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.

Non-Invasive Diagnostic System Based on Light for Detecting Early-Stage Oral Cancer and High-Risk Precancerous Lesions-Potential for Dentistry

Simple Summary

The early detection of oral cancer and oral potentially malignant disorders can facilitate minimum intervention and subsequent improvements in prognosis and quality of life after treatment. Recently, several non-invasive adjunctive fluorescence-based detection systems have improved the accuracy of detection and diagnosis of oral cancer and oral potentially malignant disorders. This article summarizes current knowledge about fluorescence-based diagnostic methods and discusses their benefits and drawbacks from a clinical viewpoint.

Abstract

Oral health promotion and examinations have contributed to the early detection of oral cancer and oral potentially malignant disorders, leading to the adaptation of minimally invasive therapies and subsequent improvements in the prognosis/maintenance of the quality of life after treatments. However, the accurate detection of early-stage oral cancer and oral epithelial dysplasia is particularly difficult for conventional oral examinations because these lesions sometimes resemble benign lesions or healthy oral mucosa tissues. Although oral biopsy has been considered the gold standard for accurate diagnosis, it is deemed invasive for patients. For this reason, most clinicians are looking forward to the development of non-invasive diagnostic technologies to detect and distinguish between cancerous and benign lesions. To date, several non-invasive adjunctive fluorescence-based detection systems have improved the accuracy of the detection and diagnosis of oral mucosal lesions. Autofluorescence-based systems can detect lesions as a loss of autofluorescence through irradiation with blue-violet lights. Photodynamic diagnosis using 5-aminolevulinic acid (ALA-PDD) shows the presence of very early oral cancers and oral epithelial dysplasia as a red fluorescent area. In this article, currently used fluorescence-based diagnostic methods are introduced and discussed from a clinical point of view.

Simultaneous Photodiagnosis and Photodynamic Treatment of Metastatic Melanoma

Metastatic melanoma (MM) has a poor prognosis and is attributed to late diagnoses only when metastases has already occurred. Thus, early diagnosis is crucial to improve its overall treatment efficacy. The standard diagnostic tools for MM are incisional biopsies and/or fine needle aspiration biopsies, while standard treatments involve surgery, chemotherapy, or irradiation therapy. The combination of photodynamic diagnosis (PDD) and therapy (PDT) utilizes a photosensitizer (PS) that, when excited by light of a low wavelength, can be used for fluorescent non-destructive diagnosis. However, when the same PS is activated at a higher wavelength of light, it can be cytotoxic and induce tumor destruction. This paper focuses on PS drugs that have been used for PDD as well as PDT treatment of MM. Furthermore, it emphasizes the need for continued investigation into enhanced PS delivery via active biomarkers and passive nanoparticle systems. This should improve PS drug absorption in MM cells and increase effectiveness of combinative photodynamic methods for the enhanced diagnosis and treatment of MM can become a reality.

Photodynamic Detection of Peritoneal Metastases Using 5-Aminolevulinic Acid (ALA)

In the past, peritoneal metastasis (PM) was considered as a terminal stage of cancer. From the early 1990s, however, a new comprehensive treatment consisting of cytoreductive surgery and perioperative chemotherapy has been established to improve long-term survival for selected patients with PM. Among prognostic indicators after the treatment, completeness of cytoreduction is the most independent predictors of survival. However, peritoneal recurrence is a main cause of recurrence, even after complete cytoreduction. As a cause of peritoneal recurrence, small PM may be overlooked at the time of cytoreductive surgery (CRS), therefore, development of a new method to detect small PM is desired. Recently, photodynamic diagnosis (PDD) was developed for detection of PM. The objectives of this review were to evaluate whether PDD using 5-aminolevulinic acid (ALA) could improve detection of small PM.

Usefulness of Photodynamic Diagnosis and Therapy using Talaporfin Sodium for an Advanced-aged Patient with Inoperable Gastric Cancer (a secondary publication)

BACKGROUND AND AIMS

In Japan the rise in the average life expectancy has caused an increase in the proportion of the population who are classed as geriatric. Accordingly, the number of elderly people being treated for cancer is increasing concomitantly. However, with the increase in age, the numbers of prior complications also increase. This is especially so in the advanced-aged patients, defined in Japan as those over the age of 85. Such complications may be too high risk for radical surgery and a less invasive treatment is warranted. Photodynamic therapy (PDT) is a noninvasive treatment approved by the Japanese National Health Insurance for the treatment of early stage superficial type esophageal and gastric cancers, early stage uterine cervical cancers and dysplasia, and early and advanced lung cancer. We report herein on the efficacy of palliative PDT using talaporfin sodium (Laserphyrin(®)) for a case of inoperable gastric cancer.

MATERIAL AND METHODS

The patient was an 87-year-old-man, a diabetic with histories of diabetic nephropathy, cerebral infarction and myocardial infarction. This patient was first diagnosed as having gastric cancer in 2007 but surgery and chemotherapy were contraindicated due to his poor physical status and poor renal function, respectively, owing to the anticipated side effects. The patient was referred to our institution after hearing of PDT in 2009. He was treated with 1 course of porfimer sodium PDT and 3 courses of talaporfin sodium PDT with photodynamic diagnosis (PDD) during the period from September, 2009 to June, 2011.

RESULTS

The massive gastric cancer located in the cardia was successfully treated with 4 PDT sessions without any serious complications; therefore the patient was able to orally ingest food until his death due to natural causes other than the cancer, in October, 2011.

CONCLUSION

Talaporfin sodium PDT is safe and effective treatment for advanced-aged patients suffering from inoperable gastric cancer.