Researchers from Tohoku University and University Hospital have discovered why some existing treatments are ineffective in dealing with early-stage lung cancer. The team under the guidance of Professor Tetsuya Kodama investigated the ability of anti-cancer agents affect the metastatic lung tumors at an early stage.
The team developed a mouse model of metastasis in the lungs, which can cause damage (less than 100 microns), which could not be detected at present. Micro X-ray CT and histopathology were used for the analysis of light. It was shown that small arteries obstructed by tumor cells, which greatly reduces the overall length of the vessel, the volume and number of branches of blood vessels in the lung. Such artery hinder adequate penetration of anti-tumor agents with low molecular weight in the tumor.
Past experiments on animals have shown that the enhanced permeability and retention effect occurs in the formation of new tumor blood vessels. This allows the molecules of a certain size (100-200 nm) to accumulate in tumors than in normal tissue. Experiments conducted by Professor Kodama team indicate that liposome dyed with a fluorescent dye (diameter 145 mm) is not present around the damage at an early stage tumor. This means that high anticancer agents can not be considered an effective method of delivery hematogenous medicament for the treatment of lung cancer at an early stage.
Surgery followed by chemotherapy course, for some time has been the main method of treatment of lung cancer at an early stage. However, based on this study, Professor Kodama suggests that these results indicate a need for new methods of drug delivery system to replace conventional chemotherapy and the development of new treatments for lung cancer.