Urine test substitute for prostate biopsy

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List,

All too often I see skeletal metastasis show

up a year or two after a prostate

biopsy. Because our cancer retreat center is a

small operation I don't know how statistically

relevant this observation is -- it could simply

be a reflection of my own bias. With many cancers

there is evidence that chemotherapy itself and

narcotic analgesics also encourage metastasis.

There is almost always a way to determine if a

detectable lesion is cancerous without molesting

it. On the other hand AFTER the presence of

cancer is determined through non-invasive

methods, there are instances where biopsy can be

very useful in rational selection among the

therapeutic options. The type of biopsy should

be carefully considered. Concurrent self

administration of the non-prescription drug

cimetidine (Tagamet) might also be useful as it

is an antimetastatic agent with a strong record

of safety. Usual dosage would be about 1,000 mg /day in divided doses.

Almost all of the popular urine tumor

marker tests are very unreliable. The best ones

have fallen by the wayside. There is a new urine

test for prostate cancer that seems very useful,

though there may be market forces that lessen the likelihood of FDA approval.

(see below)

Medscape Medical News

Prostate Cancer Urine Test Predicts Biopsy Test Results

Nick Mulcahy

March 8, 2010 ­ A urine test that detects

prostate cancer cells can help predict whether a

prostate biopsy will reveal cancer, according to

research presented at the 2010 Genitourinary

Cancer Symposium (GUCS) in San Francisco, California.

The urine test, known as the PCA3 (prostate

cancer gene 3) assay, measures a gene that is

overexpressed in prostate cancer. It is approved

in Europe and marketed as Progensa. Its uses

include guiding biopsy decisions in men who have

an elevated prostate-specific antigen (PSA) level

but who also have one or more prior negative

biopsy results, despite the PSA results.

The assay has not yet been submitted for Food and

Drug Administration approval in the United States.

In the new study of 1072 men, those who had

higher PCA3 scores were more likely to have a

positive biopsy result and thus prostate cancer,

said Jack Groskopf, PhD, at a meeting press

conference. He is director of research and

development in cancer diagnostics at Gen-Probe

Incorporated, the manufacturer of the PCA3 test.

PCA3 is overexpressed in more than 90% of prostate cancers.

" PCA3 provides direct detection of prostate cancer cells, " said Dr Groskopf.

" PCA3 is overexpressed in more than 90% of

prostate cancers, " said Dr. Groskopf. Unlike PSA,

it is not expressed in other prostate disorders,

such as prostatitis or benign prostatic hyperplasia, he added.

Results from the new study also indicated that

higher PCA3 scores were associated with a higher

biopsy Gleason score (>7), Dr. Groskopf added.

" This is evidence that PCA3 may help identify

aggressive cancers, " he commented.

" Most prostate biopsies are negative, " pointed

out Dr. Groskopf. However, in men who have a

continuously elevated PSA level, there may be a

need to undergo repeat biopsies. The PCA3 test

might have a role to play in the management of

these men, including selecting men for active surveillance, said Dr. Groskopf.

" The authority of this test is potentially

helpful, " said J. Vogelzang, MD, chair

and medical director of the Developmental

Therapeutics Committee of US Oncology, who moderated the GUCS press conference.

Study Results

The men in the new study come from REDUCE

(REduction by DUasteride of prostate Cancer

Events), a large, multinational chemoprevention

trial evaluating dutasteride (Avodart,

GlaxoKline) in healthy men to see if it

reduces the risk of prostate cancer.

The new study was performed on men in the placebo

arm of the REDUCE trial because all participants

undergo regular 10-core biopsies at 2 and 4 years into the study.

The men all had previous negative biopsy results

and serum PSA levels between 2.5 and 10 ng/mL.

Urine specimens were collected and stored before

year 2 and year 4 biopsies and then subsequently analyzed with the PCA3 assay.

In the placebo arm, 18% of 1072 men had positive biopsy results at year 2.

Of those men with prostate cancer, the

researchers found that the PCA3 score was

correlated with a positive prostate biopsy result.

Specifically, cancer was diagnosed in only 6% of

men with a PCA3 score below 5 but in 57% of men

with a PCA3 score over 100, reported Dr. Groskopf.

Among the men with negative biopsy results at

year 2, the PCA3 test also predicted the

likelihood of having prostate cancer diagnosed at the year 4 biopsy.

Specifically, men with elevated PCA3 scores (>35)

and a negative biopsy result at year 2 were twice

as likely as men with lower PCA3 scores to have

cancer detected through biopsy at year 4.

Serum PSA and percentage of free PSA had no

correlation with future biopsy outcome.

The investigators also looked at PSA values at 2

and 4 years in these same men. " Serum PSA and

percentage of free PSA had no correlation with

future biopsy outcome, " said Dr. Groskopf.

GUCS is cosponsored by the American Society for

Clinical Oncology, the American Society for

Radiation Oncology, and the Society of Urologic Oncology.

Dr. Groskopf is an employee of and stockholder in

Gen-Probe. Dr. Vogelzang is a consultant or

adviser to Allos Therapeutics, Ambit, Amgen,

Bayer, Celgene, Genentech, Keryx, Novartis, Onyx,

Pfizer, Wilex, Honoraria, Amgen, ArQule, Bayer,

Clinical Care Options, Cougar Biotechnology,

Genentech, Imedex, Lippincott, and

Wilkins, Novarti, Onyx, Pfizer, and Wyeth. He

also has research funding from Argos

Therapeutics, ArQule, AstraZeneca, Cougar

Biotechnology, Endocyte, GlaxoKline, Keryx,

Medarex, Novartis, Pfizer, and Wilex.

2010 Genitourinary Cancers Symposium (GUCS):

Abstract 5. Presented March 5, 2010.