36. Colorectal Cancer: Management of Stage IV Disease

Despite screening protocols, approximately 20 % of colorectal cancer patients present with established distant metastasis (Siegel et al. CA Cancer J Clin., 65(1), 5–29, 2015). Computed tomography (CT) scan or magnetic resonance imaging (MRI) generally detects this metastasis at the time of the initial staging of the cancer. Once the diagnosis of stage IV disease is made, a multidisciplinary team should plan appropriate curative or palliative therapy. Unfortunately for the clinician, there is enormous heterogeneity with respect to sites of disease, extent of disease and symptoms, performance status, and comorbidities in these patients. Stage IV patients have a range of presentation from the asymptomatic patient with a single metastatic lesion to the rapidly deteriorating patient with colon obstruction and advanced multiorgan metastases. While treatment algorithms may exist for some forms of metastatic disease such as a solitary liver lesion, others, especially for those with multiple sites of metastases, are still being defined. This chapter aims to provide a reference source for colorectal surgeons managing patients who present with metastatic stage IV colorectal cancer.