Overview

Gastrointestinal (GI) cancers, of which there are more than 200,000 new cases annually in the U.S., are specific malignancies found in the various organs along the digestive tract. These include colorectal cancer, which affects nearly 150,000 people annually; pancreatic cancer, 26,000; stomach cancer, 24,000; esophageal cancer, 11,000; liver cancer, 5,000; and anal cancer, which affects approximately 3,000 people annually. Though each disease has unique characteristics, and should therefore be looked at individually, GI cancers as a group affect both men and women and usually develop after age 50.

Causes and Risk Factors and Warning Signs

Causes
While the precise causes of gastrointestinal cancers are yet unknown, Columbia Weill Cornell Cancer Centers are conducting research into the genesis of these cancers.

Risk Factors and Warning Signs
Each GI cancer has different risk factors and warning signs, but they do share some commonalities: 

• Family history of cancer plays an important role in all GI cancers, especially colorectal cancer.
• The roles of diet, smoking, and the environment are being examined for their effect on cell structure and organ structure and the development of cancer.
• Prior medical problems in the esophagus, colon, pancreas, anus, and other organs can have a significant tie to the later development of cancer in these areas.
• Excessive cigarette smoking and alcohol use can play a very significant role in the specific development of colon, rectal, esophageal, pancreatic, and stomach cancers.
• Particular work environments are linked to the development of certain GI cancers (see specific section).
• Exposure to specific chemicals appears to be linked to the development of particular GI cancers (see specific section).

Early Detection and Screening

Early detection and screening can make a significant difference in outcomes, both in terms of survival and recovery, in cancers of the gastrointestinal tract. In general, knowing risk factors and consulting a physician with any unusual or persistent symptoms can improve survival rates and treatment outcomes.

Diagnosis

Since symptoms often do not appear until lung cancer has progressed, the following signs warrant immediate medical attention:

• Persistent cough
• Coughing up of blood
• Wheezing and shortness of breath
• Discomfort during breathing
• Constant chest pain
• Pneumonia symptoms, such as a fever and a mucus-producing cough
• Discomfort during swallowing
• Hoarseness
• Weight loss and poor appetite

The following tests help confirm the presence of lung cancer, predict its stage and guide treatment recommendations.

Needle Biopsy. A needle biopsy is a procedure in which a piece of the tumor is removed using a small needle. This tissue is examined under a microscope to determine if it is malignant

Bronchoscopy. This procedure is used to explore the lungs to determine if there is a tumor or blockage present and is also used to take tissue samples for biopsy purposes

CT Scan. The CT scan is a simple and effective study that provides information about the size of the tumor, and can suggest whether the tumor has spread to nearby lymph glands or organs.  Findings on a CT scan, however, must be interpreted with caution. A CT scan alone is not sufficient to make the diagnosis of lung cancer. For example, enlarged lymph nodes seen on a CT scan do not always mean the cancer has spread. They may be enlarged for other reasons, such as chronic infection. Other studies, such as bone scans or CT scans of the brain, may provide complimentary information

PET Scan.  A relatively new technique, the PET scan is also used to help determine the stage of lung cancer.  Unlike a CT scan, the PET scan can image the entire body at one time, and can indicate whether the cancer has spread to distant organs such as the bone or liver.

Mediastinoscopy. This surgical procedure, performed under general anesthesia, is one of the most important and accurate tools used to determine the stage of lung cancer. The procedure is preformed through a small incision made above the collarbone. Here a telescope is inserted, and samples are taken from lymph glands within the chest. A pathologist will then determine whether the cancer has spread to these lymph glands. Mediastinoscopy is a simple procedure that usually requires less than one hour. It may be performed as an outpatient procedure or before a larger operation to remove the lung tumor.