Gastrointestinal Cancer
The gastrointestinal (GI) tract is 25-foot-long pathway that extends from the mouth to the anus. Everything you eat passes through the esophagus and gets processed in the stomach and small intestines to extract nutrients. Ultimately, the waste is removed from your body through the colon and rectum. Sometimes, a tumor can form in one of these organs, after a change in the DNA causes abnormal cells to grow. What’s behind this kind of change (known as a mutation). It could be anything from underlying conditions to lifestyle choices to genetics.
Gastrointestinal cancer is common and treatments are more effective when the cancer is detected at an early stage—which, unfortunately, can be a challenge.
Colorectal cancers are the most common and most treatable GI cancers. About 5 to 10 percent occur from an inherited genetic risk factor, but the remaining cases happen sporadically. Most of these cases are related to unhealthy behaviors.
Healthy lifestyle changes can help reduce the risk for GI cancer. There is a clear reduction in risk with a lifestyle that includes regular exercise, a low-fat diet high in fruits and vegetables, minimal red meat and moderate alcohol. Routine colorectal screening also markedly reduces the risk of colon cancer by finding and removing polyps before they have the chance to become cancerous.
Types of gastrointestinal cancers
The most common types of gastrointestinal cancers are as follows:
- Esophageal cancer
- Gastric (stomach) cancer
- Colorectal cancer
- Pancreatic cancer
- Liver cancer
Other types are much less common, including neuroendocrine tumors, gastrointestinal stromal tumors and anal cancer.
Generally speaking, gastrointestinal cancers are more likely to develop in men, and the risk increases with age. Studies have linked these cancers to cigarette smoking, alcohol consumption and unhealthy diets.
Tumors may also result from specific underlying conditions—like gastroesophageal reflux disease in the esophagus, Helicobacter pylori infection in the stomach, diabetes in the pancreas, inflammatory bowel disease in the large intestine (colon and rectum), hepatitis B or C virus infection or cirrhosis in the liver.
A small percentage of gastrointestinal cancers are inherited.
Symptoms of gastrointestinal cancers
Most of the time, symptoms of gastrointestinal cancers don’t occur until the tumor has become more advanced. Then, they depend on the type of cancer. Patients with esophageal cancer may have difficulty swallowing, whereas those with gastric cancer will notice ulcer-like symptoms (e.g., indigestion, loss of appetite, bloating and pain). Liver cancer and pancreatic cancer can also lead to abdominal pain, and colorectal cancer—as you might expect—causes changes in bowel function or bleeding.
Diagnosis of gastrointestinal cancers
If patients have symptoms and the doctor has reason to suspect a diagnosis of gastrointestinal cancer, they may perform some of the following tests:
- Endoscopy or esophagogastroduodenoscopy (EGD) to check the lining of the esophagus, stomach and small intestine for tumors
- Colonoscopy to check the colon and rectum for polyps, which can become cancerous
- Lab tests to look for changes in the blood that could be signs of cancer
- Imaging studies (MRI, X-ray, ultrasound, CT scan or PET scan) to check for abnormal tissue anywhere in the digestive system
- Biopsy to obtain a sample of abnormal tissue and analyze it for the presence of cancer cells
