P.S.A. Test No Longer Gives Clear Answers
Last November, Rabbi Samuel M. Stahl was worried that he might have
prostate cancer. He had had two P.S.A. tests in the past six months.
Both times, his levels were well within the range that had been
considered normal, but the second level was higher than the first.
His internist told him to relax. The blood test looks for a
protein, the prostate specific antigen, which can signal cancer.
Only test results higher than 4 were worth worrying about, the
doctor contended, and both tests were below that.
But Rabbi Stahl, who lives in San Antonio, remembered advice he
had gotten from a stranger three years ago that suddenly felt eerily
prescient.
The rabbi was walking out of the city's Ecumenical Center for
Religion and Health when he passed a man who was walking in.
"The man said, 'Are you here for the prostate cancer support
group?' " Rabbi Stahl recalled. "I said no. Then he said: 'I just
want to give you a bit of advice. Don't pay attention to the
absolute P.S.A. number, but if you see it rising, that's a cause for
concern.' "
Rabbi Stahl's first P.S.A. was 2.4. But the second one was 3.4.
He had to find out: was that jump ominous or inconsequential?
Rabbi Stahl had stumbled into one of the great issues in medicine
today. No longer is the P.S.A. test a simple screen with a sharp
cutoff at 4. Now, prostate cancer experts say, all bets are off.
The P.S.A. test "is just not as discriminating as we thought it
was," said Dr. Michael J. Barry, a professor of medicine at Harvard
Medical School.
As a result, many experts are suggesting that the P.S.A. not be
the single focus of prostate cancer screening, but rather one piece
in a puzzle with other risk factors. Some experts are also asking
doctors to be more open to the idea that some men may be better off
forgoing treatment and instead be monitored regularly for changes in
their tumor's growth. The muddied story emerged in a sequence of
medical papers over the last year.
First Dr. Ian M. Thompson Jr., chief of urology at the University
of Texas Health Science Center at San Antonio, published a paper in
The New England Journal of Medicine reporting that biopsies found
prostate cancer in as many as 15 percent of men with P.S.A. levels
below 4.
Then Dr. Thomas Stamey, professor of urology at Stanford
University School of Medicine, published a paper in The Journal of
Urology saying that P.S.A. tests were virtually useless. In most
men, P.S.A. levels of 2 to 10 are caused by nothing more than a
harmless enlargement of the prostate that occurs when men age. But
prostate cancer is so common that biopsies find prostate cancer in
most middle-aged and older men if doctors look hard enough. So the
results would be the same if doctors simply biopsied men age 50 and
older than if they did a P.S.A. test first.
And last month, Dr. Peter C. Albertsen of the University of
Connecticut Health Center published a study in The Journal of the
American Medical Association saying men with prostate cancers that
do not look particularly aggressive under a microscope - the
majority of men whose cancers are found with P.S.A. tests these days
- can do perfectly well with no treatment for at least 20 years. All
they need is to be monitored by a doctor to ensure that their P.S.A.
levels are not shooting up.
On the other hand, a Swedish study published last month in The
New England Journal of Medicine lumping men with more as well as
less aggressive cancers found that those who had their prostates
removed had a lower risk of death and of metastatic cancers than
those who did nothing. But these men generally started out with
larger tumors than the ones that are now being found with P.S.A.'s.
So what is a man to do?
The problem, said Dr. Timothy Wilt, a professor of medicine at
the Minneapolis V.A. Medical Center, is that most men eventually
develop prostate cancer, but most of the time it grows so slowly
that it never causes problems and eventually they die of something
else, never knowing they had cancer. Unless, of course, a doctor
starts biopsying their prostate. With annual P.S.A. tests, sooner or
later many men will end up with a biopsy.
"And as we repeatedly biopsy men, we are likely to find these
subclinical prostate cancers," Dr. Wilt said. "There is no doubt
that we will label more people as abnormal," telling them they have
cancer and throwing them into a terrifying whirl of decision making.
Despite the arguments in the academic medical community about what
the test means, most men are still having it done. But now they have
to address these questions: When should a low P.S.A. level lead to a
biopsy, and when should a tiny tumor be treated?
There is no easy answer, Dr. Thompson said. In deciding whether
to do a biopsy, doctors must weigh other factors along with the
P.S.A. Did the patient's father die of prostate cancer? Is he fat?
(Fat men tend to have lower P.S.A. levels than thinner men, so a low
level in a fat man might be more ominous.) Is he African-American?
(Blacks tend to develop more aggressive prostate cancers and at
younger ages.) Are his P.S.A. levels steadily rising with no
apparent cause, like an enlarged prostate or an infection, both of
which cause elevations in the P.S.A.? Or does he have an enlarged
prostate, no family history and a previous biopsy that found no
cancer?
"You can't condense it to a sound bite," Dr. Thompson said.
But many doctors, he added, are either unaware of the new views
on P.S.A. or are ignoring them.
"I was presenting some of the data recently to a gentleman over
50 who was visiting our institution," Dr. Thompson said. "He looked
at me with kind of wide eyes and said, 'Do people know this?' " The
answer, Dr. Thompson said, is that it appears that most general
practitioners do not know it. "They don't know that there is no such
thing as a normal P.S.A. level."
Dr. Wilt has another concern. Most patients, he said, are not
being counseled that even if they have prostate cancer, they may not
need treatment. Only a small percentage of prostate cancers are
dangerous, and older men, in particular, with small tumors may be
better off monitored instead of treated. Dr. Wilt is directing a
study that should help settle the question of whether treatment with
surgery helps save lives in men whose prostate cancer is detected by
P.S.A. screening, but its results will not be in until 2010.
Often the decision about what to do is thrust upon men who
underwent a P.S.A. test without knowing it; their doctor just
ordered it as part of a routine physical exam. Then the results came
in and the doctor said the dreaded word, cancer.
That is what happened to Michael Karp, a 78-year-old retired
pharmacist who lives in Faribault, Minn.
Back in November 1994, he said, his doctor told him he had had a
P.S.A. test and his level was high. He was astonished. He had no
idea he'd been tested. "I didn't even know what a P.S.A. was," Mr.
Karp said.
A biopsy was done, but no cancer was found. His P.S.A., 7.2, was
presumably from a urinary tract infection.
But, Mr. Karp said, his doctor insisted on yearly tests, and Mr.
Karp, having experienced a cancer scare, did not dare refuse. The
doctors, with their talk about P.S.A.'s and cancer, had made an
indelible impression. "They've got you worried, they're in your
head," he said.
Then, a few years ago, his P.S.A. rose to 11.4 and a biopsy
uncovered cancer.
"I was all shook," Mr. Karp said. Should he have his prostate
removed or destroyed, risking impotence or incontinence?
"I went to Dr. Wilt," he said, who gave him another option.
"He says to me: 'If you were in Sweden, you know what would
happen? Nothing,' " Mr. Karp said. "It kind of woke me up." His
P.S.A. level has continued to rise, but he is happy with his
decision to have regular monitoring and no treatment. "I'm doing
fine," he said.
As for Rabbi Stahl, at age 65, he had hoped for many more healthy
years ahead and did not want to ignore his rising P.S.A. At his
insistence, his internist reluctantly referred him to a urologist
who did a biopsy, finding a small cancer but one with cells showing
the kind of deranged structure associated with an aggressive cancer.
On Feb. 28, the rabbi had his prostate removed.
He said his internist defended his decision to ignore those low
P.S.A. levels, telling him he had no regrets. "He said he'd do it
again the same way," Rabbi Stahl said. So he changed doctors.
And, he said, he will always be grateful to the stranger who gave
him the unsolicited advice. "If I had not run into that man, I would
have done nothing," Rabbi Stahl said. "It was a message from God."