Study Shows Prostate Cancer Gene 3 (PCA3) Correlates With Severity of Prostate Cancer

LONDON, May 9/PRNewswire/ --

A study published in the May 2008 issue of the peer-reviewed
Journal of Urology demonstrates that the prostate cancer gene 3 (PCA3) can be
used to detect and stratify stage and grade of prostate cancer.(1) Following
recent calls for a more accurate test for the detection of prostate
cancer,(2)(3) the results of this study indicate the PROGENSA(TM) PCA3
gene-based urine test may be clinically useful in identifying men with
low-grade or low-volume cancer for whom active surveillance would be more
appropriate than aggressive treatment, and also shows the test as a more
reliable method than existing diagnostic tools such as serum-PSA.(1)

"More and more data is emerging that the PCA3 score is a useful measure
to fine tune the diagnosis and classification prostate cancer," says Mr.
Ranjan Thilagarajah, Consultant Urological Surgeon at Broomfield Hospital,
Mid Essex Health Trust. "PROGENSA PCA3 appears to help differentiate between
those that are candidates for active surveillance, and those who need
aggressive treatments, making it a vital part of cutting-edge prostate cancer
management. Here at Broomfield Hospital, we have already used the test in
over 100 men, and hope that it will become a useful tool for more men across
the country."

The study found that PCA3 scores correlate with tumour volume,
and with prostatectomy Gleason scores (grade of prostate cancer). When
compared to other standard measures, (including serum-PSA) the PCA3 score was
found to be the best predictor of tumour volume.

In addition, PCA3 was the most successful measure for
predicting low volume cancer, indicating that a PCA3 score could be
beneficial when identifying men for non-aggressive therapies, such as active
surveillance, for men with low-grade/low-volume cancer. Over the past 20
years, the greater utilisation and reliance on serum-PSA has led to an
increase in identifying those with low grade cancer,(4)(5) therefore PROGENSA
PCA3 may be a valuable tool for ensuring aggressive treatment or invasive
biopsies are limited to those needing it most.

For more information about PROGENSA PCA3 and prostate cancer,
please visit http://www.PCA3.org.

Notes to editors:

- A PCA3 score can be measured using PROGENSA PCA3 - a
commercially available non-invasive urine test that measures the amount of
PCA3 in the urine. Unlike serum-PSA, which measures the level of Prostate
Specific Antigen - a substance not exclusively associated with prostate
Cancer(6)(7) - PCA3 is over-expressed only by prostate cancer,(8) and
therefore is seen as a more reliable diagnostic measure.

- PCA3 is a prostate-specific gene that is highly over-expressed in
prostate tumours.(8) The PROGENSA(TM) PCA3 test uses Transcription
Mediated Amplification (TMA) to quantify the amount of PCA3 mRNA in a patient
urine sample; the higher the PCA3 score, the more likely prostate cancer is
present.(9)

- Previous studies have indicated that in men who have
previously had a negative biopsy, PROGENSA(TM) PCA3 can more accurately
predict which men are likely to have a positive follow-up biopsy than a PSA
test alone.(9)

- The prostate is a walnut-shaped gland that sits beneath the
bladder and in front of the rectum. It is a fundamental part of the male
reproductive system.

- Prostate cancer is the most common male cancer in the UK,
with more than 34,000 men diagnosed every year, 24 per cent of all new male
cancers.(10) Despite improved treatment options for prostate cancer over the
past 20 years, the number of prostate cancer deaths in the UK has slightly
increased. In 2005, there were 10,000 deaths in the UK, accounting for 13 per
cent of all male cancer deaths.(11)

About Gen-Probe

Gen-Probe Incorporated is a global leader in the development,
manufacture and marketing of rapid, accurate and cost-effective nucleic acid
tests (NATs) that are used primarily to diagnose human diseases and screen
donated human blood. Gen-Probe has more than 25 years of NAT expertise, and
received the 2004 National Medal of Technology, America's highest honor for
technological innovation, for developing NAT assays for blood screening.
Gen-Probe is headquartered in San Diego, California and employs approximately
1,000 people. For more information, go to http://www.gen-probe.com.

Forward-Looking Statements

Any statements in this press release about our expectations,
beliefs, plans, objectives, assumptions or future events or performance are
not historical facts and are forward-looking statements. Forward-looking
statements are not guarantees of performance. They involve known and unknown
risks, uncertainties and assumptions that may cause actual results, levels of
activity, performance or achievements to differ materially from those
expressed or implied by any forward-looking statement. Some of the risks,
uncertainties and assumptions that could cause actual results to differ
materially from estimates or projections contained in the forward-looking
statements include but are not limited to: (i) the risk that subsequent
studies of our PCA3 assay may not reflect the results discussed here, (ii)
the risk that new products, such as our PCA3 assay, will not be cleared for
marketing in other markets in the timeframes we expect, if at all, (iii) the
possibility that the market for the sale of our new products, such as our
PCA3 test, may not develop as expected, (iv) we may not be able to compete
effectively, (v) we may not be able to maintain our current corporate
collaborations and enter into new corporate collaborations or customer
contracts, and (vi) we are dependent on third parties for the distribution of
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Reference List

1) Nakanishi,H. et al. (2008) PCA3 molecular urine assay correlates with
prostate cancer tumor volume: implication in selecting candidates for active
surveillance. J Urol 179, 1804-1809

2) Stamey,T.A. et al. (2004) The prostate specific antigen era in the
United States is over for prostate cancer: what happened in the last 20
years? J Urol 172, 1297-1301

3) Bradford,T.J. et al. (2006) Molecular markers of prostate cancer. Urol
Oncol. 24, 538-551

4) Loeb,S. et al. (2006) Pathological characteristics of prostate cancer
detected through prostate specific antigen based screening. J Urol 175,
902-906

5) Stamey,T.A. et al. (1993) Localized prostate cancer. Relationship of
tumor volume to clinical significance for treatment of prostate cancer.
Cancer 71, 933-938

6) The Prostate Cancer Charity (2007) The PSA test.
http://www.prostate-cancer.org.uk/info/tests_psa.asp

7) The Prostate Cancer Charity (2007) PSA background.
http://www.prostate-cancer.org.uk/news/features/psa_screening.asp

8) Bussemakers,M.J. et al. (1999) DD3: a new prostate-specific gene,
highly overexpressed in prostate cancer. Cancer Res 59, 5975-5979

9) Marks,L.S. et al. (2007) PCA3 molecular urine assay for prostate
cancer in men undergoing repeat biopsy. Urology 69, 532-535

10) Office for National Statistics (2007) Cancer Statistics registrations:
Registrations of cancer diagnosed in 2003, England (Series MB1 no.34. ed.
Vol. 2005 edn)

11) Office for National Statistics (2007) Review of the Registrar General
on deaths by cause, sex and age, in England and Wales, 2005. In Series DH2
no.32

Source: Gen-Probe

For more information, please contact: Victoria Asare-Archer, Porter Novelli, +44-20-7853-2269 / +44-7812-986160, Victoria.asare-archer@porternovelli.co.uk ; Alyssa Eggum, Gen-Probe, +1-858-410-8647, alyssae@gen-probe.com .

2008-05-08 19:05:40 0357285 PRNEWSWIRE