PSA - new way to evaluate prostate cancer danger

The NYT has an AP news piece about a promising finding re evaluating the significance of PSA levels in regard to decision making on treatment.

I think it would be good if this news helps in the decision making, which has been in quite a confused state lately, what with finding people with low levels of PSA having serious problems, a situation that has thwarted predictability.


New York Times -
Study Offers New Solid Indicator of Prostate Cancer Danger Level
By THE ASSOCIATED PRESS

Published: July 8, 2004

Prostate cancer is much more likely to kill if the level of a protein rises rapidly before the cancer is even diagnosed, researchers are reporting today.

The finding could help patients and doctors make a decision on whether go ahead with surgery to remove the prostate or to wait. The test for the protein, prostate specific antigen, or P.S.A., is widely used to diagnose prostate cancer by measuring levels of a substance in the blood called prostate-specific antigen. Until now, doctors had focused largely on the P.S.A. level itself and not on how it had changed over time.
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But the researchers found that how fast the level of P.S.A. increased in the year before prostate cancer was diagnosed predicted which tumors were deadly nearly 10 times better than the P.S.A. level itself.

"The study is pretty definitive," said its lead author, Dr. Anthony D'Amico, a radiation oncologist at Brigham and Women's Hospital in Boston and a professor at Harvard. "It's not the level of P.S.A. that matters, it's the change from year to year."

When doctors find prostate cancer, they often recommend "watchful waiting" over surgery to remove the prostate, as the operation can cause impotence and incontinence and because some prostate tumors grow so slowly that men may die of something else before the cancer kills them. But most men do not want to wait, so doctors are seeking better ways of predicting which tumors will be lethal.

P.S.A. levels alone are not always reliable. A recent study found that the tests missed about 15 percent of prostate cancers in older men whose readings were supposedly normal, which is four or below for that age. The new study, in today's New England Journal of Medicine, followed 1,095 men who were 65 years old on average, who had prostate cancer. They received P.S.A. screenings at least once a year and underwent prostate surgery from 1989 to 2002.

Twenty-eight percent of the men whose level rose more than two points the year before diagnosis died of prostate cancer within seven years, despite having the gland and adjacent lymph nodes and seminal vesicles surgically removed.

P.S.A. helps liquefy semen for ejaculation. An elevated P.S.A. level can indicate benign prostate enlargement or prostate cancer. So when a man is found to have an elevated level, doctors do a biopsy, withdrawing cells from the gland by needle for examination under the microscope for signs of cancer.

Some medical groups have issued guidelines that call for annual P.S.A. tests beginning at age 50, or 45 for men with a family history of prostate cancer. But Dr. D'Amico said a baseline P.S.A. level should be determined at age 35 to spot changes.