October 14, 2011 > A Life-saving Screening
A Life-saving Screening
New technologies improve colorectal cancer screening and staging
The Centers for Disease Control and Prevention (CDC) estimates that approximately 142,500 people will be diagnosed with colorectal cancer this year-and nearly 51,400 will die of the disease. But up to 60 percent of those deaths could be prevented by screening tests that detect colorectal cancer early, when it can be more successfully treated.
"The gold standard of screening is a colonoscopy," says Arun Srivatsa, M.D., a gastroenterologist on the medical staff at Washington Hospital. "With a colonoscopy, we can detect and remove pre-cancerous polyps-growths inside the large intestine. This prevents them from turning into cancer. Tests that only detect cancer, such as tests that measure blood in the stool, don't allow for removing polyps."
Making Testing More Effective
In a colonoscopy, a thin, flexible tube with a miniature camera is inserted through the rectum to look inside the large intestine while the patient is under moderate anesthesia. Flexible sigmoidoscopy, a similar procedure, only views about the first half of the colon. Plus, anesthesia is generally not used for sigmoidoscopy, so there may be some discomfort.
"Doing a sigmoidoscopy is a bit like doing a mammogram only on one side," Dr. Srivatsa notes. "The worst part of a colonoscopy or sigmoidoscopy usually is preparing for it, taking medication the night before to clean out the colon and possibly an enema that morning. Since preparation is the same for either procedure, you might as well view the entire colon."
Another new diagnostic tool, endoscopic ultrasound (EUS), combines endoscopy and ultrasound to obtain detailed images of internal body structures. A small ultrasound device embedded in the tip of the endoscope is inserted via the mouth or rectum. EUS equipment was installed this spring at Washington Hospital, making it the first facility in the East Bay to offer EUS.
"Endoscopic ultrasound can be used for 'staging,' providing information about the spread of cancer within the colon and adjacent tissues," Dr. Srivatsa says. "It also can scan other nearby body structures, giving us a much wider view with very detailed images. We can use EUS to evaluate the pancreas, liver, esophagus, stomach, gall bladder, spleen, lungs and the adrenal gland above the kidney in addition to the colon.
"If a CT scan shows a lump somewhere, we can use EUS to get a better picture and biopsy the suspicious area at the same time without puncturing through the skin," he says. "It's a less invasive method of imaging and performing biopsies that avoids damage to other body structures."
Getting a Better View
Recent improvements in colonoscopy include high-definition endoscopes that produce clearer, high-resolution images. Washington Hospital now has PENTAX i-SCAN equipment that uses a high-definition video chip and monitors that are like HD TVs.
"The i-SCAN provides better polyp detection, especially in the right colon, which is harder to view," Dr. Srivatsa says. "We are the only facility in Fremont to offer i-Scan colonoscopies. The i-Scan also can be used to examine the esophagus, stomach and small bowel."
The risk of colorectal cancer increases with age, so the CDC and American Cancer Society both recommend colonoscopy screenings at least every 10 years for people over age 50. People with a higher risk for colorectal cancer should be screened earlier and more often. In addition to age and family history, some other risk factors include smoking, lack of exercise, obesity, a diet high in red meat and excess alcohol consumption.
"With the latest technology right here in Fremont, patients don't have to cross the bay for accurate diagnosis and treatment of colorectal cancer or other gastrointestinal disorders," Dr. Srivatsa says. "The preparation is still not a pleasant prospect, but that's one night of discomfort in exchange for peace of mind knowing that your insides are healthy."