Minimal liver resection strongly stimulates the growth of human colon cancer in the liver of nude mice

Partial hepatectomy has been widely employed in clinical practice as the th erapy of choice for primary and metastatic liver tumors. However, the recur rence rate after the treatment remains high, which is most likely due to th e growth of residual microscopic lesions. Previous studies in murine models demonstrated that a 70% hepatectomy significantly accelerated the growth o f ectopically implanted tumors. In this study, we reported the effect of pa rtial hepatectomy on the growth of two human colon cancers (Co-3 and AC3603 ) implanted in the liver of nude mice using the technique of surgical impla ntation of histologically intact tumor tissue. Our results showed a dramati c acceleration of tumor growth following 30% partial hepatectomy, which res embles clinical procedures. Tumor volumes were assessed with calipers on da y-15 by abdominal palpation and on day-30 at autopsy by direct measurement. For both Co-3 and AC3603, tumor volumes in the hepatectomized animals were significantly larger than the control at the above two time points (P < 0. 001). The results demonstrate the stimulating effect of partial hepatectomy directly on the tumor growth in the liver, in contrast to previous studies on ectopic tumors. Furthermore, since conservative partial hepatectomy (30 %) is normally used in clinical practice for surgical treatment of liver me tastasis, the animal models presented here should be useful for the clinica l investigation of the high recurrence rate of liver metastasis following p artial hepatectomy.