Gastrointestinal cancer affects the organs in the digestive system, including the oesophagus, stomach, pancreas, gallbladder, liver, small and large intestine, anus and rectum. It is characterised by the uncontrolled growth of normal cells that make up the digestive tract.
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.
The gastrointestinal system is a long tube running right through the body, with specialised sections that are capable of digesting and extracting useful components of the diet and expelling waste products. Once food has been chewed and mixed with saliva in the mouth, it is swallowed and passes down the oesophagus into the stomach.
The stomach secretes acid and other digestive enzymes for digestion and stores food before it enters into 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 before excretion.
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. Sometimes there are no symptoms.
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 tumour marker tests.
- Gastroscopy: Gastroscopy is a procedure in which a long, thin flexible telescope is passed through your mouth to examine the lining of the oesophagus, stomach and duodenum.
- Faecal test: Faecal samples are examined under the microscope for abnormalities and blood.
- Biopsy: A small sample of tissue may be removed and examined under the microscope for abnormal cells.
- Colonoscopy: A colonoscope, a long narrow flexible telescope is inserted from the rectum to examine your colon.
These tests help identify the location and stage of cancer, which is important for designing the treatment plan.
Treatment depends on the stage of the cancer, location, your age and general health. Several treatment options are available for treating gastrointestinal cancers. The standard approaches may include surgery, radiation therapy, chemotherapy and target therapy.
- Surgical procedures vary depending upon the size and site of cancer. It often involves resecting or removing the cancer
- Radiation therapy is a procedure where high-energy rays are targeted at the cancer cells to destroy them.
- Chemotherapy involves the use of anti-cancer drugs given intravenously or orally. This type of treatment is extremely useful in cases where the cancer has spread to different parts of the body. These drugs work against the cells that divide quickly; thereby, slowing down the growth of cancer.
- Target therapy stops new blood vessels from developing in the cancer cells. With no blood supply, the growths of cancer cells slow down.
The outcome of treatment varies from person to person. Treatment in some cases can make you free of cancer, while in others, it is given to slowdown the progression of the cancer. The factors that can affect your prognosis include the location, stage and type of cancer, your age, health before cancer, and your response to treatment.
If left untreated, cancer may spread to other areas of the body.
Surgery for gastrointestinal cancers is indicated for stages 0, I, II and III cancers and surgical removal is often considered the primary treatment for cancer. It involves the complete removal of the primary tumour along with a margin of healthy tissue to ensure that there are no residual cancer cells. The surgical procedure depends to a large degree on the spread of the cancer to other organs or to the lymph nodes. If involved, lymph nodes and adjoining organs are removed along with the gastrointestinal cancer. In some cases, surgery is combined with radiotherapy or chemotherapy.
Gastrointestinal cancer surgery is performed under general anaesthesia. Some of the common surgeries are mentioned below.
Oesophageal cancer surgery aims at treating cancer by surgically removing the oesophagus (oesophagectomy) and the surrounding tissue that is affected. The remaining oesophagus is then reattached to the stomach. Surgery for oesophageal cancer can be performed by either an open approach or minimal invasively using laparoscopy.
Gastrectomy is the removal of the stomach to treat gastric cancer. It can be subtotal gastrectomy, where only a part of the stomach is removed, or total gastrectomy, where the whole stomach is removed. The remaining part of the stomach is joined to the bowel.
Pancreatectomyis the removal of the entire or part of the pancreas. There are many types of pancreatectomy. Also known as pancreaticoduodenectomy. A Whipple procedure involves the removal of the head of the pancreas along with parts of the gallbladder, small intestine, bile duct, and sometimes a part of the stomach. The remaining structures are reconnected so that enzymes and bile can flow normally into the intestine. Distal pancreatectomy is usually performed when cancer is found in the middle or tapering end of the pancreas. Total pancreatectomy or complete resection is undertaken when the tumour extends across the pancreas.
Cholecystectomyis surgery to treat cancers of the gallbladder. The procedure may also involve the removal of parts of other neighbouring organs such as the liver, common bile duct, pancreas and lymph nodes.
Hepatectomy is surgery to remove the liver along with some of the healthy tissue around it. It may involve the excision of only a part or the whole liver, in which case a healthy liver is transplanted to replace the diseased one.
Endoscopic mucosal resection (EMR)
The endoscopic mucosal resection (EMR) procedure is indicated to treat gastrointestinal cancer that is in the lining of the tract. Your surgeon inserts a gastroscope through the mouth to the area present in the oesophagus or stomach. Cancers in the colon are reached by a colonoscope inserted through the anus. Surgical tools are passed through the scope to perform EMR to remove the cancerous tissue. The surgery is non-invasive as it does not involve any cuts on the body.
Palliative surgery is performed to provide relief from symptoms. Some examples of palliative surgery include the placement of a stent to open up a blocked duct or bypassing a tumour so food or other substances can flow freely.
The post-operative guidelines differ for different cancer surgery. You should discuss this with your surgeon.
Benefits of this approach
The biggest benefit of gastrointestinal cancer surgery is the ability to completely remove the cancer. For extensive cancers, surgery is indicated to remove cancer cells to a maximum extent making it easier to be treated with other therapies such as chemo or radiation therapy. Surgery can also be used to treat symptoms of cancer and in many cases prevent/control its growth.
You may be instructed not to eat or drink or smoke anything before the procedure. If the procedure is performed in the colon your surgeon will prescribe a solution for you the day before surgery to cleanse your bowel. Your surgeon will review your daily medications and may instruct you on the medications that you need to avoid.
Surgery may be the only reliable option for a curative treatment. However, as with any procedure, gastrointestinal cancer surgery may involve certain risks and complications which include bleeding, infection, leaks from the newly connected region after excision, formation of blood clots, damage to nearby organs, frequent heartburn and vitamin deficiencies.
Post-op stages of recovery and care plan
After the procedure, you will be given specific instructions with regard to your diet. You are advised not to lift heavy objects for some time after the surgery. The care plan varies depending upon the type of surgery and location of cancer.
For gastrectomy, your doctor may refer you to a nutritionist to plan your diet and you need to eat more often with small meals as the size of the new stomach is smaller.
Downtime - lifestyle or off work duration
You can gradually resume your daily activities after the surgery.
Any costs involved will be discussed with you prior to your surgery.