Аннотация:Background. At present liver resection combined with chemotherapy is the only treatment for isolated resectable colorectal cancer liver me- tastases that potentially can achieve cure. Effective preoperative chemotherapy allows us to evaluate chemoresponsiveness of the tumor and increase metastases resectability. Materials and methods. Between 2006 and 2011, 60 patients with potentially resectable colorectal cancer liver metastases were included in the study. All patients received preoperative oxaliplatin- or irinotecan-based chemotherapy; average duration of treatment was 3.6 ± 0.11 months. Liver resection was performed after chemotherapy: 29 (48.3 %) pts underwent hemihepatectomy, 11 (18.3 %) pts - extended hemi- hepatectomy and 20 (33.4 %) pts - segmentectomy. Pathologic response in liver metastases was assessed to analyze efficacy of preoperative chemotherapy. Results. Objective response to preoperative chemotherapy was observed in 33 (55 %) pts. 23 (38.3 %) patients had stable disease. The maxi- mum effect of preoperative chemotherapy was achieved in patients with bilobar liver metastases, receiving combination with oxaliplatin - in 23 (63.9 %) cases. Side effects of 334 cycles of preoperative chemotherapy were assessed. In most cases, adverse events were not clinically signifi- cant. Side effects of grade III/IV in 18 (5.4 %) cycles were observed in 12 (20 %) patients. 52 (86.7 %) patients underwent R0-resections; 8 pts had R1 (n = 5) и R2 (n = 3) resections of metastases. There were no postoperative deaths. Pathologic response was observed in 55/60 (91.7 %) cases: grade I was seen in 17 (28.3 %) cases; grade II - in 14 (23.3 %); grade III - in 20 (33.3 %) and grade IV - in 4 (6.8 %) cases. Patho- logic response of grade III/IV occurred in 63.6 % patients with partial treatment response and 13 % pts - with stable disease (р = 0.01). Оригинальные исследования Conclusions. Highest efficacy of preoperative chemotherapy in combined treatment of colorectal cancer was achieved in patients with bi- lobar liver metastases. Safety of two-component chemotherapy regimens was confirmed. This study presents significant correlation between preoperative chemotherapy efficacy and pathologic response in liver metastases.