[Diagnosis of local recurrences and metastases from colorectal cancers]

The risk of relapse of colorectal cancer depends on tumor characteristics such as location and Dukes' stage. Recurrences may be metastatic only (70%), locoregional only (20%) or both (10%). The main objective of postoperative follow-up is to detect recurrent disease as early as possible, in order to allow curative resection. Most relapses are now diagnosed when still asymptomatic. Different imaging methods help to diagnose these recurrences. The CT scan allows to examine the liver, lymph nodes, anastomosis and the pelvic cavity. MRI can bring complementary information in some selected cases. Lastly, percutaneous needle biopsies will be useful to prove the diagnosis. For the detection of distant metastases, chest X-ray, hepatic echography and CT scan examination can be used.