Colorectal Neoplasms

The frequency of colorectal cancer (CRC) varies remarkably among different populations and regions. Most CRCs are considered to develop from adenomas. The transition from normal epithelium to adenoma and carcinoma is associated with acquired molecular alterations that occur in a stepwise fashion and affect multiple genes involved in the regulation of cell growth and differentiation. A major consequence of molecular alterations is genomic instability. Genomic instability can be divided into two categories: Chromosomal instability (CIN) and Microsatellite instability (MSI). Colonoscopy is the test of choice to establish a diagnosis when CRC is suspected. Surgery is the mainstay of treatment of CRC if no metastatic disease is identified. Surgical excision is recommended for patients without evidence of metastasis who are medically fit for surgery. Subtotal colectomy is performed in patients who have multiple neoplasms. Proctocolectomy is reserved for patients with familial cancer syndromes.