ONCOLOGY

What Is Gastrointestinal (GI) Cancer?

Gastrointestinal cancer, alternatively known as digestive tract cancer, arises within the GI tract. This extensive tract commences at the esophagus, the conduit for food from the mouth to the stomach, and culminates at the anus, where waste is expelled from the body.

Primary GI cancer originates within the GI tract itself, while metastatic gastrointestinal cancers originate in the GI tract and subsequently disseminate to other parts of the body.

Causes and Impact of Gastrointestinal Cancer

Causes: The exact cause of gastrointestinal cancer is not clear. However, certain risk factors such as excessive alcohol intake, smoking, advanced age, diet rich in animal fat and salt, poorly preserved food and obesity may increase your risk of developing gastrointestinal cancer.

Impact: Gastrointestinal cancer significantly impacts your quality of life. It not only affects you physically, but also emotionally. Pain, fatigue, stress and the side effects of treatment become a part of your life.

Anatomy

The gastrointestinal system is a long tube running right through the body, with specialized sections that are capable of digesting and extracting useful components entering the mouth and expelling waste products from the anus. Once food has been chewed and mixed with saliva in the mouth, it is swallowed and passes down the esophagus (food pipe), a long, narrow tube. The food pipe is lined by muscles that expand and contract, pushing food into the stomach.

The stomach secretes acid and other digestive enzymes for digestion and stores food before it enters the intestine. The liver is the main organ of metabolism and energy production. It produces bile, which is stored in the gallbladder, and also stores iron, vitamins and trace elements. The pancreas, located behind the stomach, produces enzymes and hormones that aid in digestion and metabolism. Once food has been mulched and partially digested by the stomach, it is pushed into the duodenum (first part of the small intestine). Secretions of the gallbladder and pancreas empty into the small intestine, the site where most of the chemical and mechanical digestion and virtually all of the absorption of useful materials takes place. The large intestine is the last part of the digestive tube and the location of the terminal phases of digestion, where waste is processed and stored in the rectum, and excreted through the anus.

Symptoms

Symptoms of gastrointestinal cancer may include abdominal pain, discomfort or tenderness, change in shape, frequency or consistency of bowels, blood in stool, bloating, vomiting, nausea, fatigue, loss of appetite and unintentional weight loss.

Diagnosis

Your doctor diagnoses gastrointestinal cancer by performing a thorough physical examination and reviewing your medical history. Certain tests may be ordered to assist and confirm the diagnosis, which includes:

Blood tests: The tests include full blood count and tumor marker tests.
Upper endoscopy: Upper endoscopy is a procedure in which a long, thin flexible tube with a tiny camera is passed through your mouth and down your throat to examine the lining of the esophagus, stomach and duodenum.
Fecal test: Fecal samples are examined under the microscope for abnormalities.
Barium swallow: You are given a liquid that contains barium to swallow. X-ray imaging can detect this barium, which coats the walls of the esophagus and stomach, making abnormalities visible more clearly.
Biopsy: A small sample of tissue is removed and examined under the microscope for abnormal cells.
Colonoscopy: A colonoscope, a long narrow tube with a camera is inserted from the rectum to examine your colon.

These tests help identify the location and stage (stage 0 to stage 4, in order of severity) of cancer, which is important for designing the treatment plan.