limited to the lung and there are few lesions, possibly contributing to long-term OS. Endoscopic resection and photodynamic therapy are indicated for cT1a and cT1-2 residual or recurrent tumors, respectively, and can yield favorable outcomes. Re-CRT and re-radiotherapy are performed for the patients with contraindications for surgery, but neither appears to contribute to long-term OS despite high incidences of esophageal fistula and perforation.

Clinical Practice of Photodynamic Therapy Using Talaporfin Sodium for Esophageal Cancer

Photodynamic therapy (PDT) using a conventional photosensitizer was approved for esophageal cancer in the early 1990s; however, it was replaced by other conventional treatment modalities in clinical practice because of the high frequency of cutaneous phototoxicity and esophageal stricture after the procedure. The second-generation photosensitizer, talaporfin sodium, which features more rapid clearance from the body, was developed to reduce skin phototoxicity, and talaporfin sodium can be excited at longer-wavelength lights comparing with a conventional photosensitizer. Endoscopic PDT using talaporfin sodium was initially developed for the curative treatment of central-type early lung cancer in Japan, and was approved in the early 2000s. After preclinical experiments, PDT using talaporfin sodium was investigated for patients with local failure after chemoradiotherapy, which was the most serious unmet need in the practice of esophageal cancer. According to the favorable results of a multi-institutional clinical trial, PDT using talaporfin sodium was approved as an endoscopic salvage treatment for patients with local failure after chemoradiotherapy for esophageal cancer. While PDT using talaporfin sodium is gradually spreading in clinical practice, further evaluation at the point of clinical benefit is necessary to determine the importance of PDT in the treatment of esophageal cancer.

Recent research progress in the construction of active free radical nanoreactors and their applications in photodynamic therapy

Photodynamic therapy is the most important treatment strategy in free radical therapy. However, tumor microenvironment hypoxia is a key obstacle in PDT. In order to overcome this obstacle, the strategy of in situ production of O₂/radicals by catalytic reaction in solid tumors was proposed. In recent years, it has been found that there are many oxygen-independent carbon-based free radicals that can generate toxic active free radicals under laser irradiation and lead to tumor cell death. Based on the rational design of multifunctional nano-medicine, the active free radical nano-generator has opened up a new way for the highly developed nanotechnology and tumor cooperative therapy to improve the therapeutic effect. In this paper, the research status of active free radical nano-generators, especially reactive oxygen species, including the construction mechanism of active free radical nanomaterials, is reviewed and the application of free radical nano-generators in tumor therapy is emphasized.