The article "A New Blood Test to Detect Colorectal Cancer" (June 17) is confusing two critical issues involving health care: prevention and detection. Ideally, it is nearly always best to prevent a malignant condition; a far second place objective is, while not preventing a malignancy, to detect it early before it spreads.
Colonoscopy, performed at regular intervals, is the best method to prevent colorectal cancer, since this is the only known method that safely allows not only direct vision of the large intestine but also removal of polyps. Since almost all -- if not all -- of these cancers originate from polyps, by removing the polyps, the patient will, practically speaking, never get a colon or rectal cancer in the first place.
The article is critical toward colonoscopy on the basis of the bowel prep and patient discomfort. I've been performing colonoscopies for 30 years and have consistently recommended bowel preps requiring far less than a gallon of fluid; second, be assured, patient discomfort is a very rare situation, since all the patients are asleep (sedated by an anesthesiologist) during the entire approximately 20-minute procedure.
On the other hand, the blood test the author describes, which is not even available to the public, does nothing to prevent colorectal cancer; it merely detects it once already present. While this blood test may detect the cancer at an earlier stage than usual, it will not avoid the necessity for surgery to eradicate the cancer.
A bowel prep, along with a short but restful sleep every few years, in preventing cancer is far superior than the alternative of major surgery in attempting to remove a cancer. Rather than employing limited resources in detecting a cancer that is already present, it remains far more practical for our patients and physicians to encourage prevention of malignancies, especially involving malignancies such as colorectal cancer, that are completely preventable.
BRAD LEVINSON, M.D.
The writer is a board certified colorectal surgeon with 30 years of experience and is a fellow of the American Society of Colon and Rectal Surgeons and of the American College of Surgeons.