Duh......Needless Prostatectomies Etc....What Else Is New?

[Guest guest]

PSA Test a Thing of the Past?

 

http://www.ajc.com/health/content/shared-auto/healthnews/-

pro/518850.html

 

 

MONDAY, May 10 (HealthDayNews) -- The PSA test, long the gold

standard for

deciding who

should have a biopsy for prostate cancer, may have outlived its

usefulness for

the most

part.

 

Stanford University researchers say PSA (prostate specific antigen)

levels bear

little

relationship to the severity of a cancer these days. They presented

their

finding May 9

at the American Urology Association's annual meeting in San Francisco.

 

" We need to recognize that PSA is no longer a marker for prostate

cancer, " said

study

author Dr. Thomas A. Stamey, a professor of urology at Stanford

University

School of

Medicine. " We urgently need to find a new marker for prostate cancer,

and that

marker

must be proportional to how much cancer you have. "

 

" We have been so thorough and effective in screening for prostate

cancer over

this

20-year period that PSA no longer has a relationship to prostate

cancer, " Stamey

said.

" Because we all develop the cancer, we're now removing prostates from

men whose

cancer is

so small that they do not need the procedure. We're finding all these

little

cancers that

are never going to be a danger to the patient. "

 

" In smaller cancers, the PSA test is not relevant anymore, " Stamey

explained.

" You might

as well biopsy a man because he has blue eyes. "

 

PSA is a protein produced by the cells of the prostate gland. Because

blood

levels of the

antigen tend to rise as the gland enlarges, it has been used for

years as a test

of

whether a person needs a biopsy for cancer. The test, however, is not

foolproof.

 

" People's perceptions [are] that if your PSA is a certain level,

you're very

likely or

you do have prostate cancer, and that is incorrect, " said Dr. Mark

Soloway,

chairman of

the department of urology at the University of Miami School of

Medicine.

 

" The PSA test is a very good test. It's not a perfect test,

especially in

younger men, "

added Dr. Jay Brooks, chief of hematology/oncology at the Ochsner

Clinic

Foundation in

New Orleans.

 

To see how the efficacy of the PSA test might have waned, researchers

in

Stamey's lab

reexamined every prostate that had been removed since 1983 (1,317 of

them) and

compared

the size of the cancer with blood PSA levels. None of the cancers had

been

treated with

chemotherapy, radiation, or hormones before surgery.

 

Each cancer was rated on eight or 10 different parameters thought to

indicate

how

aggressive the cancer was, including the size of the tumor and its

grade.

 

Stamey then divided the samples into four five-year periods to see

what had

happened to

the qualities of the cancers over time.

 

" What we showed was that in the first five years, the cancers were

related to

the level

of serum PSA, " Stamey said. " Then in the next five years, they were

still bad

but not as

bad as the first five years. Then in the third five-year period, they

were

better and

better. And in the last five years ending Jan. 1 of this year, the

cancers were

so small

they had no relationship to serum PSA. "

 

Twenty years ago, 80 percent of cancers were detected by digital

rectal

examination; only

20 percent of cancers are now detected that way, Stamey explained.

 

Instead, PSA levels today are driven by benign enlargement of the

prostate, a

condition

that does not usually require surgery.

 

The concept that the PSA test is not foolproof is not an entirely new

one. " The

point is

well taken that in microscopic disease, the volume of cancer is

clearly

overshadowed by

the volume of noncancer, so that the cancer cannot be the cause of

the elevated

PSA, "

said Dr. John Phillips, physician-in-charge of urologic oncology at

Beth Israel

Medical

Center in New York City.

 

The question now is what can replace it. " People are trying to find

other ways

of finding

cancer, " Phillips added.

 

As a matter of fact, University of Pittsburgh researchers who

presented at the

same

conference reported that additional testing for a protein called

early prostate

cancer

antigen (EPCA) might mean prostate cancer could be detected as many

as five

years earlier

than with just the PSA test.

 

" We would like a perfect test that would only find biologically

significant

cancers, "

Soloway said. " Today we can't distinguish between those with indolent

cancer and

those

whose cancers threaten their life. We need another way. That's going

to be a

difficult

task. "

 

In the meantime, the American Urological Association issued a

statement that,

for the

time being, the PSA test in combination with a digital rectal exam

and a full

medical

history is the best way to determine when a biopsy might be necessary.

 

More information

 

The National Cancer Institute has more on the PSA test while the

American

Urological

Association has more on prostate cancer screening.