Complicated Colorectal Cancer: Role of Imaging

Colorectal cancer is the third most common cancer and the fourth most common cancer cause of death globally, accounting for roughly 1.2 million new cases and 600,000 deaths per year [1]. Incidence is low at ages younger than 50 years, but strongly increases with age. Median age at diagnosis is about 70 years in developed countries [2]. Colorectal cancer develops mostly without any symptoms in the early stages. In 15–30% of cases, however, CRC patients present with symptoms of acute abdomen such as bowel perforation, obstruction, or gastrointestinal bleeding [3]. Those complications mostly occur in elderly patients and are associated with poor prognosis [4]. These poor outcomes start at their initial hospital admission and also impacts long-term survival [3]. Elderly patients with CRC may be specifically at risk for emergent presentation because of medical comorbid conditions, insufficient screening, unrecognized symptoms, and inadequate overall access to the health-care system [4]. Imaging hence plays a key role in this setting. Its first objective is to provide the earliest diagnosis of any complication. Its second objective is increasingly dealing with interventional therapy of some complications associated with colorectal cancer treatment. This chapter will go through the role of imaging in the four major complications occurring in colorectal cancer setting, with a special focus on the pre-therapeutic imaging strategy in complicated or advanced CRC.