Gastrointestinal Carcinoma

Gastrointestinal carcinoma is a group of cancers that develop in the digestive system, affecting organs from the mouth to the anus. These cancers can form anywhere along the 25-foot pathway that processes food, and while treatments are more effective when detected early, many cases are not discovered until later stages.

Table of contents

• What is gastrointestinal carcinoma?
• Types of gastrointestinal cancers
• Risk factors
• Symptoms
• Diagnosis
• Treatment options
• Prevention and screening
• Living with gastrointestinal cancer

What is gastrointestinal carcinoma?

Gastrointestinal carcinoma refers to cancers that develop in the organs of the digestive tract (the system that processes food and removes waste from your body). The gastrointestinal tract is a 25-foot-long pathway that extends from the mouth to the anus^[1]. Everything you eat passes through the esophagus and gets processed in the stomach and small intestines to extract nutrients. Ultimately, waste is removed from your body through the colon and rectum^[1].

These cancers develop when changes in DNA (the code that tells cells when to grow and when to die) cause abnormal cells to grow. Because of these changes, called mutations, the cells grow rapidly and eventually form a tumor instead of dying. The cancer cells overtake healthy cells and may spread to other parts of your body, a process called metastasis^[10].

Gastrointestinal cancer is common both in the United States and worldwide. In the United States, colorectal cancers are the most common and most treatable gastrointestinal cancers^[1]. Globally, gastrointestinal cancers represent the fifth most common cancer diagnosis worldwide and the third most deadly^[15].

Types of gastrointestinal cancers

Gastrointestinal carcinoma includes all cancers in your digestive tract organs. The most common types include^[1]:

• Esophageal cancer – cancer that forms in the esophagus, the tube that carries food from your mouth to the stomach
• Gastric (stomach) cancer – cancer that develops in the cells lining the stomach
• Colorectal cancer – cancer that begins in the colon or rectum
• Pancreatic cancer – cancer that forms in the pancreas
• Liver cancer – cancer that begins in liver cells

Other, much less common types include neuroendocrine tumors (cancers that begin in cells that make hormones to help control digestive processes), gastrointestinal stromal tumors (a type of cancer that begins in nerve cells found in the walls of digestive organs), and anal cancer^[1][4].

Most stomach cancers, for example, are a type called adenocarcinoma, which begins in the mucus-producing cells in the innermost lining of the stomach. Nearly all stomach cancers are adenocarcinomas^[4]. About 95% of the time, stomach cancer starts in the stomach lining and progresses slowly^[10].

Risk factors

Gastrointestinal cancers are more likely to develop in men, and the risk increases with age^[1]. Studies have linked these cancers to cigarette smoking, alcohol consumption, and unhealthy diets^[1].

Several factors can increase your likelihood of developing gastrointestinal cancer. Risk factors include^[1][6][10]:

• Family history of gastrointestinal cancer
• Helicobacter pylori (H. pylori) infection in the stomach
• Gastroesophageal reflux disease (GERD) – a condition where stomach acid frequently flows back into the esophagus
• Gastritis – inflammation of the stomach lining
• Hepatitis B or C virus infection or cirrhosis (scarring) in the liver
• History of stomach ulcers or stomach polyps
• A diet high in fatty, salty, smoked, or pickled foods
• A diet that doesn’t include many fruits and vegetables
• Smoking, vaping, or chewing tobacco
• Drinking too much alcohol
• Obesity

A small percentage of gastrointestinal cancers are inherited. About 5 to 10 percent of colorectal cancers occur from an inherited genetic risk factor, but the remaining cases happen sporadically^[1].

Symptoms

Most of the time, symptoms of gastrointestinal cancers don’t occur until the tumor has become more advanced^[1]. Stomach cancer doesn’t typically cause symptoms during the early stages. Even the most common early signs of stomach cancer—often unexplained weight loss and stomach pain—don’t usually show up until the cancer is more advanced^[10].

When symptoms are present, they depend on the type of cancer. Common symptoms may include^[1][10]:

• Loss of appetite
• Trouble swallowing
• Fatigue or weakness
• Nausea and vomiting
• Unexplained weight loss
• Heartburn and indigestion
• Black stool or vomiting blood
• Feeling bloated or gassy after eating
• Stomach pain, often above your belly button
• Feeling full even after eating a small meal or snack
• Changes in bowel function or bleeding
• Abdominal pain

Patients with esophageal cancer may have difficulty swallowing, whereas those with gastric cancer will notice symptoms similar to ulcers, such as indigestion, loss of appetite, bloating, and pain^[1].

Many of these symptoms are common in other conditions, too. It’s important to see your healthcare provider to check if your symptoms are a sign of gastrointestinal cancer or another disease^[10].

Diagnosis

If patients have symptoms and the doctor has reason to suspect a diagnosis of gastrointestinal cancer, they may perform several tests^[1]:

• Endoscopy or esophagogastroduodenoscopy (EGD) – a procedure where a thin, tube-like instrument with a light and lens is used to check the lining of the esophagus, stomach, and small intestine for tumors
• Colonoscopy – a procedure to check the colon and rectum for polyps, which can become cancerous
• Lab tests – blood tests to look for changes that could be signs of cancer
• Imaging studies – tests such as MRI, X-ray, ultrasound, CT scan, or PET scan to check for abnormal tissue anywhere in the digestive system
• Biopsy – removal of a small sample of tissue for examination under a microscope

An endoscopic ultrasound (EUS) may also be necessary. In this procedure, a doctor inserts an endoscope to get detailed images of the digestive tract^[1].

Treatment options

Treatment of gastrointestinal cancer depends on where the disease started and how far it has spread throughout the body. Your treatment plan may include more than one type of treatment^[12].

Surgery

Surgery is a common treatment for gastrointestinal cancer. The type of surgery depends on where the cancer is located^[1]. For gastric cancer that hasn’t traveled to a different organ, cure is possible, and surgery can achieve cure^[11].

For stomach cancer, surgery may involve^[12]:

• Subtotal gastrectomy – removal of the part of the stomach that contains cancer, nearby lymph nodes, and parts of other tissues and organs near the tumor
• Total gastrectomy – removal of the entire stomach, nearby lymph nodes, and parts of the esophagus, small intestine, and other tissues near the tumor. The surgeon then attaches the esophagus to the small intestine so the patient can continue to eat and swallow

Chemotherapy

Chemotherapy uses anti-cancer drugs to destroy cancer cells. You might have it before or after surgery for stomach cancer, or as your main treatment if your cancer is advanced^[1]. Chemotherapy may be given before surgery to shrink the tumor and reduce the amount of tissue that needs to be removed. After surgery, chemotherapy may be given to lower the risk that the cancer will come back^[12].

Radiation therapy

Radiation therapy uses high-energy waves to kill cancer cells or keep them from growing^[1]. It may be given with chemotherapy, or to help with symptoms of advanced cancer^[1].

Immunotherapy

Immunotherapy is a class of treatments that takes advantage of a person’s own immune system to help kill cancer cells. There are currently six FDA-approved immunotherapy options for stomach cancer, including checkpoint inhibitors that help the immune system recognize and attack cancer cells^[15].

Targeted therapy

Targeted therapy uses drugs that target specific pathways or proteins in cancer cells. Several targeted antibodies are approved for subsets of patients with advanced stomach or gastroesophageal cancer^[15].

Other treatments

Other treatments that can help control symptoms include^[1]:

• Endoluminal stent placement – a thin, expandable tube placed to keep passages open when tumors cause blockages
• Endoluminal laser therapy – using a laser attached to an endoscope to open blocked passages

Prevention and screening

Early detection is the most important way to prevent serious gastrointestinal cancer. Screening tests can diagnose colon and rectal cancer in early, highly treatable stages, often catching cancer before symptoms develop^[6].

Routine colorectal screening markedly reduces the risk of colon cancer by finding and removing polyps before they have the chance to become cancerous^[1]. The American Cancer Society recently recommended that routine colorectal cancer screening should start at age 45^[1].

Healthy lifestyle changes can help reduce the risk for gastrointestinal cancer. There is a clear reduction in risk with a lifestyle that includes^[1]:

• Regular exercise
• A low-fat diet high in fruits and vegetables
• Minimal red meat consumption
• Moderate alcohol use
• Not smoking
• Maintaining a healthy weight

Living with gastrointestinal cancer

Gastrointestinal cancer and its treatments may affect your ability to eat enough food or absorb nutrients from food. If part or all of your stomach has been removed, you might need to eat smaller amounts of food more often or make changes to what you eat^[19][21].

Nutrition and eating

Common nutrition problems may include weight loss, loss of appetite, and difficulty digesting food. These problems are caused by the removal of all or part of the stomach, damage to glands and cells that affect digestion, or side effects of treatment^[21].

Your doctor or dietitian may recommend that you^[19][21]:

• Eat smaller amounts of food more often—six to eight small meals a day
• Stay upright for some time after eating
• Choose foods and drinks that are high in protein and calories
• Drink high-calorie, high-protein beverages between meals

It is common for people with stomach cancer to have problems eating and digesting food. A registered dietitian can provide counseling about proper nutrition that’s right for you^[21].

Follow-up care

Many people who have been treated for gastrointestinal cancer need to visit their doctor regularly to get follow-up exams or tests. Your healthcare team can talk with you about ways to reduce side effects so you feel better^[19].

Life after cancer treatment involves adjusting to physical and emotional changes and coping with fear of the cancer coming back^[19]. Speaking up about any problems you have can give you a greater sense of control^[19].