RESUMEN
BACKGROUND: The indications of preoperative chemotherapy, for initially resectable synchronous colorectal liver metastases, remain controversial. This meta-analysis aimed to assess the efficacy and safety of preoperative chemotherapy in such patients. METHODS: Six retrospective studies were included in the meta-analysis with 1036 patients. Some 554 patients were allocated to the preoperative group, and 482 others were allocated to the surgery group. RESULTS: Major hepatectomy was more common in the preoperative group than in the surgery group (43.1% vs. 28.8%, p < 0.001). Furthermore, the percentage of patients with more than three liver metastases was higher in the preoperative group compared to the surgery group (12.6% vs. 5.4%, p < 0.002). Preoperative chemotherapy showed no statistically significant impact on overall survival. Combined disease free/relapse survival analysis of patients with high disease burden (liver metastases > 3, maximum diameter > 5 cm, clinical risk score ≥ 3) demonstrated that there is a 12% lower risk of recurrence in favor of preoperative chemotherapy. Combined analysis showed a statistically significant (77% higher probability) of postoperative morbidity in patients who received preoperative chemotherapy (p = 0.002). CONCLUSIONS: Preoperative chemotherapy should be suggested in patients with high disease burden. The number of cycles of preoperative chemotherapy should be low (3-4) to avoid increased postoperative morbidity. However more prospective studies are needed to clarify the exact role of preoperative chemotherapy in patients with synchronous resectable colorectal liver metastases.