Barrett's Esophagus (cont.)

What does endoscopic biopsy surveillance in Barrett's esophagus involve?

Periodic random biopsies

In established Barrett's esophagus, endoscopic surveillance is done at periodic intervals to look for dysplasia. At the time of endoscopy, many biopsies are taken of the Barrett's mucosa. The recommended approach is to do four mucosal biopsies (one in each quadrant of the circumference of the esophagus) at the junction of the stomach and esophagus, and four more biopsies (again, one in each quadrant) should be repeated every two centimeters (about 3/4 inch) proximally until the length of the Barrett's has been completely biiopsied. If available, a large forceps (the so-called jumbo forceps) is desirable to procure biopsy specimens.

The current trend is to increase the surveillance intervals in patients who do not have dysplasia. For example, the approach may be to do the surveillance biopsies initially and then a year later. If no dysplasia is found, the surveillance can be done every three years. Other doctors would do it every two years. The bottom line for endoscopists doing surveillance, however, is: "Do it right so we can do it less often." There is some evidence showing that patients with cancers found during the course of surveillance have a better survival rate than those who come to the doctor because of cancer symptoms without any previous surveillance. The ultimate proof that surveillance works, however, will be obtained only when surveillance is applied to a large population at risk and not just to those who seek medical attention. The same issues pertain to other cancer screening tests (such as, mammography and prostate cancer screening). If cancers are found in Barrett's patients under surveillance, the 5-year survival rate is at least 80%. This means that at least 80% of the cancer patients would be alive 5 years after treatment. The problem is that only 5% of patients who undergo surgery for esophageal adenocarcinoma had been diagnosed with Barrett's esophagus preoperatively. Thus, only the 5% with known Barrett's were eligible for surveillance before their surgery. In other words, the challenge is not to do more surveillance, but to conduct more screening to identify those who have Barrett's esophagus in the population with chronic GERD.

Other ways to diagnose dysplasia

There is great interest in developing techniques that would use targeted, rather than random biopsies in identifying areas of dysplasia or early cancer. Dysplasia often is endoscopically invisible, which means that it can't be seen just by looking at the esophageal lining through the endoscope. So, different optical enhancing techniques are being evaluated. The idea is to highlight the areas of dysplasia so that targeted biopsies can be obtained. These optical methods include the use of dye sprays (chromoendoscopy), spectrophotometry to measure light wave intensity, and a technique called optical coherence tomography. These procedures, however, remain experimental at present.

Next: How is high grade dysplasia managed? »

Printer-Friendly Format

|

Email to a Friend