Pre-operative Diagnosis and Staging of Colorectal Cancer

With the increasing incidence of colorectal cancer and the rapid development in multi-modal treatment of colorectal cancer, early pre-operative diagnosis and precise staging have assumed increasing importance. Different diagnostic and staging modalities can often be complementary (and not competitive) and yet it
may not be possible to have access to all the available options. Colon cancer is best staged by a multi-detector contrast-enhanced computed tomography (CT)
scan while rectal cancer is best staged by magnetic resonance imaging (MRI). The treatment of rectal cancer is often based on precise pre-treatment staging. Tumours with a T stage of T3 and above and/ or nodal stage N1 and above, are subjected to preoperative chemoradiation while lesser stages are subjected
to upfront surgery. Early stage rectal cancer can also be precisely mapped by endorectal ultrasound (ERUS). This chapter, without undermining the importance of a careful clinical history and examination, covers all aspects of modern staging modalities and discusses in detail their strengths and weakness and recommends the optimal and practical approach in various scenarios while diagnosing and staging colorectal cancer.