Photodynamic therapy in colorectal cancer treatment--The state of the art in preclinical research.

BACKGROUND: Photodynamic therapy (PDT) is used in many different oncologic fields. Also in gastroenterology, where have been a few attempts to treat both the premalignant lesion and advanced colorectal cancer (CRC). This review aims to give a general overview of preclinical photodynamic studies related to CRC cells and animal studies of photodynamic effects related to CRC treatment to emphasize their potential in study of PDT mechanism, safety and efficiency to translate these results into clinical benefit in CRC treatment. MATERIALS AND METHOD: Literature on in vitro preclinical photodynamic studies related to CRC cells and animal studies of photodynamic effects related to CRC treatment with the fallowing medical subject headings search terms: colorectal cancer, photodynamic therapy, photosensitizer(s), in vitro, cell culture(s), in vivo, animal experiment(s). The articles were selected by their relevance to the topic. RESULTS: The majority of preclinical studies concerning possibility of PDT application in colon and rectal cancer is focused on phototoxic action of photosensitizers toward cultured colorectal tumor cells in vitro. The purposes of animal experiments are usually elucidation of mechanisms of observed photodynamic effects in scale of organism, estimation of PDT safety and efficiency and translation of these results into clinical benefit. CONCLUDING REMARKS: In vitro photodynamic studies and animal experiments can be useful for studies of mechanisms and efficiency of photodynamic method as a start point on PDT clinical research. The primary disadvantage of in vitro experiments is a risk of over-interpretation of their results during extrapolation to the entire CRC.

Photodynamic therapy in colorectal cancer treatment: the state of the art in clinical trials.

BACKGROUND: Photodynamic therapy (PDT) is used in many different oncologic fields. Also in gastroenterology, where have been a few attempts to treat both the premalignant lesion and advanced colorectal cancer. This review aims to give a general overview of the PDT application to colorectal cancer in the field of clinical trials to emphasize its curative, and insufficiently exploited potential. MATERIALS AND METHODS: Literature on PDT for colorectal cancer with the following medical subject headings search terms: colorectal cancer, photodynamic therapy, clinical trials was reviewed. The articles were selected by their relevance to the topic. RESULTS: There are many positive and promising trial results from I to II/III phase for the use of PDT in colorectal cancer both in less advanced tumors as well as in the palliative therapy of advanced lesions. CONCLUDING REMARKS: PDT seems to be a safe and a feasible treatment option for colorectal cancer. Theoretical assumptions confirmed by many results of preclinical studies taking into consideration an increasing number of analyzed clinical trials, should lead to the development of optimized standards by using PDT in colorectal cancer treatment.

Photodynamic therapy in treatment of cutaneous and choroidal melanoma.

Melanoma is a malignant, the most aggressive and dreaded skin cancer. This form of cancer arises from melanocytes and may grow rapidly and metastasize. Melanoma predominantly occurs in skin, but could also be found in the mouth, iris and retina of the eye. Melanoma is the most dangerous form of skin cancer, with a steeply rising incidence and a poor prognosis in its advanced stages. It is highly resistant to traditional chemotherapy and radiotherapy, although modern biological therapies are showing some promise. Photodynamic therapy (PDT), as a novel effective modality of the treatment of skin cancers, opens up new possibilities in melanoma treatment also. Many experimental photodynamic therapy studies were performed. The results of many experiments indicate that that photodynamic therapy may be a promising tool for adjuvant treatment in advanced melanoma.