Ultrasound Helps Detect Small Prostate Cancers
CHICAGO (AP) _ Ultrasound could become a routine method for early detection of prostate cancer, which kills 25,000 American men each year, two researchers say.
Doctors using ultrasound to screen male patients over age 60 at an Ann Arbor, Mich., hospital detected six cases of prostate cancer that were not found using traditional methods, Dr. Richard McLeary said today.
A total of 13 cases of prostate cancer were found in tests of 388 men, seven of them detected by conventional means as well, he said.
McLeary, of St. Joseph Mercy Hospital, said the screenings were part of a continuing project comparing ultrasound with the traditional method of probing with a finger for nodular enlargement of the prostate gland during a rectal examination.
″The problem with the digital exam is that by the time someone feels something, it’s often too big to be cured,″ McLeary said in a telephone interview.
In another study, Dr. Fred Lee, one of McLeary’s associates, used ultrasonically guided biopsies of the prostates of 80 men and detected small tumors that were missed by doctors using the traditional examination.
Ultrasound generates an image by beaming sound waves at portions of the body, then capturing and depicting the reflected waves.
″The finger is not sensitive enough for early detection,″ Lee said. ″Hopefully, the earlier detection of prostate cancer will lead to a decrease in the numbers of death due to this ubiquitous cancer.″
Lee spoke at the annual meeting of the Radiologial Society of North America on Wednesday.
The prostate gland secretes seminal fluid. Cancer of the prostate is diagnosed in 90,000 American men each year, and the deth toll of 25,000 makes it the second largest cause of cancer deaths in men after lung cancer, Lee said.
A man in his 50s has a 30 percent chance of developing prostate cancer. The risk climbs to 40 percent for men in their 60s and continues to increase with age.
In his study, Lee used ultrasound to guide a tissue-sampling needle to suspected cancer sites in the prostates of 80 patients while they were under local anesthetic. The method confirmed the presence of tumors in 61 percent of the 80 patients.
Doctors using the traditional finger-probe method could not feel the tumors in two-thirds of the patients with tumors under 1 centimeter in diameter, Lee said.
In half of the patients in whom ultrasound detected tumors of 1 to 1.5 centimeters, the tumors could not be felt or did not appear suspicious to doctors using the traditional technique, he said.