What Is an Endoscopy?

Endoscopy is a medical procedure that uses a thin, flexible tube with a light and camera (called an endoscope) to look inside the body. It allows doctors to directly view internal organs and tissues, and often take biopsies at the same time.

Unlike imaging tests (X-ray, CT, MRI, PET, Ultrasound), which show pictures from outside the body, endoscopy provides direct visualization and often tissue sampling in one procedure.

 

How Endoscopy Is Used in Cancer

1. Detection & Diagnosis

• Detects tumors, polyps, or abnormal areas in hollow organs.
• Enables biopsy of suspicious tissues.

2. Screening

• Colonoscopy (a type of endoscopy) is the gold standard for colon cancer screening.
• Upper endoscopy is often used to check for esophageal, stomach, and duodenal cancers.

3. Staging

• Assesses how far a tumor has spread within the wall of an organ.
• Endoscopic ultrasound (EUS) can show depth of invasion and nearby lymph nodes.

4. Treatment & Monitoring

• Removes precancerous polyps (e.g., during colonoscopy).
• Monitors high-risk patients or recurrence after treatment.

 

Types of Endoscopy Commonly Used in Cancer

• Colonoscopy: Examines the colon and rectum.
• Gastroscopy (Upper Endoscopy): Examines esophagus, stomach, and duodenum.
• Bronchoscopy: Examines airways and lungs.
• Cystoscopy: Examines the bladder.
• Endoscopic Ultrasound (EUS): Combines endoscopy with ultrasound for deeper views.

 

What to Expect During the Procedure

• Typically done as an outpatient procedure.
• You may be given sedation or anesthesia for comfort.
• The endoscope is inserted through the mouth, nose, or rectum depending on the organ being examined.
• A biopsy can often be taken during the same session.
• Most procedures last 15–60 minutes.

 

Benefits

• Direct visualization of internal organs.
• Can combine diagnosis and treatment (e.g., polyp removal).
• High accuracy for detecting early cancers and precancerous changes.
• Minimally invasive compared to surgery.

 

Risks & Limitations

• Discomfort: bloating, sore throat, or cramping.
• Bleeding or perforation (rare but possible, especially if biopsy/polyp removal is done).
• Requires sedation, meaning patients need recovery time and someone to drive them home.
• Limited to hollow organs — not useful for solid organs (e.g., brain, liver).

 

Alternatives & Related Tests

• Imaging (CT, MRI, PET, Ultrasound): Shows structure but not direct view.
• Capsule Endoscopy: Swallowed camera pill for small intestine (limited availability).
• Biopsy: Can be performed during endoscopy for confirmation.

 

Questions to Ask Your Doctor

• Why do I need an endoscopy?
• What type of endoscopy will be performed?
• Will I need sedation or anesthesia?
• What are the risks of biopsy or polyp removal?
• How often will I need this test for follow-up?

 

Patient Tips

• Fasting: No food or drink for several hours before the procedure.
• Bowel prep: For colonoscopy, a laxative prep is needed to clear the intestines.
• Arrange for transportation after sedation.
• Ask how long you will need to rest before resuming normal activities.

 

References

• National Cancer Institute (NCI): Endoscopy and Cancer
• American Cancer Society: Colonoscopy and Endoscopy
• Mayo Clinic: Endoscopy Overview