New Criteria May Help Predict Insignificant Form of Prostate Cancer


ROCHESTER--A common form of prostate cancer that is clinically insignificant can be predicted with reliability using a new set of criteria according to study from the Mayo Clinic.

Prostate cancer killed over 40,000 Americans in 1995. Prostate cancer is second only to lung cancer as a male cancer killer in the United States. While 40% of men in their 40s and 50s have at least tiny areas of undetected cancer in their prostate glands, prostate cancer accounts for only 3% of US male deaths.

The ability to define clinically insignificant prostate cancer in a patient with a relatively short life expectancy could help avoid unnecessary surgery, radiation therapy, or other treatments, and, until now has not been possible.

In a study recently published in the Journal of the American Medical Association, Joseph Oesterling, M.D. and associates described their data which resulted from a review of 337 prostate specimens.

The authors concluded that by using a combination of criteria they were able to define an individual prostate cancer as clinically insignificant. These criteria included cancer volume, grade, cancer volume doubling time, and the life expectancy of the patient.

These criteria basically allowed the authors of the study to define relatively slow-growing cancers in aging men. The authors point out that "prostate cancer is clinically insignificant until it causes bladder outlet obstruction, local invasion, mass effect, or symptomatic metastases."

In order to become "clinically significant" the cancer must grow to a certain size. The authors of the study emphasize that technologic advances will permit more accurate measurements, and therefore, predictability in the future. They further note that the prostate specific antigen (PSA) test doubling time can also provide useful information about the current cancer growth rate.

Later studies may refine these criteria, but they are certainly an encouraging approach to the evaluation of patients with this common and often silent cancer.

Readers are referred to the Prostate Cancer site of the Diseases and Treatments section for more information on prostate cancer.