Enhancement of chemotherapeutic effects with focused shock waves: extracorporeal shock wave chemotherapy (ESWC)

The effects of shock waves in combination with various anti-cancer agents i.e. Bleomycin(BLM), Cis-platinum (CDDP) and 5-fluorouracil(5-FU) on various human cancer cells were examined. It was only with BLM that enhancement was evident in all cell lines. The degree of chemotherapeutic enhancement was proportional to the amount of shock wave energy applied. Ladder formation of DNA in GCIY, a gastric cell line, was observed only when treated with both BLM and shock waves in combination. When SW 480, a colon cancer cell line, transplanted into the back of nude mice were treated with a combination of i.v. injected BLM and regional exposure to shock waves, a significant enhancement of chemotherapeutic effects was observed in terms of the tumor growth curve. When cancer cells exposed to shock waves and observed under scanning and transmission electron microscopes, microvilli on the cell surface disappeared and numerous dimples(diameters distributed from 0.05 to 0.5 microns) became apparent. These dimples were concluded to be pores penetrating through the cell membrane, because reagents such as propidium iodide or 5(6)-carboxyfluorescein could enter cells treated shock waves.