Digestive System

General Information / Anatomy / Function / Statistics

• Organs of the digestive system prepare food for absorption and for use by the millions of body cells
• The main organs form a tube open at both ends known as the alimentary canal or gastrointestinal tract
• Organs making up the tract are: mouth, pharynx, esophagus, stomach and intestines
• Accessory organs located in the main digestive organs or open into them are: the salivary glands, teeth, liver, gall bladder, pancreas and vermiform appendix
• Cancers of the G.I. tract account for roughly 15% of cancer diagnosed in men and women

Esophagus

General Information / Anatomy / Function / Statistics

• Tube that connects the mouth to the stomach
• Contraction of muscles in the wall of the esophagus passes food and liquids into the stomach when swallowing
• Cancer of the esophagus is more common in men than women by 3 to 1
• Blacks are afflicted 3.5 times more often than whites
• Marked geographic differences
• Increasing in SE United States
• Hunan province in N. China, one of the most common cancers
• Some parts of Iran 20% more common than in U.S., accounting for more than half of all malignancies
• Common in parts of South Africa
• High mortality rate
• Overall five-year survival for cases amenable to surgery is about 5 to 20 percent ; only 25 to 40 percent of cases are amenable to surgery
• For statistics, please click here.

Symptoms / Signs

• Dysphagia: difficulty in swallowing, at first with solid foods but as the cancer grows even liquids and soft foods become difficult to swallow
• Unexplained choking
• Painful spasms after eating
• Frequent bouts of "indigestion" or reflux
• Persistent anemia
• Weight loss
• Vocal cord paralysis
• Coughing up blood

Etiology / Carcinogens / Risks

• In North America, heavy smoking and alcohol consumption have been linked to this site
• When used together the carcinogen effect multiplies
• People who both smoke and drink are 30 times more likely to develop esophageal cancer than those who neither drink or smoke
• Chronic irritation of the lower esophagus due to gastric reflux (backward flow of stomach acid) appears to increase the risk of esophageal cancer
• There is an increased risk to those exposed to large burns of the esophagus; e.g., exposure to lye during a suicide attempt or accidental swallowing by a child

Prevention

• Patients with Barrett's esophagus should have cell analysis which has a 75 percent detection rate for cancerous changes
• Avoid fats
• Should be directed at discouraging people from smoking and encouraging moderation in alcohol use

Diagnosis / Screening / Staging / Grading / Types

• Early diagnosis is critical for successful treatment
• Metastasis has already occurred in at least half of the patients at the time of diagnosis
• X-ray, including Barium meal
• Esophagoscopy-examination with a fiberoptic instrument passed down the throat with flexible tubing. Can be done in a day care centre under mild sedation
• Biopsy-may be taken during esophagoscopy
• CT scanning may be done
• Esophageal endoscopic ultrasound of the surrounding tissue

Staging

Stage 0	very early cancer; has not spread below the lining of the first layer of esophageal tissue
Stage I	tumour involves inner lining only
Stage II	tumour may involve entire wall or may involve nodes and inner lining only
Stage III	tumour involves entire wall and lymph nodes
Stage IV	metastases

• Tumor may spread by local invasion quite rapidly
• Metastases through the lymph systems commonly occur. Can also spread by the bloodstream to the lung, liver and bone

Types

• Sixty percent of esophageal cancers appear in the cells lining the esophageal tube (squamous cell), usually in the upper two-thirds of the esophagus
• About 40 percent develop in the glands (adenocarcinoma) in the lower third
• Barrett's esophagus is a premalignant condition thought to be caused by chronic inflammation where the normal squamous epithelium (lining of the esophagus) is replaced by glandular (columnar) epithelium resembling the stomach lining

Treatment

• Lower esophagus-surgery is usually performed involving removal of the lower part of the esophagus and upper part of the stomach with anastomosis (surgical connection with opening). Often it is preferable to remove the entire esophagus.
• Radiation is the major treatment for cancers of the mid and upper esophagus
• Radiation and chemotherapy may be used in combination with surgery to prevent recurrence and to slow the spread of metastases. If surgery is not possible, then radiation may be useful in providing relief of symptoms.
• With tumours that cannot be treated by surgery or further radiation, patients may have their ability to swallow restored by the insertion of a special prosthetic tube
• Laser-therapy--opening of blockage and relieve dysphagia, usually needs to be repeated every four to six weeks
• Artificial feeding through a tube inserted into the stomach may occasionally be recommended to maintain nutritional status
• In some research centers chemotherapy is being added as an adjunctive treatment either before or after surgery or radiation. Used most commonly are 5-fluorouracil and cisplatin
• Surgery--removal of most, or all of the esophagus and the surrounding tissues and lymph nodes

Treatment by Stage

Revised May 1999

March 2007  We are currently reviewing and updating these pages.  If you have any questions about your cancer and its treatment, please discuss with your oncologist or physician.  Thank you.