[How to manage a rectal cancer with synchronous liver metastases? A question of strategy]

The prognosis of patients with rectal cancer and synchronous liver metastasis has improved thanks to chemotherapy and rectal and liver surgery progresses. However, there is no consensus about optimal management and practices remain heterogeneous. A curative treatment may be considered for 20 to 30% of patients with complete resection of metastasis and primary tumor after induction chemotherapy. To this end, a primary optimal evaluation by a multidisciplinary board including hepatic and colorectal surgeons is crucial. The therapeutic strategy associates chemotherapy, radiotherapy, hepatic and rectal surgery. The most threatening site guides the sequence of treatments. If hepatic resectability is uncertain, a "liver first" strategy associating induction chemotherapy and hepatic surgery is preferred. In non-resectable metastatic cases, chemotherapies with targeted therapies might lead to secondary resection for 30% of patients (conversion). This has changed our practice and triggers reconsidering resectability after chemotherapy. When metastases remain non-resectable, additional treatment focusing on primary tumor should control pelvic symptoms otherwise hardly impacting quality of life. Rectal surgery, short-course radiotherapy (5×5Gy), conformational long-course chemoradiotherapy or intensity-modulated radiation therapy with dose escalation are options discussed in this review.