New Prostate Cancer Marker Helps Identify Men Whose Cancer Is Likely To Spread

Many men with prostate cancer have their prostate glands removed, but only a proportion of these men will later develop life-threatening metastatic disease -- where the cancer spreads to other parts of the body such as the bones. This new marker can identify which men are at the highest risk of metastatic disease at the time of their initial surgery leading to tailored treatment for individual prostate cancer sufferers, something that is not currently possible.

A/Prof Sue Henshall, who leads the prostate cancer research group, says: "We have discovered that men who have low levels of a marker called AZGP1 in the prostate at the time of surgery, have a greatly increased risk of developing metastatic cancer. This means two things: that these men could benefit from more aggressive treatment such as radiotherapy or chemotherapy around the time of surgery when they still have potentially curable cancer; and that patients with a low risk of developing metastatic disease will have the option of deferring treatments that have a negative impact on quality of life."

The next step is to explore the relationship between low levels of AZGP1 and the development of metastatic cancer in other groups of men with prostate cancer (i.e. other prostate cancer tissue banks). "It is important to begin testing for this marker now because in the next decade, when the outcomes for some of these new patients is known, we will be able to see just how predictive our marker is in the clinic", said Garvan's Cancer Program Director Professor Rob Sutherland.

"A/Prof Sue Henshall's research has put Australia at the forefront of world research in developing efficient prognostic tools in prostate cancer," said Prof Jim Bishop, Chief Cancer Officer NSW and CEO of Cancer Institute NSW, which funded the research as part of a $3.7 million Program Grant for Excellence in Translational Research.

The research is published in the current edition of the Journal of the National Cancer Institute, which is the most cited cancer research journal.

This work was the result of a $3.7 million Program Grant from the Cancer Institute NSW to identify risk in prostate cancer. Authors A/Prof Sue Henshall and Dr Andrew Biankin are Career Development and Support Fellows of the Cancer Institute NSW. The Cancer Institute NSW is funded by the NSW State Government. It is a statutory body governed by the Cancer Institute NSW Board appointed by the Minister for Health, the Hon. John Hatzistergos MLC. and the Minister Assisting the Minister for Health (Cancer), the Hon. Frank Sartor, MP.

Citation: Zinc-alpha2-glycoprotein Expression as a Predictor of Metastatic Prostate Cancer Following Radical Prostatectomy. Susan M. Henshall, Lisa G. Horvath, David I. Quinn, Sarah A. Eggleton, John J. Grygiel, Phillip D. Stricker, Andrew V. Biankin, James G. Kench , Robert L. Sutherland. Journal of the National Cancer Institute. Oct 4 2006.

Background

The prostate is a walnut-sized organ that lies close to the bladder and bowel and is only found in men. Its main function is to store and produce seminal fluid. Prostate cancer is potentially curable if detected early and treated while still confined to the prostate gland.

Prostate cancer is rare before the age of 50, but most common from the age of 55, with the median age on diagnosis of prostate cancer being 71 years. It rates first in incidence and second in mortality for all male cancers.

Prostate cancer affects 13,000 men in Australia. Of these, approximately 20% of prostate cancer sufferers will develop metastatic disease within 10 years of surgery. The rate of change in PSA (prostate-specific antigen) levels is monitored for about ten years after surgery. If it increases at a rapid rate, for which there is an accepted definition, treatment with hormone depletion is likely to ensue.