It is estimated that approximately 132,000 new cases of large bowel cancer are diagnosed annually in the US. Nearly 49,700 Americans die each year and it is the third most common cause of cancer death in the US. One in five patients with colorectal cancer presents with metastatic disease. The increasing of screening through colonoscopy has led to more cases being diagnosed at an asymptomatic stage. However, symptoms can include rectal bleeding, abdominal pain, unexplained iron deficiency anemia, and/or a change in bowel habits. Tests such as a fecal occult blood test or endoscopy are performed. Once the diagnosis is established, the disease is staged by physical exam and CT of the chest, abdomen, and pelvis. A carcinoembryonic antigen is drawn.
Treatment options can include surgery, adjuvant chemotherapy, chemotherapy and radiation in rectal cancers, and chemotherapy alone in metastatic disease. Chemotherapy gents used include 5-FU, leucovorin, oxaliplatin, irinotecan, cetuximab, panitumumab, and regorafenib.