Long-term survival after photodynamic therapy for esophageal cancer

Cytocidal Effect of Irradiation on Gastric Cancer Cells Infected with a Recombinant Mammalian Orthoreovirus Expressing a Membrane-Targeted KillerRed

The outcomes of unresectable gastric cancer (GC) are unfavorable even with chemotherapy; therefore, a new treatment modality is required. The combination of an oncolytic virus and photodynamic therapy can be one of the promising modalities to overcome this. Mammalian orthoreovirus (MRV) is an oncolytic virus that has been used in clinical trials for several cancers. In this study, we developed and evaluated a recombinant MRV strain type 3 Dearing (T3D) that expresses membrane-targeting KillerRed (KRmem), a phototoxic fluorescent protein that produces cytotoxic reactive oxygen species upon light irradiation. KRmem was fused in-frame to the 3' end of the σ2 viral gene in the S2 segment using a 2A peptide linker, enabling the expression of multiple proteins from a single transcript. RNA electrophoresis, Western blotting, and immunofluorescence analyses confirmed functional insertion of KRmem into the recombinant virus. The growth activity of the recombinant virus was comparable to that of the wild-type MRV in a cultured cell line. The recombinant virus infected two GC cell lines (MKN45P and MKN7), and a significant cytocidal effect was observed in MKN45P cells infected with the recombinant virus after light irradiation. Thus, recombinant MRV-expressing KRmem has the potential to serve as a novel treatment tool for GC.

Endoscope Capsules: The Present Situation and Future Outlooks

This paper presents new perspectives on photonic technologies for capsule endoscopy. It first presents a review of conventional endoscopy (upper endoscopy and colonoscopy), followed by capsule endoscopy (CE), as well as their techniques, advantages, and drawbacks. The technologies for CEs presented in this paper include integration with the existing endoscopic systems that are commercially available. Such technologies include narrow-band imaging (NBI), photodynamic therapy (PDT), confocal laser endomicroscopy (CLE), optical coherence tomography (OCT), and spectroscopy in order to improve the performance of the gastrointestinal (GI) tract examination. In the context of NBI, two optical filters were designed and fabricated for integration into endoscopic capsules, allowing for the visualization of light centered at the 415 nm and 540 nm wavelengths. These optical filters are based on the principle of Fabry-Perot and were made of thin films of titanium dioxide (TiO2) and silicon dioxide (SiO2). Moreover, strategies and solutions for the adaptation of ECs for PDT are also discussed.

Hypoxia signaling in cancer: Implications for therapeutic interventions

Hypoxia is a persistent physiological feature of many different solid tumors and a key driver of malignancy, and in recent years, it has been recognized as an important target for cancer therapy. Hypoxia occurs in the majority of solid tumors due to a poor vascular oxygen supply that is not sufficient to meet the needs of rapidly proliferating cancer cells. A hypoxic tumor microenvironment (TME) can reduce the effectiveness of other tumor therapies, such as radiotherapy, chemotherapy, and immunotherapy. In this review, we discuss the critical role of hypoxia in tumor development, including tumor metabolism, tumor immunity, and tumor angiogenesis. The treatment methods for hypoxic TME are summarized, including hypoxia-targeted therapy and improving oxygenation by alleviating tumor hypoxia itself. Hyperoxia therapy can be used to improve tissue oxygen partial pressure and relieve tumor hypoxia. We focus on the underlying mechanisms of hyperoxia and their impact on current cancer therapies and discuss the prospects of hyperoxia therapy in cancer treatment.

A two-pronged strategy to alleviate tumor hypoxia and potentiate photodynamic therapy by mild hyperthermia

The application of photodynamic therapy (PDT) is limited by tumor hypoxia. To overcome hypoxia, catalase-like nanozymes are often used to catalyze endogenous H2O2 enriched in tumor tissues to O2. Nonetheless, the catalase activity may not be optimal at body temperature and the O2 supply may not meet the rapid O2 consumption of PDT. Herein, we provide a two-pronged strategy to alleviate tumor hypoxia based on hollow mesoporous Prussian blue nanoparticles (HMPB NPs). HMPB NPs can efficiently load the photosensitizer chlorin e6 (Ce6) and exhibit photothermal capability and temperature-dependent catalase activity. Under 808 nm laser irradiation, the photothermal effect of HMPB NPs elevated the catalase activity of HMPB NPs for O2 production. Furthermore, mild hyperthermia reduced cancer associated fibroblasts (CAFs) and induced extracellular matrix (ECM) degradation. The reduction of CAFs and the ECM decreased the solid stress of tumor tissues and normalized the tumor vasculature, which was beneficial for the external supplementation of O2 to tumors. Thereafter, under 606 nm laser irradiation, Ce6-mediated PDT generated excessive reactive oxygen species (ROS) that induced tumor cell apoptosis and achieved a high tumor inhibition rate of 92.2% in 4T1 breast tumors. Our work indicated that the alleviation of tumor hypoxia from both internal and external pathways significantly enhanced Ce6-mediated PDT against breast cancers.

J, M.D.P. DE. C, RAJENDRAM S. Photodynamic Therapy : An Overview and Insights into a Prospective Mainstream Anticancer Therapy

Photodynamic therapy (PDT) procedure has minimum invasiveness in contrast to conventional anticancer surgical procedures. Although clinically approved a few decades ago, it is not commonly used due to its poor efficacy, mainly due to poor light penetration into deeper tissues. PDT uses a photosensitizer (PS), which is photoactivated on illumination by light of appropriate wavelength and oxygen in the tissue, leading to a series of photochemical reactions producing reactive oxygen species (ROS) triggering various mechanisms resulting in lethal effects on tumor cells. This review looks into the fundamental aspects of PDT, such as photochemistry, photobiological effects, and the current clinical applications in the light of improving PDT to become a mainstream therapeutic procedure against a broad spectrum of cancers and malignant lesions. The side effects of PDT, both early and late-onset, are elaborated on in detail to highlight the available options to minimize side effects without compromising therapeutic efficacy. This paper summarizes the benefits, drawbacks, and limitations of photodynamic therapy along with the recent attempts to achieve improved therapeutic efficacy via monitoring various cellular and molecular processes through fluorescent imagery aided by suitable biomarkers, prospective nanotechnology-based targeted delivery methods, the use of scintillating nanoparticles to deliver light to remote locations and also combining PDT with conventional anticancer therapies have opened up new dimensions for PDT in treating cancers. This review inquires and critically analyses prospective avenues in which a breakthrough would finally enable PDT to be integrated into mainstream anticancer therapy.

Advances in chlorin-based photodynamic therapy with nanoparticle delivery system for cancer treatment

Introduction: The treatment of tumors is one of the most difficult problems in the medical field at present. Patients often use a comprehensive therapy that combines surgery, radiotherapy, and chemotherapy. Photodynamic therapy (PDT) has prominent potential for eradicating various cancers. Chlorin-based photosensitizers (PSs), as one of the most utilized photosensitizers, have many advantages over conventional photosensitizers; however, a successful chlorin-based PDT needs multi-functional nano-carriers for selective photosensitizer delivery. The number of researches about nanoparticles designed for improved chlorin-based PSs is increasing in the current era. In this article, we give a brief review focused on the recent research progress in design of chlorin-based nanoparticles for the treatment of malignant tumors with photodynamic therapy.Areas covered: This review focuses on the current nanoparticle platforms for PDT, and describes different strategies to achieve controllable PDT by chlorin-nano-delivery systems. The challenges and prospects of PDT in clinical applications are also discussed.Expert opinions: The requirement for PDT to eradicate cancers has increased exponentially in recent years. The major clinically used photosensitizers are hydrophobic. The main obstacles in effective delivery of PSs are associated with this intrinsic nature. The design of nano-delivery systems to load PSs is pivotal for PSs' widespread use.

Ring-Fused Diphenylchlorins as Potent Photosensitizers for Photodynamic Therapy Applications: In Vitro Tumor Cell Biology and in Vivo Chick Embryo Chorioallantoic Membrane Studies

Ring-fused diphenylchlorins as potent low-dose photosensitizers for photodynamic therapy of bladder carcinoma and esophageal adenocarcinoma are described. All studied molecules were very active against HT1376 urinary bladder carcinoma and OE19 esophageal adenocarcinoma cell lines, showing IC50 values below 50 nM. The in vivo evaluation of the more promising photosensitizer, using an OE19 tumor/chick embryo chorioallantoic membrane model, showed a tumor weight regression of 33% with a single photodynamic therapy treatment with the photosensitizer dose as low as 37 ng/embryo.

Endoscopic management of esophageal cancer

Esophageal cancer (EC) generally consists of squamous cell carcinoma (which arise from squamous epithelium) and adenocarcinoma (which arise from columnar epithelium). Due to the increased recognition of risk factors associated with EC and the development of screening programs, there has been an increase in the diagnosis of early EC. Early EC is amenable to curative therapy by endoscopy, which can be performed by either endoscopic resection or endoscopic ablation. Endoscopic resection consists of either endoscopic mucosal resection (preferred in cases of adenocarcinoma) or endoscopic submucosal dissection (preferred in cases of squamous cell carcinoma). Endoscopic ablation can be performed by either radiofrequency ablation, cryotherapy, argon plasma coagulation or photodynamic therapy, amongst others. Endoscopy can also assist in the management of complications post-esophageal surgery, such as anastomotic leaks and perforations. Finally, there is a growing role for endoscopy to manage end-of-life palliative symptoms, especially dysphagia. The growing use of esophageal stents, debulking therapy and dilation can assist in improving a patient’s quality of life. In this review, we examine the multiple roles of endoscopy in the management of patients with EC.

High-affinity graphene oxide-encapsulated magnetic Zr-MOF for pretreatment and rapid determination of the photosensitizers hematoporphyrin and hematoporphyrin monomethyl ether in human urine prior to UPLC-HRMS

In this paper, a high-affinity graphene oxide-encapsulated magnetic Zr-MOF (GO-Mag@Zr-MOF) was synthesized and characterized by SEM, TEM, and XPS for its morphology, structure, and components. Subsequently, the as-prepared GO-Mag@Zr-MOF was, for the first time, employed as magnetic solid-phase extraction (MSPE) adsorbent for pretreatment and determination of photodynamic therapy (PDT) with the photosensitizers hematoporphyrin (Hp) and hematoporphyrin monomethyl ether (HMME) in human urine samples coupled with ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). The synthesized GO-Mag@Zr-MOF revealed excellent adsorption efficiency for Hp and HMME in urine samples. Under optimal conditions, the spiked recoveries of the developed method were in the range of 89.5-105.6% with RSDs less than 10%. The limits of detection (LODs) were found to be 0.036 and 0.042 μg/L for Hp and HMME, respectively, while limits of quantitation (LOQs) were 0.12 and 0.14 μg/L. The proposed method was found to be rapid, effective, sensitive, and accurate for clinical analysis. Moreover, this paper, for the first time, carefully expounded the mass spectrum cracking mechanisms of Hp and HMME. Graphical abstract ᅟ.

Multi-OMIC profiling of survival and metabolic signaling networks in cells subjected to photodynamic therapy

Photodynamic therapy (PDT) is an established palliative treatment for perihilar cholangiocarcinoma that is clinically promising. However, tumors tend to regrow after PDT, which may result from the PDT-induced activation of survival pathways in sublethally afflicted tumor cells. In this study, tumor-comprising cells (i.e., vascular endothelial cells, macrophages, perihilar cholangiocarcinoma cells, and EGFR-overexpressing epidermoid cancer cells) were treated with the photosensitizer zinc phthalocyanine that was encapsulated in cationic liposomes (ZPCLs). The post-PDT survival pathways and metabolism were studied following sublethal (LC₅₀) and supralethal (LC₉₀) PDT. Sublethal PDT induced survival signaling in perihilar cholangiocarcinoma (SK-ChA-1) cells via mainly HIF-1-, NF-кB-, AP-1-, and heat shock factor (HSF)-mediated pathways. In contrast, supralethal PDT damage was associated with a dampened survival response. PDT-subjected SK-ChA-1 cells downregulated proteins associated with EGFR signaling, particularly at LC₉₀. PDT also affected various components of glycolysis and the tricarboxylic acid cycle as well as metabolites involved in redox signaling. In conclusion, sublethal PDT activates multiple pathways in tumor-associated cell types that transcriptionally regulate cell survival, proliferation, energy metabolism, detoxification, inflammation/angiogenesis, and metastasis. Accordingly, tumor cells sublethally afflicted by PDT are a major therapeutic culprit. Our multi-omic analysis further unveiled multiple druggable targets for pharmacological co-intervention.

Translational research in thoracic surgery-the National Taiwan University Hospital experience

Thoracic surgeons should be more aware of the latest information about histopathological, genetic and epigenetic alterations that may influence treatment policy and patient outcome in the biomolecular era. Translational research studies often produce a promising diagnostic tool or new treatment that can be used clinically. The results of these translational studies may even change the practical guidelines and current staging system in thoracic malignancies. The following article summarizes the experiences of translational research in esophageal cancer and non-small cell lung cancer (NSCLC) at National Taiwan University Hospital in Taiwan.

Salvage photodynamic therapy for local failure after chemoradiotherapy for esophageal squamous cell carcinoma

BACKGROUND AND AIMS

Photodynamic therapy (PDT) is a less-invasive salvage treatment option for local failure at the primary site after chemoradiotherapy (CRT) for esophageal squamous cell carcinoma. The objective of this study was to clarify the long-term outcomes and prognostic factors of salvage PDT.

METHODS

One hundred thirteen consecutive patients treated in our institution with PDT for local failure limited to within T2 without any metastases after definitive CRT performed between 1998 and 2008 were retrospectively enrolled. The complete response rate, adverse events, and survival outcomes were assessed and prognostic factors were investigated using a multivariate analysis.

RESULTS

The complete response rate was 58.4% (95% confidence interval [CI], 49.3%-67.5%). The progression-free survival (PFS) and the overall survival (OS) rates at 5 years after salvage PDT were 22.1% (95% CI, 14.3%-30.0%) and 35.9% (95% CI, 26.7%-45.1%). N0 before CRT was significantly associated with OS (hazard ratio [HR], 0.54; 95% CI, 0.33-0.91, P = .020), whereas the impact of T1 or T2 before CRT on PFS (HR, 0.63; 95% CI, 0.38-1.04, P = .068) and that of a longer period between CRT and PDT on OS (HR, 0.64; 95% CI, 0.39-1.05, P = .078) were marginal. The treatment-related death rate was 1.8%.

CONCLUSIONS

Salvage PDT was found to have a superior outcome and a satisfactory safety profile. An earlier clinical stage before CRT and a longer interval between CRT and PDT may be associated with a longer survival period.

Local efficacy and survival outcome of salvage endoscopic therapy for local recurrent lesions after definitive chemoradiotherapy for esophageal cancer

BACKGROUND

Salvage endoscopic therapy (SET), such as endoscopic mucosal resection (EMR) and photodynamic therapy (PDT), is a less-invasive treatment for local failure at the primary site after chemoradiotherapy (CRT) for esophageal squamous cell carcinoma (ESCC). We conducted this retrospective study to clarify the risk factors for local recurrence along with the long term results after SET for recurrent lesions after definitive CRT for ESCC.

METHODS

We enrolled 77 consecutive patients who underwent EMR or PDT for local recurrence without any metastasis after definitive CRT at our institution. We evaluated the local efficacy, local recurrence-free survival (LRFS), and overall survival (OS), and investigated the risk factors associated with survival outcome using a multivariate analysis.

RESULTS

The complete resection rate of EMR was 84.6 % (33/39), and the complete response rate for PDT was 65.8 % (25/38). Twenty-two patients (28.6 %) exhibited local recurrence without metastasis. Thirty-four patients (44.2 %) were alive at 5 years after undergoing only initial SET or with repeated SET. The 5-year LRFS rate was 59.6 %, and the presence of lesions occupying an esophageal circumference of 1/4 or larger was the only significant risk factor (HR: 3.10, 95 % CI: 1.35-7.15, P = 0.008). The 5-year OS rate was 48.4 %, and an advanced T factor before CRT was marginally associated with a poor OS (HR: 1.96, 95 % CI: 0.98-3.92, P = 0.055).

CONCLUSIONS

SET enabled a preferable local control and survival outcome for patients with local recurrence after definitive CRT for ESCC. Careful endoscopic follow-up is needed for patients with a large lesion before SET and those with an advanced T factor before CRT.

Low-power photodynamic therapy induces survival signaling in perihilar cholangiocarcinoma cells

Background

Photodynamic therapy (PDT) of solid cancers comprises the administration of a photosensitizer followed by illumination of the photosensitizer-replete tumor with laser light. This induces a state of local oxidative stress, culminating in the destruction of tumor tissue and microvasculature and induction of an anti-tumor immune response. However, some tumor types, including perihilar cholangiocarcinoma, are relatively refractory to PDT, which may be attributable to the activation of survival pathways in tumor cells following PDT (i.e., activator protein 1 (AP-1)-, nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB)-, hypoxia-inducible factor 1-alpha (HIF-1α)-, nuclear factor (erythroid-derived 2)-like 2 (NFE2L2)-, and unfolded protein response-mediated pathways).

Methods

To assess the activation of survival pathways after PDT, human perihilar cholangiocarcinoma (SK-ChA-1) cells were subjected to PDT with zinc phthalocyanine (ZnPC)-encapsulating liposomes. Following 30-minute incubation with liposomes, the cells were either left untreated or treated at low (50 mW) or high (500 mW) laser power (cumulative light dose of 15 J/cm²). Cells were harvested 90 min post-PDT and whole genome expression analysis was performed using Illumina HumanHT-12 v4 expression beadchips. The data were interpreted in the context of the survival pathways. In addition, the safety of ZnPC-encapsulating liposomes was tested both in vitro and in vivo.

Results

PDT-treated SK-ChA-1 cells exhibited activation of the hypoxia-induced stress response via HIF-1α and initiation of the pro-inflammatory response via NF-кB. PDT at low laser power in particular caused extensive survival signaling, as evidenced by the significant upregulation of HIF-1- (P < 0.001) and NF-кB-related (P < 0.001) genes. Low-power PDT was less lethal to SK-ChA-1 cells 90 min post-PDT, confirmed by annexin V/propidium iodide staining. In vitro toxicogenomics and toxicological testing in chicken embryos and mice revealed that the ZnPC-encapsulating liposomes are non-toxic.

Conclusions

PDT-treated perihilar cholangiocarcinoma cells exhibit extensive survival signaling that may translate to a suboptimal therapeutic response and possibly tumor recurrence. These findings encourage the development of photosensitizer delivery systems with co-encapsulated inhibitors of survival pathways.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1994-2) contains supplementary material, which is available to authorized users.

A Surgical View of Photodynamic Therapy in Oncology: A Review

Clinical photodynamic therapy (PDT) has existed for over 30 years, and its scientific basis has been known and investigated for well over 100 years. The scientific foundation of PDT is solid and its application to cancer treatment for many common neoplastic lesions has been the subject of a huge number of clinical trials and observational studies. Yet its acceptance by many clinicians has suffered from its absence from the undergraduate and/or postgraduate education curricula of surgeons, physicians, and oncologists. Surgeons in a variety of specialties many with years of experience who are familiar with PDT bear witness in many thousands of publications to its safety and efficacy as well as to the unique role that it can play in the treatment of cancer with its targeting precision, its lack of collateral damage to healthy structures surrounding the treated lesions, and its usage within minimal access therapy. PDT is closely related to the fluorescence phenomenon used in photodiagnosis. This review aspires both to inform and to present the clinical aspect of PDT as seen by a surgeon.

Photodynamic therapy downregulates the function of regulatory T cells in patients with esophageal squamous cell carcinoma

Photodynamic therapy (PDT) by selective photosensitization of cancer cells and subsequent laser application results in local tumor necrosis. However, the effects of PDT on immune function, which may depend on the type of immune response, are controversial. We investigated the immunological changes induced by PDT and the effect of PDT on level and function of regulatory T cells (Treg) in patients with invasive esophageal squamous cell carcinoma (ESCC). We analyzed patient's blood samples before and after PDT. Blood CD4+CD25+CD127-FoxP3+ Treg levels were quantified by FACS, and Treg function was evaluated by coculture proliferation assays with T effector (Teff) cells. We found that PDT abrogated the suppressive capacity of peripheral Treg (Days 7 and 14, p = 0.016) but had no effect on Treg levels. The effect of PDT on Treg function at Day 7 was accompanied by slight but statistically significant increases in peripheral neutrophil granulocytes (p = 0.035) and monocytes (p = 0.013) and a statistically significant increase (approximately 18-fold) in serum IL-6 levels (p = 0.008). In conclusion, PDT abolished Treg function, possibly due to increased IL-6 levels in treated ESCC patients. This may be crucial for an improved therapeutic outcome.

Treatment modalities for T1N0 esophageal cancers: a comparative analysis of local therapy versus surgical resection

BACKGROUND

To investigate the role of nonsurgical treatment for early-stage esophageal cancer, we compared the outcomes of local therapy to esophagectomy, using a large, national database.

METHODS

Five-year cancer-specific and overall survival (OS) of patients, with T1N0M0 squamous cell or adenocarcinoma of the mid or distal esophagus treated with either surgery or local therapy, with ablative and/or excision techniques, in the Surveillance Epidemiology and End Results cancer registry from 1998 to 2008, were compared using the Kaplan-Meier approach, and multivariable and propensity-score adjusted Cox proportional hazard, and competing risk models.

RESULTS

Of 1458 patients with T1N0 esophageal cancer, 1204 (83%) had surgery and 254 (17%) had local therapy only. The use of local therapy increased significantly from 8.1% in 1998 to 24.1% in 2008 (p < 0.001). The 5-year OS after local excisional therapy and surgery was not significantly different (55.5% versus 64.1% respectively, p = 0.07), and 5-year cancer-specific survival (CSS) also did not differ (81.7% versus 75.8%, p = 0.10). However, after propensity-score adjustment, CSS was better for patients who underwent local therapy compared with those who underwent surgery (hazard ratio: 0.46, 95% confidence interval: 0.27-0.77, p = 0.003), whereas OS remained similar.

CONCLUSION

The use of local therapy for T1N0 esophageal cancers increased significantly from 1998 to 2008. Compared with those treated with esophagectomy, patients treated with local therapy had similar OS but improved CSS, indicating a higher chance of dying from other causes. Further studies are needed to confirm the oncologic efficacy of local therapy when used in patients whose lifespans are not limited by conditions other than esophageal cancer.

Targeting-triggered porphysome nanostructure disruption for activatable photodynamic therapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) possess advantages over the conventional therapies with additional treatment selectivity achieved with local laser irradiation. Comparing to PTT that ablates target tissue via thermal necrosis, PDT induces target cell death via singlet oxygen without damaging the underling connective tissue, thus preserving its biological function. Activatable photosensitizers provide an additional level of treatment selectivity via the disease-associated activation mechanism. In this study, folate-conjugated porphysomes are introduced as targeting-triggered activatable nano-sized beacons for PDT. Porphysomes are reported previously as the most stable and efficient delivery system of porphyrin, but their nanostructure converts the singlet oxygen generation mechanism to thermal ablation mechanism. By folate-receptor-mediated endocytosis, folate-porphysomes are internalized into cells rapidly and resulted in efficient disruption of nanostructures, thus switching back on the photodynamic activity of the densely packed porphyrins for effective PDT. In both in vitro and in vivo studies, folate-porphysomes can achieve folate receptor-selective PDT efficacy, which proves the robustness of targeting-triggered PDT activation of porphysome nanostructure for highly selective tumor ablation. The formulation of porphysomes can be modified with other targeting ligands as activatable photosensitizers for personalized treatment in future.

Esophageal cancer: staging system and guidelines for staging and treatment

Survival of esophageal cancer is improving but remains poor. Esophageal cancer stage is based on depth of tumor invasion, involvement of regional lymph nodes, and the presence or absence of metastatic disease. Appropriate work-up is critical to identify accurate pre-treatment staging so that both under-treatment and unnecessary treatment is avoided. Treatment strategy should follow guideline recommendations, and generally should be developed after multidisciplinary evaluation.

Improved photodynamic efficacy of Zn(II) phthalocyanines via glycerol substitution

Phthalocyanines are excellent photosensitizers for photodynamic therapy as they have strong absorbance in the near infra-red region which is most relevant for in vivo activation in deeper tissular regions. However, most phthalocyanines present two major challenges, ie, a strong tendency to aggregate and low water-solubility, limiting their effective usage clinically. In the present study, we evaluated the potential enhancement capability of glycerol substitution on the photodynamic properties of zinc (II) phthalocyanines (ZnPc). Three glycerol substituted ZnPc, 1–3, (tetra peripherally, tetra non-peripherally and mono iodinated tri non-peripherally respectively) were evaluated in terms of their spectroscopic properties, rate of singlet oxygen generation, partition coefficient (log P), intracellular uptake, photo-induced cytotoxicity and vascular occlusion efficiency. Tetrasulfonated ZnPc (ZnPcS₄) was included as a reference compound. Here, we showed that 1–3 exhibited 10–100 nm red-shifted absorption peaks with higher molar absorptivity, and at least two-fold greater singlet oxygen generation rates compared to ZnPcS₄. Meanwhile, phthalocyanines 1 and 2 showed more hydrophilic log P values than 3 consistent with the number of glycerol attachments but 3 was most readily taken up by cells compared to the rest. Both phthalocyanines 2 and 3 exhibited potent phototoxicity against MCF-7, HCT-116 and HSC-2 cancer cell-lines with IC₅₀ ranging 2.8–3.2 µM and 0.04–0.06 µM respectively, while 1 and ZnPcS₄ (up to 100 µM) failed to yield determinable IC₅₀ values. In terms of vascular occlusion efficiency, phthalocyanine 3 showed better effects than 2 by causing total occlusion of vessels with diameter <70 µm of the chorioallantoic membrane. Meanwhile, no detectable vascular occlusion was observed for ZnPcS₄ with treatment under similar experimental conditions. These findings provide evidence that glycerol substitution, in particular in structures 2 and 3, is able to improve the photodynamic properties of ZnPc.

Efficacy of 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a in photodynamic therapy of human esophageal squamous cancer cells

The present study investigated the effects of 2-(1-hexyloxyethyl)-2-devinylpyro pheophorbide-a (HPPH)-mediated photodynamic therapy (PDT) on in vitro cell survival and in vivo tumor growth derived from human esophageal squamous cancer cells (Eca109). A cell counting kit 8 (CCK8) assay was used to assess the phototoxicity of HPPH-mediated PDT in cultured Eca109 cells. The inhibition of tumor growth was determined by the changes in the relative tumor volume (RTV) and tumor weight. The results revealed that HPPH, in the range of 0.005-1 μg/ml, exhibited no cytotoxicity in the Eca109 cells without light exposure and that the in vitro efficiency of HPPH-mediated PDT was higher compared with that of Photofrin^®-mediated PDT. The in vivo results indicated that graded doses of HPPH-mediated PDT significantly inhibited the xenograft tumor growth derived from the Eca109 cells in a dose-dependent manner. The inhibition efficacy of 0.6 and 1.0 mg/kg HPPH-mediated PDT was similar to that of 10 mg/kg Photofrin-mediated PDT. Furthermore, HPPH possessed a lower toxicity than Photofrin at the dose that achieved the same efficacy in mice bearing Eca109 subcutaneous tumors. The histopathological findings indicated that the tumor tissues in the photosensitizer (PS)-treated mice demonstrated varying degrees of necrosis. HPPH and Photofrin exhibited vascular cytotoxicity on the treated tumors. In conclusion, the present study demonstrated that the phototoxicity of HPPH-mediated PDT is higher than that of Photofrin-mediated PDT of the same dose. HPPH possessed lower toxicity than Photofrin at the dose that achieved the same efficacy. Therefore, HPPH may be a promising agent for treating human esophageal squamous cell cancer (ESCC).

Advances in endoluminal therapy for esophageal cancer

Advances in endoscopic therapy have resulted in dramatic changes in the way early esophageal cancer is managed as well as in the palliation of dysphagia related to advanced esophageal cancer. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are effective therapies for accurate histopathologic staging and provide a potential for complete cure. Mucosal ablative techniques (radiofrequency ablation and cryotherapy) are effective adjuncts to EMR and ESD and reduce the occurrence of synchronous and metachronous lesions within the Barrett esophagus. The successes of these techniques have made endoscopic therapy the primary means of management of early esophageal cancer.

Photodynamic therapy as salvage treatment for local failure after chemoradiotherapy in patients with esophageal squamous cell carcinoma: a phase II study

Local failure at the primary site is a major problem after chemoradiotherapy (CRT) in patients with esophageal squamous cell carcinoma (ESCC). Salvage surgery is the only treatment option with curative intent, but it is associated with high morbidity and mortality. The aim of this study was to evaluate the efficacy and safety of salvage photodynamic therapy (PDT) after CRT. Patients with histologically proven local failure limited to the submucosal layer, and without any metastasis after definitive CRT (≥50 Gy) for ESCC were enrolled in the study. PDT began with intravenous administration of 2 mg/kg of porfimer sodium followed 48-72 hr later by excimer dye laser irradiation with a fluence of 75 J/cm2. The primary endpoint was a complete response (CR) to treatment with PDT, and the secondary endpoints were toxicity related to PDT, progression-free survival (PFS) and overall survival (OS). Twenty-five patients were enrolled in the study. A CR was attained in 19 of 25 patients treated with PDT (CR rate, 76%; 95% CI, 55-91%). One treatment-related death (4%) caused by gastrointestinal hemorrhage at the irradiated site occurred 33 days after PDT. No adverse events greater than grade 3 were related to PDT in the other patients. After a median follow-up of 48 months after PDT, the PFS and OS at 3 years were 40% (95% CI, 21-59%) and 38% (95% CI, 17-60%), respectively. PDT is a potentially curative and tolerable salvage treatment after CRT for carefully selected patients with local failure without any metastasis.

Endoscopic therapies for the prevention and treatment of early esophageal neoplasia

Esophageal cancers have traditionally been diagnosed late and prognosis has been dire. For many years the only real treatment option was esophagectomy with substantial morbidity and mortality. This situation has now changed dramatically. Improvements have been achieved in surgical outcomes and there is an array of new effective treatment options now available, particularly for the increasing proportion diagnosed with early-stage disease. Minimally invasive endoscopic therapies can now prevent, cure or palliate esophageal cancers. This article aims to investigate the role and evidence base for these new therapeutic options.

Photodynamic therapy for large superficial squamous cell carcinoma of the esophagus

BACKGROUND

Photodynamic therapy (PDT) has been found to be safe and effective in patients with small early esophageal squamous cell carcinoma (SCC). However, its efficacy for widespread superficial SCC has not yet been confirmed.

OBJECTIVE

To assess the long-term survival, complications, and recurrence of PDT for large superficial esophageal SCC.

DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

A total of 38 patients with superficial SCC of the esophagus. All patients had a large unifocal lesion or multifocal lesions that were too large to be resected endoscopically. In addition, all patients were physiologically unfit for esophagectomy or had refused surgery.

INTERVENTIONS

PDT with porfimer sodium.

MAIN OUTCOME MEASUREMENTS

Clinical follow-up, long-term survival, complications, and recurrence were evaluated.

RESULTS

Thirty-one patients (82%) had mucosal cancer (T1m), and 7 (18%) had submucosal cancer (T1sm). No patient had lymph node involvement. Nineteen patients had other primary malignancies. Complete remission was achieved in 33 (87%). At the time of writing, 28 patients (74%) were alive without recurrence. After a median follow-up period of 64 months (range, 7-125 months) after PDT, the overall 5-year survival rate was 76%. There was no treatment-related mortality.

LIMITATIONS

Retrospective study with a small number of patients.

CONCLUSIONS

This long-term follow-up study revealed that PDT was a potentially curative treatment for large superficial esophageal SCC. PDT might be a reasonable alternative to esophagectomy or to endoscopic resection for patients with superficial SCC of the esophagus without lymph node metastasis.

Esophageal cancer in the elderly: an analysis of the factors associated with treatment decisions and outcomes

BACKGROUND

Only limited data has been reported so far regarding oesophageal cancer (EC) in elderly patients. The aim of the study is to identify the baseline parameters that influenced therapeutic decision.

METHODS

All consecutive patients 70 years or older being treated for EC were retrospectively analyzed. Patients without visceral metastasis were divided into two groups: treatment with curative intent (chemoradiotherapy, surgery, radiotherapy, mucosectomy or photodynamic therapy) or best supportive care (BSC). Patients with metastasis were divided into two groups: palliative treatment (chemotherapy, chemoradiotherapy or radiotherapy) or BSC.

RESULTS

Two hundred and eighty-two patients were studied. Mean age was 76.5 ± 5.5 years and 22.4% of patients had visceral metastasis. In patients without visceral metastasis (n = 220) the majority had treatment with curative intent (n = 151) whereas in patients with metastasis (n = 62) the majority had BSC (n = 32). Severe adverse events (≥ grade 3) were observed in only 17% of the patients. Patients without specific carcinologic treatment were older, had more weight loss, worse WHO performance status and Charlson score in multivariate analysis.

DISCUSSION

Our results suggest that elderly patients with an EC could benefit from cancer treatment without major toxicities. Weight loss, WHO performance status and the Charlson score could be used to select the appropriate treatment in an elderly patient.

Endoscopic versus surgical therapy for early cancer in Barrett's esophagus: a decision analysis

BACKGROUND

Esophagectomy for early esophageal adenocarcinoma is associated with increased operative mortality and morbidity, but possibly a decreased recurrence rate compared with endoscopic therapy when using EMR and radiofrequency ablation.

OBJECTIVE

To compare the cost-effectiveness of esophagectomy and endoscopic therapy in the treatment of early esophageal adenocarcinoma.

DESIGN

Decision analysis model.

MAIN OUTCOME MEASUREMENTS

Incremental cost-effectiveness ratio.

RESULTS

During the 5-year study period, endoscopic therapy cost $17,000.00 and yielded 4.88 quality-adjusted life years, compared with $28,000.00 and 4.59, respectively, for esophagectomy. Varying the recurrence rates of cancer or Barrett's esophagus metaplasia after endoscopic therapy did not change the overall outcome. The sensitivity analysis demonstrated, however, that the outcome depended on the rate of lymph node involvement and operative mortality. Under the best of circumstances in favor of esophagectomy, such as 2% operative mortality, no reduced quality of life after esophagectomy, and a low 5-year survival rate after recurrence of endoscopic ablation, the risk of positive lymph nodes still needed to exceed 25% before esophagectomy became the preferred treatment option. This threshold is twice as high as the values reported for early submucosal cancer invasion.

LIMITATIONS

Limited data are available about the long-term outcome of EMR and radiofrequency ablation.

CONCLUSIONS

Endoscopic therapy for early Barrett's esophagus adenocarcinoma is more effective and less expensive than esophagectomy. Even in early esophageal adenocarcinoma with submucosal invasion, endoscopic therapy is a cost-effective alternative to esophagectomy, especially in patients with a high operative risk.

Photodynamic therapy and Klatskin tumour: An overview

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

Surgical efficiency or eradication sufficiency

The management of local and early mucosal cancer of the esophagus is an enormous challenge. There is a change in the practice developing with the establishment of endoscopic mucosal resection and other ablative techniques. Das et al. in this issue have used the Surveillance Epidemiology and End Results (SEER) database of the National Cancer Institute data to compare survival of 99 patients treated using endotherapy (endoscopic mucosal resection, thermal ablation, and photodynamic therapy), with 742 patients treated with surgical resection. Using the Cox proportional hazards model, there was no survival difference between the groups. The survival predictors were the age at diagnosis and the absence of radiotherapy. Although many patients are unsuitable for surgical excision and are offered alternative therapy, these data provide evidence that endotherapy may be an equally effective alternative for many patients with early esophageal cancer. It supports the need for randomized data where this can be achieved. These population-based data open up the possibility of wider acceptance of endoscopic techniques.

Effect of local therapy for the treatment of superficial esophageal cancer in non-operative candidates

Surgical resection is the current standard treatment for patients with early stage cancer of the esophagus. In a subset of these patients, comorbidities prohibit the operative risks of a potentially curative esophagectomy. Such patients may be candidates for local endoscopic treatment. We sought to look at a large cohort of patients with clinically localized esophagus cancer to determine whether high-risk patients survive significantly longer after endoscopic therapy than those who receive no local treatment. T0 or T1, N0 esophageal cancer (EC) patients who did not receive surgery or radiation were identified from the Surveillance, Epidemiology, and End Results cancer registry (1998-2003). The patients were assigned into two groups: local endoscopic therapy (excisional biopsy, photodynamic, local destruction, thermal laser, polypectomy, electrocautery, or cryoablation) versus no endoscopic therapy. Differences in survival were calculated using the Kaplan-Meier method, and a multivariate Cox regression analysis adjusting for potential confounders was used to analyze the effect of local therapy on survival. The study cohort included 166 T0 or T1, N0 EC patients. (75% male; 50% >70 years old). Tumors were adenocarcinoma (60%), squamous cell carcinoma (24%), and other (16%). The 4-year disease-specific survival rate was 84% for patients receiving local therapy compared with 64% for patients receiving no therapy (P < 0.01). On multivariate analysis, patients receiving local therapy had a significantly lower hazard of EC-related death (P = 0.04). There was no difference in survival curves for deaths secondary to causes other than EC. Local endoscopic therapy significantly prolonged survival in high-risk patients with clinical T0 or T1, N0 EC and is a reasonable alternative for those patients who are not candidates for potentially curative esophagectomy.

Outcome of photodynamic therapy for early esophageal cancer

BACKGROUND/AIMS

Endoscopic treatment as an alternative to surgery has become increasingly popular for improving the quality of life. Although photodynamic therapy (PDT) has been used for the endoscopic treatment of digestive cancer, its curative efficacy remains unclear. We evaluated the curative efficacy of PDT in superficial esophageal cancer in inoperable patients.

METHODS

Ten male patients with histologically proven early esophageal cancer (surgery was contraindicated for age > 80 years, surgery was contraindicated, Karnofsky performance status of at least 30%, or refusal of surgery) were intravenously injected with a hematoporphyrin derivative (2 mg/kg), and PDT was performed 48 h later. The response to treatment was assessed by gastroscopy with biopsies.

RESULTS

The mean follow-up period was 27.6 months (range, 9.6-58.7 months). Endoscopic ultrasonography revealed that all ten cases were at tumor stage T1. Complete remission (CR) to initial and subsequent PDT was observed in all patients. For the CR cases, the recurrence rate was 10% (1/10) and the time from initial PDT to recurrence was 9.6 months.

CONCLUSIONS

For patients in whom surgery is risky or refused, PDT may represent an acceptable alternative treatment modality, especially for superficial esophageal cancer without lymph node metastasis. However, a study involving long-term follow-up in a large population is needed for confirmation.

The multidisciplinary management of gastrointestinal cancer. Multimodal treatment of oesophageal cancer

Treatment of oesophageal cancer requires a multidisciplinary approach. Single modality treatment, especially surgical excision, is only indicated in small tumours or in patients unable to support multimodal treatment. In Stage I-II adenocarcinoma, multimodal treatment using neoadjuvant therapy is indicated in the absence of contra-indications. However, this statement is not universally accepted. The choice between radio-chemotherapy and chemotherapy depends on patients' characteristics and the preferences of the treatment centre. In selected Stage III adenocarcinomas, especially from the lower oesophagus, neoadjuvant chemotherapy (with post-operative chemotherapy when feasible) may induce tumour regression, which may facilitate surgical resection and improve survival rates, as has been demonstrated for cancers of the oesophagogastric junction.

Liver transplantation for hilar cholangiocarcinoma

Hilar cholangiocarcinoma was accepted as an indication for liver transplantation at the beginning of the transplantation era. Owing to disappointing long-term results for this indication, and in parallel, encouraging results in patients with benign disease, hilar cholangiocarcinoma has generally not been accepted as an indication for liver transplantation in recent years. To improve results, more aggressive approaches have been used: "abdominal organ cluster transplantation" and "extended bile duct resection", which lead to increased long-term survival rates. However, with improving results after conventional extrahepatic bile duct resection in combination with partial hepatectomy, extended procedures in combination with liver transplantation never became a real option in the treatment of hilar cholangiocarcinoma. However, new awareness of liver transplantation in the treatment of this cancer has been raised for patients with hilar cholangiocarcinoma in the context of underlying liver diseases such as primary sclerosing cholangitis, which preclude liver resection. Current results show increased survival figures, in particular in well-selected patients with early tumor stages. Further improvements in long-term survival may be reached with new adjuvant and neoadjuvant protocols. Patients with neoadjuvant radiochemotherapy show long-term results similar to those for liver transplantation for other indications. Also, photodynamic therapy and the use of new antiproliferative immunosuppressive agents may be an approach for further improvement of the long-term results. Currently, liver transplantation for the treatment of hilar cholangiocarcinoma should be restricted to centers with experience in the treatment of this cancer and should be taken into consideration in patients with contraindications to liver resection.

Photodynamic Therapy in Oncology

Photodynamic therapy (PDT) is increasingly being recognized as an attractive, alternative treatment modality for superficial cancer. Treatment consists of two relatively simple procedures: the administration of a photosensitive drug and illumination of the tumor to activate the drug. Efficacy is high for small superficial tumors and, except for temporary skin photosensitization, there are no long-term side effects if appropriate protocols are followed. Healing occurs with little or no scarring and the procedure can be repeated without cumulative toxicity. Considering the efficacy and lack of long-term toxicity of PDT, and the fact that the first treatment of cancer with PDT was done more than 100 years ago, one might expect that this treatment had already become an established therapy. However, PDT is currently offered in only a few selected centers, although it is slowly gaining acceptance as an alternative to conventional cancer therapies. Here, we show the developmental steps PDT underwent and summarize the current clinical applications. The data show that, when properly used, PDT is an effective alternative treatment option in oncology.