Background/aims: Although microwave coagulation therapy (MCT) has been performed for liver cancer, there has been no report examining the influence of this therapy on the growth of possible remnant cancer.
Methods: A solid cube of AH-130 cells (ascites hepatoma cell line) was implanted into the left lateral lobe of the rat liver. Five days later, MCT was applied to the middle liver lobe of these rats. Tumor growth and cytokine levels in plasma and the liver were compared between rats that underwent MCT and rats that did not.
Results: The mean tumor weight in the MCT group (222.6+/-51.5 mg, mean+/-SD) was significantly greater than that in the control group (126.7+/-19.7 mg, P<0.01) at postoperative day (POD) 5. Immunohistochemistry for anti-proliferating cell nuclear antigen showed the labeling index in the MCT group (90.4%) to be higher than that in the control group (76.7%, P<0.01). Liver basic fibroblast growth factor and transforming growth factor-beta 1 levels in the MCT group on POD 3 were significantly higher than levels in the control group.
Conclusions: The present study suggests the clinically important finding that MCT accelerates the growth of small residual tumors in the liver.