Hi, I have had blood in my stool about a year ago. Since then I have had blood semi-frequently, as well as flat, loose, stool with undigested food. About three months ago, I had a colonoscopy and endoscopy, both came back normal. I am still so paranoid I have colon cancer. I am 25 with no history. It was done by a gastroenterologist in Minneapolis. How accurate are colonoscopies at detecting tumors? Thanks so much in advance.
Regular screening is the key to colon cancer prevention. When precancerous colon polyps and cancers are found and treated in the earliest stages, the cure rate approaches 100 percent. Colonoscopy is generally considered the best screening and diagnostic test for colon cancer. Although it remains the standard by which other tests are measured, Mayo Clinic has been at the forefront of the search for simpler, more comfortable options. Tests used to screen for and diagnose colon cancer at Mayo Clinic include:
Long considered the procedure of choice for colon cancer screening, colonoscopy is a visual examination of your colon and rectum using a colonoscope, a thin, flexible tube — about the thickness of an adult finger — with a lighted camera inside its tip. The camera sends magnified images of your colon to a television screen.
If your doctor discovers small polyps during the exam, they're usually removed immediately using instruments inserted through the colonoscope. Large polyps and tumors generally require surgical removal. In such cases, Mayo Clinic endoscopists tattoo the tissue to help guide future surgery.
Most people find that preparation for colonoscopy — a liquid diet and bowel cleansing with laxatives and sometimes enemas — is by far the most unpleasant part of the procedure. There's also a slight risk — about one in 1,500 for therapeutic colonoscopy and one in 6,000 for screening or diagnostic colonoscopy — of perforation of the colon or rectum wall.
Virtual colonoscopy (CT colonography)
CT colonography — popularly called virtual colonoscopy — is a minimally invasive alternative to colonoscopy. Mayo Clinic has led the way in studying and using CT colonography since the test was introduced in 1991 and was the first to offer it for routine care. Over the years, Mayo physicians have performed thousands of CT colonographies.
CT colonography uses a CT scanner to produce hundreds of cross-sectional images of your abdomen. The images are digitally manipulated to provide a detailed view of the interior of your colon without having to insert a colonoscope. This makes the procedure especially beneficial for people who are older, frail or can't undergo colonoscopy for other reasons. Studies at Mayo Clinic have demonstrated that in skilled hands, CT colonography is as accurate as traditional colonoscopy at detecting polyps.
Because polyps can't be removed during this test, Mayo offers "one-day colonoscopy" to people undergoing CT colonography. If polyps are found during the procedure, endoscopists can remove them the same day, sparing you an extra trip to the clinic and another round of bowel preparation.
Sigmoidoscopy: Similar to colonoscopy, this test uses a flexible tube to examine the rectum and sigmoid — the last two feet of your intestine. Mayo Clinic physicians don't use sigmoidoscopy as often as other tests because the procedure can't find problems in the upper two-thirds of your colon.
DNA Stool Tests
Colon polyps and cancers continuously shed DNA that eventually makes its way into stool. Mayo Clinic studies have shown that analyzing this DNA for genetic mutations can accurately detect both polyps and early-stage cancers. By refining existing stool test technology, Mayo researchers created a highly sensitive, noninvasive colon cancer test — one that doesn't require bowel cleansing, sedation or even a trip to the doctor's office. In most cases, you simply mail a stool sample to a lab.
Although not yet widely used, this test is likely to become much more common in the future. Because most cancers shed mutated DNA, Mayo researchers are also developing DNA stool tests for malignancies throughout the digestive tract, including those in the throat, esophagus, stomach, pancreas, bile ducts and small bowel.
Probe-Based Laser Confocal Endomicroscopy
Mayo Clinic was the first medical center in the United States to test this technique, which allows skilled endoscopists to detect cancerous changes without removing tissue for laboratory analysis. The laser confocal endomicroscopy probe system can be used during colonoscopy to distinguish benign from malignant polyps, thereby sparing patients unnecessary polyp removal. The system uses a fiberoptic probe that can be passed through an endoscope. Essentially a miniature microscope, the probe can provide the same level of detail that a pathologist sees using a traditional microscope outside the body.
If you're diagnosed with colon cancer, it's important to determine how deeply the cancer has penetrated into the colon wall and whether it has spread to nearby lymph nodes or organs — a process called staging. Precisely identifying the extent and spread of the disease is a critical step in selecting appropriate therapies. Before undergoing surgery or other treatments, you are likely to have an abdominal CT scan and lung X-ray to determine whether cancer has spread to these areas. But at Mayo Clinic, most colon cancer staging is performed postoperatively by pathologists specializing in colorectal cancer.
Total hysterectomy July 23 2008, mass in colon.
Colonoscopy Aug 2008
Rigid Sigmoidoscopy with a laparoscopic-assisted partial colectemy with enbloc small bowel resection Sep 2008
Diagnosed: Stage IV Colon Cancer mets to lungs and liver. (T3,N2,M1,G2) KRAS Mutation
Started chemotherapy: 09/14/09 Folfox-6/Avastin then Camptosar/Avastin & last Folfox-6/Avastin
On Hospice, started 11/12/10
Last PET scan: Oct 12th
Most recent CEA Level: 09/27/10: 696.7 up from 08/16/10: 284.8