Neoadjuvant chemotherapy or primary surgery for colorectal liver metastases. Pro primary surgery

Approximately 50 % of patients with colorectal cancer (CRC) develop liver metastases, with the liver being the only site of metastasis in the majority of patients. Liver resection is the standard treatment of CRC liver metastases as it achieves a 5-year survival of 36-51%. The primary goal in the treatment of non-resectable liver metastases is to achieve resectability by preoperative chemotherapy as even secondary liver resection after down-sizing is associated with improved overall survival. Furthermore, resectability can be increased by two-stage surgical procedures; however, the assessment of resectability varies widely even among experts in the field. In cases of suspected non-resectability patients should therefore be liberally admitted for a second opinion to centers of liver surgery. Perioperative chemotherapy in primarily resectable cases has only demonstrated an improvement in recurrence-free survival in subgroup analyses. Moreover, modern potent chemotherapy regimens increase the surgical morbidity depending on the duration of treatment: the lower the histological response of the metastases and the more treatment cycles are applied, the higher is the parenchymal damage with related surgical morbidity. Therefore, perioperative chemotherapy of resectable liver metastases should be viewed with caution and should not be considered the standard of care.